The document discusses the immune system, including its ability to recognize foreign substances, produce an appropriate response through nonspecific and specific defenses, and maintain tolerance of self cells. The immune response involves white blood cells, antibodies, inflammation, and memory cells that provide a faster response upon repeat exposure. The summary also outlines how HIV attacks lymphocytes and progresses to AIDS by destroying the immune system's ability to fight infection.
IB Biology 1.2 Slides: Ultrastructure of CellsJacob Cedarbaum
Electron microscopes have much higher resolution than light microscopes due to the shorter wavelengths of electron beams. Prokaryotes like E. coli have a simple cell structure without compartments, containing a cell wall, plasma membrane, ribosomes, nucleoid, cytoplasm and other structures. They divide via binary fission. Eukaryotes have a compartmentalized cell structure containing organelles like the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles. Organelles in specialized cells like pancreatic and leaf cells are adapted for their functions like enzyme secretion and photosynthesis.
This document discusses the four major types of adult tissues - epithelial, connective, muscle and nervous tissue. It provides details on the classification, structure and functions of each type of tissue. The key points are:
1) Tissues are classified based on structure, composition and function. The four major types are epithelial, connective, muscle and nervous tissue.
2) Epithelial tissues cover surfaces, line organs and form glands. They protect, absorb, secrete and transport. Connective tissues connect, support and protect other tissues. Muscle tissues contract to cause movement and pumping blood. Nervous tissues transmit electrical signals.
3) Each tissue contains different cell types and extracellular matrix to suit their functions.
The document summarizes key points about the origin of cells:
1. Cell theory states that all living things are made of cells, the cell is the smallest unit of life, and cells only come from pre-existing cells.
2. Pasteur's experiments in 1864 disproved spontaneous generation and provided evidence that cells only arise from other cells.
3. Miller and Urey's experiments in 1953 simulated early Earth conditions and formed simple organic molecules like amino acids, providing evidence that the first cells could have originated from non-living materials.
4. The endosymbiotic theory explains the origin of eukaryotic cells, proposing that organelles like mitochondria and chloroplasts originally came from
The lymphatic system consists of lymph vessels, lymph nodes, spleen, thymus, tonsils, and other lymphoid tissues. The lymph vessels return interstitial fluid to the blood circulation and help protect the body from disease. Primary lymphoid organs like the bone marrow and thymus produce immune cells, while secondary organs like lymph nodes, spleen, and mucosa-associated lymphoid tissue house and transport lymphocytes throughout the body. Histologically, lymphoid tissues contain aggregates of lymphocytes and other immune cells organized into structures like follicles, cords, and sheaths that vary between organs.
The document summarizes the body's primary defenses against infectious disease. The skin and mucous membranes form the first line of defense through physical and chemical barriers. Cuts in the skin are sealed by blood clotting initiated by platelets. Phagocytic white blood cells provide non-specific immunity by ingesting pathogens. Lymphocytes produce specific antibodies in response to antigens that provide long-term immunity. Antibiotics target bacterial rather than viral or eukaryotic cells. Overuse of antibiotics can lead to resistant bacterial strains.
1. Cells are the basic unit of all living things. Robert Hooke first observed cells in 1665 using a microscope. The cell theory states that all living things are made of cells, cells come only from pre-existing cells, and cells contain the basic components necessary for life.
2. Cells vary in size but have limitations based on their surface area to volume ratio. As cells increase in size, their ability to exchange materials decreases. Multicellular organisms overcome this through specialized tissues, organs and circulatory systems.
3. Cells carry out the basic functions of life including metabolism, reproduction, homeostasis, growth, response to stimuli, waste removal and nutrition. Unicellular organisms carry out all life functions
The document discusses the origin of the first cells on Earth. It states that cells can only be formed through the division of pre-existing cells, so the first cells must have arisen from non-living material through a process known as abiogenesis. Abiogenesis likely occurred in four stages: 1) the non-living synthesis of simple organic molecules, 2) the assembly of these molecules into complex polymers, 3) the development of polymers that could self-replicate, and 4) the encapsulation of these molecules within membranes. Early Earth had a reducing atmosphere containing gases like hydrogen, nitrogen, and methane that could have contributed to the non-living synthesis of organic compounds from which the first cells developed.
IB Biology 1.2 Slides: Ultrastructure of CellsJacob Cedarbaum
Electron microscopes have much higher resolution than light microscopes due to the shorter wavelengths of electron beams. Prokaryotes like E. coli have a simple cell structure without compartments, containing a cell wall, plasma membrane, ribosomes, nucleoid, cytoplasm and other structures. They divide via binary fission. Eukaryotes have a compartmentalized cell structure containing organelles like the nucleus, mitochondria, endoplasmic reticulum, Golgi apparatus, lysosomes, and vacuoles. Organelles in specialized cells like pancreatic and leaf cells are adapted for their functions like enzyme secretion and photosynthesis.
This document discusses the four major types of adult tissues - epithelial, connective, muscle and nervous tissue. It provides details on the classification, structure and functions of each type of tissue. The key points are:
1) Tissues are classified based on structure, composition and function. The four major types are epithelial, connective, muscle and nervous tissue.
2) Epithelial tissues cover surfaces, line organs and form glands. They protect, absorb, secrete and transport. Connective tissues connect, support and protect other tissues. Muscle tissues contract to cause movement and pumping blood. Nervous tissues transmit electrical signals.
3) Each tissue contains different cell types and extracellular matrix to suit their functions.
The document summarizes key points about the origin of cells:
1. Cell theory states that all living things are made of cells, the cell is the smallest unit of life, and cells only come from pre-existing cells.
2. Pasteur's experiments in 1864 disproved spontaneous generation and provided evidence that cells only arise from other cells.
3. Miller and Urey's experiments in 1953 simulated early Earth conditions and formed simple organic molecules like amino acids, providing evidence that the first cells could have originated from non-living materials.
4. The endosymbiotic theory explains the origin of eukaryotic cells, proposing that organelles like mitochondria and chloroplasts originally came from
The lymphatic system consists of lymph vessels, lymph nodes, spleen, thymus, tonsils, and other lymphoid tissues. The lymph vessels return interstitial fluid to the blood circulation and help protect the body from disease. Primary lymphoid organs like the bone marrow and thymus produce immune cells, while secondary organs like lymph nodes, spleen, and mucosa-associated lymphoid tissue house and transport lymphocytes throughout the body. Histologically, lymphoid tissues contain aggregates of lymphocytes and other immune cells organized into structures like follicles, cords, and sheaths that vary between organs.
The document summarizes the body's primary defenses against infectious disease. The skin and mucous membranes form the first line of defense through physical and chemical barriers. Cuts in the skin are sealed by blood clotting initiated by platelets. Phagocytic white blood cells provide non-specific immunity by ingesting pathogens. Lymphocytes produce specific antibodies in response to antigens that provide long-term immunity. Antibiotics target bacterial rather than viral or eukaryotic cells. Overuse of antibiotics can lead to resistant bacterial strains.
1. Cells are the basic unit of all living things. Robert Hooke first observed cells in 1665 using a microscope. The cell theory states that all living things are made of cells, cells come only from pre-existing cells, and cells contain the basic components necessary for life.
2. Cells vary in size but have limitations based on their surface area to volume ratio. As cells increase in size, their ability to exchange materials decreases. Multicellular organisms overcome this through specialized tissues, organs and circulatory systems.
3. Cells carry out the basic functions of life including metabolism, reproduction, homeostasis, growth, response to stimuli, waste removal and nutrition. Unicellular organisms carry out all life functions
The document discusses the origin of the first cells on Earth. It states that cells can only be formed through the division of pre-existing cells, so the first cells must have arisen from non-living material through a process known as abiogenesis. Abiogenesis likely occurred in four stages: 1) the non-living synthesis of simple organic molecules, 2) the assembly of these molecules into complex polymers, 3) the development of polymers that could self-replicate, and 4) the encapsulation of these molecules within membranes. Early Earth had a reducing atmosphere containing gases like hydrogen, nitrogen, and methane that could have contributed to the non-living synthesis of organic compounds from which the first cells developed.
The document provides an overview of cells, including their history, structures, and differences between plant and animal cells. It explains that cells are the basic unit of life, first observed by Robert Hooke in 1660 when he looked at bark through a microscope and saw small compartments that he named "cells." The presentation then details the structures found in typical animal cells like the cell membrane, nucleus, mitochondria, and Golgi bodies. It concludes by noting additional structures like the cell wall, chloroplasts, and chlorophyll that are present in plant cells but not animal cells.
The cell theory states that cells are the basic unit of life, new cells are formed from existing cells, and cells and their products make up living organisms. Evidence for the cell theory came from early microscope observations by Hooke, van Leeuwenhoek, and others showing the presence of cells. Schleiden and Schwann combined these observations with their own work to propose the first two principles of the cell theory. Virchow later added the third principle that cells only arise from pre-existing cells. Unicellular organisms carry out all the functions of life, while multicellular organisms show emergent properties and cell differentiation allows specialization of function.
The pituitary gland controls many body functions through the release of hormones into the bloodstream. It is located at the base of the skull and has anterior and posterior lobes. The anterior lobe secretes growth hormone and other hormones that target various endocrine glands and body systems. The posterior lobe stores and releases hormones produced by the hypothalamus. The thyroid gland regulates metabolic rate through the hormones thyroxine and triiodothyronine. It has follicles that store and release these hormones into the bloodstream. The adrenal glands sit atop the kidneys and consist of an outer cortex and inner medulla. The cortex secretes corticosteroids and the medulla secretes epinephrine and norepinephrine
01.26.09: Histology of the Endocrine SystemOpen.Michigan
Slideshow is from the University of Michigan Medical School's M1 Endocrine / Reproduction sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1Endo
Smooth muscle cells are found within organs and blood vessels. There are two main types - multi-unit smooth muscle composed of separate fibers, and unitary (visceral) smooth muscle with fibers joined by gap junctions. Smooth muscle contraction is activated by calcium ions and sustained through a latch mechanism using little ATP. Contraction can be stimulated by nerves releasing acetylcholine or norepinephrine, hormones, stretch of the muscle, or local chemical factors and pacemaker potentials in some muscles. Prolonged contraction is enabled through action potentials with plateaus or slow wave potentials.
Chromosomes carry genes in a linear sequence that is shared by members of a species. In prokaryotes, DNA exists as a single circular chromosome, while eukaryotes have multiple linear chromosomes associated with histone proteins. Homologous chromosomes in diploid cells contain the same genes but can have different alleles. Sex is determined by X and Y chromosomes in most species. Karyotyping allows visualization of chromosomes and can be used for analysis.
The cell is the basic unit of life. It contains a nucleus and cytoplasm, which includes organelles like the cell membrane, mitochondria, and endoplasmic reticulum. The cell membrane regulates what enters and exits the cell, and maintains homeostasis. Inside the cell, the nucleus contains DNA and directs cell activities, while the cytoplasm and organelles work together to carry out essential functions and keep the cell alive.
This document provides information about the three main types of muscle tissue: skeletal muscle, cardiac muscle, and smooth muscle. It describes key identifying characteristics such as nuclear arrangement, striations, contraction properties, location in the body, and degree of voluntary control for each type of muscle tissue. The document is in a question and answer format where each question asks "What tissue is this?" followed by descriptions to help identify the tissue type.
Mitochondria are rod-shaped organelles found in cells that contain two membranes. The inner membrane is highly folded into cristae which increases its surface area. It contains the electron transport chain and ATP synthase complexes that produce ATP from ADP using a hydrogen ion gradient established by the electron transport chain. The matrix contains enzymes for the citric acid cycle and oxidative phosphorylation to generate ATP. During anaerobic respiration without oxygen, yeast perform alcoholic fermentation by converting pyruvate to ethanol to regenerate NAD+, while mammals produce lactic acid from pyruvate. Mitochondria can also respire lipids and amino acids by breaking them down into acetyl-CoA for the citric acid cycle. Lipids have
The document summarizes key aspects of lymphatic histology. It discusses the distinction between primary and secondary lymphoid organs and describes the organization and function of mucosa-associated lymphoid tissue, lymph nodes, spleen, and thymus. It explains that primary lymphoid organs support antigen-independent differentiation of lymphocytes, while secondary lymphoid organs facilitate antigen-dependent activation and proliferation. The summary highlights trafficking of lymphocytes between tissues, lymphatic vessels, and lymph nodes.
Meiosis is the process by which diploid cells in organisms undergo two cell divisions to produce four haploid gametes. In meiosis I, homologous chromosomes pair up and undergo crossing over, then separate so each daughter cell has one of each type of chromosome. Meiosis II then separates the sister chromatids, resulting in four haploid cells each containing one set of chromosomes. This allows for genetic variation between gametes and offspring through independent assortment of chromosomes and new combinations from crossing over during meiosis I.
Simple squamous epithelium consists of a single layer of flattened cells on a basement membrane. It functions as a selective barrier allowing filtration, passive diffusion, and pinocytosis. Cuboidal epithelium is a single layer of cuboidal cells with rounded nuclei on a basement membrane, often found in ducts and possessing basal infoldings. It transports fluids and may modify luminal contents through selective absorption. Pseudostratified epithelium resembles stratified epithelium but with nuclei at different heights due to cell shapes; it lines areas like the trachea.
The lymphatic system consists of cells, tissues, and organs that monitor the body for harmful substances. The main components are lymphocytes, lymphatic tissues found in lymph nodes and other structures, and lymphatic organs like the spleen, thymus, bone marrow, and lymph nodes. Lymphatic tissues contain lymphocytes that fight infection and other threats. The lymphatic system's functions include monitoring the body, responding to harmful substances, and producing immune cells. Key lymphatic organs are the thymus, which produces T cells, and lymph nodes, spleen, and skin/mucosal tissues, which help the immune response.
Lecture 5 (membrane potential and action potential)Ayub Abdi
This document discusses membrane potentials and action potentials in excitable cells like neurons and muscles. It covers:
1. The resting membrane potential of -70mV that is maintained by selective permeability of potassium ions and active transport by the sodium-potassium pump.
2. How an action potential is generated when the membrane reaches its threshold voltage due to an influx of sodium ions, causing rapid depolarization. It then repolarizes as potassium ions efflux.
3. The propagation of action potentials along neurons or muscle fibers to transmit electrical signals and cause effects like muscle contraction or neurotransmitter release.
Cells in tissues work together in groups for specific functions. There are four main types of tissues: epithelial, connective, muscle, and nervous. Epithelial tissues line surfaces and form glands. They are classified based on the number of cell layers (simple vs stratified) and cell shape (squamous, cuboidal, columnar). Simple epithelia are single layers, while stratified have multiple layers. Epithelial tissues have specialized junctions and polarity. Their main functions are protection, secretion, absorption, and filtration.
This document provides information about the four main types of tissues in the body: epithelial, connective, muscle, and nervous tissue. It focuses on epithelial tissue, which covers and lines body surfaces and cavities. There are two main types of epithelial tissue: covering/lining epithelium and glandular epithelium. Covering and lining epithelia form boundaries and protect underlying tissues. Epithelial tissue is further classified based on the number of cell layers (simple vs stratified) and cell shape (squamous, cuboidal, columnar). Simple epithelia are single layers including simple squamous, simple cuboidal, and simple columnar. Stratified epithelia have multiple layers and include stratified squamous, transitional, pseudostrat
The epithelium lining the respiratory tract from the nasal fossa through the bronchi is called the respiratory mucosa and is characterized by a pseudostratified ciliated epithelium with abundant non-ciliated cells known as goblet cells. - [Source: medcell.med.yale.edu/histology/respiratory_system_lab.php]
Cells are the smallest living units that make up all living things. All cells share characteristics outlined in the cell theory, including being enclosed by a membrane and containing DNA. There are two main types of cells - prokaryotic cells which lack organelles, and eukaryotic cells which contain organelles and a nucleus bound by a membrane. Eukaryotic cells contain various organelles that carry out specific functions like mitochondria which generate energy and chloroplasts which facilitate photosynthesis. Molecules can move across the cell membrane through passive diffusion, facilitated diffusion, active transport, endocytosis, and exocytosis.
Here are the key steps in order:
1. Chemotaxis - Phagocytes are attracted to the site of infection.
2. Attachment - The phagocyte attaches to the pathogen via cell surface receptors binding to proteins on the pathogen.
3. Phagocytosis - The phagocyte membrane envelops and engulfs the pathogen, forming an internal vesicle called a phagosome.
4. Phagosome formation - The phagosome containing the engulfed pathogen forms inside the phagocyte.
5. Lysosome fusion - Lysosomes containing digestive enzymes fuse with the phagosome.
6. Digestion - Enzymes within the phagolysosome break down the pathogen.
7
The document discusses the results of a study on the effects of a new drug on memory and cognitive function in older adults. The double-blind study involved giving either the new drug or a placebo to 100 volunteers aged 65-80 over a 6 month period. Testing showed those receiving the drug experienced statistically significant improvements in short-term memory retention and processing speed compared to the placebo group.
The document provides an overview of cells, including their history, structures, and differences between plant and animal cells. It explains that cells are the basic unit of life, first observed by Robert Hooke in 1660 when he looked at bark through a microscope and saw small compartments that he named "cells." The presentation then details the structures found in typical animal cells like the cell membrane, nucleus, mitochondria, and Golgi bodies. It concludes by noting additional structures like the cell wall, chloroplasts, and chlorophyll that are present in plant cells but not animal cells.
The cell theory states that cells are the basic unit of life, new cells are formed from existing cells, and cells and their products make up living organisms. Evidence for the cell theory came from early microscope observations by Hooke, van Leeuwenhoek, and others showing the presence of cells. Schleiden and Schwann combined these observations with their own work to propose the first two principles of the cell theory. Virchow later added the third principle that cells only arise from pre-existing cells. Unicellular organisms carry out all the functions of life, while multicellular organisms show emergent properties and cell differentiation allows specialization of function.
The pituitary gland controls many body functions through the release of hormones into the bloodstream. It is located at the base of the skull and has anterior and posterior lobes. The anterior lobe secretes growth hormone and other hormones that target various endocrine glands and body systems. The posterior lobe stores and releases hormones produced by the hypothalamus. The thyroid gland regulates metabolic rate through the hormones thyroxine and triiodothyronine. It has follicles that store and release these hormones into the bloodstream. The adrenal glands sit atop the kidneys and consist of an outer cortex and inner medulla. The cortex secretes corticosteroids and the medulla secretes epinephrine and norepinephrine
01.26.09: Histology of the Endocrine SystemOpen.Michigan
Slideshow is from the University of Michigan Medical School's M1 Endocrine / Reproduction sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1Endo
Smooth muscle cells are found within organs and blood vessels. There are two main types - multi-unit smooth muscle composed of separate fibers, and unitary (visceral) smooth muscle with fibers joined by gap junctions. Smooth muscle contraction is activated by calcium ions and sustained through a latch mechanism using little ATP. Contraction can be stimulated by nerves releasing acetylcholine or norepinephrine, hormones, stretch of the muscle, or local chemical factors and pacemaker potentials in some muscles. Prolonged contraction is enabled through action potentials with plateaus or slow wave potentials.
Chromosomes carry genes in a linear sequence that is shared by members of a species. In prokaryotes, DNA exists as a single circular chromosome, while eukaryotes have multiple linear chromosomes associated with histone proteins. Homologous chromosomes in diploid cells contain the same genes but can have different alleles. Sex is determined by X and Y chromosomes in most species. Karyotyping allows visualization of chromosomes and can be used for analysis.
The cell is the basic unit of life. It contains a nucleus and cytoplasm, which includes organelles like the cell membrane, mitochondria, and endoplasmic reticulum. The cell membrane regulates what enters and exits the cell, and maintains homeostasis. Inside the cell, the nucleus contains DNA and directs cell activities, while the cytoplasm and organelles work together to carry out essential functions and keep the cell alive.
This document provides information about the three main types of muscle tissue: skeletal muscle, cardiac muscle, and smooth muscle. It describes key identifying characteristics such as nuclear arrangement, striations, contraction properties, location in the body, and degree of voluntary control for each type of muscle tissue. The document is in a question and answer format where each question asks "What tissue is this?" followed by descriptions to help identify the tissue type.
Mitochondria are rod-shaped organelles found in cells that contain two membranes. The inner membrane is highly folded into cristae which increases its surface area. It contains the electron transport chain and ATP synthase complexes that produce ATP from ADP using a hydrogen ion gradient established by the electron transport chain. The matrix contains enzymes for the citric acid cycle and oxidative phosphorylation to generate ATP. During anaerobic respiration without oxygen, yeast perform alcoholic fermentation by converting pyruvate to ethanol to regenerate NAD+, while mammals produce lactic acid from pyruvate. Mitochondria can also respire lipids and amino acids by breaking them down into acetyl-CoA for the citric acid cycle. Lipids have
The document summarizes key aspects of lymphatic histology. It discusses the distinction between primary and secondary lymphoid organs and describes the organization and function of mucosa-associated lymphoid tissue, lymph nodes, spleen, and thymus. It explains that primary lymphoid organs support antigen-independent differentiation of lymphocytes, while secondary lymphoid organs facilitate antigen-dependent activation and proliferation. The summary highlights trafficking of lymphocytes between tissues, lymphatic vessels, and lymph nodes.
Meiosis is the process by which diploid cells in organisms undergo two cell divisions to produce four haploid gametes. In meiosis I, homologous chromosomes pair up and undergo crossing over, then separate so each daughter cell has one of each type of chromosome. Meiosis II then separates the sister chromatids, resulting in four haploid cells each containing one set of chromosomes. This allows for genetic variation between gametes and offspring through independent assortment of chromosomes and new combinations from crossing over during meiosis I.
Simple squamous epithelium consists of a single layer of flattened cells on a basement membrane. It functions as a selective barrier allowing filtration, passive diffusion, and pinocytosis. Cuboidal epithelium is a single layer of cuboidal cells with rounded nuclei on a basement membrane, often found in ducts and possessing basal infoldings. It transports fluids and may modify luminal contents through selective absorption. Pseudostratified epithelium resembles stratified epithelium but with nuclei at different heights due to cell shapes; it lines areas like the trachea.
The lymphatic system consists of cells, tissues, and organs that monitor the body for harmful substances. The main components are lymphocytes, lymphatic tissues found in lymph nodes and other structures, and lymphatic organs like the spleen, thymus, bone marrow, and lymph nodes. Lymphatic tissues contain lymphocytes that fight infection and other threats. The lymphatic system's functions include monitoring the body, responding to harmful substances, and producing immune cells. Key lymphatic organs are the thymus, which produces T cells, and lymph nodes, spleen, and skin/mucosal tissues, which help the immune response.
Lecture 5 (membrane potential and action potential)Ayub Abdi
This document discusses membrane potentials and action potentials in excitable cells like neurons and muscles. It covers:
1. The resting membrane potential of -70mV that is maintained by selective permeability of potassium ions and active transport by the sodium-potassium pump.
2. How an action potential is generated when the membrane reaches its threshold voltage due to an influx of sodium ions, causing rapid depolarization. It then repolarizes as potassium ions efflux.
3. The propagation of action potentials along neurons or muscle fibers to transmit electrical signals and cause effects like muscle contraction or neurotransmitter release.
Cells in tissues work together in groups for specific functions. There are four main types of tissues: epithelial, connective, muscle, and nervous. Epithelial tissues line surfaces and form glands. They are classified based on the number of cell layers (simple vs stratified) and cell shape (squamous, cuboidal, columnar). Simple epithelia are single layers, while stratified have multiple layers. Epithelial tissues have specialized junctions and polarity. Their main functions are protection, secretion, absorption, and filtration.
This document provides information about the four main types of tissues in the body: epithelial, connective, muscle, and nervous tissue. It focuses on epithelial tissue, which covers and lines body surfaces and cavities. There are two main types of epithelial tissue: covering/lining epithelium and glandular epithelium. Covering and lining epithelia form boundaries and protect underlying tissues. Epithelial tissue is further classified based on the number of cell layers (simple vs stratified) and cell shape (squamous, cuboidal, columnar). Simple epithelia are single layers including simple squamous, simple cuboidal, and simple columnar. Stratified epithelia have multiple layers and include stratified squamous, transitional, pseudostrat
The epithelium lining the respiratory tract from the nasal fossa through the bronchi is called the respiratory mucosa and is characterized by a pseudostratified ciliated epithelium with abundant non-ciliated cells known as goblet cells. - [Source: medcell.med.yale.edu/histology/respiratory_system_lab.php]
Cells are the smallest living units that make up all living things. All cells share characteristics outlined in the cell theory, including being enclosed by a membrane and containing DNA. There are two main types of cells - prokaryotic cells which lack organelles, and eukaryotic cells which contain organelles and a nucleus bound by a membrane. Eukaryotic cells contain various organelles that carry out specific functions like mitochondria which generate energy and chloroplasts which facilitate photosynthesis. Molecules can move across the cell membrane through passive diffusion, facilitated diffusion, active transport, endocytosis, and exocytosis.
Here are the key steps in order:
1. Chemotaxis - Phagocytes are attracted to the site of infection.
2. Attachment - The phagocyte attaches to the pathogen via cell surface receptors binding to proteins on the pathogen.
3. Phagocytosis - The phagocyte membrane envelops and engulfs the pathogen, forming an internal vesicle called a phagosome.
4. Phagosome formation - The phagosome containing the engulfed pathogen forms inside the phagocyte.
5. Lysosome fusion - Lysosomes containing digestive enzymes fuse with the phagosome.
6. Digestion - Enzymes within the phagolysosome break down the pathogen.
7
The document discusses the results of a study on the effects of a new drug on memory and cognitive function in older adults. The double-blind study involved giving either the new drug or a placebo to 100 volunteers aged 65-80 over a 6 month period. Testing showed those receiving the drug experienced statistically significant improvements in short-term memory retention and processing speed compared to the placebo group.
The document discusses command terms used in IB Biology questions and assessments. It provides definitions for various command terms grouped according to the three objectives of IB Biology: demonstrating understanding, applying and using, and constructing, analyzing and evaluating. Tips are provided for understanding and answering questions involving different command terms.
The document provides an overview of the immune system, including definitions of immunity, classifications of immunity as natural or innate versus acquired, and mechanisms of the immune response. It describes physical and chemical barriers, white blood cells, inflammation, humoral immunity, cellular immunity, complement system, and abnormal immune responses. It also discusses nursing assessment and management related to immune function and health education topics.
The document describes the structure and function of the blood system, including the three main types of blood vessels (arteries, capillaries, and veins), how blood flows through the circulatory system from the heart to tissues and back again, and some pathologies that can occur like atherosclerosis and heart attacks. The heart functions as a pump to circulate blood through the arteries and veins, with capillaries allowing for exchange of oxygen, nutrients, and waste between the blood and body tissues. Valves in the veins and heart prevent backflow of blood and ensure forward circulation.
T cells recognize antigens presented on MHC proteins by antigen presenting cells such as macrophages, dendritic cells, and B cells. Activated T cells clone and differentiate into cytotoxic T cells that directly attack pathogens and infected cells, or helper T cells that coordinate both innate and adaptive immune responses. Cytotoxic T cells express CD8 and kill infected cells, while helper T cells express CD4 and stimulate B cell antibody production, macrophage activation, and proliferation of other immune cells through cytokine signaling. Suppressor T cells regulate the immune response to prevent excessive damage to self tissues.
Type I hypersensitivity, also known as immediate hypersensitivity, is an exaggerated immune response mediated by IgE antibodies. It causes allergic reactions and is triggered by exposure to common allergens like pollen, dust mites, animal dander, etc. Type IV hypersensitivity is a delayed cell-mediated response that occurs 48-72 hours after exposure and is characterized by induration and erythema, as seen in tuberculin skin tests. HIV attacks CD4 T cells, weakening the immune system and leaving the body vulnerable to opportunistic infections. If untreated, HIV develops into AIDS, defined by a CD4 count below 200 or the presence of AIDS-defining illnesses.
The document discusses the structure and function of muscles and sarcomeres. It describes how muscles are made up of sarcomeres, which contain thick myosin filaments and thin actin filaments. Sarcomeres shorten during muscle contraction as the actin and myosin filaments slide past each other through a cross bridge cycle of formation, power stroke, detachment and reactivation of the myosin head. This causes the A band width to remain the same and the H zone and I bands to decrease in size.
This document defines types of hypersensitivity reactions and summarizes their mechanisms. It discusses:
1) The four types of hypersensitivity reactions - Type I (immediate), Type II (antibody-dependent cytotoxic), Type III (immune complex-mediated), Type IV (cell-mediated/delayed).
2) Mechanisms of each type, including roles of antibodies, mast cells, T cells, and immune complexes.
3) Examples of conditions that fall under each type such as allergic reactions, autoimmune diseases, and contact dermatitis.
Allergen immunotherapy (AIT) involves controlled exposure to allergens to reduce symptoms of allergic diseases like rhinitis, asthma, and conjunctivitis. It was first attempted in the early 1900s by immunizing people with plant extracts. While initial attempts caused adverse reactions, later studies found controlling the dose prevented this. Today, AIT is accepted for treating respiratory allergies and insect sting reactions but not food allergies or other conditions.
5-1. Review of complement system. Khadizha Emirova (eng)KidneyOrgRu
The document provides an overview of the complement system. It discusses that the complement system is composed of blood proteins that interact with each other and other immune system proteins to provide antimicrobial protection. It is activated via an enzymatic cascade reaction and its proteins only become active under pathological conditions. There are three pathways of complement activation: the classical, lectin, and alternative pathways. Complement activation leads to opsonization, inflammation, chemotaxis, and membrane attack complex formation. Tight regulation is needed as too much or too little complement can be harmful. Deficiencies in complement regulators can lead to innate autoreactivity.
This document provides an overview of hypersensitivity reactions. It begins with an introduction to immune responses and defines hypersensitivity as an inappropriate or exaggerated immune response that causes tissue damage. It then summarizes the four main types of hypersensitivity reactions: Type I is an immediate, IgE-mediated allergy; Type II involves antibody-mediated cell destruction; Type III occurs via immune complex deposition; and Type IV is a delayed, cell-mediated response. Each type is described in 1-2 sentences with examples given for Type I such as anaphylaxis and atopy.
Cellular respiration involves the breakdown of glucose in the presence or absence of oxygen to produce ATP. In aerobic respiration, glucose undergoes glycolysis, producing pyruvate, and then the pyruvate enters the mitochondria and undergoes the Krebs cycle and electron transport chain to yield much more ATP than anaerobic respiration. The mitochondria are specialized organelles that contain an inner membrane with cristae to increase surface area for ATP production via ATP synthase using a proton gradient generated by the electron transport chain.
VCE Biology Plants Responding to the EnvironmentLakshmi Sharma
The document discusses how plants respond to various environmental stimuli. It describes several types of stimuli including phototropism, the response to light, geotropism, the response to gravity, and chemotropism, the response to chemicals. It explains that environmental stimuli cause sensitive plant cells to produce hormones that trigger responses like flowering, stem elongation, or leaf movement. The document also discusses how plants use strategies like seed and bud dormancy to survive harsh conditions.
The document discusses the human immune system, including both non-specific (innate) and specific (adaptive) immunity. Non-specific immunity involves physical and chemical barriers that provide a first line of defense against pathogens. If pathogens breach these barriers, white blood cells such as phagocytes, natural killer cells, and the complement system work to destroy invading microorganisms. Specific immunity involves B cells and T cells that can recognize specific pathogens and mount faster and stronger responses upon re-exposure through the production of antibodies and memory cells. The document also discusses immune system disorders like allergies, autoimmune diseases, and immunodeficiencies.
The document summarizes the immune system's defenses against various pathogens. It describes both innate and acquired immunity. The innate immune system provides non-specific defenses like physical barriers, chemicals, and phagocytosis. The acquired immune system mounts pathogen-specific responses through antibodies, B cells, T cells, and cytokines. Together these defenses protect the body from bacteria, viruses, and parasites through mechanisms like inflammation, phagocytosis, and cell-mediated or antibody-mediated immunity.
The document discusses the major histocompatibility complex (MHC) in mammals. It notes that MHC acts as antigen presenting receptors and are involved in cell-cell interaction, antigen presentation, and recognition of self and non-self molecules. MHC is found on chromosome 6 in humans and is referred to as the HLA complex. MHC molecules are divided into three main classes - Class I MHC present antigens to cytotoxic T cells, Class II MHC present antigens to helper T cells, and Class III MHC genes encode complement components and cytokines. The structures and functions of Class I and Class II MHC molecules are described in detail.
Protein is composed of amino acids linked together in chains. It is essential for life and is contained in every part of the body. There are two main types of protein - fibrous proteins found in animals that serve structural functions, and globular proteins that usually do not have structural roles and can be enzymes or transporters. Protein has critical physiological functions including building, maintaining, and repairing body tissues, and can also be converted to energy when intake is greater than requirements. The structure of proteins involves four levels - primary, secondary, tertiary, and quaternary.
The document summarizes the complement system, which comprises a group of serum proteins that play an important role in innate and adaptive immunity. There are three pathways of complement activation - classical, lectin, and alternative. All three pathways lead to cleavage of C3 and C5, generating factors that opsonize pathogens, recruit inflammatory cells, and directly kill pathogens. Complement activation is tightly regulated to prevent damage to host cells. Deficiencies in complement proteins can increase susceptibility to certain infections.
The lymphatic system includes lymphatic organs such as the bone marrow, thymus gland, tonsils, spleen, lymph vessels, and lymph nodes. The lymphatic system helps defend the body against disease by transporting excess fluid, immune cells, and fat particles. It contains several organs that aid immune functions such as filtering blood cells, developing immune cells, and mounting immune responses.
1) The document discusses the immune system's response to infection and injury, including chemotaxis, vasodilation, and diapedesis which bring white blood cells to infected areas, and phagocytosis which eliminates bacteria.
2) It also summarizes the three lines of immune defense - non-specific, inflammatory response, and specific response through B and T lymphocytes and memory cells.
3) The immune system distinguishes self from non-self through a diverse repertoire of lymphocyte antigen receptors generated from inherited gene libraries to recognize any potential pathogen.
section 2, chapter 16: defense against pathogensMichael Walls
The lymphatic system and innate/adaptive defenses work together to protect the body from infection. Innate defenses provide general protection and include mechanical/chemical barriers that prevent pathogen entry. Adaptive defenses provide targeted protection through lymphocytes like T and B cells. T cells lead cellular immunity responses, while B cells produce antibodies for humoral immunity. When pathogens breach innate defenses, lymphocytes are activated through processes like antigen presentation and cytokine signaling to mount tailored immune responses through memory cells and targeted destruction of infected cells.
Section 2, chapter 16: defense and immunityMichael Walls
The lymphatic system and innate/adaptive defenses work together to protect the body from infection. Innate defenses provide general protection and include mechanical, chemical, cellular barriers and inflammation. Adaptive defenses provide targeted protection through lymphocytes and antibodies. When pathogens evade innate defenses, lymphocytes mount a response by cloning into memory and effector cells to recognize and eliminate the pathogen upon future exposures. T cells activate other immune cells and destroy infected cells while B cells produce antibodies to neutralize pathogens. Together these coordinated defenses provide robust protection against a wide range of infectious threats.
Overview of the Immune System: Innate vs. Adaptive Defenses
Innate-Nonspecific Defenses
First Line of defense: Physical barriers
Second Line of defense:
- Major cellular components
Phagocytes
Basophils
Eosinophils
NK cells
- Chemical signals
Interferons
Complement Proteins
Inflammation
Fever (pyrogens)
When a pathogen enters the body, it’s confronted by elements of the innate immune system, which constitute the first line of defense.
Once breached, the adaptive response takes over, but it typically takes few days to be effective.
Immunity is the processes that occur to defend the body against foreign organisms or molecules.
Immunity includes:
Inflammation.
Complement activation.
Phagocytosis.
Antibody synthesis.
Effector T lymphocytes.
The document summarizes the innate and adaptive immune response strategies of the host. It describes how innate immunity provides the first line of defense through physical and chemical barriers like the skin and mucous membranes. It also discusses cellular components of innate immunity including neutrophils, macrophages, dendritic cells, and NK cells that recognize and destroy pathogens. The adaptive immune response is antigen-specific and develops after exposure through antibody-mediated and cell-mediated responses, involving B cells, T helper cells, and cytotoxic T cells. Antigen presentation and the roles of MHC proteins in activating these responses are also outlined.
The innate immune system provides the first line of defense against pathogens through physical, chemical, and cellular barriers. Physical barriers include the skin and mucous membranes. Chemical barriers secrete antimicrobial peptides. Cellular responses involve phagocytes such as macrophages and neutrophils that engulf and destroy pathogens. Natural killer cells attack virus-infected cells. Mast cells and dendritic cells help initiate inflammation and adaptive immune responses. The innate system provides broad but non-specific protection against microbes.
The lymphatic/immune system has two main roles:
1. To destroy and remove invading microbes and viruses from the body.
2. For the lymphatic system to also remove fat and excess fluids from the blood.
The major organs of the lymphatic/immune system include lymph, lymph nodes and vessels, white blood cells, and T- and B- cells. The immune system acts through both specific responses using B and T cells and non-specific responses like inflammation.
The document discusses the mechanisms of innate and adaptive immunity. It describes the three lines of defense in the immune system: physical and chemical barriers, nonspecific resistance, and specific resistance. The mechanisms of innate immunity include epithelial surfaces, antibacterial substances, cellular factors, inflammation, fever, and acute phase proteins. Adaptive immunity involves B cells, T cells, and immunological memory. The humoral immune response involves antibody production by B cells, while cell-mediated immunity involves T cell activation and cytotoxic T cells destroying infected cells.
The immune system has both nonspecific defenses that provide immediate protection against pathogens and specific defenses that develop over time through exposure or vaccination. The specific defenses include B cells and T cells. B cells produce antibodies that identify pathogens for destruction. T cells identify and destroy infected cells. Immunity can be active, developing through natural exposure or vaccination, or passive, providing temporary protection through transfer of antibodies. Vaccines provide active immunity by exposing the immune system to antigens in a controlled way. The immune system defends the body but can also cause allergic reactions and autoimmune diseases when improperly activated.
1. Pathogens must gain access to the body, attach to and enter host cells, and reproduce to cause disease while evading the immune system.
2. The innate immune system is made up of physical and chemical barriers that provide nonspecific defenses against pathogens, including the skin, mucous membranes, and antimicrobial chemicals.
3. The adaptive immune system provides specific defenses through lymphocytes and antibodies that recognize and remember distinct pathogens. B cells produce antibodies while T cells help activate other immune responses.
This document outlines the three lines of defense of the immune system: physical and chemical barriers of the skin and mucous membranes as the first line of defense; formed elements in the blood like neutrophils, basophils, eosinophils, monocytes, macrophages, dendritic cells, and natural killer cells as the second line of defense; and the third line of defense involving B cells that produce antibodies, T cells that target specific pathogens, and memory cells that provide faster responses during reexposure. Cytokines are also discussed as chemical messengers that mediate communication between immune cells.
The document summarizes the principles of immunity and the immune system. It describes the requirements for an immune response, including detecting foreign objects, preventing the host from being killed, limiting replication of foreign objects, and limiting damage. It then outlines the types of infectious agents and describes both innate/nonspecific immunity including anatomical, physiological, inflammatory barriers and cellular and humoral responses as well as adaptive/specific cellular and humoral immunity responses.
White blood cells (leukocytes) are an essential part of the immune system. There are two main types: granulocytes and agranulocytes. Granulocytes include neutrophils, eosinophils, and basophils which have granules and fight infection. Agranulocytes are monocytes and lymphocytes which develop into macrophages and antibodies to identify and destroy pathogens. Leukocytes originate from stem cells in the bone marrow and have varying lifespans from hours to months depending on the type.
White blood cells & Immunity (The Guyton and Hall Physiology)Maryam Fida
Leukocytes or WBCs are the mobile units of the body’s immune defense system.
Immunity is the body’s ability to resist or eliminate potentially harmful foreign materials or abnormal cells.
WBC count: 5000 to 11000/ul of blood
GRANULOCYTES
Polymorphonuclear neutrophils 60-70%
Polymorphonuclear eosinophils 2-3%
Polymorphonuclear basophils 0.4%
NON-GRANULOCYTES
Monocytes 5.3%
Lymphocytes 30%
Granulocytes and monocytes are formed and stored only in bone marrow
Lymphocytes and plasma cells are formed and stored mainly in various lymphoid tissue such as lymph node, spleen, thymus and tonsils as well as in bone marrow.
GRANULOCYTES
4 to 8 hours in blood and 4 to 5 days in tissues
MONOCYTES
Monocytes also have a short transit time:
10 to 20 hours in blood and In tissue they swell to much larger size to become tissue macrophages.
LYMPHOCYTES
weeks to months
neutrophil
. 60-70% of leukocytes
nucleus: 2-5 lobes
Counting the number of lobes and grouping them is called Arneth count.
Shift to left means (increase no of young and predominant WBCs) e.g During acute infection.
Shift to right means, old cells are predominant. e.g During recovery phase
NEUTROPENIA
Decrease in neutrophils count
Typhoid
AIDS and viral hepatitis
Kalazar fever
Bone marrow depression by drugs and radiations
NEUTROPHILIA
Increase in neutrophils count
Appendicitis , Tonsillitis, Pneumonia
Burns, Hemorrhage, MI, Pain
Hypoxia, Pregnancy
BASOPHIL
Their cytoplasmic granules take up basic dyes and appear deep blue
MAST CELLS are derived from basophils under the influence of interleukins 3 and 4
Under many allergic conditions basophils and mast cells bursts and releases
Histamine
Bradykinin
Serotonin
Slow reacting substance of anaphylaxis
Heparin
Lysosomal enzymes
It is the capacity of the human body to resist and destroy the invading organisms or toxins.
The document discusses the immune system and its defenses against pathogens. It describes three lines of defense: innate immunity as the first line using physical and chemical barriers; inflammatory response as the second line if pathogens breach the first; and adaptive immunity as the third line involving specialized immune cells that recognize and remember specific pathogens. It provides details on the components of the immune system including white blood cells, antibodies, antigens, B cells, T cells, and immune memory.
The immune system defends the body against pathogens through layered lines of defense. The innate immune system provides immediate nonspecific responses while the adaptive immune system mounts targeted responses through lymphocytes. B and T lymphocytes recognize pathogens through antigen receptors and mount humoral or cell-mediated responses involving antibody production or cytotoxic killing. Immune memory develops from these responses to provide faster protection upon reexposure. A balanced immune response is needed, as deficiencies or issues with self-tolerance can lead to infection or autoimmunity.
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Biological screening of herbal drugs: Introduction and Need for
Phyto-Pharmacological Screening, New Strategies for evaluating
Natural Products, In vitro evaluation techniques for Antioxidants, Antimicrobial and Anticancer drugs. In vivo evaluation techniques
for Anti-inflammatory, Antiulcer, Anticancer, Wound healing, Antidiabetic, Hepatoprotective, Cardio protective, Diuretics and
Antifertility, Toxicity studies as per OECD guidelines
it describes the bony anatomy including the femoral head , acetabulum, labrum . also discusses the capsule , ligaments . muscle that act on the hip joint and the range of motion are outlined. factors affecting hip joint stability and weight transmission through the joint are summarized.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
June 3, 2024 Anti-Semitism Letter Sent to MIT President Kornbluth and MIT Cor...Levi Shapiro
Letter from the Congress of the United States regarding Anti-Semitism sent June 3rd to MIT President Sally Kornbluth, MIT Corp Chair, Mark Gorenberg
Dear Dr. Kornbluth and Mr. Gorenberg,
The US House of Representatives is deeply concerned by ongoing and pervasive acts of antisemitic
harassment and intimidation at the Massachusetts Institute of Technology (MIT). Failing to act decisively to ensure a safe learning environment for all students would be a grave dereliction of your responsibilities as President of MIT and Chair of the MIT Corporation.
This Congress will not stand idly by and allow an environment hostile to Jewish students to persist. The House believes that your institution is in violation of Title VI of the Civil Rights Act, and the inability or
unwillingness to rectify this violation through action requires accountability.
Postsecondary education is a unique opportunity for students to learn and have their ideas and beliefs challenged. However, universities receiving hundreds of millions of federal funds annually have denied
students that opportunity and have been hijacked to become venues for the promotion of terrorism, antisemitic harassment and intimidation, unlawful encampments, and in some cases, assaults and riots.
The House of Representatives will not countenance the use of federal funds to indoctrinate students into hateful, antisemitic, anti-American supporters of terrorism. Investigations into campus antisemitism by the Committee on Education and the Workforce and the Committee on Ways and Means have been expanded into a Congress-wide probe across all relevant jurisdictions to address this national crisis. The undersigned Committees will conduct oversight into the use of federal funds at MIT and its learning environment under authorities granted to each Committee.
• The Committee on Education and the Workforce has been investigating your institution since December 7, 2023. The Committee has broad jurisdiction over postsecondary education, including its compliance with Title VI of the Civil Rights Act, campus safety concerns over disruptions to the learning environment, and the awarding of federal student aid under the Higher Education Act.
• The Committee on Oversight and Accountability is investigating the sources of funding and other support flowing to groups espousing pro-Hamas propaganda and engaged in antisemitic harassment and intimidation of students. The Committee on Oversight and Accountability is the principal oversight committee of the US House of Representatives and has broad authority to investigate “any matter” at “any time” under House Rule X.
• The Committee on Ways and Means has been investigating several universities since November 15, 2023, when the Committee held a hearing entitled From Ivory Towers to Dark Corners: Investigating the Nexus Between Antisemitism, Tax-Exempt Universities, and Terror Financing. The Committee followed the hearing with letters to those institutions on January 10, 202
2. Immunity
• Immunity
– The ability of the body to fight infection and/or foreign
invaders by producing antibodies or killing infected cells.
• Immune System
– The system in the body responsible for maintaining
homeostasis by recognizing harmful from non-harmful
organisms and produces an appropriate response.
• Highly specific recognition of foreign antigens
• Mechanisms for elimination of microbes bearing such
antigens
• A vast universe of distinct antigenic specifies
• Immunologic memory
• Tolerance of self-antigens
3. Key attributes of immune system
• 4 attributes that characterize the
immune system as a whole
– specificity
• antigen-antibody specificity
– diversity
• react to millions of antigens
– memory
• rapid 2° response
– ability to distinguish self vs. non-self
• maturation & training process to reduce auto-
immune disease
4. Foreign Invaders
• Called Pathogens
– Viruses, bacteria or
other living thing that
causes
disease/immune
response.
• Antigens
– Toxins that pathogens
produce that cause
harm to an organism.
5. Avenues of attack
• Points of entry
– digestive system
– respiratory system
– urogenital tract
– break in skin
• Routes of attack
– circulatory system
– lymph system
6. Parts of the Immune System
1. Blood - White Blood Cells in particular.
2. Lymph nodes
3. Thymus Gland – Produces T Lymphocytes
4. Bone Marrow – Produces B Lymphocytes
7. Production & transport of leukocytes
Lymph system Traps foreign invaders
lymph vessels
(intertwined amongst blood vessels)
lymph node
9. How does the body fight infection/foreign invaders?
First Line of Defense – The Skin
• Provides Physical and Chemical barriers
• Physical – hard to penetrate, made of indigestible keratin
• Chemical – tears, sweat
11. 2nd Line – Nonspecific Immune Response
These are defenses the body uses no matter what the invader
may be. These defenses include:
– Phagocytosis – done by Macrophages
– Natural Cell Killers
– Inflammation - caused by release of Histamine from
leukocytes
– Fever – caused by histamines. The fever (high temp) kills
invaders by denaturing their proteins.
12. 2nd line: Internal, broad range patrol
• Innate, general defense leukocytes
– rapid response
• Patrolling cells & proteins
– attack invaders that penetrate
body’s outer
barriers
• leukocytes
– phagocytic white blood cells
• complement system
– anti-microbial proteins
• inflammatory response
13. Leukocytes: Phagocytic white blood cells (WBCs)
• Attracted by chemical
signals released by damaged cells
– enter infected tissue, engulf & ingest microbes
• lysosomes
• Neutrophils
– most abundant WBC (~70%)
– ~ 3 day lifespan
• Macrophages
– “big eater”, long-lived
• Natural Killer Cells
– destroy virus-infected cells
& cancer cells
19. Fever
• When a local response is not enough
– systemic response to infection
– activated macrophages release interleukin-1 (IL-1)
• triggers hypothalamus in brain to readjust body thermostat to raise
body temperature
– higher temperature helps defense
• inhibits bacterial growth
• stimulates phagocytosis
• speeds up repair of tissues
• causes liver & spleen to store
iron, reducing blood iron levels
– bacteria need large amounts
of iron to grow
20. The Inflammatory Response
• 1- Tissue injury; release of chemical signals~
• histamine (basophils/mast cells): causes Step 2...
• prostaglandins: increases blood flow & vessel permeability
• 2/3- Dilation and increased permeability of capillary~
• chemokines: secreted by blood vessel endothelial cells
mediates phagocytotic migration of WBCs
• 4- Phagocytosis of pathogens~
• fever & pyrogens: leukocyte-released molecules increase body
temperature
21. 3rd line: Acquired (active) Immunity
• Specific defense
– lymphocytes
• B lymphocytes (B cells)
• T lymphocytes (T cells)
– antibodies
• immunoglobulins
• Responds to…
– antigens
• specific pathogens
• specific toxins
• abnormal body cells
(cancer)
22. 3rd Line – Specific Immune Response
This is a specific response to a specific
pathogen/antigen.
The response involves the creation of Antibodies.
23. Antibodies
• Y-shaped protein
molecule.
• Made up of variable and
constant regions.
• Made up of Heavy and
Light chains.
• Produced by B-
Lymphocytes
• Function: Recognize
antigens, bind to and
deactivate them.
– Note: Variable region
recognizes the anitgens.
24. Antigens- recognition of invaders
• Antigens
– proteins that serve as cellular name tags
• foreign antigens cause response from WBCs
– viruses, bacteria, protozoa, parasitic worms, fungi, toxins
– non-pathogens: pollen & transplanted tissue
• B cells & T cells respond to different antigens
– B cells recognize intact antigens
• pathogens in blood & lymph
– T cells recognize antigen fragments
• pathogens which have already infected cells
“self” “foreign”
25. How an antibody operates/works?
Deactivation of a bacterium by an antibody.
26. How are cells tagged with antigens?
• Major histocompatibility (MHC) proteins
– antigen glycoproteins
– MHC I – on all nucleated cells
– MHC II – on macrophages, B-Ly, activated T-Ly
• MHC proteins constantly carry bits of cellular
material from the cytosol to the cell surface
– “snapshot” of what is going on inside cell
– give the surface of cells a unique label or “fingerprint”
T cell
MHC proteins
displaying self-antigens
27. The Pathway of Specific Immune Response
Step 1
Pathogens eaten by Macrophage
Step 2
Displays portion of Pathogen
on surface
Step 3
Pathogens
Helper-T cell recognizes
Pathogen
29. Cellular Immunity vs. Antibody Immunity
Cellular Immunity Antibody or Humoral Immunity
• Carried out by T-Cells • Carried out by B-cells
• Infected cells are killed by • Antibodies are produced
Cytotoxic T –Cells. and dumped into blood
stream.
• Antibodies bind to
antigens and deactivate
them.
30. Immune Response Explained
1. Antigen infects cells.
2. Macrophage ingests antigen and displays portion on its surface.
3. Helper T- Cell recognizes antigen on the surface of the
macrophage and becomes active.
4. Active Helper T-Cell activates Cytotoxic T-Cells and B-Cells.
5. Cytotoxic T-Cells divide into Active Cytotoxic T-cells and Memory
T – Cells.
6. Active Cytotoxic T-Cells kill infected cells.
7. At the same time, B-Cells divide into Plasma Cells and Memory
B- Cells.
8. Plasma cells produce antibodies that deactivate pathogen.
9. Memory T and Memory B cells remain in the body to speed up the
response if the same antigen reappears.
10. Supressor T-Cells stop the immune response when all antigens
have been destroyed.
31. Immune Response Summary
Displays copy of antigen
on surface of cell
Antigen
Macrophage
Helper T - Cell Antibody Immunity
Cellular Immunity
Active Cytotoxic T-Cell Active B - Cell
Kills Infected Cells Memory T- Cell Plasma Cell Memory B-Cell
Antibodies
Deactivates Antigens
32. Primary .vs. Secondary Immune Response
• Primary Immune Response
– This is a response to an invader the 1st time the
invader infects the body.
• No measurable immune response for first few days.
• Next 10 – 15 days antibody production grows steadily
• Secondary Immune Response
– A more rapid response to an invader the 2nd time it
invades the body.
• Antibody production increases dramatically and in a much
shorter time period..
34. Induction of Immune Responses
• Primary immune response: lymphocyte proliferation and
differentiation the 1st time the body is exposed to an antigen
• Plasma cells: antibody-producing effector B-cells
• Secondary immune response: immune response if the individual
is exposed to the same antigen at some later time~ Immunological
memory
35. Passive vs. Active Immunity
1. Active Immunity
This is immunity where the body is “actively” producing antibodies
to fight infection.
Ex: You have a throat infection and you are actively creating
antibodies to fight it.
Vaccination: An injection of a weakened strain of an
infectious microbe (pathogen) that causes the body to
undergo active immunity (produce antibodies).
1. Passive Immunity
This is immunity where antibodies are given to a
person from the blood of another person or animal.
This immunity only lasts for a short period of time.
ex: Breastfeeding mothers pass antibodies to their
children through the milk.
36. Autoimmune Disease
• Autoimmune diseases are diseases where the immune
system begins to attack itself.
– Ex:
• Rheumatoid Arthritis – crippling disease of the
joints.
• Lupus – disease of blood and organs.
• Multiple Sclerosis – disease of nervous system
• Cause(s): unknown
• Cures/Treatments: No known cures.
37. Allergies
Allergy
- An exaggerated response by the immune system to an allergen.
Allergen: a normally harmless substance that causes an allergic
reaction.
ex: dust, pollen, mould, food, insect stings
Types of Allergic reactions
There are two types of allergic reactions.
a. Immediate – occurs within seconds and normally lasts for about
30 mins.
b. Delayed – takes longer to react and can last for a much longer
time.
38. What happens during an allergic reaction?
• During an allergic reaction antibodies cause histamines to be
released from certain cells.
Histamines cause:
a. Swelling of tissues
b. Release of fluids (runny noses and eyes)
c. muscle spasms (some cases)
Anaphylaxis or anaphylactic shock:
This is the sudden and severe allergic reaction to a substance that
can cause death.
Treatments for Allergies
1. Avoidance of material – especially food.
2. Epinephrine – “epi – pen”
3. Antihistamines -- benadryl
40. HIV & AIDS
• Human Immunodeficiency Virus
– virus infects helper T cells
– helper T cells don’t activate rest of immune
system: T cells & B cells
• also destroy T cells
• Acquired ImmunoDeficiency Syndrome
– infections by opportunistic
diseases
– death usually from other
infections
• pneumonia, cancer
41. HIV
• HIV is a virus that specifically attacks the
lymphocytes.
• This means the number of lymphocytes
decreases.
• Less antibodies are made.
• Predict the consequences…
43. Transmission of HIV
• Infected blood – blood transfusions,
sharing needles,
• Infected semen and vaginal mucus –
unprotected sex
• Infected mother’s milk – low risk
• Infected saliva – almost zero risk
44. AIDS
• Caused by the HIV virus that selectively
infects the immune system leaving the
body open to infection by removing the
specific immunity.
45. Social implications of AIDS
• Cases of AIDS are not evenly distributed in the
world, for example there are severe problems in
Africa (some populations with 30% of their
people are infected).
• What cultural and economic reasons are there
for differences in the prevalence of AIDS?
• Is there a moral obligation of those with the
technology and the wealth to help others lacking
these things in the fight against AIDS?
Editor's Notes
Certain bacterial infections can induce an overwhelming systemic inflammatory response leading to a condition known as septic shock . Characterized by high fever and low blood pressure, septic shock is the most common cause of death in U.S. critical care units. Clearly, while local inflammation is an essential step toward healing, widespread inflammation can be devastating.
Major Histocompatability Complex (MHC): body cell surface antigens coded by a family of genes Class I MHC molecules: found on all nucleated cells Class II MHC molecules: found on macrophages, B cells, and activated T cells
----- Meeting Notes (11/25/12 20:21) -----
AIDS: Acquired Immuno deficiency syndrome . Acquired relates the infectious nature of AIDS through the transmission of the HIV virus. Immuno deficient relates to the way diseases cannot be resisted. Syndrome relates to the variation in the way the disease manifest itself. People who develop AIDS can be a affected by quite different set of diseases.