Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Phase 2a Medicine (JH) > Endocrinology > Flashcards

Endocrinology Flashcards

1
Q

Endocrinology is the study of what four things?

A
  1. Hormones and their respective glands.
  2. Their receptors.
  3. Intracellular signalling pathway.
  4. Associated diseases.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How are endocrine glands different to exocrine glands?

A

Endocrine glands are ductless so release hormones directly into the blood. Exocrine glands pour secretions through a duct.

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

Give four important physiological characteristics that endocrine glands are responsible for.

A

Rapid adaptive changes.
Integration of whole body physiology.
Chronic maintenance of metabolic environment.
Communication for multicellular organisms.

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

Give three examples of an exocrine gland.

A

Submandibular glands.
Parotid.
Pancreas.

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

Endocrine hormones have effects where in relation to their release?

A

Distant sites.

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

Paracrine hormones have effects where in relation to their release?

A

Neighbouring cells.

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

Autocrine hormones have effects where in relation to their release?

A

The same cell.

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

Give three characteristics of water-soluble hormones.

A

Transported unbound.
Bind to surface receptor of cells.
Short half-life.

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

Give three characteristics of fat-soluble hormones.

A

Transported bound.
Diffuse into cells.
Long half-life.

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

Give three characteristics of peptide hormones.

A

Stored in secretory granules.
Released in pulses/bursts.
Created by tissue/circulating enzymes.

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

Describe the conversion involved in the synthesis of peptide hormones.

A

Preprohormone to prohormone.

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

Describe the conversion involved in the packaging of peptide hormones.

A

Prohormone to hormone.

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

Give an example of a peptide hormone.

A

Insulin.

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

Name the amino acid that catecholamines are derived from.

A

L-tyrosine.

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

L-tyrosine can be derived from dietary sources or synthesis from which compound?

A

Phenylalanine.

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

Describe the steps involved in the conversion of phenylalanine to adrenaline/epinephrin.

A 
Phenylalanine. 
L-tyrosine. 
L-DOPA. 
Dopamine. 
Noradrenaline/norepinephrine. 
Adrenaline/epinephrine.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is COMT?

A

Catechol-O-methyl transferase.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

COMT converts adrenaline and noradrenaline to what?

A

Metanephrine and normetanephrine respectively.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Why are metanephrine and normetanephrine useful compounds?

A

They can be measured in the serum so can be used as indicators or adrenaline and noradrenaline activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Amines bind to which receptors?

A

Alpha receptors or beta receptors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Give four possible effects when an amine binds to an alpha receptor.

A

Vasoconstriction.
Bowel muscle contraction.
Sweating.
Anxiety.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Give four possible effects when an amine binds to a beta receptor.

A

Vasodilation.
Increase in heart rate.
Increase in heart contractility.
Relaxation of bronchial smooth muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Why must iodothyronines be bound to a protein?

A

They aren’t water soluble.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Name the protein that 99% of iodothyronines are bound to?

A

Thyroid-binding globulin (TBG).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Give the full name of hormones T3 and T4.
Triiodothyronine (T3). | Thyroxine (T4).
26
How many molecules of iodine is bound to thyroxine in thyroxine?
Four.
27
Explain why T4 is a reservoir for T3.
T4 can be converted to T3 under the action of deiodinases.
28
How is the activity and concentration of T3 and T4 different?
T3 is more active. | T4 is more produced.
29
What is the primary feature of thyroid microanatomy?
Follicles.
30
Describe the structure of thyroid follicles.
A protein-rich core of colloid surrounded by follicular cells.
31
Describe how follicular cells trap iodide.
By actively cotransporting iodide with Na+ across its basolateral membrane.
32
Colloid contains large amounts of which protein?
Thyroglobulin.
33
Thyroglobulin is produced by which cells?
Follicular cells.
34
Iodide is transported into the colloid where it undergoes what change?
Rapid oxidisation to iodine.
35
Newly formed iodine in the colloid binds to what?
Tyrosine residues.
36
Where are tyrosine residues found?
On thyroglobulin molecules.
37
Iodine binds to tyrosine residues under the action of which enzyme?
Thyroid peroxidase.
38
Which two compounds can be formed from the binding of iodine to tyrosine residues?
Monoiodotyrosine (T1). | Diiodotyrosine (T2).
39
What must happen before T1/T2 join with T2 to produce thyroid hormone?
T2 and T1 must be cleaved from their tyrosine backbones, but remain attached to thyroglobulin.
40
How are thyroid hormones transported out of the colloid during secretion?
Follicular cells engulf the colloid by endocytosis.
41
How are T3 and T4 released from thyroglobulin during secretion?
Proteolysis of thyroglobulin by lysosomes.
42
Describe the solubility of vitamin D.
Fat-soluble.
43
Vitamin D is transported by which protein?
Vitamin D binding protein.
44
Give four examples of adrenocortical and gonadal steroids that bind to cytoplasm receptors to bring about an effect.
Cortisol. Aldosterone. Progesterone. Testosterone.
45
How do hormones that bind to cytoplasm receptors stimulate transcription?
The receptor-hormone complex enters the nucleus and bind to the glucocorticoid response element.
46
Name three types of hormone secretion.
Continuous release. Pulsatile. Circadian rhythm.
47
Growth hormone and GHRH are inhibited by what?
Somatostatin.
48
What is the function of glucose?
Energy source.
49
Why is the brain solely dependent on glucose for energy?
Free fatty acids cannot cross the blood-brain barrier.
50
How does the brain differ from other tissues in its glucose uptake?
Does not depend on insulin.
51
Name the two hormones involved in the regulation of blood glucose concentration.
Insulin and glucagon.
52
What should blood glucose levels be under normal conditions?
3.5-8mmol/L.
53
Insulin is produced by which cells?
Beta cells.
54
What is the function of insulin?
To reduce blood glucose concentration.
55
Describe how insulin functions to reduce blood glucose concentration?
Insulin binds to insulin receptors which causes glucose transporter-containing vesicles to fuse with the membrane of cells and allow glucose to enter.
56
Name the glucose transporter that is promoted by insulin.
GLUT-4.
57
Glucose enters cells via GLUT-4 transport proteins by what process?
Facilitated diffusion.
58
Insulin is coded for on which chromosome?
Chromosome 11.
59
Describe the process involved in the production of insulin.
Proinsulin (insulin precursor) is cleaved from its c-peptide and the alpha and beta chains of insulin are joined together. Insulin is packaged into secretory granules.
60
Describe how insulin acts in the liver to reduce blood glucose concentration.
Insulin promotes the conversion of glucose to glycogen and inhibits the production of glucose by gluconeogenesis.
61
What is the action of insulin when maximum glucose storage is reached?
Insulin promotes glycolysis and the production of pyruvate, which can be converted to fatty acids and stored in adipose tissue.
62
Give examples of stimulatory factors for insulin secretion.
Glucagon and cortisol. Increased fatty acid or amino acid concentration. Acetylcholine.
63
Describe how glucagon and cortisol stimulate insulin secretion.
The stimulatory effect of glucagon and cortisol is indirect by increasing glucose levels.
64
Describe why acetylcholine is a good stimulatory factor for insulin secretion.
Acetylcholine is released from activation of the parasympathetic nervous system during digestion to reduce the concentration of recently absorbed glucose.
65
Give to inhibitory factors of insulin secretion.
Norepinephrine and somatostatin.
66
Describe why norepinephrine is a good inhibitory factor for insulin secretion.
Norepinephrine is released from the activation of the sympathetic nervous system during stressful situations when readily available glucose is needed.
67
Glucagon is produced by which cells?
The alpha cells of the pancreas.
68
What is the function of glucagon?
To increase blood glucose concentration when fasting or during physical activity.

Phase 2a Medicine (JH) (7 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions