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
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]
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
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]
B.Pharm-Ist sem-HAP-Chapter 3-tissue level of organization.pptxSheetal Patil
Introduction
The term tissue is used to describe a group of cells found together in the body.
Types of tissues
1. Epithelial tissue:]
2. Connective tissue: ]
3. Muscular tissue: ]
4. Nervous tissue: ]
-Development of Tissues
Tissues of the body develop from three primary germ layers: Ectoderm, Endoderm and Mesoderm.
1. Epithelial cell
Epithelial tissue consists of cells arranged in continuous sheets, in either single or multiple layers.
Closely packed and held tightly together.
-General Features of Epithelial Cells:
1. Apical (free) surface
2. Lateral surfaces
3. Basal surface
Basement membrane
Basal lamina
Reticular lamina
-Classification of epithelial tissues
Epithelial tissues are classified according to :
Number of the cell layers formed
1. Simple epithelium (one layer)
2. Stratified epithelium(several layer)
-The shape of the cells
1. Squamous (flat cell)
2. Cuboidal (cube like)
3. Columnar (rectangular)
4. Transitional (variable)
- Glandular Epithelium and Glands
There are main two types of glands
1. Endocrine Glands
2. Exocrine Glands
-Structural Classification of Exocrine Glands
1. Simple gland
2. Compound gland
-Functional Classification of 1. Exocrine Glands
2. Merocrine glands
3. Aprocrine glands
4. Holocrine glands
2. Connective Tissue
-Functions of connective tissues
-Classification of Connective Tissues
Embryonic connective tissue
Mesenchyme
Mucous connective tissue
Mature connective tissue
Loose connective tissue
Areolar connective tissue
Adipose tissue
Reticular connective tissue
Dense connective tissue
Dense regular connective tissue
Dense irregular connective tissue
Elastic connective tissue
Cartilage
Hyaline cartilage
Fibrocartilage
Elastic cartilage
Bone tissue
-Blood and Lymph
--Characteristics of Connective Tissue
1. Extra cellular matrix
2. Fibers
3. Cells of various types
Extracellular matrix of Connective Tissue
-Connective Tissue Cells
1. Fibroblasts
2. Adipocytes (fat cells)
3. Mast cells
4. White blood cells
5. Macrophages
6. Plasma cells
-Connective Tissue Extracellular Matrix;
Ground substance and fibres make up the ECM.
a. Ground substance
-Complex combination of proteins and polysaccharides (hyaluronic acid, chondroitin sulphate dermatan sulphate and keratan sulphate).
b. Fibres
-Collagen fibers
-Elastic fibers
-Reticular fibers
3. Muscular Tissue
-Skeletal muscle tissue (Attached to bone by tendons)
-Cardiac muscle tissue (Heart wall)
-Smooth muscle tissue (Iris of eyes, walls of hollow internal structures such as blood vessels, airways of lungs, stomach, intestine, gall bladder, urinary bladder and uterus)
--Consists of elongated cells called muscle fibers or myocytes for contraction.
--Cells use ATP to generate force.
4. Nervous Tissue
-Neurons or nerve cells
-Neuroglia
--Exhibit sensitivity to various types of stimuli, converts them into nerve impulses (action potentials) and conducts nerve impulses to other neurons.
Tissues, types and functions(Anatomy)- Easy explanationSwatilekha Das
Easy explanation on Tissues , types of tissues and functions of tissues with pictures.......
Easy anatomy topic for 1 st yera GNM and B.Sc nursing students.....
What is tissue?
Tissue is a group of cells which work together to perform a particular
functions.
Several kinds of tissue grouped together to form an organ.
Branch of biology that deals with the study of tissue is known as histology.
Word animal tissue was coined by – Bichat
Study of tissue – Histology
Histology word was given by – Mayar
Father of Histology – Bichat
Study of tissue is also called Microscopic anatomy.
Founder of microscopic anatomy – Marcello Malpighi
The four types of tissue in the body are epithelial, connective, muscle, and nervous. Epithelial tissue is made of layers of cells that cover the surfaces of the body that come into contact with the exterior world, line internal cavities, and form glands.
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
a quick review of the articles issued by WHO, CDC and other medical experts...
>>>
on its epidemiology, etiology, clinical manifestations, diagnosis, management and prevention.
Amyotrophic lateral sclerosis (ALS), AKA "Lou Gehrig's Disease," is a progressive neurodegenerative disease that affects nerve cells in the brain and the spinal cord. Motor neurons reach from the brain to the spinal cord and from the spinal cord to the muscles throughout the body. The progressive degeneration of the motor neurons in ALS eventually leads to their death. When the motor neurons die, the ability of the brain to initiate and control muscle movement is lost. With voluntary muscle action progressively affected, patients in the later stages of the disease may become totally paralyzed.
Pulmonary Thromboembolism - etilogy, types, medical- Surgical and nursing man...VarunMahajani
Disruption of blood supply to lung alveoli due to blockage of one or more pulmonary blood vessels is called as Pulmonary thromboembolism. In this presentation we will discuss its causes, types and its management in depth.
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
Ethanol (CH3CH2OH), or beverage alcohol, is a two-carbon alcohol
that is rapidly distributed in the body and brain. Ethanol alters many
neurochemical systems and has rewarding and addictive properties. It
is the oldest recreational drug and likely contributes to more morbidity,
mortality, and public health costs than all illicit drugs combined. The
5th edition of the Diagnostic and Statistical Manual of Mental Disorders
(DSM-5) integrates alcohol abuse and alcohol dependence into a single
disorder called alcohol use disorder (AUD), with mild, moderate,
and severe subclassifications (American Psychiatric Association, 2013).
In the DSM-5, all types of substance abuse and dependence have been
combined into a single substance use disorder (SUD) on a continuum
from mild to severe. A diagnosis of AUD requires that at least two of
the 11 DSM-5 behaviors be present within a 12-month period (mild
AUD: 2–3 criteria; moderate AUD: 4–5 criteria; severe AUD: 6–11 criteria).
The four main behavioral effects of AUD are impaired control over
drinking, negative social consequences, risky use, and altered physiological
effects (tolerance, withdrawal). This chapter presents an overview
of the prevalence and harmful consequences of AUD in the U.S.,
the systemic nature of the disease, neurocircuitry and stages of AUD,
comorbidities, fetal alcohol spectrum disorders, genetic risk factors, and
pharmacotherapies for AUD.
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.
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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
- Video recording of this lecture in English language: https://youtu.be/lK81BzxMqdo
- Video recording of this lecture in Arabic language: https://youtu.be/Ve4P0COk9OI
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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.
Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
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.
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
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists
Basic Histology
1. BASIC HISTOLOGY
http://crisbertcualteros.page.tl
Histology – study of tissues
Tissues – group of cells with similar functions and morphology
Fundamental or Basic Tissues of the Human Body:
A. Epithelial
B. Connective
C. Muscular
D. Nervous
EPITHELIAL TISSUE:
I - Characteristics:
A. Formed by epithelial cells
B. Cells are close together or packed together.
C. Cells are extremely cohesive and relatively strong force is necessary to
separate them.
D. Provided with a basement membrane / basal lamina on their basal surface.
E. Avascular tissue.
F. Maybe derived from 3 germ layers:
Ex. Ectoderm – epidermis of skin; epithelium of cornea
Mesoderm – lining epithelium of kidneys, male & female reproductive
tracts
Endoderm – lining epithelium of gastrointestinal tract
II - Functions:
A. Protection – covering and lining surfaces of the body ex. Epidermis
B. Absorption – lining epithelium of intestines
C. Secretion – glands
D. Excretion – lining epithelium of tubules of kidney
E. Filtration – lining epithelium of kidneys
F. Lubrication – glands secreting mucus ( goblet cells, Brunner’s gland,
esophageal glands)
G. Sensory receptors – neuroepithelium
III – Classification:
A. Covering / Surface Epithelium – membranous layers that cover the external
surfaces or line the cavities of the body
2. B. Glandular Epithelium
COVERING / SURFACE EPITHELIUM:
Subtypes:
A. According to the number of cell layers:
1. Simple – lined by single layer of cells
According to cell shape:
a. simple squamous – single layer of flat cells
ex. Endothelium of blood vessels
Mesothelium of body cavities
Thin loop of Henle in kidneys
Parietal layer of Bowman’s capsule
- well adapted for exhange and filtration functions
b. simple cuboidal – single layer of cuboidal cells
ex. Tubules of kidneys
Thyroid follicles
Covering of Ovary
Pigment epithelium of Retina
c. simple columnar – single layer of columnar cells
ex. Lining epithelium of Intestines and Gall bladder
Lining epithelium of Uterus and Oviducts
2. Stratified – lined by several layer of columnar cells
- well adapted for protection purposes
According to cell shape:
b. Stratified squamous
1. Stratified squamous keratinized / cornified
Ex. Epidermis of skin
2. Stratified squamous non-keratinized / non-cornified
Ex. Lining epithelium of Esophagus, Mouth , Anal canal,
Vagina
c. Stratified cuboidal
Ex. Ducts of sweat glands
Developing ovarian follicles
d. Stratified columnar
Ex. Parts of male urethra
3. 3. Pseudostratified -
a. Modification of simple epithelium.
b. All cells are in contact with the basal lamina but not all of them reach
the apical surface.
c. Cell shapes are variable.
d. False stratification
ex. Respiratory epithelium – Pseudostratified columnar epithelium
with Goblet cells
4. Transitional –
a. Modification of stratified epithelium
b. The number of cells varies with the functional state of the
organ
c. Also called as Uroepithelium.
Ex. Lining epithelium of excretory passages of the Urinary
system
GLANDULAR EPITHELIUM:
Classification:
A. According to number of cells
1. Unicellular gland – single secreting cell; Goblet cell of the lining of
respiratory and intestinal tracts
2. Multicellular gland
B. According to manner of secretion
1. Exocrine gland – provided with ducts
Ex. Gastric glands, Salivary glands
2. Endocrine gland – “ductless gland”
Ex. Pituitary gland, Thyroid gland
C. According to fate of secretion
1. Apocrine gland – partial destruction of secretory cells
Ex. Mammary gland
2. Holocrine gland – total destruction of secretory cells
Ex. Sebaceous gland
3. Merocrine gland – no destruction
Ex. Sweat gland
4. D. According to type of secretion
1. Serous gland – thin and watery secretion
Ex. Sweat gland
2. Mucous gland – thick and viscous
Ex. Sebaceous gland
3. Mixed gland – Muco-serous secretion
Ex. Sublingual and Submaxillary glands
4. Cytogenic gland – secretion produces cells
Ex. Testis and Ovary
E. According to morphology
1. Simple –
a. Simple tubular –simple epithelium lined tubules w/c open to the
surface; entire tubule in a straight course
Ex. Intestinal glands
b. Simple coiled tubular – deeper portion of the tubule is coiled or
convoluted
Ex. Sweat glands
c. Simple branched tubular – deeper portion of the tubule divides
into tube-like structures
Ex. Uterine glands
d. Simple branched alveolar / acinar – made up of numerous sac-
like structures
Ex. Sebaceous glands
2. Compound –
a. Compound tubular – Cardiac glands of stomach
Brunner’s glands
b. Compound alveolar – Mammary glands
c. Compound tubulo-alveolar – Salivary glands
Esophageal glands
5. JUNCTIONAL COMPLEXES – structures that provides for cell attachment
4 Types:
1. Macula adherens / Desmosomes – found in the stratified epithelia of mouth,
esophagus, vagina and skin.
2. Zonula adherens / Intermediate junction / Fascia adherens – found in intercalated
disc of cardiac muscles
3. Zonula occludens / Tight junction – found in epithelia of urinary bladder & GIT
4. Nexus or Gap junction – found in epithelial, muscular and nervous tissues
CONNECTIVE TISSUE:
I: Characteristics:
A. Cells are relatively few and far apart.
B. With abundant intercellular substance containing tissue fluid, ground matrix
( extracellular matrix ) and intercellular fibers.
C. Very vascular.
D. Derived from mesoderm.
II: Functions:
A. Connect, bind and support organs and tissues of the body
B. Protection
C. Fat storage and insulator
D. Hematopoetic functions
E. Immunity
F. Repair
III: Connective tissue cells: Categorized as:
A. Fixed cells – permanent
1. Fibroblasts – principal cells responsible for the synthesis of fibers and
ground matrix ; stellate shaped with multiple processes
2. Mesenchymal cells – known as pluripotential cells
3. Fat / Adipose cells – characteristic “signet ring” appearance
4. Reticular cells
B. Wandering cells – transient
1. Plasma cells – ovoid cells with eccentric nucleus and intensely basophilic,
“cartwheel or spokeswheel appearance of nucleus”
6. 2. Mast cells – w/ cytoplasmic granules containing heparin & histamine
3. WBC’s
IV: Connective tissue fibers:
Collagen Elastic Reticular
Colorless to white Yellow Argyrophilic reacts with
silver stains
Elastic and have greater Slender, refractile fibers Very slender forming
strenght delicate net like patterns
Most abundant and widely Walls of blood vessels and Hematopoetic and
distributed organs capable of lymphoid organs
distention
Types of Collagen fibers and their distribution:
Type I: Most abundant and widely distributed
Dermis, bone, tendon, dentine, Fascia, Sclera of Eyeball, Capsules of
Organs, Fibrous cartilage
Type II: Hyaline and Elastic cartilages
Type III: Smooth muscles, Hematopoetic and Lymphoid organs ( liver & spleen)
Type IV: Basement membranes
Type V: Fetal membranes
V: Classification of Connective tissue:
A. Fibrous
1. Collagenous
2. Elastic
3. Reticular
B. Adipose
C. Mucous
D. Bone / Osseous
E. Cartilage
F. Myeloid
G. Blood
7. H. Lymphatics
A. Fibrous Connective Tissue – depending on the type of fiber that predominates, it is
divided into:
1. Collagenous – collagen fiber predominates
Depending on the amount of collagen fiber – subdivided into:
a. Loose – also called as “Areolar tissue”- with numerous
potential spaces which can be distended by fluid, blood or pus;
found in the papillary layer of dermis, hypodermis, serosal
linings of the peritoneal and pleural cavities, pia mater of spinal
cord, endomysium of muscles, endoneurium of nerves
b. Dense – close packing of its fibers; occur in the form of bands,
sheets, cords or bundles
b.1 – Dense, irregular – fibers are randomly oriented
ex. Reticular layer of dermis, submucosa of esophagus,
capsules of organs, periosteum, perichondrium
b. 2 – Dense, regular – fibers are oriented in one direction
only, giving it great tensile strength
ex. Tendons, ligaments, aponeurosis
2. Elastic – elastic fiber predominates
Ex. Walls of visceral organs and blood vessels, Yellow
ligaments of the vertebral column, suspensory ligament of the penis
3. Reticular – reticular fiber predominates; forms the supporting
framework of bone marrow and most of the lymphoid and hematopoietic
organs
B. Adipose tissue – special type of connective tissue wherein adipose cell predominates.
Characteristic “signet ring appearance”
Functions:
1. Storage of fat
2. Insulation against heat loss
3. Mechanical support
8. 2 Types of Adipose Tissues:
A. Yellow / White / Unilocular – forms the main bulk of fats in the body. It is
the adult or mature form; contains a single large fat droplet
B. Brown / Multilocular – fetal or immature form; with multiple lipid
droplets
C. Mucous Connective tissue – abundance of ground matrix composed mainly of
hyaluronic acid; jelly-like consistency containing collagen fibers and few elastic or
reticular fibers; Wharton’s jelly of the umbilical cord.
D. Bone / Osseous tissue - specialized type of connective tissue wherein the intercellular
matrix is infiltrated with Calcium salts
I. Functions:
a. Mainly for support of fleshy structures
b. Performs protection of vital organs
c. Serves as attachment of muscles, tendons and ligaments
d. Contributes shape to the body
e. Acts as levers by which movement of the body is performed
II. Composition:
a. Organic – main component is Collagen ( type I ) 95%;
responsible for elasticity of bones
b. Inorganic – in the form of salts, CaPO4 – responsible for the
hardness of bones
III. Bone cells:
a. Osteocytes – mature bone cells
b. Osteoblasts – bone forming cells; responsible for the synthesis
of the organic components of bone matrix
c. Osteoclasts – multinucleated giant cells involved in bone
resorption
Parathyroid gland secretes PTH which stimulates Osteoclasts
to release Ca from bone ( to increase Ca blood level )
9. IV. Bone development:
a. Intramembranous – derived from mesenchyme; bones referred
as membrane bones
ex. Flat bones of skull, maxilla, mandible
b. Intracartilagenous / Endochondral – derived from hyaline
cartilage
ex. Bones at the base of skull, vertebral column, pelvis,
extremities
V. BoneGrowth:
a. Appositional- increase in circumference of bones
b. Interstitial – increase in length of bones
VI. Bone Coverings
a. Periosteum-outer covering, dense irregular connective tissue,
Sharpey’s fibers – bind periosteum to bones
b. Endosteum-inner covering, lined by single layer of flat cells
VII. Classification as to Structure:
a. Spongy – made up of bony processes called trabeculae giving it a
porous appearance; found in the epiphysis and metaphysic of long
bones, diploe of flat bones and in the medullary cavities
b. Compact – more solid, found in the diaphysis of long bones and
plates of flat bones; unit structure of a compact bone is called as
Osteon or Haversian system.
Components of Haversian System:
1. Haversian canal
2. Concentric lamellae
3. Osteocytes
4. Canaliculi
Volkmann’s canal – communication between haversian canals or
haversian system / osteon.
10. E. Cartilage:
I. Characteristics:
a. Chondrocyte / Cartilage cell is the characteristic cell
b. Firm, pliable type of connective tissue – the intercellular matrix
has a rigid consistency but less resistant to pressure than bone
c. Provided with fibers – collagen and elastin.
d. Avascular tissue.
e. Covered with Perichondrium – dense, irregular connective tissue
II. Functions:
a. Support to soft tissues.
b. Provide a sliding area for joints.
c. Essential for growth of bones.
III. Types: Based on the types of fibers present.
a. Hyaline – most common and widely distributed; with moderate
amount of collagen fibers; found in the costal cartilages of ribs,
thyroid and cricoid cartilages of larynx, cartilaginous rings of
trachea and bronchi, and articular cartilages.
b. Elastic – contains collagenous fibers plus large number of elastic
fibers; most flexible type; found in the auricles of the external ear,
in the walls of the external auditory canal, Eustachian tube,
epiglottic, corniculate and cuneiform cartilages of the larynx.
c. Fibrous – Also called as fibrocartilage, intermediate tissue
between dense connective tissue and cartilage; contains large
large amounts of collagen fibers; found in the intervertebral
discs and pubis symphysis
F. Myeloid – referred also as bone marrow, located in the medullary canals of long
bones and medullary cavities of spongy bones.
I. Types:
a. Red bone marrow – also called as hematogenous or active bone
marrow. In newborns, all the bone marrow is red type. In adults,
it is found in flat bones ( sternum, ribs, clavicle ), bones of pelvis,
diploe of skull bones, in vertebrae and in proximal epiphysis of
femur and humerus. Main function is for production of blood
cells.
b.Yellow bone marrow – In adults, most of the bone marrow is
this type. This type contains great amounts of adipose cells. Main
function is for storage of fats.
11. G. Blood
I. Characteristics:
a. Specialized connective tissue consisting of formed elements and a fluid
intercellular plasma.
b. Total quantity constitutes about 8 % of total body weight.
II. Components:
a. Plasma: 55% of the total quantity
Formed primarily by water; contains plasma
proteins like albumin, globulin and fibrinogen.
Slightly alkaline fluid.
b. Formed elements: 45 % of the total quantity
1. Red blood cells / Erythrocytes
- non nucleated
- biconcave disc, average diameter 7.5 um
2. White blood cells / Leucocytes
2.1 Granular
- Neutrophils / Polymorphonuclears
55 to 65 % of the total count
Nucleus consists of 3 to 5 sausage masses
of chromatin
Granules contain lyzosomal enzymes which
has anti-bacterial activity
First line of defense against infection
- Eosinophils
1 to 3 %
Nucleus is usually bilobed and its cytoplasm
contains coarse acidophilic granules
Increase in parasitic and allergic infections
- Basophils
0.5 to 1 %
Nucleus may assume a S, U or J shaped and
its cytoplasm contains larger basophilic
granules with histamine and heparin.
2.2 Agranular
- Lymphocytes
25 to 35 %
With large spherical nucleus slightly indented
on one side and thin cytoplasm
Increase in viral infections
- Monocytes
2 to 8 %
Largest WBC
Nucleus is kidney shaped and cytoplasm has
a grayish blue tint
12. Source of Monocyte formation
3. Platelets / Thrombocytes
Non – nucleated, biconvex discs avemeter diameter
of 2 to 3 um
Liberates thromboplastin which is important in
blood coagulation
H. Lymphatics