BL Glands

Question 1

What is a gland?

Answer 1

A collection of epithelia cells that secrete a substance

Question 2

What is secretion?

Answer 2

The production and release of material by cells

Question 3

What the two types of glands?

Answer 3

Endocrine - ductless
Exocrine- ducted

Question 4

Compare and contrast what epithelial cells secrete substances in different ducts + what is secreted

Answer 4

Endocrine - All of them
- hormones
Exocrine - only at the apex of the duct
- enzymes or lubricants

Question 5

Examples of endocrine glands and what they secrete

Answer 5

Anterior pituitary gland - ACTH, LH, TSH, FSH
Posterior pituitary gland - ADH + oxytocin
Thyroid gland - T3 + T4
Parathyroid gland - parathyroid hormone

Question 6

Examples of exocrine gland and what they secrete

Answer 6

Salivary glands - saliva
Mammary - colostrum + milk
Sweat glands - sweat
Sebaceous - sebum

Question 7

Outline adenogenesis

Answer 7

1- growth signal received
2- proliferation of cells + extracellular protein degradation enzymes produced
3- epithelial cells invade space created

Exocrine glands:
4- canalicularistion - central cells die off to produce a duct
5- link to ‘mother’ cells remains
6- lots of branching

Endocrine glands
4- produce angiogenic factors to stimulate blood vessel growth in and around epithelial cells
5- link to ‘mother’ cells broken via apoptosis
6- little branching

Question 8

Classifications of ducts according to their structure

Answer 8

Tubular or alveolar
Coiled or branched
Simple or compound

Question 9

Classification based of mode of secretion

Answer 9

Merocrine - fusion of vesicle with apical membrane
- exocytosis
Apocrine - partial loss of cytoplasm
Holocrine - complete loss of cytoplasm
- whole cell breaks down

Question 10

What are the two pathways of merocrine secretion?

Answer 10

• Regulated secretion
• Constitutive secretion

Question 11

Outline regulated merocrine secretion

Answer 11

Active process
Released by exocytosis upon stimulation from Ca2+ ions causing large vesicle to fuse with plasmalemma

Question 12

Outline constitutive merocrine secretion

Answer 12

Continuous release
Small vesicles
Used to repopulate plasma membrane with plasma proteins

Question 13

What type of secretion is at the breast?

Answer 13

Apocrine secretion - fats and proteins
Merocrine secretion - milk

Question 14

What type of secretion is at sebaceous glands?

Answer 14

Holocrine secretion

Question 15

Outline Holocrine secretion

Answer 15

1- secretory cells fill up with secretory granules
2- cell organelle degenerate + cell dies
3- plasma membrane breaks
4- secretum is released
5- dead cells are replaced by mitotic division

Question 16

What is glycosylation?

Answer 16

The covalent attachment of sugars by enzymes to proteins + lipids to form glycoproteins and glycolipids

Question 17

5 functions of glycosylation

Answer 17

1- to aid protein folding
2- prevent protein digestion
3- prevent lipid digestion
4- cellular recognition - blood groups
5- matrix attachment

Question 18

What is exocytosis?

Answer 18

Secretion of molecules outside the cell via vesicle fusing to a membrane

Question 19

What is endocytosis?

Answer 19

Engulfing of molecules inside the cell via vesicle formation

Question 20

What is pinocytosis?

Answer 20

Process where liquid droplets are ingested by cells

Question 21

What is gland secretion controlled by?

Answer 21

Negative feedback
- humoral
- hormonal
- neural

Question 22

Example of apocrine secretion

Answer 22

The breast for fats + proteins

Question 23

Example of Holocrine secretion

Answer 23

Sebaceous glands

Question 24

What are myoepithelial cells and what is their function?

Answer 24

Cells that have feature of smooth muscle cells and epithelial cells

Help eject secretions from ducts