Principles of Endocrinology Flashcards

1
Q

Define Hormone.

A

A hormone is a substance that is released into the blood in response to a specific stimulus, and acts at a distant target tissue, where it exerts its specific effects.

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

What are endocrine substances?

A

Substances released from a gland that act at a remote target tissue.

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

What are paracrine substances?

A

Substances released from a gland cell that act on cells in the same gland.

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

What are autocrine substances?

A

Substances released from a gland that act back on the same gland.

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

What are the 4 kinds of hormones?

A

Protein/Peptide, Steroids, Amine hormones, Eicosanoids.

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

What are peptide/protein hormones? What are they made from? Where do they have receptors? How do they circulate? Does it exhibit species variation? Example?

A

Protein hormones are synthesized from AA. They vary in size and exhibit species differences. They have extracellular receptors as they are not lipid soluble. Usually circulate not bound. e.g. Insulin.

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

What are steroid hormones? What are they made from? Where do they have receptors? How do they circulate? Does it exhibit species variation?

A

Steroid hormones are made from Cholesterol. They have intracellular receptors, and circulate usually bound to a protein. Usually do not exhibit species differences. Slow acting.

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

What are the 4 kinds of steroid hormones? Examples?

A

Corticosteroids (C21), Progesterone (C21), Testosterone (C19), Oestrogens (C18)

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

What are amine hormones? How can they be separated?

A

Amine hormones are hormones derived from Tyrosine or Tryptophan. Catecholamines and Thyroid hormones are made from Tyrosine. Indoleamines are made from Tryptophan.

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

What are Indoleamines hormones? What are they made from? Where do they have receptors? How do they circulate? Does it exhibit species variation? Example?

A

Indoleamines are made from Tryptophan. They are not lipid soluble, and so have extracellular receptors. No species variation. E.g. Serotonin, Melatonin.

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

What are Catecholamines hormones? What are they made from? Where do they have receptors? How do they circulate? Does it exhibit species variation? Example?

A

Catecholamines are made from Tyrosine. They are not lipid soluble, and so have extracellular receptors. They do not exhibit species variation. e.g. Adrenaline, Noradrenaline, Dopamine.

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

What are Thyroid hormones? What are they made from? Where do they have receptors? How do they circulate? Does it exhibit species variation? Example?

A

Thyroid hormones are made from Tyrosine. They have intracellular receptors, and usually circulate bound. No species variation. e.g. Triiodotyrosine (T3), Thyroxine (T4)

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

What are Eicosanoids hormones? What are they made from? Where do they have receptors? How do they circulate? Does it exhibit species variation? Example?

A

Eicosanoids are derived from Arachadonic acid in the plasma membrane. They act locally, as they have a short half life. Interact with plasma membrane receptors. No species variation. E.g. Prostaglandins, Leukotrienes.

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

What kind of receptors do prolactin and Growth hormone use? How do these work?

A

JAK-STAT. Receptor ligand complex recruits second receptor. Dimerised receptor activates JAK. JAK phosphorylates STAT.

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

How does the secretion of Protein and Steroid hormones differ?

A

Protein hormones are usually stored in vesicles. Steroid hormones are usually secreted as and when they are needed.

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

How does phospholipase affect Eicosanoids? How do glucocorticoids affect PLA?

A

PLA catalyses Phospholipid to Arachadonic acid. Glucocorticoids block PLA synthesis.

17
Q

What two enzymes convert arachadonic acid to a) Protaglandins and B) Leukotrienes?

A

A) Cyclooxygenase.

B) 5-lipooxygenase

18
Q

What important hormones are made by the Hypothalamus? (7) Can they be categorised?

A

Releasing hormones: GHRH, CRH, TRH, GnRH, Vasopressin. Inhibitory hormones: Somatostatin, Dopamine.

19
Q

What important hormones are released by the Posterior pituitary?

A

Oxytocin, Vasopressin.

20
Q

What important hormones are released by the anterior pituitary? (7)

A

GH, ACTH, MSH, TSH, LH, FSH, Prolactin.

21
Q

What important hormones are released by the Thyroid gland?

A

T3, T4, Calcitonin

22
Q

What important hormone is released by the Parathyroid gland?

A

Parathyroid hormone.

23
Q

What important hormones are released by the adrenal glands?

A

Medulla: Adrenaline, Noradrenaline.
Cortex: Cortisol, Aldosterone, Adrenal Androgens.

24
Q

What important hormones are released by the Endocrine pancreas?

A

Insulin and Glucagon.