Session 2.2 Glands

Question 1

Definition of a gland

Answer 1

An epithelial cell or collection of cells specialised for secretion

Question 2

Give the four ways in which glands can be defined

Answer 2

Destination of secretion, structure of the gland, nature of the secretion and method of discharge

Question 3

Whena are multicellular glands classed as simple?

Answer 3

When their ducts don’t branch

Question 4

Name the two types of structure glands can be?

Answer 4

Alveolar (acinar) or tubular

Question 5

What type of gland is this? Where is it found?

Answer 5

Simple Tubular

Intestinal glands

Question 6

What type of gland is this? Where is it found?

Answer 6

Simple Coiled tubular

Merocrine Sweat Glands

Question 7

What type of gland is this?

Where is it found?

Answer 7

Simple branched tubular

Gastric Glands

Question 8

What gland type is this? Where is it found?

Answer 8

Simple branched alveolar

Sebacous glands

Question 9

What type of gland is this? Where is it found?

Answer 9

Compound alveolar

Mammary glands

Question 10

What kind of gland is this? Where is it found?

Answer 10

Compound tubular, mucous glands

Question 11

What kind of gland is this, and where is it found?

Answer 11

Compound tubuloalveolar

Salivary glands, pancreas

Question 12

What are the two types of classification by destination?

Answer 12

Exocrine and endocrine

Question 13

Define exocrine

Answer 13

A gland with ducts

Question 14

Define endocrine

Answer 14

A ductless gland that secretes directly into blood

Question 15

What are the two types of secretory gland?

Answer 15

Mucous and Serous

Question 16

What do mucous glands produce? How well do they stain?

Answer 16

Secretions contain mucous, rich in mucins (highly glycosylated polypeptides). Stain poorly in H&E.

Question 17

What do serous glands secrete? How well do they stain, and what colour?

Answer 17

Watery, mucus free secretions which often contain enzymes. Eosinophillic (pink) in H&E stains.

Question 18

Give three methods of secretion

Answer 18

Merocrine, Apocrine, Holocrine

Question 19

Name two merocrine glands, and give the process of secretion (5)

Answer 19

Salivary glands, pancreas
Membrane bound vesicle approaches cell surface
Vesicle fuses with plasma membrane
Contents of vesicle are in continuity with the extracellular space
Plasma membrane is very slightly larger
Membrane retrieved, stabilising cell surface area

Question 20

Name an apocrine gland and give its step by step method of secretion (6)

Answer 20

mammary gland (myoepithelial cells assist secretion)
Non-membrane bound structure (e.g. a lipid) approaches cell surface
Makes contact and pushes up apical membrane
Thin layer of apical cytoplasm drapes around droplet
Membrane surrounding droplet pinches off from cell
Plasma membrane is very slightly smaller
Membrane added to regain original surface area

Question 21

Give a holocrine gland, and outline its method of secretion (3)

Question 22

What is endocytosis, and in what process is it useful?

Answer 22

Endocytosis is the process of engulfing material initially outside the cell.

Endo/Exocytosis are coupled in transepithelial transport.

Question 23

What is merocrine secretion also known as?

Answer 23

Exocytosis

Question 24

Why is transepithelial transport good?

Answer 24

Because it allows molecule too large to penetrate membranes to be shunted across from one component of the body to another.

Question 25

Give process of transepithelial transport (3)

Answer 25

Material is endocytosed at one surface of the cell
The transport vesicle shuttles it across the cytoplasm
The material/vesicle is then exocytosed at the opposite surface.

Question 26

Give four features of the structure of the golgi apparatus

Answer 26

Stack of disc-shaped cisternae
One side of the discs are flattened, other side is concave
Discs have swelling at their edges (Vesicles that bud off)
Distal swellings pinch off as migratory Golgi Vacuoles

Question 27

Give four functions of golgi apparatus

Question 28

Give three product destinations of golgi apparatus

Question 29

What does glycosylation do to a cell?

Answer 29

Branching sugars offer complex shapes for specific interactions in the glycocalyx

Allows

Adhesion to substrates & neighbouring cells
Communication with neighbouring cells
Contact inhibition of movement and division
Mobility of cells

Question 30

What does enzymatic destruction of glycocalyx alter?

Answer 30

Adhesion to substrates & neighbouring cells
Communication with neighbouring cells
Contact inhibition of movement and division
Mobility of cells

Question 31

Give four mechanisms of secretory control

Answer 31

Nervous Control

Endocrine control

Neuro-endocrine control

Negative feedback chemical mechanism

Question 32

Give example of nervous control

Question 33

Give example of endocrine control

Answer 33

adrenocorticotrophic hormone (ACTH) stimulates the cortex of the adrenal gland to secrete hormones (e.g. Cortisol)

Question 34

Give example of Neuro-endocrine control

Answer 34

nervous cells of the hypothalamus control ACTH secretion from the anterior pituitary gland

Question 35

Give example of Negative feedback chemical mechanism

Answer 35

the inhibitory effect of high thyroxine (T3 & T4) levels on TSH synthesis by the anterior pituitary gland.

Question 36

Give three example of exocrine glands

Question 37

Give four examples of endocrine glands