Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

PCS Unit 3 - Communication and Control > Week 8 - Hormonal Control > Flashcards

Week 8 - Hormonal Control Flashcards

1
Q

What are the three broad categories of hormones?

A

steroids, peptides, amino acid derivatives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the two lobes of the pituitary gland?

A

anterior and posterior pituitary

linked to the hypothalamus by the pituitary stalk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the adenohypophysis?

A

anterior pituitary

posterior pituitary - neurohypophysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What hormones are secreted by the posterior pituitary gland?

A

oxytocin and vasopressin (ADH)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What two physiological signals generate the CNS stimulus for ADH secretion?

A

rise in osmolarity of the blood

decrease in blood volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the main physiological action of ADH?

A

increase water reabsorption in the collecting ducts and distal tubule of the kidneys

results in decreased water secretion and osmotically concentrated urine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the two physiological signals that stimulate the secretion of oxytocin?

A

breast-feeding

neural input from the female reproductive tract during childbirth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the mechanism of action of oxytocin?

A

stimulates contraction of myoepithelial cells causing milk ejection

stimulates contraction of smooth muscle cells in the uterus during labour

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the five different cell types located in the anterior pituitary?

A

somatotrophs

lactotrophs

gonadotrophs

corticotrophs

thyrotrophs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What hormone do the somatotrophs secrete?

A

Growth Hormone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What hormone inhibits GH secretion?

A

somatostatin

GHRH and ghrelin stimulate GH secretion and it is the net effect of these antagonistic hormones on somatotrophs that determines the rate of GH secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How does GHRH cause GH secretion?

A

GHRH binds to receptors on plasma membranes of somatotrophs

Sets off a cAMP G protein cascade (Gs)

PKA phosphorylates proteins that stimulate GH gene expression and secretion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does GH do?

A

regulates growth during childhood and puberty

GH plays no role in foetal development, becomes important at about 2yrs

exerts important effects through adult life

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How does somatostatin regulate the release of GH?

A

binds to g protein-coupled receptors on somatotrophs

these receptors are coupled to an inhibitary g-protein (Gi) which decreases adenylyl cyclase activity, reducing intracellular cAMP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Where does GH exert its effect?

A

almost every cell type except neurons

principle targets are bone and skeletal muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is acromegaly?

A

a condition that occurs when the anterior pituitary produces excess growth hormone later in life after fusion of epiphyses

17
Q

What is the difference between gigantism and acromegaly?

A

Gigantism occurs when GH is produced in excess prior to epiphyseal growth plate closure

18
Q

What metabolic disorder may patients with acromegaly develop?

A

diabetes

GH stimulates glycolysis, inhibits glycogenesis and increases gluconeogenesis, antagonises insulin

19
Q

What is the precursor molecule for all steroid hormones?

A

cholesterol

20
Q

What is the first step in the conversion of cholesterol to a steroid hormone?

A

conversion to pregnenolone

21
Q

What is the indirect effect of GH?

A

stimulates production of IGF - 1 by the liver

22
Q

What are the effects of IGF -1/2 in the body?

A

skeletal growth - bone deposition, cartilage formation

soft tissue growth - protein synthesis, cell proliferation and hypertrophy

23
Q

What hormone stimulates the breakdown of glycogen in the liver?

A

glucagon

  1. glucagon binds to a GPCR on the extracellular membrane
  2. activates G protein binding
  3. Gs subunit is released and activates adenylyl cyclate
  4. increase in concentration of cAMP
24
Q

Describe how acetylcholine signalling induces nitric oxide production

A

ACTIVATION OF ENDOTHELIAL NITRIC OXIDE SYNTHASE

PCS Unit 3 - Communication and Control (15 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions