detail notes on connective tissue..
Connective tissue (CT) is one of the four basic types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesoderm. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. In the central nervous system, the three outer membranes (the meninges) that envelop the brain and spinal cord are composed of connective tissue.
All connective tissue consists of three main components: fibers (elastic and collagenous fibers), ground substance and cells. Not all authorities include blood or lymph as connective tissue because they lack the fiber component. All are immersed in the body water.
Cartilage is a resilient and smooth elastic connective tissue, a rubber-like padding that covers and protects the ends of long bones at the joints, and is a structural component of the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, and many other body components.
Histology
Junqueira’s Basic Histology Text and Atlas, 15th Ed
11.03.08(c): Histology of the Cardiovascular SystemOpen.Michigan
Slideshow is from the University of Michigan Medical School's M1 Cardiovascular / Respiratory sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1Cardio
The mucose membrane lining of gastrointestinal tract is stratified squamous epithelium at the esophagus which slowly convert into simple columnar epithelium at the stomach until the anus it converts back into the stratified squamous epithelium at the lower half of the anal canal. The stratified epithelium is a wear and tear epithelium.
As it passes down from the small to large intestine, goblet cells increase because as it passes down water was absorb, goblet cells function to produce mucous.
This is just a rough idea, for better slides with more reference please PM the author at davidgqf@gmail.com.
detail notes on connective tissue..
Connective tissue (CT) is one of the four basic types of animal tissue, along with epithelial tissue, muscle tissue, and nervous tissue. It develops from the mesoderm. Connective tissue is found in between other tissues everywhere in the body, including the nervous system. In the central nervous system, the three outer membranes (the meninges) that envelop the brain and spinal cord are composed of connective tissue.
All connective tissue consists of three main components: fibers (elastic and collagenous fibers), ground substance and cells. Not all authorities include blood or lymph as connective tissue because they lack the fiber component. All are immersed in the body water.
Cartilage is a resilient and smooth elastic connective tissue, a rubber-like padding that covers and protects the ends of long bones at the joints, and is a structural component of the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, and many other body components.
Histology
Junqueira’s Basic Histology Text and Atlas, 15th Ed
11.03.08(c): Histology of the Cardiovascular SystemOpen.Michigan
Slideshow is from the University of Michigan Medical School's M1 Cardiovascular / Respiratory sequence
View additional course materials on Open.Michigan:
openmi.ch/med-M1Cardio
The mucose membrane lining of gastrointestinal tract is stratified squamous epithelium at the esophagus which slowly convert into simple columnar epithelium at the stomach until the anus it converts back into the stratified squamous epithelium at the lower half of the anal canal. The stratified epithelium is a wear and tear epithelium.
As it passes down from the small to large intestine, goblet cells increase because as it passes down water was absorb, goblet cells function to produce mucous.
This is just a rough idea, for better slides with more reference please PM the author at davidgqf@gmail.com.
Epithelial tissue, also known as the epithelium, is one of the four tissues found in the human body. It exists in various parts of the body, such as our digestive system, outer surfaces of organs and blood vessels throughout the body, as well as the inner surfaces of cavities in many internal organs.
Histology
Junqueira’s Basic Histology Text and Atlas, 15th Ed
Tissue Definition
Tissues are groups of cells that have a similar structure and act together to perform a specific function. The word tissue comes from a form of an old French verb meaning “to weave”. There are four different types of tissues in animals: connective, muscle, nervous, and epithelial. In plants, tissues are divided into three types: vascular, ground, and epidermal. Groups of tissues make up organs in the body such as the brain and heart.
Types of Animal Tissues
Connective
Connective tissue connects or separates groups of other tissues. It is found in between all the other tissues and organs in the body. Connective tissue is made up of cells and ground substance, which is a gel that surrounds cells. Most connective tissue, except for lymph and blood, also contains fibers, which are long, narrow proteins. Fibers can be collagenous, which bind bones to tissues; elastic, which allow organs like the lungs to move; or reticular, which provide physical support to cells. Connective tissue also allows oxygen to diffuse from blood vessels into cells.
About 1 in 10 people are have a disorder involving connective tissue. Some connective tissue disorders include sarcomas, Marfan syndrome, lupus, and scurvy, which is a Vitamin C deficiency that leads to fragile connective tissue.
Muscle
Muscle tissue comprises all the muscles in the body, and the specialized nature of the tissue is what allows muscles to contract. There are three types of muscle tissue: skeletal muscle, cardiac muscle, and smooth muscle. Skeletal muscle anchors tendons to bones and allows the body to move. Cardiac muscle is found in the heart and contracts to pump blood. Smooth muscle is found in the intestines, where it helps move food through the digestive tract, and it is also found in other organs like blood vessels, the uterus, and the bladder. Skeletal and cardiac muscles are striated; this means that they contain sarcomeres (a unit of muscle tissue) that are arranged in a uniform pattern. Smooth muscle does not have sarcomeres.
Duchenne muscular dystrophy is an example of a muscle tissue disorder. It is an inherited disorder that causes muscles to atrophy over time. The muscles shorten as they atrophy, which can cause scoliosis and immobile joints. Individuals with the disorder are usually male because the gene responsible for it is found on the X chromosome (of which males have only one).
Nervous
Nervous tissue is found in the brain, spinal cord, and peripheral nerves, which are all parts of the nervous system. It is made up of neurons, which are nerve cells, and neuroglia, which are cells that help nerve impulses travel. Nervous tissue is grouped into four types: gray matter and white matter in the brain, and nerves and ganglia in the peripheral nervous system. The main difference between gray and white matter is that axons of the neurons in gray matter are unmyelinated, while white matter is myelinated. Myelin is a white, fatty substance that insulates neurons and
Tissues are a group of similar cells of the same origin that carry out a specific function together. Humans have four different types of basic tissues. Connective tissues such as bone tissue are made up of fibrous cells and give shape and structure to organs. Muscle tissue is made up of cells that can contract together and allow animals to move. Epithelial tissues make up the outer layers of organs, such as the skin or the outer layer of the stomach. Nervous tissue is made of specialized cells that transmit information through electrochemical impulses, such as the tissue of nerves, the spinal cord, and the brain.
NVBDCP.pptx Nation vector borne disease control programSapna Thakur
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
These lecture slides, by Dr Sidra Arshad, offer a quick overview of physiological basis of a normal electrocardiogram.
Learning objectives:
1. Define an electrocardiogram (ECG) and electrocardiography
2. Describe how dipoles generated by the heart produce the waveforms of the ECG
3. Describe the components of a normal electrocardiogram of a typical bipolar leads (limb II)
4. Differentiate between intervals and segments
5. Enlist some common indications for obtaining an ECG
Study Resources:
1. Chapter 11, Guyton and Hall Textbook of Medical Physiology, 14th edition
2. Chapter 9, Human Physiology - From Cells to Systems, Lauralee Sherwood, 9th edition
3. Chapter 29, Ganong’s Review of Medical Physiology, 26th edition
4. Electrocardiogram, StatPearls - https://www.ncbi.nlm.nih.gov/books/NBK549803/
5. ECG in Medical Practice by ABM Abdullah, 4th edition
6. ECG Basics, http://www.nataliescasebook.com/tag/e-c-g-basics
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
HOT NEW PRODUCT! BIG SALES FAST SHIPPING NOW FROM CHINA!! EU KU DB BK substit...GL Anaacs
Contact us if you are interested:
Email / Skype : kefaya1771@gmail.com
Threema: PXHY5PDH
New BATCH Ku !!! MUCH IN DEMAND FAST SALE EVERY BATCH HAPPY GOOD EFFECT BIG BATCH !
Contact me on Threema or skype to start big business!!
Hot-sale products:
NEW HOT EUTYLONE WHITE CRYSTAL!!
5cl-adba precursor (semi finished )
5cl-adba raw materials
ADBB precursor (semi finished )
ADBB raw materials
APVP powder
5fadb/4f-adb
Jwh018 / Jwh210
Eutylone crystal
Protonitazene (hydrochloride) CAS: 119276-01-6
Flubrotizolam CAS: 57801-95-3
Metonitazene CAS: 14680-51-4
Payment terms: Western Union,MoneyGram,Bitcoin or USDT.
Deliver Time: Usually 7-15days
Shipping method: FedEx, TNT, DHL,UPS etc.Our deliveries are 100% safe, fast, reliable and discreet.
Samples will be sent for your evaluation!If you are interested in, please contact me, let's talk details.
We specializes in exporting high quality Research chemical, medical intermediate, Pharmaceutical chemicals and so on. Products are exported to USA, Canada, France, Korea, Japan,Russia, Southeast Asia and other countries.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
Follow us on: Pinterest
Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
HISTOLOGY: EPITHELIA AND GLANDS CONNECTIVE TISSUE PROPER CARTILAGE AND BONE
1. HISTOLOGY:
EPITHELIA AND GLANDS
CONNECTIVE TISSUE PROPER
CARTILAGE AND BONE
Olaleye O.O.
2B10
2. INTRODUCTION
The four basic types of tissues in the body are the:
•Epithelial tissue
•Connective tissue
•Muscular tissue
•Nervous tissue
These tissue exist and function in close association with one another.
3. Epithelia
Epithelia are a diverse group of tissues which cover or line all body
surfaces, cavities and
Tubes. They function as interfaces between different biological
compartments. As such, the mediate a wide range of activities such
as;
•Selective diffusion
•Absorption and/or secretion
•Physical protection
•Containment
4. They are closely bound to one another by a variety of membrane
specialisations called cell junctions which provide physical strength
and exchange of info and metabolites.
All epithelia are supported by basement membrane which separates
epithelia from underlying supporting tissues and are never penetrated
by blood vessels. Thus, epithelia are dependent on the diffusion of
oxygen and metabolites from adjacent supporting tissues.
5. Arrangement and structure of Epithelial cells
Epithelium is named according to:
• Shape
• Structure
• Arrangement of cells
6. Arrangement and structure of Epithelial cells
• Squamous- thin and flat shaped cells
• Cuboidal- cube shaped cells
• Columnar- column shaped cells
• Simple- single layer of cells
• Stratified- multilayered cells
• Pseudo-stratified- false stratified
• Transitional- stretchable
• Ciliated- cells possess cilia
7. Basement Memebrane
The basement membrane is a
thin, noncellular region that
separates the epithelium from
the underlying conective tissue.
Can easily be seen with a light
microscope.
8. Classification of Epithelia tissues
Epithelium is traditionally classified according to three
morphological characteristics:
•The number of cell layer: a single layer of epithelial cells is
termed SIMPLE epithelium, whereas epithelia composed of
several layers are termed STRATIFIED epithelium
9. •The shape of the component cells: This is based on appearance of
sections taken at right angles to the epithelial surface.
NB: In stratified epithelia the shape of the outermost layer of cells
determines the descriptive classification. Cellular outline are often
difficult to distinguish, but the shape of epithelial cells is usually
reflected in the shape of their nuclei.
10. •The presence of surface specialisation such as cilia and keratin:
an example is the epithelia surface of skin whis is classified as
stratified squamous keratinized epithelium.
NB: Epithelial maybe derived from ectoderm, mesoderm or
endoderm origin.
12. Epithelium which is primarily involved in secretion is often arranged into
structures called GLANDS
Glands are merely invaginations of epithelial surfaces which are formed
during embryonic development by proliferation of epithelium into the
underlying tissues
13. There different types of glands:
Glands which maintain their continuity with the epithelial surface,
discharging their secretions onto the free surface via a duct, are called
EXOCRINE glands.
In some cases, the duct degenerates during development leaving
isolated islands of epithelial secretory tissue deep within other tissues.
The secretory products of such glands, known as ENDOCRINE or
DUCTLESS glands, pass into the bloodstream; their secretions are
know as hormones.
14. Glands are cells or aggregations of cells whose function is secretion.
Exocrine glands release the secretory product via a system of ducts that
opens upon one of the surfaces of the body which are in contact with the
external world (skin, gastrointestinal tract etc.).
15. Endocrine glands release their secretory product (typically hormones)
into the spaces between the secretory cells (extracellular space) from
which it enters the bloodstream.
16. Both endocrine and exocrine glands are developmentally derived from
epithelia, which form a down-growth into the underlying connective tissue.
The cells forming this down-growth then develop the special
characteristics of the mature gland.
NB: Exocrine glands maintain the connection with the surface epithelium,
whereas the connection is lost by endocrine glands.
17. Exocrine glands
Exocrine glands may be classified according to cell number,
and/or the shape and branching pattern of their secretory portions
and ducts.
18. Unicellular Glands: consist of a single secretory cell. In mammals the
only example of unicellular exocrine glands are goblet cells, which occur
in the epithelium of many mucous membranes. Goblet cells secrete the
glycoprotein mucin, which by the uptake of water is converted into a slimy
substance, mucus.
19. Multicellular glands: The simplest form of a multicellular gland is a secretory
epithelial sheath - a surface epithelium consisting entirely of secretory cells (e.g.
the epithelium lining the inner surface of the stomach, where the mucous secretion
protects the stomach wall from the acidic contents of the stomach). Other
multicellular glands have their secretory portion embedded in the connective
tissue underlying the epithelium. The secretion is either discharged directly from
the secretory portion onto the epithelium or reaches the epithelium via a duct
system that consists of non-secretory cells.
20. The secretory portion may have a variety of shapes. Secretory cells
may form
tubes in tubular glands,
acini in acinar glands or
alveoli in alveolar glands
21. Combinations exist - the pancreas is a tubulo-acinar gland, in which each
section of the secretory system has a specialized function.
The precursors of digestive enzymes are produced by the acinar cells. Tubular
cells secrete the alkaline bicarbonate solution which eventually neutralizes the
acidic contents of the stomach that are released into the duodenum.
22. Multicellular glands with an unbranched excretory duct are
called simple.
When the excretory duct is branched, it is called a compound gland.
Finally, the part of the gland consisting of secretory cells is branched in a
branched gland.
23. Secretory Mechanisms
The secretory cells can release their secretory products by one of three
mechanisms:
• Merocrine secretion
• Apocrine secretion
• Holocrine secretion
24. Merocrine secretion: corresponds to the process of
exocytosis. Vesicles open onto the surface of the cell, and the
secretory product is discharged from the cell without any
further loss of cell substance.
25. Apocrine secretion: designates a mechanism in which part of the
apical cytoplasm of the cells is lost together with the secretory product.
The continuity of the plasma membrane is restored by the fusion of the
broken edges of the membrane, and the cell is able to accumulate the
secretory product anew. This mechanism is used by apocrine sweat
glands, the mammary glands and the prostate.
26. Holocrine secretion: designates the breakdown and
discharge of the entire secretory cell. It is only seen in
the sebaceous glands of the skin.
27. There are two additional mechanisms by which secretory cells can release their
products. Lipid soluble substances may diffuse out of the secretory cell (e.g.
steroid hormone-producing endocrine cells). Transporters (membrane proteins)
may actively move the secretory product across the plasma membrane (e.g. the
acid producing parietal cells of the gastric glands). These secretory mechanisms
may not involve any light microscopically visible specialisations of the cell.
28. Connetive Tissue Proper
This is the most widespread and abundant type of tissue in the human
body. Its function is primarily to support, anchor and connect various
parts of the body. Although connective tissue exists in a number of
forms, all types have three basic structural elements --
cells, fibres and intercellular substance (ground substance).
29. Connective tissue serves as:
• Packing
• Holds the cells of organs together
• Passes on nutrients to other tissues from the blood
• And active in fighting disease-causing organisms.
The cells in connective tissue are always well spaced in a thick, fluid base
substance, or matrix, in which there may also be long, thin threads called
fibers.
30. The most common cell types are fibroblasts, which produce fibres and other
intercellular materials. The two most common types of fibres are:
• collagen (collagenous)
• and elastic.
Collagen fibres are for strength while the elastic ones are for elasticity of the
tissue. Both the cells and the fibres are embedded in the intercellular
substance. The consistency of this substance is highly variable from gelatin-
like to a much more rigid material.
31. The proportions of the cells, fibres, and intercellular substance vary, depending
on a particular nature and function of the connective tissue. For example, a
strong connective tissue needs a greater proportion of the collagen fibres and
fewer cells. An example would be a dense regular connective tissue, which is
found in tendons and ligaments. On the other hand, a connective tissue
composed of mostly cells would not be very strong. An example would be an
adipose (fat) connective tissue.
33. Connective tissue proper: encompasses all organs and body cavities
connecting one part with another and, equally important, separating one
group of cells from another. This is a very large and diverse group of
tissues and includes adipose tissue (fat), areolar (loose) tissue, and
dense regular tissue, among others.
34. Specialized connective tissues: this group includes cartilage, bone,
and blood. Cartilage and bone form the skeletal framework of the body
while blood is the vascular (transport) tissue of animals.
35. Connective tissue proper
Areolar (Loose) Connective Tissue
• Is the most widespread connective tissue of the body.
• It is used to attach the skin to the underlying tissue.
• It also fills the spaces between various organs and thus holds them in
place as well as cushions and protects them.
• It also surrounds and supports the blood vessels.
36. • The fibres of areolar connective tissue are arranged in no particular
pattern but run in all directions and form a loose network in the
intercellular material. Collagen (collagenous) fibres are predominant.
• They usually appear as broad pink bands.
• Some elastic fibres, which appear as thin, dark fibres are also
present.
37. • The cellular elements, such as fibroblasts, are difficult to distinguish in the
areolar connective tissue. But, one type of cells - the mast cells are
usually visible.
• They have course, dark-staining granules in their cytoplasm.
• Since the cell membrane is very delicate it frequently ruptures in slide
preparation, resulting in a number of granules free in the tissue
surrounding the mast cells.
• The nucleus in these cells is small, oval and light-staining, and may be
obscured by the dark granules.
38. Adipose Connective Tissue
The cells of adipose (fat) tissue are characterized by a large internal fat droplet,
which distends the cell so that the cytoplasm is reduced to a thin layer and the
nucleus is displaced to the edge of the cell.
These cells may appear singly but are more often present in groups.
When they accumulate in large numbers, they become the predominant cell
type and form adipose (fat) tissue.
Adipose tissue, in addition to serving as a storage site for fats (lipids), also pads
and protects certain organs and regions of the body. As well, it forms an
insulating layer under the skin which helps regulate body temperature.
39. Dense (Fibrous) Regular Connective Tissue
• Dense connective tissue is characterized by:
• an abundance of fibres with fewer cells, as compared to the loose
connective tissue.
• It is also called fibrous or collagenous connective tissue because of the
abundance of collagen (collagenous) fibres.
• Little intercellular substance is present.
40. • Furthermore, in this tissue type, the fibres are organized in a regular, parallel
pattern. Hence, the name – dense regular (fibrous or collagenous)
connective tissue.
• In addition to the tendons, this type of tissue is also found in ligaments.
Hence, the function of this tissue is to anchor skeletal muscle to bone, to
attach bone to bone as well as to stabilize the bones within a joint.
Fibroblasts are the only cells visible, and are arranged in rows between the
fibres. These fibroblasts function to lay down or create the fibres of the tissue
41. Cartilage: Specialized Connective Tissues
Cartilage is a somewhat elastic, pliable and compact type of connective
tissue.
It is characterized by three traits:
• lacunae,
• chondrocytes,
• a rigid matrix.
The matrix is a firm gel material that contains fibres and other
substances.
42. There are three basic types of cartilage in the human body:
• hyaline cartilage,
• elastic cartilage and
• fibrocartilage.
43. The most common type of cartilage is the hyaline cartilage.
Most of the skeleton of the mammalian fetus is composed of hyaline cartilage.
As the fetus ages, the cartilage is gradually replaced by more supportive bone.
In the mammalian adult, hyaline cartilage is mainly restricted to:
• the nose,
• trachea,
• Bronchi,
• ends of the ribs,
• and the articulating surfaces of most joints
44. The function of the hyaline cartilage is to provide
slightly flexible support and reduce friction within
joints. It also provides structural reinforcement.
45. The matrix appears as a smooth, solid, blue or pink-coloured
substance. Fine protein fibres, are embedded in the matrix, but
they are not visible with the light microscope since they do not
stain well.
The large cartilage cells called chondrocytes, are trapped within
the matrix in spaces called lacunae (singular, lacuna).
Cartilage is a non-vascular tissue. As such, the chondrocytes rely
on blood vessels in the tissue surrounding the cartilage for nutrient
supply and waste removal.
46. BONE
Bone is the main component of the skeleton in the adult human.
Like cartilage, bone is a specialised form of dense connective tissue.
Bone gives the skeleton the necessary rigidity to function as attachment
and lever for muscles and supports the body against gravity.
Two types of bone can be distinguished macroscopically:
• Trabecular or cancellous or spongy bone
• Compact bone
47. Trabecular or cancellous or spongy bone consists of delicate bars
and sheets of bone, trabeculae, which branch and intersect to
form a sponge like network. The ends of long bones
(or epiphyses) consist mainly of trabecular bone.
48. Compact bone does not have any spaces or hollows in the bone matrix
that are visible to the eye. Compact bone forms the thick-walled tube of
the shaft (or diaphysis) of long bones, which surrounds the marrow cavity
(or medullary cavity). A thin layer of compact bone also covers the
epiphyses of long bones.
49. Bone is, again like cartilage, surrounded by a layer of dense connective
tissue, the periosteum.
A thin layer of cell-rich connective tissue, the endosteum, lines the surface of
the bone facing the marrow cavity.
Both the periosteum and the endosteum possess osteogenic potency.
Following injury, cells in these layers may differentiate into osteoblasts (bone
forming cells) which become involved in the repair of damage to the bone.
50. Compact Bone
Compact bone consists almost entirely of extracellular substance, the matrix.
Osteoblasts deposit the matrix in the form of thin sheets which are
called lamellae.
Lamellae are microscopical structures.
Collagen fibres within each lamella run parallel to each other.
Collagen fibres which belong to adjacent lamellae run at oblique angles to each
other.
Fibre density seems lower at the border between adjacent lamellae, which
gives rise to the lamellar appearance of the tissue. Bone which is composed by
lamellae when viewed under the microscope is also called lamellar bone.
51. In the process of the deposition of the matrix, osteoblasts become encased in
small hollows within the matrix, the lacunae.
Unlike chondrocytes, osteocytes have several thin processes, which extend
from the lacunae into small channels within the bone matrix , the canaliculi.
Canaliculi arising from one lacuna may anastomose with those of other lacunae
and, eventually, with larger, vessel-containing canals within the bone.
Canaliculi provide the means for the osteocytes to communicate with each other
and to exchange substances by diffusion.
52. In mature compact bone most of the individual lamellae form concentric rings
around larger longitudinal canals (approx. 50 µm in diameter) within the bone
tissue.
These canals are called Haversian canals. Haversian canals typically run
parallel to the surface and along the long axis of the bone. The canals and the
surrounding lamellae (8-15) are called a Haversian system or an osteon. A
Haversian canal generally contains one or two capillaries and nerve fibres.
53. Irregular areas of interstitial lamellae, which apparently do not belong to any
Haversian system, are found in between the Haversian systems.
Immediately beneath the periosteum and endosteum a few lamella are found
which run parallel to the inner and outer surfaces of the bone. They are
the circumferential lamellae and endosteal lamellae.
54. A second system of canals, called Volkmann's canals, penetrates the
bone more or less perpendicular to its surface.
These canals establish connections of the Haversian canals with the inner
and outer surfaces of the bone.
Vessels in Volkmann's canals communicate with vessels in the Haversian
canals on the one hand and vessels in the endosteum on the other.
A few communications also exist with vessels in the periosteum.
55. Trabecular Bone
The matrix of trabecular bone is also deposited in the form of lamellae.
In mature bones, trabecular bone will also be lamellar bone.
However, lamellae in trabecular bone do not form Haversian systems.
Lamellae of trabecular bone are deposited on pre-existing trabeculae
depending on the local demands on bone rigidity.
Osteocytes, lacunae and canaliculi in trabecular bone resemble those in
compact bone.