5 - Gland Intro

Question 1

Merocrine

Answer 1

Fusion of vesicles with the apical membrane (exocytosis)

Question 2

Apocrine

Answer 2

Partial loss of cytoplasm

Example: sweat gland in the axillary

Question 3

Halocrine

Answer 3

Complete loss of cytoplasm

Example: sebaceous gland

Question 4

Constitutive secretion

Answer 4

Merocrine

Small vesicles 
Repopulate plasma membrane 
Not modified 
No granules 
No signal stimulus

Question 5

Regulated secretion

Answer 5

Merocrine
Granules
Stimulus needed

Secretary granules are accumulated into large vesicles
Ca2+ is required
ATP is required
Granules are modified before secreted

Question 6

Apocrine example

Answer 6

In neonates, Fats secreted by apocrine secretion via signet fragments.

When big they can take a portion of cytoplasm with them.

Question 7

Glycosylation

Answer 7

Covalent attachment of sugars by enzymes to protein and lipids

1. Aids protein folding
2. Cell recognition
3. Prevents lipase digestion
4. Prevents protein digestion

Question 8

Where does glycosylation occur

Answer 8

Golgi apparatus

Question 9

Golgi mechanism

Answer 9

1. RER transfers protein via vescicle to cis region of Golgi
2. Then glycosylated
3. Packaged into a vesicle at trans end and transported

Question 10

Transcytosis

Answer 10

1. Impermeable substance- endocytosis at one end
2. Transported across the cytoplasm via vesicle
3. Substance is secreted by exocytosis at other end

Question 11

Difference between humoral, neural and hormonal

Answer 11

Humoral - negative feedback loop control (change in level of substance in fluid)
Neural - use nerves
Hormonal - use hypothalamus which release hormones to stimulate more hormones

Question 12

Hypothalamo-hypophyseal portal sytem

Answer 12

Hypothalamus has neurones that stop at the hypthalamo-hypophyseal portal sytem.

Blood travels through 2 sets of cappilaries via the portal before entering the anterior pituitary

Question 13

Anterior pituitary

Answer 13

ACTH
LH
FSH
GH
TSH 

Prolactin
MSH- melanocyte stimulating

Question 14

Posterior pituitary

Answer 14

Base of brain - hypothalamus

Oxytocin
Vasopressin
ADH- anti diuertic hormone

Question 15

Thyroid

Answer 15

Butterfly shaped
Anterior to trachea

T4 and T3

Question 16

Parathyroid

Answer 16

4 glands (2 pairs) 
Dorsal region of the thyroid 

Parathyroid hormone

Question 17

Adrenal glands

Answer 17

Top of each kidney - adrenal medulla and adrenal cortex

Corticosteroids
Oestrogen
Androgen
Progestin

Question 18

Pancreas

Answer 18

Left and behind the stomach

Exocrine - digestive enzymes
Endocrine - insulin and glucagon

Question 19

Stomach

Answer 19

Gastrin - gastric acid secretion
Ghrelin - feeding behaviour 
Leptin - appetite control
Somatostatin - inhibits hormones 
Secretin - stimulates water and bicarbonate secretion from the pancreas

Question 20

Liver

Answer 20

Angiotensinogen
Angiotensin
Thrombopoietin

Question 21

Duodenum

Answer 21

Secretin - stimulate release of water and bicarbonate ions by the pancreas

Question 22

Kidney

Answer 22

Renin - converts angiotensin 1 to angiotensin 2
Erythropoietin
Calcitriol - ca2+ absorption by intestine
Thrombopoietin

Question 23

Peptide hormones

Answer 23

Stored in secretory vesicles
Dissolved in plasma
Receptor on the plasma membrane
Activates 2nd messenger

E.g insulin, glucagon, ACTH, PTH, Gastrin

Question 24

Steroid hormones

Answer 24

Synthesised on demand by precursors
Bound to carrier proteins
Receptors are present in the cytoplasm or nucleus
Activate transcription factors

E.g oestrogen, androgens, progesterone, aldosterone,cortisol

Question 25

Catecholamines - amino acid derived

Answer 25

Mad in advanced 
Stored in vesicles 
Dissolved in the plasma 
Receptors of the plasma membrane 
Activate 2nd messengers 

E.g adrenaline, noradrenaline

Question 26

Thyroid hormones - amino acid derived

Answer 26

Made in advanced
Bound to carrier proteins
Receptor in the nucleus
Activate transcription factor

E.g T3 and T4