Ex.1-Chapter 4, Tissue: The Living Fabric

Question 1

Define “tissue”

Answer 1

an ensemble of similar cells that have a common function

Question 2

Define “histology”

Answer 2

study of the microscopic anatomy of tissue

Question 3

What are the four main tissue types in the body?

Answer 3

Epithelia, Connective, Muscle, Nervous

Question 4

What are the functions of the epithelia?

Answer 4

Covers surfaces, lines body cavities, protection (skin), absorption (small intestines), secretion (glands), filtration (kidneys) and sensory reception (nerve endings).

Question 5

What are the epithelia characteristics?

Answer 5

polarity, specialized contacts, supported by connective tissue, being avascular but innervated, and having the ability to regenerate.

Question 6

What is does “polarity” of the epithelia mean?

Answer 6

All epithelia have an apical surface and a basal surface. The two surfaces differ in both structure and function. For this reason, we say that epithelia exhibit apical-basal polarity.

Question 7

What is the apical surface?

Answer 7

an upper free surface exposed to the body exterior or the exterior cavity of an internal organ- faces the surface

Question 8

What is the basal surface?

Answer 8

a lower attached- lining the organ or inner cavity

Question 9

What is the “specialized contacts” of the epithelia?

Answer 9

proteins, which help form continuous sheets, which are call “tight junctions” and “desmosomes”. These bind adjacent cells together at many points

Question 10

What does the tight junctions do?

Answer 10

help keep proteins in the apical region of the plasma membrane from diffusing into the basal region.

Question 11

What is epithelia supported by?

Answer 11

Connective tissue

Question 12

What does the basement membrane do?

Answer 12

reinforces the epithelial sheet, and helps adhere the epithelia to the connective tissue

Question 13

Although epithelium is avascular (no blood vessels) it is what?

Answer 13

innervated (supplied by nerve fibers). Epithelia cells are nourished by substances diffusing from blood vessels in the underlying connective tissue

Question 14

If epithelium cells rub off, are damaged, or lateral contacts are destroyed what can the epithelium do?

Answer 14

Regenerate, by rapidly reproducing themselves (mitosis)

Question 15

How is epithelium named?

Answer 15

First name indicates the number of layers, and the second name describes the shape of its cells.

Question 16

Consist of a single layer?

Answer 16

Simple epithelia

Question 17

Composed of two of more layers?

Answer 17

Stratified epithelia

Question 18

Where is simple epithelia typically found?

Answer 18

where absorption, secretion, and filtration occur and a thin epithelial barrier is desired.

Question 19

Where is stratified epithelia typically found?

Answer 19

high abrasion areas where protection is important, such as the skin surface and the lining of the mouth

Question 20

What are the three common shapes of epithelial cells?

Answer 20

Squamous (flat), cuboidal (boxlike), and columnar (tall and column shaped)

Question 21

Describe simple squamous epithelia

Answer 21

single layer, flattened, cytoplasm is sparse, resemble fried eggs

Question 22

What is the function of simple squamous epithelia?

Answer 22

Filtration and diffusion

Question 23

Where is some places in the body that simple squamous epithelia can be found?

Answer 23

kidneys and lungs

Question 24

What are the two simple squamous epithelia in the body that have special names that reflect their location?

Answer 24

Endothelium and Mesothelium

Question 25

What does endothelium do?

Answer 25

provides a slick, friction reducing lining in lymphatic vessels and in hollow organs of the cardiovascular system-blood vessels and the heart.

Question 26

What does mesothelium do?

Answer 26

is the epithelium found in serous membranes, the membranes lining the ventral cavity and covering its organs.

Question 27

Describe simple cuboidal epithelia?

Answer 27

single layer of cells as tall as they are wide, spherical nuclei.

Question 28

What is the function of simple cuboidal epithelia?

Answer 28

secretion and absorption

Question 29

Where can you find simple cuboidal epithelia in the body?

Answer 29

walls of ducts of glands and may kidney tubules

Question 30

Describe simple columnar epithelia?

Answer 30

single layer of tall, closely packed cells, aligned like soldiers in a row

Question 31

What is the function of simple columnar epithelia?

Answer 31

absorption and secretion

Question 32

Where can you find simple columnar epithelia?

Answer 32

lining the digestive track from the stomach to the rectum

Question 33

Describe pseudo-stratified columnar epithelia?

Answer 33

vary in height, all of its cells rest on the basement membrane, but only the tallest reach the free surface. Because the cell nuclei lie at different levels above the basement membrane, the tissue gives the false (pseudo) impression that several layers are present

Question 34

What is the function of pseudo-stratified columnar?

Answer 34

secretes and absorbs, can be ciliated or non-ciliated

Question 35

Where can you find pseudo-stratified in the body?

Answer 35

Respiratory track