Human Anatomy - Epithelial tissue

Question 1

What is a tissue?

Answer 1

A group of closely associated cells that perform related functions and are similar in structure.

Question 2

What are the four tissue types?

What are their general functions?

Answer 2

Epithelial - covering
Connective - support
Nervous - control
Muscle - movement

Question 3

Epithelial Tissue
______ a body surface or ____ a body cavity.
Forms parts of most ______.

Answer 3

Covers
Lines
Glands

Question 4

What are the different functions of epithelial tissue?

Answer 4

protection
absorption, filtration and ion transport
excretion, secretion
Forms slippery surface

Question 5

What are the special characteristics of epithelium?

Answer 5

1. Cellularity
2. Specialized contacts
3. Polarity
4. Supported by connective tissue
5. Avascular but innervated
6. Regeneration

Question 6

Describe cellularity as it pertains to epithelial tissue.

Answer 6

Epithelial tissue is almost entirely composed of cells.

Question 7

Describe specialized contacts as it pertains to epithelial tissue.

Answer 7

Cells of epithelial tissue are joined by special junctions.

These gap junctions allow for communication and for the cells to work as functional unit.

Question 8

Describe polarity as it pertains to epithelial tissue.

Answer 8

Cell regions of the apical surface differ from the basal surface

Question 9

How does epithelium receive nutrients without a dedicated blood supply?

Answer 9

Epithelia receive nutrients from underlying connective tissue.
Capillaries go through connective tissue but not through epithelium

Question 10

Describe regeneration as it pertains to epithelial tissue.

Answer 10

Lost cells are quickly replaced by cell division.

Question 11

How is epithelium classified?

Answer 11

First name of the tissue indicates the number of cells:
Simple - 1
Stratified 2 or more

Last name of the tissue describes the shape of the cells:
Squamous - flat
Cuboidal - cube-shaped
Columnar - column-shaped

Question 12

How does structure relate to function?
Protection = \_\_\_\_\_\_\_\_
Transport = \_\_\_\_\_\_\_\_
Filter = \_\_\_\_\_\_\_\_\_
Stomach = \_\_\_\_\_\_\_\_

Answer 12

Stratified
Simple
Simple
Simple

Question 13

Endothelium and mesothelium are both what type of epithelium?

Answer 13

Simple squamous

Question 14

What is endothelium?

Answer 14

Slick lining of hollow organs in the circulatory system and in the inner layer of the heart.
Inner covering

Question 15

What is mesothelium?

Answer 15

Lines peritoneal, pleural and pericardial cavities.
Covers the visceral organs of those cavities.
Middle covering.

Question 16

What is the function of simple squamous epithelium?

Answer 16

Passage of materials by passive diffusion, osmosis and filtration.
Secretion in serous membranes.

Question 17

Where is simple squamous epithelium located?

Answer 17

Renal corpuscles
Alveoli of lungs
Lining of heart, blood and lymphatic vessels (endothelium)
Lining of ventral body cavity and serosae (mesothelium)

Question 18

What is the function of simple cuboidal epithelium?

Answer 18

Secretion and absorption

Question 19

What is the location of simple cuboidal epithelium?

Answer 19

Kidney tubules
Secretory portions of small glands
Ovary surface

Question 20

What lines the duct of a lumen?

Answer 20

Simple cuboidal epithelium

Question 21

Describe simple columnar epithelium.

Answer 21

Single layer of column shaped epithelial cells.
Some bear cilia on their apical surface.
May contain goblet cells.

Question 22

What is the function of simple columnar epithelium?

Answer 22

Absorption
Secretion of mucus, enzymes and other substances
Ciliated type propels mucus or reproductive cells

Question 23

Where is simple columnar epithelium located?

Answer 23

Non-ciliated forms
- line GI tract, gallbladder, ducts of some glands
Ciliated form:
- lines small bronchi, uterine tubes, uterus

Question 24

What is the purpose of cilia?

Answer 24

Move material across the surface of cells.

Question 25

What do goblet cells do?

Answer 25

Secrete mucin

Question 26

What is the lamina propria?

Answer 26

Connective tissue underlying mucus secreting membranes.

Question 27

Pseudostratified epithelium: All cells originate at the ________ _______ Only ______ cells reach the apical surface May contain ______ ____ and bear _____ ______ lie at varying heights within cells, giving the false impression of _________

Answer 27

``` Basement membrane tall goblet cells cilia Nuclei stratification ```

Question 28

Describe pseudostratified epithelium.

Answer 28

All cells originate at the basement membrane but, nuclei at varying heights give the impression of stratification. May contain goblet cells and some bear cilia. Only tall cells reach the apical surface.

Question 29

What is the function of pseudostratified columnar epithelium?

Answer 29

Secretion of mucus | Propulsion of mucus by cilia

Question 30

Where is pseudostratified epithelium located?

Answer 30

``` Non-ciliated: - ducts of male reproductive tubes - ducts of large glands ciliated: - lines trachea and most of URT ```

Question 31

Describe the mucociliary escalator.

Answer 31

Mucus lubricates the respiratory system and catches bacteria and debris. Cilia of the URT beats unidirectionally back up the URT to either expel the mucus or swallow it and digest it with stomach acid

Question 32

What are the properties of stratified epithelia?

Answer 32

Contains two or more cells Regenerate from below Major role is protection Named according to the shape of cells at the apical layer

Question 33

Describe stratified squamous epithelium.

Answer 33

Multiple layers of flat cells. (squamous on apical layer) Thickest epithelial tissue. Adapted for protection against abrasion. Can be keratinized or non-keratinized

Question 34

Describe keratinized stratified squamous epithelium.

Answer 34

``` Dry Located in the epidermis Contains the protective protein keratin Waterproof Surface cells are dead and full of keratin ```

Question 35

Describe non-keratinized stratified squamous epithelium.

Answer 35

Apical layer and layers deep to it remain moist. Forms moist lining of body openings. Wet

Question 36

What is the function of stratified squamous epithelium?

Answer 36

Protects underlying tissues from abrasion.

Question 37

Where is stratified squamous epithelium located?

Answer 37

Keratinized - epidermis | non-keratinized - mouth, esophagus, anus, vagina, urethra

Question 38

What is the function of stratified cuboidal epithelium?

Answer 38

Protection

Question 39

Where is stratified cuboidal epithelium located?

Answer 39

Forms the ducts of: | - mammary glands, salivary glands, largest sweat glands

Question 40

Stratified cuboidal epithelium is generally ___ layers.

Answer 40

2

Question 41

Describe stratified columnar epithelium.

Answer 41

Multiple layers; | Basal cells are generally cuboidal, apical cells are elongated

Question 42

What is the function of stratified columnar epithelium?

Answer 42

Protection and secretion

Question 43

Where is stratified columnar epithelium located?

Answer 43

Rare | Found in male urethra and large ducts of some glands

Question 44

Describe transitional epithelium.

Answer 44

Basal cells are usually cuboidal/columnar and apical cells are squamous. Not as many layers as stratified squamous.

Question 45

What is the function of transitional epithelium?

Answer 45

Stretches and permits distension of urinary bladder

Question 46

Where is transitional epithelium located?

Answer 46

lines inside of hollow urinary organs.

Question 47

What are exocrine glands?

Answer 47

Glands who secrete their products onto the body surface or into a body cavity. Local activity

Question 48

Which glands are exocrine?

Answer 48

Mucus-secreting glands Salivary glands Sweat and oil glands Liver and pancreas

Question 49

Describe the goblet cell.

Answer 49

Produce the glycoprotein mucin. | Unicellular exocrine gland.

Question 50

What is the purpose of mucin?

Answer 50

When combined with water, becomes mucus which, protects and lubricates internal body surfaces.

Question 51

Where is the mucin located in a goblet cell?

Answer 51

Secretory vesicles in goblet cells contain mucin.

Question 52

What are the different epithelial surface features?

Answer 52

``` Apical: Cilia and Microvilli Basal: Basal lamina Basement membrane ```

Question 53

What are microvilli?

Answer 53

Finger-like extensions of plasma membrane which function to increase surface area. Important for secretion and absorption.

Question 54

Where are microvilli located?

Answer 54

Small intestine and kidney

Question 55

What are cilia?

Answer 55

Whip-like, highly motile extensions of apical surface membranes. Move in one direction to push material over the surface of epithelial tissue

Question 56

What is the basal lamina?

Answer 56

Acellular supporting sheet between the epithelial tissue and underlying connective tissue. Consists of proteins secreted by epithelial cells

Question 57

What are the functions of the basal lamina?

Answer 57

Selective filter - prevents inside-out/outside-in movement of material Scaffolding: for tissue regeneration

Question 58

What is the basement membrane?

Answer 58

Basal lamina + reticular lamina | Often interchangeable with basal lamina.

Question 59

What is the basis of a scar?

Answer 59

Caused by the destruction of the scaffolding of the basement membrane leading to improper tissue regeneration.

Question 60

What is the purpose of stitching?

Answer 60

Minimize appearance of a scar by getting tissue close enough for communication.

Question 61

Kartagener's syndrome is an _______ issue. | Diabetes is a ______ issue.

Answer 61

Apical | Basal

Question 62

What is Kartagener's Syndrome?

Answer 62

Immotile cilia in which dynein arms fail to form.

Question 63

What are symptoms of Kartagener's?

Answer 63

Chronic respiratory infections, infertility, hearing loss, frequent headaches due to stagnant CSF.

Question 64

If left untreated, diabetes can cause _______ of the basement membrane. Why?

Answer 64

Thickening Increased glucose causes thickening of basement membrane. Symptoms include loss of eyesight and kidney problems.