Epithelium

Question 1

From which embryological origins does epithelium arise?

A) Mesoderm

B) Ectoderm

C) Endoderm

D) All of the above

Answer 1

D) All of the above

Ectoderm gives rise to the epidermis, mesoderm gives rise to the inner lining of body cavities and the endoderm gives rise mucous membranes lining the digestive and respiratory tracts.

Question 2

What are the 2 main functions of epithelia?

Answer 2

To line body surfaces and form secretory glands

Question 3

What 2 layers make up the basement membrane?

Answer 3

1) Basal lamina
2) Reticular lamina

Question 4

Label this image

Answer 4

A) apical surface

B) Lateral surfaces

C) Epithelium

D) Basal lamina

E) Reticular lamina

F) Basement membrane

G) connective tissue

Question 5

Kidney tubules are lined by __?__ epithelium

Answer 5

Simple cuboidal

Question 6

Alveoli are lined by __?__ epithelium

Answer 6

Simple squamous

Question 7

The small intestine is lined by __?__ epithelium

Answer 7

Simple columnar

Question 8

The oesophagus is lined by __?__ epithelium

Answer 8

Stratified squamous

Question 9

Where would you find keratinised stratified squamous epithelium?

Answer 9

Only found in skin

Question 10

An epithelial basement membrane consists of __1__ lamina and __2__ lamina

Answer 10

1) basal lamina 2) reticular lamina

Question 11

The trachea is lined by __?__ epithelium

Answer 11

Pseudostratified columnar

Question 12

Sweat gland ducts are lined by __?__ epithelium

Answer 12

Stratified cuboidal

(stratified as the cells beneath can store sweat)

Question 13

Salivary gland ducts are lined by __?__ epithelium

Answer 13

Stratified columnar

Question 14

Exocrine glands secrete into __?__

Answer 14

ducts that open into lumen of organ or onto the skin

Question 15

Endocrine glands secrete into __?__

Answer 15

empty tissue spaces, eventually hormones enter the blood stream (no ducts)

Question 16

What is the difference between merocrine, apocrine, and holocrine secretion?

Answer 16

• Merocrine: secretion passes from cells via exocytosis without damaging the cell or cell membrane. (think mediocre so the normal way u would think) e.g. saliva, sweat.
• Apocrine: Apical surface of cells pinched off to release pockets of the hormone. (think Apocrine = Apical) e.g. mammary glands.
• Holocrine: Whole-cell dies for secretion. (think of holocaust) e.g. sebum from sebaceous glands.

Question 17

Epithelial membranes contain epithelium and __?__

Answer 17

An underlying connective tissue

Question 18

Synovial membranes contain only __1__ tissues and line __2__

Answer 18

1) connective
2) joint cavities

Question 19

Serous membranes are generally simple __1__ epithelium resting on a thin layer of __2__. The epithelium is also known as __3__(originating from mesoderm). The serosa is found lining __4__ or the 3 Ps __5__, __6__ and __7__. Produces ___5___ which gives lubrication.

Answer 19

1) Squamous
2) Loose connective tissue
3) Mesothelium (as it is formed from the mesoderm)
4) Closed internal body cavities
5) Pleura
6) Pericardium
7) Peritoneum
5) Serous fluid (that reduces friction between joints)

Question 20

Cavities open to the external environment are generally lined by __1__ membranes. In the digestive tract, the mucosa has [microvilli/cilia], and in the respiratory tracts the mucosa has [microvilli/cilia].

Answer 20

1) mucous
2) microvilli
3) cilia

Question 21

Serous membranes have two layers: the __1__ layer (attaches to the body wall around the organ) and the __2__ layer (attaches to the organ it surrounds).

Answer 21

1) parietal
2) visceral

Question 22

The pleura (surrounding the __1__),

The__2__ (surrounding the heart)

The peritoneum (in the abdomen) are all prominent examples of __3__ membranes.

Answer 22

1) lungs
2) pericardium
3) serous

Question 23

Between the two layers of the serous membrane is a fluid called __?__ fluid.

Answer 23

serous

Question 24

Synovial membranes line the cavities of freely movable joints, and contain on __?__ tissues.

Answer 24

connective

Question 25

Describe transitional cells and where they are found.

Answer 25

Layers which change their shape when stretched. Only found in the urinary tract.

Question 26

How does the basal surface connect to underlying tissues?

Answer 26

Connect to it via the basement membrane derived from connective tissue.

Question 27

Label this diagram

Answer 27

* A = Enterocytes * B = Microvilli * C = Villi

Question 28

What are the roles of desmosomes? Where are they found and what proteins do they include?

Answer 28

The roles include holding epithelia together at their lateral surfaces. They are found as spots on the lateral surfaces and involve cadherin proteins.

Question 29

What is the role of tight junctions?

Answer 29

Allows plasma membranes of neighbouring cells to fuse. This ensures nothing can get through except what the plasma membrane allows.

Question 30

What is a glandular epithelium?

Answer 30

These are aggregates of epithelial cells that cluster together to perform certain secretory and excretory actions.

Question 31

What type of membranes line: 1. Digestive, respiratory, reproductive and urinary system 2. Body cavities 3. Skin 4. Joints

Answer 31

1. Mucous membranes 2. Serous membranes 3. Cutaneous membranes 4. Synovial membranes

Question 32

What type of membrane is this? Label it.

Answer 32

Mucous membrane A) Mucus B) Epithelium C) Lamina propria (areolar connective tissue which is a type of loose connective tissue. Notice that under the skin, it is loose.)

Question 33

Label this portion of a membrane.

Answer 33

This is the skin. A) Epidermis B) Dermis

Question 34

What type of membrane is this? Label it.

Answer 34

Serous membrane A) Transudate (serous fluid) B) Mesothelium C) Areolar tissue

Question 35

What is this membrane? Label it.

Answer 35

Cutaneous. A) Epithelium B) Areolar connective tissue C) Dense irregular connective tissue

Question 36

What membrane is this? Label it

Answer 36

Synovial A) Articular (hyaline cartilage) B) Synovial fluid C) Capsule D) Capillary E) Adipocytes F) Areolar tissue G) Epithelium H) Synovial membrane

Question 37

What is the difference between mesothelium and endothelium?

Answer 37

* The mesoderm originates from the mesoderm whilst the endothelium originates from ectoderm or endoderm. * Mesothelium found within serous membranes and the endothelium is found lining inner surface of walls of vessels