Glands Flashcards Preview

TOB > Glands > Flashcards

Flashcards in Glands Deck (55)
Loading flashcards...
0
Q

What is an exocrine gland?

A

A gland that secretes via a duct.

1
Q

What is a gland?

A

An epithelial cell or collection of epithelial cells specialised for secretion.

2
Q

What is an endocrine gland?

A

A gland that secretes directly into the blood stream (without a duct)

3
Q

How can we classify the secretory part of a gland?

A

Unicellular/multicellular
Branched/coiled
Alveolar (acinar)/tubular

4
Q

How can we classify the duct system of a gland?

A

Simple/compound.

5
Q

What granules are contained in a goblet cell?

A

Mucinogen.

6
Q

What protein is absent/malformed in cystic fibrosis? What is its normal function?

A

CFTR (cystic fibrosis transmembrane regulator).

Transport of chloride ions from the cell into the mucus.

7
Q

What is the consequence of viscous mucous in the respiratory tract in patients with cystic fibrosis?

A

Frequent, severe pulmonary infections.

8
Q

What are the consequences of viscous mucous in the GI tract:

a) in newborns
b) in adults

A

a) inability to pass the first faeces (meconium ileus)

b) constipation and invaginations of parts of the GI tract.

9
Q

How are glands derived?

A

Invaginations of epithelium specialised for secretion.

10
Q

Which glands are simple tubular?

A

Glands in the intestine

11
Q

Which glands are coiled tubular?

A

Merocrine sweat glands.

12
Q

Which glands are simple branched tubular?

A

Gastric glands.

Mucous glands of tongue, duodenum, oesophagus.

13
Q

Where are simple alveolar glands found?

A

They are not found in adults, but they are a stage in the development of simple branched glands.

14
Q

Where are simple branched found?

A

Sebaceous glands.

15
Q

Where are compound tubular glands found?

A
Mucous glands (in mouth)
Bulbourethral glands (male reproductive system)
Seminiferous tubules (testes)
16
Q

Where are compound acinar glands found?

A

Mammary glands

17
Q

Where are compound tubuloalveolar glands found?

A

Salivary glands
Pancreas
Glands in respiratory passages.

18
Q

What is the nature of the secretion of a mucous gland, and how does it stain with H&E?

A

The secretions include mucus, which is rich in mucins (highly glycosylated polypeptides)
Don’t stain well with H&E.

19
Q

What is the nature of the secretions of a serous gland, and how do they stain with H&E?

A

Secretions are often enzymes - watery and free of mucus. Stained by eosin (pink)

20
Q

What is a serous demilune?

A

Artefact formed by fixing tissue - serous cells appear to lie outside of the acinus.

21
Q

What is the nature of secretions of the submandibular gland?

A

Mixed - serous and mucous.

22
Q

What are the three methods of secretion?

A

Merocrine (vast majority)
Apocrine
Holocrine

23
Q

What is holocrine secretion?

A

Disintegration of the whole cell and release of contents.

24
Q

What is merocrine secretion?

A

Exocytosis.

25
Q

What is apocrine secretion?

A

Lipid or other non membrane bound droplet makes contact with apical cell membrane, drapes around droplet and pinches off.
Plasma membrane added to regain original surface area.

26
Q

Where does apocrine secretion occur?

A

Lactating mammary gland.

27
Q

What is the role of myoepithelial cells in the mammary gland?

A

Contract, assist with secretion of milk from acini. Experienced as “let down”.

28
Q

Why might apocrine sweat glands appear to undergo apocrine secretion?

A

Cytoplasmic blebbing.

29
Q

By what means do apocrine sweat glands secrete?

A

Merocrine secretion.

30
Q

Where are apocrine sweat glands found?

A

Axillae, areolae of nipples, genitals and perineum.

31
Q

By what method do eccrine sweat glands secrete?

A

Merocrine

32
Q

What cells facilitate the transport of luminal contents to the duct?

A

Myoepithelial cells (they contract)

33
Q

Why does the sweat of someone with cystic fibrosis have a high content of sodium ions and chloride ions?

A

Faulty CFTR protein means chloride ions are not reabsorbed from the sweat. This means a high concentration of sodium and chloride ions sis present in the sweat.

34
Q

What glands undergo holocrine secretion?

A

Sebaceous glands.

35
Q

What is endocytosis?

A

Engulfment of material outside the cell (opposite of exocytosis)

36
Q

What is transepithelial transport, and for what molecules is it useful?

A

Coupling of endocytosis and exocytosis.

Large molecules that cannot cross the plasma membrane.

37
Q

What are the two types of secretion of products from the Golgi apparatus?

A

Constitutive and regulated.

38
Q

Where does glycosylation occur?

A

Cisternae of Golgi apparatus.

39
Q

Describe the structure of the Golgi apparatus

A

Stack of disc shaped cisternae
One side flattened, one side concave.
Swellings at the edges - pinch off as vesicles.

40
Q

What does the Golgi apparatus do?

A

Glycosylation of proteins and lipids - confers specificity.
Sorting of proteins
Packaging - condensation of contents
Transport of vesicles.

41
Q

What are the destinations of products from the Golgi apparatus?

A

Secretory vesicles
Lysosomes
Plasma membrane (glycocalyx)

42
Q

What are the possible consequences of the enzymatic destruction of the glycocalyx?

A

Alters specificity based properties - adhesion to substrates and neighbouring cells; mobility of cells; communication with neighbouring cells; contact inhibition of movement and division.

43
Q

What are the four methods of controlling secretion? Give an example for each.

A

Nervous - the sympathetic nervous stimulation of the adrenal medulla to produce adrenaline.
Endocrine - ACTH stimulates the adrenal cortex to release cortisol.
Neuroendocrine - control of the secretion of ACTH and other hormones of the anterior pituitary by the hypothalamus.
Negative feedback - T3 and T4 inhibit synthesis of TSH.

44
Q

What are the three salivary glands?

A

Submandibular, sublingual, parotid.

45
Q

What is the nature of secretions from the parotid gland?

A

Serous.

46
Q

What is the nature of the secretions of the submandibular gland?

A

Mixed (serous and mucous)

47
Q

What is the nature of the secretions of the sublingual gland?

A

Mixed - small proportion of serous.

48
Q

What is secreted by the endocrine pancreas, and by which cells?

A

Glucagon -alpha cells
Insulin and amylin - beta cells
Somatostatin - delta cells
Gamma cells - pancreatic polypeptide

49
Q

What does the exocrine pancreas secrete?

A
Bicarbonate ions
Pancreatic lipase
Pancreatic amylase
Trypsinogen
Chymotrypsinogen
50
Q

What is the effect on the pancreas of a faulty CFTR protein?

A

Secretions from the pancreas do not contain sufficient water and become thickened.
This can block the ducts of the pancreas, zymogens in the pancreas undergo autolysis to the active form of the enzyme - this can lead to pancreatitis. Pancreas can become fibrotic.
Insufficient digestive enzymes lead to malabsorption of nutrients and steatorrhea.
Endocrine pancreas deteriorates more slowly as it is ductless.

51
Q

What cells are present in the parathyroid gland?

A

Chief cells, oxyphil cells, adipose cells

52
Q

What is secreted by the adrenal medulla?

A

Adrenaline and noradrenaline

53
Q

What are the three layers of the adrenal cortex from outside yo inside and what do they secrete?

A

Zona glomerulosa - mineralocorticoids (aldosterone)
Zona fasciculata - glucocorticoids (cortisol)
Zona reticularis - androgens

54
Q

Which way does the blood flow through the adrenal gland?

A

From capsular artery to medullary vein.