ch 4

Question 1

basic body tissue types

Answer 1

Epithelial tissue: covers exposed surfaces, found in the lining of internal passageways, lumens, cavities, ducts, canals chambers.
Connective tissue: fills internal spaces, provides structural support for other tissues, transports materials withing body, stores energy reserves; found in bone and blood
Muscle tissue: specialized for contraction of smooth, cardiac, skeletal muscle.
Nervous tissue: carries information from one part of the body to another in the form of electrical impulses called action potentials

Question 2

cellular junctions

Answer 2

1. tight junctions: cell to cell, prevents the diffusion of fluids and solutes between the cells and isolates wastes in the lumen. Not designed for structure
2. Adherens junction: form adhesion belts and terminal web. built for structure where pulling, stretching, bending twisting is present.
3. Desomosome: serve to mechanically attach adjacent cells that allow stretching, bending , twisting, or compression. Contain keratin, plaque, and cadherin
4. Hemidesmosomes: Cell to basement membrane; serve to mechanically attach cells to basement membrane. Contain keratin, plaque, and integrin.
5. gap junction: serve as communication channels between cells. Channel proteins called connexins. free diffusion of ions and small molecules between two cells

Question 3

Epithelial tissue functions

Answer 3

1. protection: provides physical barrier
2. control permeability: any substance going in or out must cross an epithelium
3. secretion: gland cells can be scattered or can make up most or all of the epithelial(glandular epithelium)
4. sensation: most sensitive to stimulation; sensory cells provide sensation of smell, taste, sight, equilibrium and hearing found in Neuroepithelium.

Question 4

epithelial characteristics

Answer 4

1. Cellularity: composed of almost entirely of cells that are bound closely together. forms bonds with each other or to extracellular matrix.
2. Polarity: Apical surface vs Basal surface
3. Avascularity: no blood flow to epithelial tissue because contain no blood vessels
4. regeneration: epithelial cells that are damaged or lost are continuously replaced through cellular division.

Question 5

covering vs glandular epithelium

Answer 5

covering epithelium: layer of cells that cover or line internal or external surfaces
glandular epithelium: makes up the secreting portion of the glands

Question 6

simple epithelium

Answer 6

One cell layer thick; very fragile; allow for filtration, absorption, exchange of substances, secretion.
Mesothelium: alveoli of lungs
Endothelium: lines chambers of heart and walls of blood vessels
reduces friction; controls vessel permeability

Question 7

stratified squamous epithelium

Answer 7

Keratinized epidermis of skin; top layers die

Nonkeratinized: found in areas that need protection from chemical, biological or mechanical stress.

Question 8

simple cuboidal epithelium

Answer 8

located: glands; ducts; portions of kidney tubules; thyroid gland
functions: limited protection, secretion, absorption

Question 9

simple columnar epithelium

Answer 9

noncilitated located: lining of stomach, intestine, gallbladder
function: protection, secretion, absorption
ciliated located: lining of nasal cavity, trachea, and bronchi
function: protection, secretion, move mucus with cilia

Question 10

stratified columnar epithelium

Answer 10

locations: small areas of pharynx, epiglottis, anus, mammary glands, salivary gland ducts, and urethra
function: protection

Question 11

transitional epithelium

Answer 11

location: urinary bladder; renal pelvis; ureters
function: permits expansion and recoil after stretching.

Question 12

endocrine vs exocrine glands

Answer 12

endocrine glands: ductless glands, secrete hormones ( inside)
exocrine glands: have ducts that lead the secreted material from gland to surface (outside)

Question 13

merocrine secretion (exocrine gland)

Answer 13

released by secretory vesicle (exocytosis)

most common mode of secretion: ie seat glands (merocrine sweat)

Question 14

apocrine secretion (exocrine gland)

Answer 14

top half of cell disintegrates, produced in golgi apparatus

found in mammary glands

Question 15

holocrine secretion (exocrine gland)

Answer 15

entire cell becomes packed with secretory products then bursts i.e. sebaceous glands

Question 16

unicellular glands

Answer 16

one cell gland, independent and scattered gland cells

mucous goblet cells are the only unicellular exocrine glands

Question 17

multicellular glands

Answer 17

1. structure of the duct
   - — simple(undivided)
   - —compound(divided)
2. shape of secretory portion of gland
   - —tubular(tube shaped)
   - —alveolar or acinar (circular)
3. relationship between ducts and glandular areas
   - —branched (*all compound ducts have branched secretory)

Question 18

functions of connective tissue

Answer 18

1. establish structural framework for body
2. transporting fluids
3. protecting and insulating delicate organs
4. supporting, surrounding, and interconnecting other types of tissue
5. storing energy reserves
6. defending the body from invading microorganisms
7. compartmentalizes structures

Question 19

specialized cell types in connective tissue

Answer 19

fibroblast: most abundant, found in connective tissue proper(CTP), secrete protein fibers and certain components of ground substance
fibrocyte: second most abundant, found in all CTP
adipocyte: fat cell, store single, large fat droplet
mesenchymal cells: stem cells that respond to injury or infection; differentiate into fibroblasts, macrophages, etc
mast cells: stimulate inflammation after injury; release histamine(inflammatory agent) and heparin(anti-cagulant)
leukocytes: cells of immune system

Question 20

Extracellular Matrix (ECM)

Answer 20

ECM is made up of glycoproteins and proteins: collagen, proteolgycans, elastic fibers, and reticular fibers
functions: support, adhesion, movement, regulation

Question 21

collagen fibers

Answer 21

most abundant protein type although different types of collagen.
most common in connective tissue proper.
long, straight, and unbranched (rope shaped)
strong but still flexible
resist force in one direction

Question 22

reticular fibers

Answer 22

different type of collagen; fine collagenous fibers
branch extensively
form a network of interwoven fibers called stoma

Question 23

elastic fibers

Answer 23

composed of protein elastin and fibrillin
branched and wavey
smaller in diameter than collagen fibers
strong, flexible and extremely elastic (rubber bad of c.t. fibers)

Question 24

areolar connective tissue (loose connective tissue proper)

Answer 24

least specialized; open framework with most diverse cell population
elastic fibers, collagen fibers and reticular fibers, directly deep to basement membrane

Question 25

adipose (loose connective tissue proper)

Answer 25

located: fat cells, deep to skin, padding around eyes functions: provides and cushions shocks, insulates and stores energy

Question 26

reticular tissue (loose connective tissue proper)

Answer 26

locations: liver, kidney, spleen, bone marrow functions: provides supportive framework, complex 3-dimensional network (stroma)

Question 27

dense regular collagenous connective tissue proper

Answer 27

tightly packed found in tendons, parallel collagen fibers

Question 28

dense regular elastic connective tissue proper

Answer 28

tightly packed, parallel bundles of collagen and elastic fibers. found in vocal folds

Question 29

dense irregular collagenous CTP

Answer 29

multi-directional bundles of collagen fibers found in dermis of skin. withstands stretching from all directions

Question 30

dense irregular elastic CTP

Answer 30

multi-directional bundles of collagen and elastic fibers | found in elastic arteries, withstand pulling and then recoil

Question 31

hyaline cartilage

Answer 31

between tips of rigs and bones of sternum | function: provides stiff but somewhat flexible support

Question 32

elastic cartilage

Answer 32

location: auricle of external ear functions: provides support, but tolerates distortion without damage and returns to original shape

Question 33

fibrocartilage

Answer 33

location : pads within knee joint | functions: resists compression; prevents bone to bone contact

Question 34

skeletal muscle

Answer 34

locations: combined with connective tissues and neural tissue in skeletal muscle functions: moves or stabilizes position of the skeleton

Question 35

cardiac muscle

Answer 35

location : heart | function: circulates blood; maintain blood pressure

Question 36

smooth muscle

Answer 36

location: found in walls of blood vessels, and in digestive, respiratory, urinary, and reproductive organs functions: moves food, urine and reproductive tract secretions; controls diameter of respiratory passageways and of blood vessels

Question 37

neurons vs neuroglia

Answer 37

neurons: nerve cell; communicate via action potentials neuroglia: supporting cells; repair, protects and suppply nutrients to neurons.

Question 38

tissue membreanes

Answer 38

1. mucous membrane 2. serous membrane 3. cutaneous membrane 4. synovial membranes

Question 39

mucous membrane

Answer 39

thin layer of mucous; found in digestive, respiratory, urinary, and reproductive tracts. line passageways that have external connections. epithelial surfaces must be moist to reduce friction and facilitate absorption, exchange, and excretion lamina propria

Question 40

serous membrane

Answer 40

line cavities not open to outside thin but strong have fluid transudate to reduce friction have parietal layer covering outer cavity wall and visceral layer covering organ surface

Question 41

cutaneous membrane

Answer 41

is the skin, thick, waterproof, and dry

Question 42

synovial membranes

Answer 42

line joint cavities, produces synovial fluids, protects ends of bones