Zoo-Lab (Sem-1) Chapter 5: Animal Tissues and Organ Systems

stem cells

where it all starts; cells with the potential to develop into many different types of cells in the body

omnipotent/totipotent

cells that are able to develop into any type of cell found in the body; has the potential to divide until it creates an entire, complete organism

pluripotent

have the ability to undergo self-renewal and to give rise to all cells of the tissues of the body; can divide into most, or all, cell types in an organism, but cannot develop into an entire organism on their own

multipotent

the ability to differentiate into multiple cell types, but only a limited number of closely related lineages

oligopotent

describes the condition of being more specialized than multipotency; the condition of being able to differentiate into one of a few possible cell types

unipotent

describes the condition of being committed to a single specialized cell type

cell; tissue; organ; organ system; organism

levels of organization

longitudinal section

cut through the long axis of an organ

cross section

the intersection of a solid and a plane

oblique section

cuts made diagonally between the horizontal and the vertical planes

transverse plane

horizontal division of the body into upper and lower portions

sagittal plane

vertical division of the body into right and left portions

frontal section

divides the body into anterior and posterior parts

ventral

toward the front or belly

dorsal

toward the back or spine

anterior

toward the ventral side

posterior

toward the dorsal side

cephalic

toward the head or superior end

rostral

toward the forehead or nose

caudal

toward the tail or inferior end

superior

above

inferior

below

medial

toward the median plane

lateral

away from the median plane

proximal

closer to the point of attachment or origin

distal

farther from the point of attachment or origin

ipsilateral

on the same of side of the body (right or left)

contralateral

on the opposite sides of the body (right and left)

superficial

closer to the body surface

deep

farther from the body surface

axial regions

consists of the head, neck (cervical), and trunk

trunk

consists of the thoracic and abdominal regions

hypochondriac region; epigastric region; subcostal line; lumbar region; umbilical region; intertubercular line; inguinal region; midclavicular line; hypogastric region

nine regions of the abdomen

hypochondriac region

to the right and left of the epigastric region above the subcostal line

epigastric region

upper middle portion of the abdomen; between the midclavicular line and above the subcostal line

subcostal line

superior horizontal line; below the hypochondriac and epigastric region; above the lumbar and umbilical region

lumbar region

to the right and left of the umbilical region, near the waist; middle region between the midclavicular line and below the subcostal line

umbilical region

centermost region of the trunk

intertubercular line

inferior horizontal line; below the lumbar and umbilical region; above the inguinal and hypogastric region

inguinal region

the right and left regions of the hypogastric region; below the intertubercular line

hypogastric region

lower middle portion of the abdomen; below the intertubercular line

midclavicular line

imaginary vertical line bisecting the middle of the clavicle in each hemithorax

appendicular regions

consists of the upper and lower limbs

arm (brachial); forearm (antebrachial); wrist (carpal); hand (manual); fingers (digits)

parts of the upper limbs

brachial

arm

antebrachial

forearm

carpal

wrist

manual

hand

digits

fingers/toes

thigh (femoral); leg (crural); ankle (tarsal); foot (pedal); toes (digits)

parts of the lower limbs

femoral

thigh

crural

leg

tarsal

ankle

pedal

foot

epithelial; muscle; nervous; connective

four types of animal tissues

loose connective; bone; cartilage; blood

four types of connective tissues

epithelial tissues

a sheet of closely adhering cells; usually exposed to the environment or internal space (coelom)

coelom

body cavity; internal space

protection; absorption; secretion; excretion; filtration; sensation

six functions of epithelial tissues

tight junctions

a specialized connection of two adjacent animal cell membranes such that the space usually lying between them is absent

gap junctions

provide cytoplasmic channels between adjacent cells

adhering/anchoring junctions (desmosomes)

cement cells together

squamous

flat cells

cuboidal

cube-shaped cells

columnar

column-shaped/rectangular cells

pseudostratified

faux-layered

stratified

multiple layers

simple squamous epithelium

single layer of thin cells; shaped like fried eggs; flattened nucleus; allows rapid diffusion/transport of substances through membrane; secretes lubricating serous fluid

representative locations of simple squamous epithelia

alveoli; glomerular capsules; kidney tubules; heart and blood vessel endothelium; stomach serous membrane; intestines; pleura surface mesothelium; pericardium; peritoneum; mesenteries

simple cuboidal epithelium

single layer of cube-shaped cells; spherical, centrally placed nuclei; found in the liver, thyroid, mammary and salivary glands, most kidney tubules, bronchioles; absorption and secretion; production of protective mucous coat; movement of respiratory mucus

simple columnar epithelium

single layer of tall, narrow cells; oval or sausage-shaped nuclei; vertically oriented, usually in basal half of cell; found within the inner lining of stomach, intestines, gallbladder, uterus and uterine tubes, some kidney tubules; absorption; secretion of mucus and other products; movement of egg and embryo in uterine tube

pseudostratified columnar epithelium

some cells do not reach free surface, but all cells reach basement membrane; nuclei at several levels in deeper half of epithelium; often with goblet cells; often ciliated; found in the nasal cavity to bronchi and portions of male urethra; secretes and propels mucus

keratinized stratified squamous epithelium

multiple cell layers with cells becoming increasingly flat and scaly toward surface basal cells may be cuboidal to columnar; found in the epidermis and on palms and soles; resists abrasion and penetration by pathogenic organisms and retards water loss

nonkeratinized stratified squamous epithelium

same as keratinized epithelium but without surface layer of dead cells; found in the tongue, oral mucosa, esophagus, anal canal, and vagina; resists abrasion and penetration by pathogenic organisms

keratinization

accumulation of keratin in a tissue; a sign of vitamin A deficiency

stratified cuboidal epithelium

two or more layers of cells; surface cells are square or round; found within the sweat gland ducts, egg-producing vesicles (follicles) of ovaries, sperm-producing ducts (seminiferous tubules) of testis; contributes to sweat secretion; secretes ovarian hormones; produces sperm

gland cells

epithelial cells that produce secretions

exocrine glands

secrete chemical substances into ducts that lead either to other organs or out of the body

endocrine glands

glands that secrete chemicals called hormones directly into the bloodstream

carcinomas

cancers of the epithelial tissue

connective tissues

most abundant and widely distributed; histologically variable; cells are not in direct contact with each other; binding of organs; support; physical protection; immune protection; movement; storage; heat production; transport

fibroblast

produces fibers and ground substance

macrophages

phagocytic cells that engulf pathogens, foreign particles and dead/dying cells

leukocytes/white blood cells

neutrophils: attack bacteria; lymphocytes: react against pathogens

neutrophils

white blood cells that attack bacteria

lymphocytes

white blood cells that react against pathogens

plasma cells

detect foreign agents; produce antibodies

mast cells

produces heparin: inhibit bloodclots; and histamine: increases blood flow by dilating blood vessels

heparin

an anticoagulant which inhibits blood clots

histamine

a compound which increases blood flow by dilating blood vessels

adipocytes

fat cells for food storage and heat production

collagenous fibers

made of collagen; tough and flexible; resists stretching; synthesis requires vitamin C

reticular fibers

thin collagen fibers coated with glycoprotein; forms a sponge-like network

elastic fibers

thinner than collagenous fibers; branch and region; made of elastin coated with a glycoprotein (fibrillin); a coiled structure allowing it to stretch and recoil

ground substance

gelatinous to rubbery consistency made up of glycosaminoglycans, proteoglycans; and adhesive glycoproteins; absorbs compressive forces and protects cells from mechanical injury

loose connective tissue; dense connective tissue

two kinds of connective tissue proper

loose connective tissue

underlies most epithelia; provides elastic support and serves as a fluid reservoir

areolar tissue

loose arrangement of collagenous and elastic fibers; scattered cells of various types; abundant ground substance; numerous blood vessels

representative locations of areolar tissue

underlying nearly all epithelia; surrounding blood vessels; nerves, esophagus, and trachea; fascia between muscles; mesenteries; visceral layers of pericardium and pleura

functions of areolar tissues

loosely binds epithelia to deeper tissues; allows passage of nerves and blood vessels through other tissues; provides an arena for immune defense; blood vessels provide nutrients and waste removal for overlying epithelia