Histology - איילה גיאוגרפיתTypes of Epithelial tissue Anatomy and Histology 2014 H-4...
Transcript of 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
Anatomy and Histology 2014 H-3
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
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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
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Squamous Cuboidal Columnar
Basement membrane
Cell shapes
Covering and Lining Epithelium
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Simple Pseudostratified Stratified
Basement membrane
Layers arrangement
Classification of Covering and Lining Epithelium
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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
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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.
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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
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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
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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
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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
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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
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Keratinized stratified squamous epithelium
Location: forms
superficial layer of skin
Epidermis
Dermis
Dead keratinocytes
Keratinocyte
Stratified cuboidal epithelium
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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
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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
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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
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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
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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
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• 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.
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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
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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
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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.
Loose Connective Tissue
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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.
Loose Connective Tissue
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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
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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
Dense connective tissue
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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.
Dense connective tissue
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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
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• 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
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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
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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
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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
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Collagen Fibers
Cells Matrix
Solid Ground Substance
Osteogenic cells
Osteoblast
Osteocyte
Osteoclast
Cells of the Bone Tissue
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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
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Medullary cavity Compact
bone
Spongy
bone
Osteon
(Haversian
system)
Trabeculae
Lamellae Osteocyte
Canaliculi
Lacuna
Central (Haversian) canal
Bone Tissue
Anatomy and Histology 2014 H-36
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
Anatomy and Histology 2014 H-37
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
Anatomy and Histology 2014 H-38
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
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Skeletal Muscle Tissue
Cardiac Muscle Tissue
Smooth Muscle Tissue
Skeletal Muscle tissue
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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
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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
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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
Anatomy and Histology 2014 H-43
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.