Histology- tissues

Question 1

histology

Answer 1

study of tissues

Question 2

Histogenesis

Answer 2

is the formation of tissue from the germ layers during embryonic development

Question 3

4 basic categories of tissues

Answer 3

1. epithelium
2. connective tissues
3. muscle tissue
4. nervous tissue

Question 4

epithelial tissue- main function

Answer 4

covers the outer surfaces of the body(epidermis) & lines all passages leading to the exterior & lines most of cavities of the body (thorax, abdomen)

Question 5

What joins cells together (in EPi T)?

Answer 5

cells that are tightly joined together with desmosomes & tight junctions( necessary for tissues that cover and line)

Question 6

Epi T embryonic germ layer orgin

Answer 6

• can come from 3 germ layers
• ex. epithelium from the endoderm lines organs of digestive tract, while epithelium from the ectoderm covers the body as skin

Question 7

Epi T apical surface

Answer 7

free margin, pole which faces the lumen or exterior

-mods: microvilli or cilia

Question 8

Epi T basal surface

Answer 8

pole which faces the underlying connective tissue

Question 9

Epi T basal lamina

Answer 9

a very thin coat secreted by the cells bordering the basal surface which is composed primarily of glycoproteins and act as glue
-noncellular

Question 10

Epi T basement membrane

Answer 10

a thick layer just below the basal surface resulting from the basal lamina and the reticular layer ( layers of collagen fibers secreted by the underlying connective tissue)

Question 11

Tissues are…

Answer 11

a collection of cells and associated intercellular materials specialized for a particular function(s)

Question 12

Epithelial tissues are classified by…..

Answer 12

the shape of cells and by the number of cell layers

Question 13

Shapes

Answer 13

1. squamous
2. cuboidal
3. columnar

Question 14

squamous

Answer 14

flat

-line blood vessels and mouth

Question 15

cuboidal

Answer 15

cube shaped

-line glands and ducts

Question 16

columnar

Answer 16

tall

-line stomach and intestines

Question 17

Layers

Answer 17

1. simple
   2 stratified
2. pseudostratified
3. transitional

Question 18

simple

Answer 18

one layer

-for absorption, secretion, filtration

Question 19

stratified

Answer 19

several layers

- for protection

Question 20

pseudostratified

Answer 20

single layer of cells, but columnar cells are varying heights so the appear stratified, but its only one layer

• ciliated pseudostratified columnar Epi T lines the respiratory tract
• simple columnar can also be ciliated

Question 21

transitional

Answer 21

a variation of stratified which is found in the urinary system where the number of cell layers and shapes of the cells vary with distention and contraction of organ)

Question 22

Epithelial tissue is…

Answer 22

• avascular(no blood supply)
• relies on diffusion of Oxygen and nutrients from capillaries in underlying connective tissues
• innervated(nervous supply)
• high regeneration capacity
• damage to cells are repaired quickly

Question 23

Both serous and mucous membranes are..

Answer 23

epithelial tissue over connective tissue

Question 24

Simple squamous

Answer 24

ex. air sacs of lungs
- lining of blood vessels
- lining serosae( the chorion- outer membrane of fetus)

Question 25

simple cuboidal

Answer 25

ex. - kidney tubules - surface of uteras

Question 26

simple columnar

Answer 26

ex. - line of digestive tract - 2 mods: dense microvilli, goblet cells secrete mucous

Question 27

ciliated simple columnar

Answer 27

line fallopian tubes

Question 28

pseudostratified columnar

Answer 28

ex. ducts of large glands | - ciliated: upper respiratory tract (trachea)

Question 29

stratified squamous

Answer 29

ex. epidermis of skin | - extends a short distance into every body opening

Question 30

stratified cuboidal

Answer 30

- rare | - ex. sweat glands, mammary glands

Question 31

stratified columnar

Answer 31

- rare | - ex. large ducts of some glands

Question 32

Connective tissues(function)

Answer 32

bind together and support other structures -made up of scattered cells, formed materials or fibers, and the matrix or ground substance that is secreted by the cells

Question 33

connective tissue embryonic germ layer of origin

Answer 33

mesoderm

Question 34

Conn T examples

Answer 34

- areolar - dense regular - dense irregular - connective tissue - adipose - cartilage - bone-vascular tissue(blood, tissue fluids, lymph)

Question 35

connective tissues consist of..

Answer 35

cells and extracellular fibers embedded in a nonliving, acellular matrix

Question 36

extracellular matrix

Answer 36

is soft in connective tissue, firm & flexible in cartilage, rigid in bone( because of inorganc salts)

Question 37

fibers

Answer 37

may be collagen, elastic or reticular

Question 38

to distinguish Conn T one must...

Answer 38

-must look at the extracellular matrix in the cells, since cells look very similar in all types

Question 39

Areolar Conn T

Answer 39

- most abundant - packages internal organs & vessels - the living cells are called fibroblasts - matrix is soft and jelly like - all 3 fibers will be found in matrix and web-like pattern in gel

Question 40

Dense regular Conn T

Answer 40

- composed of living cells, fibroblast and many collagen fibers in a sparce background - very strong and elastic - it forms tendons(muscle to bone) and ligaments(bones to other bones)

Question 41

Dense irregular Conn T

Answer 41

- similar to dense but fibers not organized in regular pattern - forms in dermis of skin and fibrous coverings of kidneys

Question 42

Reticular Conn T

Answer 42

- contains only reticular fibers | - forms internal framework of lymph nodes, spleen and bone marrow

Question 43

Adipose Tissue

Answer 43

- unlike other conn Ts, it is almost all cellular - account for 90% of tissue mass - cells contain large lipid vacuole that swells and shrinks as lipid reserves fluctuate - in humans, theses cells are formed prenatally and during the first year of life - the living cells are called adipocytes - jelly like mass

Question 44

does connective tissues have a good blood supply?

Answer 44

*all have good supply except cartilage