Brainscape's Knowledge GenomeTM

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


See full index

TAS Endocrinology > Endocrine Axis and Hormonal Regulation ✅ > Flashcards

Endocrine Axis and Hormonal Regulation ✅ Flashcards

1
Q

What secretes hormones?

A

Endocrine organs

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

What happens to hormones once they have been secreted?

A

They circulate in the blood and bind to specific receptors

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

What are the sub-types of receptors that hormones may bind to?

A
  • Cell surface receptors

- Cytosolic and nuclear receptors

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

Where are cell surface receptors found?

A

On plasma membranes

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

What kind of hormones bind to cell surface receptors?

A

Hydrophilic hormones

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

Give 3 examples of hydrophilic hormones?

A
  • Insulin
  • Catecholamines
  • Pituitary hormones
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What kind of hormones bind to cytosolic and nuclear receptors?

A

Lipid soluble

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

Give 2 examples of lipid soluble hormones?

A
  • Steroids

- Thyroid hormones

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

How can cell receptor sensitivity be increased?

A

By increasing the number of binding sites

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

How can the number of hormone binding sites be increased?

A
  • Increasing receptor synthesis

- Decreased receptor degradation

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

When does desensitisation to hormones occur?

A
  • Receptors reduced in numbers
  • Receptors internalised from surface locations
  • Molecules recruited which deactivate intracellular signalling pathways
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What groups are cell-surface receptors subdivided into?

A
  • Growth factor receptors

- G-protein coupled receptors

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

What initiates signalling in growth factor receptors?

A

Tyrosine kinase

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

What can defects in GPCRs lead to?

A

Hormone resistance or upregulated activity

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

Give an example of when a defect in GPCRs leads to hormone resistance?

A

Mutations of TSH receptor can cause resistance to TSH

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

Give 2 examples of when a defect in GPCRs leads to upregulated activity?

A
  • Mutations of LH receptor lead to testotoxicosis

- Mutations of TSH can lead to neonatal hyperthyroidism

17
Q

What is the role of Gαs?

A

To activate intracellular signalling pathways in response to activation of GPCRs

18
Q

What can mutations adversely affecting Gαs function lead to?

A
  • Pseudohypoparathyroidism

- When maternally inherited, lead to downregulation of a range of GPCRs

19
Q

What is up-regulation of Gαs associated with?

A

McCune-Albright syndrome

20
Q

What happens to GPCRs in McCune-Albright syndrome?

A

The upregulation of several GPCRs lead to clinical features including;

  • Gonadotrophin-independent precocious puberty (LH receptor)
  • Thyrotoxicosis (TSH receptor)
  • Cushing’s syndrome (ACTH receptor)
  • Hyperpigmented skin lesions
  • Fibrous dysplasia
21
Q

Give 3 examples of steroid hormones?

A
  • Sex steroids
  • Glucocorticoids
  • Aldosterone
22
Q

How do steroid and thyroid hormones enter the cell?

A

They diffuse across the target cell membrane

23
Q

What kind of hormones bind to receptors in the cytoplasm?

A

Glucocorticoids

24
Q

What kind of hormones bind to receptors in the nucleus?

A
  • Androgens

- Thyroxine

25
Q

What is the result of steroid and thyroid hormones binding to receptors inside the cell, rather than the surface?

A

The response takes longer

26
Q

What can happen to some hormones once they are inside the cell?

A

They can be converted to more potent forms, or to weaker forms

27
Q

Give 2 examples of hormones are converted to more potent forms inside the cell

A
  • Testosterone

- T4

28
Q

What is testosterone converted to inside the cell?

A

Dihydrotestosterone

29
Q

What enzyme converts testosterone to dihydrotestosterone?

A

5alpha-reductase

30
Q

What is T4 converted to inside the cell?

A

T3

31
Q

What enzyme converts T4 to T3?

A

5’-deiodinase

32
Q

What hormone may be converted to a weaker form inside the cell?

A

Cortisol

33
Q

In what cells may cortisol be converted to a weaker form?

A

Aldosterone responsive cells in the kidney

34
Q

What may cortisol be converted into inside the cell?

A

Cortisone

35
Q

What enzyme converts cortisol to cortisone?

A

11beta-hydroxysteroid dehydrogenase

36
Q

Why is cortisol converted to it’s weaker metabolite cortisol in the aldosterone responsive cells in the kidney?

A

To avoid over-stimulation of the mineralocorticoid receptor

37
Q

What can defects in the genes that encode intracellular receptors lead to?

A

Hormone resistance, such as;

  • Androgen insensitivity syndrome
  • Glucocorticoid resistance
  • Resistance to thyroid hormone

TAS Endocrinology (6 decks)

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