Download Human Anatomy and Histology course Lecturer: Anna Barlasov PhD

Histology
Human Anatomy and Histology course
Lecturer: Anna Barlasov PhD
TYPES OF TISSUES
1. EPITHELIAL TISSUE
covers body surfaces, lines hollow organs, body cavities, and
ducts. It also forms glands.
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.
Anatomy and Histology 2014
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EPITHELIAL TISSUE
Apical surface
• Closely packed cells, little
intercellular space.
• Single or Multiple layers
Epithelium • Has nerve supply
Basal
surface
Connective
tissue
• No blood vessels
• Forms boundaries between
Basement
body organs or between the
membrane
body and external
environment
• Constant renewal of cells –
high rate of mitosis
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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.
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Covering and Lining Epithelium
Cell shapes
Squamous
Cuboidal
Columnar
Basement membrane
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Covering and Lining Epithelium
Layers arrangement
Simple
Pseudostratified
Stratified
Basement membrane
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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
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Simple squamous epithelium
Description: Single layer of flat cells;
centrally located nucleus.
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.
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Simple cuboidal epithelium
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
Function: Secretion and absorption.
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Simple columnar epithelium
Non-Ciliated Simple columnar epithelium
Description: Single layer of nonciliated column-like cells with nuclei near base of cells;
contains goblet cells and cells with microvilli in some locations.
lumen
Microvilli
Microvilli
Mucus in
goblet cell
Absortive
cell
Location: Lines (1) the gastrointestinal tract (from the stomach to the anus), (2)
ducts of many glands, and (3) gallbladder.
Function: Secretion and absorption.
Anatomy and Histology 2014
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Simple columnar epithelium
Ciliated Simple columnar epithelium
Description: Single layer of ciliated column-like cells with nuclei near base; contains
goblet cells in some locations.
Cilia
Cilia
Mucus in
goblet cell
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.
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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.
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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.
Function: Protection.
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.
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Stratified squamous epithelium
Keratinized stratified squamous epithelium
Location: forms
superficial layer of skin
Dead keratinocytes
Keratinocyte
Epidermis
Dermis
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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.
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Stratified columnar epithelium
Description: Several layers of irregularly shaped cells; only the apical layer has
columnar cells.
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.
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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.
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Glandular Epithelium: Endocrine glands
Thyroid
follicle
Description: Secretory products
(hormones) diffuse into blood after
passing through interstitial fluid.
Function: Produce hormones that
regulate various body activities.
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.
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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.
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CONNECTIVE TISSUE
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.
• Do not usually occur
on body surfaces.
• Highly vascular;
except for cartilage.
• Supplied with nerves,
except for cartilage
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CONNECTIVE TISSUE
Extracellular Matrix
Protein Fibers
Cells
Ground Substance
Macrophage
Reticular fiber
Fibroblast
Collagen fiber
Mast cell
Elastic fiber
Plasma cell
Ground
substance
Adipocyte
White blood cells
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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
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Loose Connective Tissue
1. Areolar connective tissue
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.
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.
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Loose Connective Tissue
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.
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Loose Connective Tissue
3. Reticular connective tissue
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.
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Dense connective tissue
1. Dense regular connective tissue
Description: Extracellular matrix looks shiny white; consists mainly of
collagen fibers regularly arranged in bundles; fibroblasts present in rows
between bundles
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.
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Dense connective tissue
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.
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Dense connective tissue
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.
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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
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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.
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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.
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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
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Bone Tissue
Matrix
Cells
Collagen Fibers
Osteogenic cells
Solid Ground Substance
Osteoblast
Osteocyte
Osteoclast
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Cells of the Bone Tissue
Osteogenic
cell
develops
into
osteoblast
Osteoblast
forms bone
tissue
Osteocyte
maintains
bone tissue
Anatomy and Histology 2014
Osteoclast
Resorption –
destruction of bone
matrix
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Bone tissue
Compact
bone
Medullary cavity
Lamellae
Osteon
(Haversian
system)
Osteocyte
Spongy
bone
Canaliculi
Trabeculae
Spongy
bone
Lacuna
Compact bone
Anatomy and Histology 2014
Central (Haversian)
canal
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Bone Tissue
Lacuna
Lamellae
Canaliculi
Osteocyte
Osteoclast
Trabeculae
Osteoblasts
aligned along
trabeculae of the
new bone
Lamellae - concentric rings
of extracellular matrix that
consist of mineral salts
Lacunae - small spaces
between lamellae that
contain mature bone
cells called osteocytes.
Anatomy and Histology 2014
Canaliculi - networks of
minute canals containing
the processes of osteocytes
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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
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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.
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MUSCULAR TISSUES
Skeletal Muscle Tissue
Cardiac Muscle Tissue
Smooth Muscle Tissue
Anatomy and Histology 2014
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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.
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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.
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Smooth Muscle Tissue
Description: Spindle-shaped (thickest in middle and tapering at both ends), nonstriated 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).
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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.
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