Endocrinology

Question 1

Where do receptors for peptide hormones lie?

Answer 1

In plasma membrane

Question 2

Where do receptors for steroid hormones lie?

Answer 2

Intracellular

Question 3

Give examples of peptide hormones

Answer 3

• FSH
• Adrenaline
• Insulin

Question 4

Which are bigger, steroid or peptide hormones?

Answer 4

Steroid hormones

Question 5

Are steroid hormones lipid-soluble?

Answer 5

Yes

Question 6

How can receptors be up-regulated?

Answer 6

• Increase in receptors

- Produce more or decrease destruction of receptors

Question 7

How can receptors be down-regulated?

Answer 7

• Decrease in receptors

- Internalise receptors or increase destruction

Question 8

Can hormones affect receptors for other hormones, if yes, give an example?

Answer 8

Yes, oestrogen needs to be present for progesterone in 2nd half of the menstrual cycle

Question 9

What is clomiphene citrate?

Answer 9

Antagonist against oestrogen

Used in treatment for IVF, body produce more oestrogen to compensate

Question 10

Signal transduction results in:

Answer 10

• Receptor enzyme activity
• Activity of JAK kinases associated with the receptor
• G-proteins generate 2nd messengers

Question 11

What can cortisol be used for?

Answer 11

Reducing inflammation

Question 12

What can progesterone be used for?

Answer 12

“Morning after” pill

Question 13

What is the endocrine system coordinated by?

Answer 13

The hypothalamic-hypophyseal axis

Question 14

Where are hormones in the hypothalamus secreted and released from?

Answer 14

Adenohypophysis (anterior)

Neurohypophysis (posterior of pituitary gland)

Question 15

Examples of hormones secreted from the neurohypophysis

Answer 15

Oxytocin and vasopressin

Question 16

Endocrine function of pancreas

Answer 16

Islets of Langerhans
α cells secrete glucagon
ß cells secrete insulin

Question 17

Reaction to form insulin

Answer 17

preproinsulin —> proinsulin —> insulin

cleaved by proteolytic enzymes

Question 18

How is insulin release stimulated?

Answer 18

Increased blood glucose

Increase blood arginine/leucine

Question 19

Which amino acids can stimulate insulin release?

Answer 19

Arginine and leucine

Question 20

What are the two types of diabetes mellitus?

Answer 20

Type 1: insulin-dependent

Type 2: non insulin-dependent

Question 21

Type 1 diabetes

Answer 21

• Lack of insulin from ß cells
• Cells can’t uptake glucose can lead to ketoacidosis
• Polyuria and high glucose levels in urine
• Chronic herperglycaemia and dehydration

Question 22

Type 2 diabetes

Answer 22

• Obese, 40+ years
• More common
• Normal insulin levels but peripheral tissues don’t respond

Question 23

Treatments for type 1 diabetes

Answer 23

Insulin injections

Question 24

Treatments for type 2 diabetes

Answer 24

Weight reduction and metformin (lowers glucose syntheses and release at liver)

Question 25

What is metformin?

Answer 25

Oral hypoglycaemic agent in the biguanide group

Question 26

What does metformin do?

Answer 26

Increase in glucose uptake in muscle, reduces hepatic production of glucose Doesn't cause hypoglycaemia - prevents hyperglycaemia

Question 27

What is diabetes insipidus?

Answer 27

Posterior pituitary gland fails to produce adequate levels of ADH

Question 28

What is the major feature of polycystic ovarian syndrome?

Answer 28

Insulin resistance

Question 29

What is the basal metabolic rate?

Answer 29

Metabolic rate when at mental and physical rest but not sleeping, at comfortable temperature and fasted for at least 12 hours

Question 30

Define metabolic rate

Answer 30

Total body energy expenditure per unit time

Question 31

What does thyroid hormone stimulate?

Answer 31

- Protein stimulates - Increase use of glucose and free fatty acids for ATP production - Increase lipolysis

Question 32

What can too little thyroid hormone(thyroxine) lead to?

Answer 32

- Cretinism | - Myxoedema

Question 33

What can too much thyroid hormone (thyroxine) lead to?

Answer 33

- Graves disease | - Goiter