A. Theory of Differentiation
B. Specialization
C. Importance of Histology to Mankind
II. Four primary types of tissues
A. Epithelial
B. Connective
C. Muscle
D. Nervous
III. Epithelial tissue
A, Covering and Lining Epithgelium
1, Squamous - simple or stratified
a. characteristics: flattened cells, single layer, centrally located nuclus, all calls make
contact
w/basemant membrane.
b. location: inside walls of blood vessels, walls of air sacs in lungs, & lining of body cavities.
c. function: protection & absorption.
2. Cuboidal
a. characteristics: single layer of cube cells, centrally located nucleus.
b. location: in ducts or small tubes in kidneys, liver, glands (thyroid, pancreas, salivary glands, etc.)
c. function: secretion (glands) & absorption (kidneys)
3. Simple Columnar - (Pseudostratified)
a. Characteristics: single layer of elongated, cylindrical cells, nuclei lie near basement membrane, goblet cells, etc..
b. location: lining inside wall of uterus & digestive organs (stomach, small intestine, etc..)
c. function: secretion (mucous) & absorption (microvilli in intestine)
4. Stratified squamous
a. characteristics: multiple layers of flat, cuboidal / columnar cells
b. location: outer layer of skin
c. function: proctection
5. Pseudostratified Columnar (Ciliated Columnar)
a. characteristics; single layer w/ all cells making contact w/ basement membrane and some ciliated cells reaching free surface
b. location: respiratory tract, (trachea, bronchi etc..)
c. function: secretion (mucous)
6. Transitional
a. characteristics: multiple layers of irregular shaped cells that can stretch (elastic) or shrink (extend) in size.
b. location: urinary bladder, ureters, etc..
c. function:
B. Glandular epithelum
1. Exocrine glands
a. characteristics: excrete products into ducts, transport to body surface of cavity.
b. location: sweat glands, oil glands, salivary glands
c. function: secretion
2. Endocrine glands
a. characteristics: secrete products into extracellular space which difuses to the bloodstream
b. location: pituitary gland, thyroid, adrenal
c. function: secretion
V. Muscle tissue - consists of cells with little intercelluar material. Special proteins called myosin & actin within these cells are arranged in parallel bundles that slide over one another as the muscle contacts or extends
A. Skeletal muscle - attached to bones by dense regular connective tissue known as tendons. this muscle is under voluntary (conscious) control.
characteristics: straitions present, multi-nucleated
location: bones of body
function: produces body movement
B. Smooth mucscle - forms walls of blood vessels and visceral organs (stomach, intestines, bladder, etc..). This muscle is under involuntary control.
characteristics: no striations, one nucleus / cell
location: walls of blood vessels and visceral organs
function: move substances through tubes and chambers
C. Cardiac muscle - found in the myocardum (middle layer) of heart. It is under involuntary control
characteristics: straitions present, one nucleus / cell
location: in the heart
function: push blood out of heart
VI. Nerve Tissue - has properties of conductivity and excitability which allows this tissue to send electrochemical signal throughout body. Two types of nerve cells are present: neurons which
which transmit electrochemical signals and neuroglia which have a supportive function (they destroy foreign agents, etc.)
characteristcs: contains a long axon, nucleus w/ in cell body, many dendrites, terminal filaments, etc..
location: brain, spinal cord, spinal & cranial nerves
function: to transmit electrochemical signals to all parts of the body in order to sense and move our bodies.