Tissues of the Body
From Cells to Organ Systems
Cells combine to form tissues, and tissues combine to form organs
Tissues are groups of cells closely associated that have a similar structure & perform a related functionCells combine to form 4 primary tissues *Epithelial *Nervous
*Connective *Muscle
Human Body Tissues
Epithelial Tissue Locations:◦ Covers the body◦ Lines the cavities, tubes, ducts and blood
vessels inside the body◦Covers the organs inside body cavities
Epithelial Tissue Functions:◦ Protection from physical & chemical injury,◦ Protection against microbial invasion,◦ Contains receptors which respond to stimuli,◦ Filters, secretes & reabsorbs materials and◦ Secretes serous fluids to lubricate structures.
Epithelial Tissue
Two types: o membranous epithelia form the coverings or
linings of organso glandular epithelia form exocrine and
endocrine glands Sheets of cells with specialized contacts & cell
junctionso Basal lamina: protein scaffolding secreted by
epithelial cellso Basement membrane: reticular fibers
(crossed collagen network) that supports epithelium--really associated connective tissue
Epithelial Tissue
Connective tissue support Nutrients from capillaries in underlying connective
tissue Nerves pass through Easily regenerates Different cell shapes & arrangements
Epithelial Tissue
Simple: just one layer or cell shape
Stratified: multiple layers and cell shapes
Classes of Epithelia
TYPE CELL SHAPE EXAMPLE Squamous Squashed
Cuboidal Cubed
Columnar Columns
Pseudo-stratified Flat cells give rise to columns
Endothelium (lines blood vessels), mesothelium (serous lining of celom)
Walls of glands
Lining of gut tube; sometimes with cilia like lining of uterine tube
With cilia in respiratory tubes to move mucous & particles out of the lungs
Simple Epithelia
Simple Squamouso One cell thicko Forms solid layer of cells
which line blood vessels, body cavities & cover organs in body cavities
o Lubrication Stratified Squamous
o Multiple layerso Forms epidermis (Skin)
lining of the moutho Lubrication & protection
Squamous Epithelia
Simple Cuboidal o One cell thick, roughly cube
shaped o Lines ovaries, kidneys, thyroid
glands, where secretion & absorption take place
Cuboidal Epithelia
Stratified Cuboidal o In multiple layers w/one layer
attached to basement membrane & one w/free edge
o Mammary & sweat glandso Secretion, absorption &
protection
Simple Columnar o One cell thick column
shaped (long & narrow) o Line digestive tract where
re-absorption & secretion occurs.
Columnar Epithelia
Stratified Columnar o Stacked nucleus on top of
nucleuso Lines vas deferans, male
urethrao Gives support and some
movement.
Pseudostratifiedo gives the appearance of
more than one layer of columnar epithelial cells
o Every cell is attached to the basement membrane
o Lines the trachea, fallopian tubes
o movement
Columnar Epithelia
Transitional EpitheliaTransitional
o Several layers of epithelial cellso Forms tissue that must stretch like the
bladdero Stretches, protects against seepage
Glandularo A gland consists of one or more cells
that make and secrete a particular product.
o Endocrine: secretions diffuse directly into the blood vessels. Ex.– thyroid, adrenals, pituitary
o Exocrine: secretions empty through the ducts to the epithelial surface. Ex.- sweat, oil
Glandular Epithelia
Types of Epithelium
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Muscle Tissue:o Associated with the bones of the
skeleton, the heart and in the walls of the hollow organs of the body.
Muscle Tissue Functions:o Movement & Locomotiono Maintains postureo Produces heato Facial expressionso Pumps bloodo Peristalsis
Muscle Tissue
Consists of specialized cells that contract when stimulated
The body has three types of muscle tissue:o Skeletalo Cardiaco Smooth muscle
Muscle Tissue
Cardiac (involuntary) HEARTSmooth (involuntary) ORGANSSkeletal (voluntary) BONES
Smooth Muscle
Cardiac Muscle
Skeletal Muscle
Muscle Tissue
Connective TissueConnective tissue location:
o Most abundant & widely distributed tissueo Connective tissue has non-living extra-
cellular material (matrix between its cellsConnective Tissue Functions:
o Connects, binds and supports structures,o Tendons, ligaments, etc.o Protects & cushions organs and tissues,o Insulates (fat) ando Transports substances (blood).
Major classes: o Boneo Cartilageo Looseo Denseo Blood
All connective tissues consist of two basic components:o Living cells o Extracellular matrix
Connective Tissue
Fiberso Collagen gives structureo Reticular fibers (crossed
collagen) gives ordero Elastin gives elasticity
Ground substanceo Jelly-like material made of
sugar-protein molecules (proteoglycans)
o Allows connective tissue to retain water and serve as support and protection of organs
Extracellular Matrix
Type: Loose, adipose
Type: Loose, areolar
Loose Fibrous
Adipose
Areolar
o Stores energy (fat) & insulateso Mostly under the skin
o Wraps the organso Cushions & protects
Contains elastinNourishes & stretches
o Provides blood vessels to skino Fills muscle gaps
Dense Fibrouso Collagen is the main
matrix elemento Thick fibers running in
many planes• Dermis, fibrous capsules
around organso Aligned parallel fibers
that resists tension• Tendon, ligaments
Dense Fibrous
Perform specific functions essential to homeostasis
The body contains three types of specialized connective tissue:o Boneo Cartilageo Blood
Specialized connective tissue
Bone o Consists of bone cells
(osteocytes) and a calcified cartilage matrix
o Two types of bone tissue exist: spongy and compact
Osseous
Tree ring-like appearance Supports & protects Mineral storage Fat storage Blood cell production
Supports while providing flexibility
Hyaline cartilage absorbs compression between bones in joints (bone ends)o Most abundant type of
cartilage found in the body
Fibrocartilage forms cushion like disks between the vertebra
The ears and nose are more flexible and are elastic cartilage
Cartilage
Bloodo Red & white blood cellso Plateletso Plasmao Regulates temperatureo Transportation system
Blood
Nervous Tissue:◦ Main component of the nervous
system ie., brain, spinal cord & nerves.Nervous Tissue Functions:
◦ Regulates & controls body functions◦ Generates & transmits nerve impulses◦ Supports, insulates and protects
impulse generating neurons.
Nervous Tissue
Contains specialized cells that conduct impulses
Conducting cells, called neurons, transmit impulses from one region of the body to another.
Nonconducting cells, neuroglia, are a type of nervous system connective tissue.
Nervous Tissue
Stomach wall tissue
Skin