histology - איילה גיאוגרפיתtypes of epithelial tissue anatomy and histology 2014 h-4...

Histology Human Anatomy and Histology course

Lecturer: Anna Barlasov PhD

TYPES OF TISSUES

Anatomy and Histology 2014 H-2

2. CONNECTIVE TISSUE protects and supports the body and its organs. Various types of

connective tissue bind organs together, store energy reserves as

fat, and help provide immunity to disease-causing organisms

3. MUSCULAR TISSUE generates the physical force needed to make body structures

move.

4. NERVOUS TISSUE detects changes in a variety of conditions inside and outside the

body and responds by generating nerve impulses that activate

muscular contractions and glandular secretions.

1. EPITHELIAL TISSUE covers body surfaces, lines hollow organs, body cavities, and

ducts. It also forms glands.

EPITHELIAL TISSUE


Basement

membrane

Epithelium

Apical surface

Basal

surface

Connective

tissue

• Closely packed cells, little

intercellular space.

• Single or Multiple layers

• Has nerve supply

• No blood vessels

• Forms boundaries between

body organs or between the

body and external

environment

• Constant renewal of cells –

high rate of mitosis

Types of Epithelial tissue


1) Covering and lining epithelium forms the outer covering of the skin and some internal organs. It also forms the inner lining of blood vessels, ducts, and body cavities, and the interior of the respiratory, digestive, urinary, and reproductive systems.

2) Glandular epithelium makes up the secreting portion of glands such as the thyroid gland, adrenal glands, and sweat glands.

Covering and Lining Epithelium


Squamous Cuboidal Columnar

Basement membrane

Cell shapes

Covering and Lining Epithelium


Simple Pseudostratified Stratified

Basement membrane

Layers arrangement

Classification of Covering and Lining Epithelium


I. Simple epithelium

A. Simple squamous epithelium

B. Simple cuboidal epithelium

C. Simple columnar epithelium (nonciliated and ciliated)

D. Pseudostratified columnar epithelium (nonciliated and ciliated)

II. Stratified epithelium

A. Stratified squamous epithelium (keratinized and nonkeratinized)

B. Stratified cuboidal epithelium

C. Stratified columnar epithelium

D. Transitional epithelium

Simple squamous epithelium


Location:

1.Lines heart, blood vessels,

lymphatic vessels,

2. Lines air sacs of lungs,

3. Lines glomerular capsule of

kidneys,

4. Forms epithelial layer of serous

membranes.

Function: Filtration, diffusion,

osmosis, and secretion in serous

membranes.

Description: Single layer of flat cells;

centrally located nucleus.


Description: Single layer of cube-shaped cells; centrally located nucleus. Location: 1. Covers surface of ovary,

2. lines anterior surface of capsule of the lens of the eye, 3. forms the pigmented epithelium at the posterior surface of the eye, 3. lines kidney tubules and smaller ducts of many glands, 4. makes up the secreting portion of some glands such as the thyroid gland

Simple cuboidal epithelium

Function: Secretion and absorption.

Simple columnar epithelium


Non-Ciliated Simple columnar epithelium

Location: Lines (1) the gastrointestinal tract (from the stomach to the anus), (2) ducts of many glands, and (3) gallbladder.

Function: Secretion and absorption.

lumen

Microvilli

Mucus in

goblet cell

Absortive

cell

Microvilli

Description: Single layer of nonciliated column-like cells with nuclei near base of cells;

contains goblet cells and cells with microvilli in some locations.

Simple columnar epithelium


Ciliated Simple columnar epithelium

Location: Lines (1) some bronchioles (small tubes) of respiratory tract, (2) uterine (fallopian) tubes, (3) uterus, (4) some Paranasal sinuses, (5) central canal of spinal cord, and ventricles of the brain.

Function: Moves mucus and other substances by ciliary action.

Description: Single layer of ciliated column-like cells with nuclei near base; contains goblet cells in some locations.

Cilia

Cilia

Mucus in goblet cell

Pseudostratified columnar epithelium


Pseudostratified Ciliated columnar epithelium lines the airways of most of upper respiratory tract. Function: Secretion and movement of mucus by ciliary action.

Pseudostratified Nonciliated columnar epithelium lines larger ducts of many glands, epididymis, and part of male urethra.

Stratified squamous epithelium


Description: Several layers of cells; cuboidal to columnar shape in

deep layers; squamous cells form the apical layer and

several layers deep to it; cells from the basal layer replace

surface cells as they are lost.

Nonkeratinized stratified squamous epithelium

Location: Lines wet surfaces, such as lining of the mouth,

esophagus, part of larynx, part of pharynx, and

vagina, and covers the tongue.

Function: Protection.

Stratified squamous epithelium


Keratinized stratified squamous epithelium

Location: forms

superficial layer of skin

Epidermis

Dermis

Dead keratinocytes

Keratinocyte

Stratified cuboidal epithelium


Description: Two or more layers of cells in which the cells in the apical layer are cube-shaped.

Location: Ducts of adult sweat glands and esophageal glands and part of male urethra. Function: Protection and limited secretion and absorption.

Stratified columnar epithelium


Location: Lines part of urethra, large excretory ducts of some glands, such as

esophageal glands, small areas in anal mucous membrane, and part

of the conjunctiva of the eye.

Function: Protection and secretion.

Description: Several layers of irregularly shaped cells; only the apical layer has

columnar cells.

Transitional epithelium


Description: Appearance is variable (transitional); shape of cells in apical layer ranges from squamous (when stretched) to cuboidal (when relaxed).

Location: Lines urinary bladder and portions of ureters and urethra.

Function: Permits distension.

Glandular Epithelium: Endocrine glands


Thyroid follicle

Description: Secretory products (hormones) diffuse into blood after passing through interstitial fluid.

Location: Examples include pituitary gland at base of brain, pineal gland in brain, thyroid and parathyroid glands, adrenal glands superior to kidneys, pancreas, ovaries , testes, and thymus. Function: Produce hormones that

regulate various body activities.

Glandular Epithelium: Exocrine glands


Lumen of duct of sweat gland

Description: Secretory products released into ducts. Function: Produce substances such as sweat, oil, earwax, saliva, or digestive enzymes.

Location: Sweat, oil, and earwax glands of the skin; digestive glands such as salivary glands, which secrete into mouth cavity, and pancreas, which secretes into the small intestine.

CONNECTIVE TISSUE


• Do not usually occur

on body surfaces.

• Highly vascular;

except for cartilage.

• Supplied with nerves,

except for cartilage

Connective Tissue is one of the most abundant and widely distributed

tissues in the body. It protects and supports the body and its organs.

Various types of connective tissue bind organs together, store energy

reserves as fat, and help provide immunity to disease-causing organisms.


Fibroblast

Mast cell

Plasma cell

Macrophage

Adipocyte White blood cells

Extracellular Matrix Cells

Ground Substance Protein Fibers

Reticular fiber

Ground

substance

Elastic fiber

Collagen fiber

CONNECTIVE TISSUE

Classification of Connective Tissues


Loose connective tissue: 1. Areolar connective tissue

2. Adipose tissue

3. Reticular connective tissue

Dense connective tissue: 1. Dense regular connective tissue

2. Dense irregular connective tissue

3. Elastic connective tissue

Cartilage: 1. Hyaline cartilage

2. Fibrocartilage

3. Elastic cartilage

Bone tissue

Blood tissue

Lymph

Loose Connective Tissue


1. Areolar connective tissue

Location: Subcutaneous layer deep to skin; papillary (superficial) region of

dermis of skin; lamina propria of mucous membranes; and around blood vessels,

nerves, and body organs.

Function: Strength, elasticity, and support.

Description: Consists of fibers (collagen, elastic, and reticular) and several

kinds of cells (fibroblasts, macrophages, plasma cells, adipocytes, and mast

cells) embedded in a semifluid ground substance.



2. Adipose tissue

Description: Consists of adipocytes, cells specialized to store triglycerides (fats) as

a large centrally located droplet; nucleus and cytoplasm are peripherally located.

Location: Subcutaneous layer deep to skin, around heart and kidneys, yellow bone

marrow, and padding around joints and behind eyeball in eye socket.

Function: Reduces heat loss through skin, serves as an energy reserve, supports,

and protects.



Description: A network of interlacing reticular fibers and reticular cells.

Location: Stroma (supporting framework) of liver, spleen, lymph nodes; red

bone marrow, which gives rise to blood cells; reticular lamina of the basement

membrane; and around blood vessels and muscles.

Function: Forms stroma of organs; binds together smooth muscle tissue cells;

filters and removes worn-out blood cells in the spleen and microbes in lymph

nodes.

3. Reticular connective tissue

Dense connective tissue


1. Dense regular connective tissue

Location: Forms tendons (attach muscle to bone), most ligaments (attach

bone to bone), and aponeuroses (sheet-like tendons that attach muscle to

muscle or muscle to bone).

Function: Provides strong attachment between various structures.

Description: Extracellular matrix looks shiny white; consists mainly of

collagen fibers regularly arranged in bundles; fibroblasts present in rows

between bundles



2. Dense irregular connective tissue

Description: Consists predominantly of collagen fibers randomly arranged and

a few fibroblasts.

Location: Fasciae (tissue beneath skin and around muscles and other organs),

reticular (deeper) region of dermis of skin, periosteum of bone, joint capsules,

perichondrium of cartilage, membrane capsules around various organs

(kidneys, liver, testes, lymph nodes), pericardium of the heart, and heart valves.

Function: Provides strength.



3. Elastic connective tissue

Description: Consists predominantly of freely branching elastic fibers; fibroblasts

are present in spaces between fibers.

Location: Lung tissue, walls of elastic arteries, trachea, bronchial tubes, true vocal

cords, suspensory ligament of penis, and some ligaments between vertebrae.

Function: Allows stretching of various organs.

Cartilage


• Cartilage consists of a dense network of collagen fibers and elastic fibers firmly embedded in gel-like component of the ground substance.

• Chondrocytes, cells of mature cartilage, occur singly or in groups within spaces called lacunae (little lakes).

• Perichondrium (membrane of dense irregular tissue) covers the surface of most cartilage

• No blood vessels (except for perichondrium) • No nerves (except for perichondrium)

Chondrocyte

Lacunae

Perichondrium

Cartilage


1. Hyaline cartilage

Description: Consists of a bluish-white, shiny ground substance with thin, fine collagen fibers and many chondrocytes; most abundant type of cartilage. Location: Ends of long bones, anterior ends of ribs, nose, parts of larynx, trachea, bronchi, bronchial tubes, and embryonic and fetal skeleton. Function: Provides smooth surfaces for movement at joints, as well as flexibility and support.

Cartilage


2. Fibrocartilage

Description: Consists of chondrocytes scattered among thick bundles of collagen fibers within the extracellular matrix. Location: Pubic symphysis (point where hip bones join anteriorly), intervertebral discs (discs between vertebrae), menisci (cartilage pads) of knee, and portions of tendons that insert into cartilage. Function: Support and fusion.

Cartilage


3. Elastic cartilage

Description: Consists of chondrocytes located in a threadlike network of elastic fibers within the extracellular matrix. Location: Lid on top of larynx (epiglottis), part of external ear (auricle), and auditory (eustachian) tubes. Function: Gives support and maintains shape

Bone Tissue


Collagen Fibers

Cells Matrix

Solid Ground Substance

Osteogenic cells

Osteoblast

Osteocyte

Osteoclast

Cells of the Bone Tissue


Osteogenic

cell Osteoblast Osteocyte Osteoclast

Resorption –

destruction of bone

matrix

develops

into

osteoblast

forms bone

tissue

maintains

bone tissue

Compact bone

Spongy

bone

Bone tissue


Medullary cavity Compact

bone

Spongy

bone

Osteon

(Haversian

system)

Trabeculae

Lamellae Osteocyte

Canaliculi

Lacuna

Central (Haversian) canal

Bone Tissue


Lamellae

Osteocyte

Canaliculi

Lacuna

Osteoclast

Osteoblasts

aligned along

trabeculae of the

new bone

Trabeculae

Lamellae - concentric rings of extracellular matrix that consist of mineral salts

Lacunae - small spaces between lamellae that contain mature bone cells called osteocytes.

Canaliculi - networks of minute canals containing the processes of osteocytes

Blood


Description: Consists of blood plasma (55%) and formed elements (45%): red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes). Location: Within blood vessels (arteries, arterioles, capillaries, venules, and veins) and within the chambers of the heart. Function: Red blood cells transport oxygen and some carbon dioxide; white blood cells carry on phagocytosis and are involved in allergic reactions and immune system responses; platelets are essential for the clotting of blood

Lymph


Lymph is the extracellular fluid that flows in lymphatic vessels. It is a connective tissue that consists of several types of cells in a clear liquid extracellular matrix that is similar to blood plasma but with much less protein. The composition of lymph varies from one part of the body to another.

MUSCULAR TISSUES


Skeletal Muscle Tissue

Cardiac Muscle Tissue

Smooth Muscle Tissue

Skeletal Muscle tissue


Description: Long, cylindrical, striated fibers with many peripherally

located nuclei; voluntary control.

Location: Usually attached to bones by tendons.

Function: Motion, posture, heat production, and protection.

Cardiac Muscle Tissue


Description: Branched striated fibers with one or two centrally

located nuclei; contains intercalated discs; involuntary control.

Location: Heart wall.

Function: Pumps blood to all parts of the body.

Smooth Muscle Tissue


Description: Spindle-shaped (thickest in middle and tapering at both ends), non-

striated fibers with one centrally located nucleus; involuntary control.

Location: Iris of the eyes, walls of hollow internal structures such as blood vessels,

airways to the lungs, stomach, intestines, gallbladder, urinary bladder, and uterus.

Function: Motion (constriction of blood vessels and airways, propulsion of foods

through gastrointestinal tract, contraction of urinary bladder and gallbladder).

NERVOUS TISSUE


Description: Consists of neurons (nerve cells) and neuroglia. Neurons

consist of a cell body and processes extending from the cell body (multiple

dendrites and a single axon). Neuroglia do not generate or conduct nerve

impulses but have other important supporting functions.

Location: Nervous system.

Function: Exhibits sensitivity to various types of stimuli, converts stimuli

into nerve impulses (action potentials), and conducts nerve impulses to

other neurons, muscle fibers, or glands.

histology - איילה גיאוגרפיתtypes of epithelial tissue anatomy and histology 2014 h-4...

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