Hormones - Introduction

Question 1

Define haemocrine

Answer 1

A chemical messenger secreted by a gland that travels in the blood to a distant target.

Question 2

Define paracrine

Answer 2

A hormone that has an effect only in the vicinity of the gland secreting it e.g a neighbouring cell

Question 3

Define autocirne

Answer 3

A cell produced substance that has an effect on the cell from which it was secreted

Question 4

Define solinocrine

Answer 4

A hormone secreted into the lumen of an organ e.g GI tract, urogenital etc

Question 5

What is ketoacidosis a sign of?

Answer 5

Hyperglycemia therefore diabetes

Question 6

What can cause hypoglycemia?

Answer 6

Insulinoma (tumour on the beta cells of the pancreas)

Question 7

What is thyrotoxicosis?

Answer 7

Excess production of thyroxine

Question 8

What causes an excess production of thyroxine?

Answer 8

Autoimmune activation of the thyroid gland

Question 9

What does excess production of thyroxine do to the body - explain the symptoms.

Answer 9

Sensitises the body to adrenaline, giving symptoms of tachycardia, weight loss, heat intolerance and tremours.

Question 10

What is hypothyroidism?

Answer 10

Lack of production of thyroxine

Question 11

What causes hypothyroidism?

Answer 11

Autoimmune disease where the thyroid is destroyed

Question 12

What does hypothyroidism lead to?

Answer 12

Goitre and weight gain.

Question 13

How do you detect hypothyroidism?

Answer 13

Test TSH and T3 and T4 levels in the blood.
TSH high
T3 and T4 levels low

Question 14

How would you detect thyrotoxicosis?

Answer 14

Test TSH and T3 and T4 levels in the blood.
TSH levels low
T3 and T3 levels high

Question 15

What are steroid hormones synthesised from?

Answer 15

Cholesterol

Question 16

What are the two main steroid hormones produced by the adrenal gland?

Answer 16

Cortisol

Aldosterone

Question 17

What conditions cause the body to release cortisol?

Answer 17

Stress and low blood glucose

Question 18

Where in the adrenal gland is cortisol produced?

Answer 18

Zona fasciculata

Question 19

What type of hormone is cortisol?

Answer 19

Glucocorticoid steroid hormone

Question 20

What type of hormone is aldosterone?

Answer 20

Mineralcorticoid steroid hormone

Question 21

Where in the adrenal gland is aldosterone produced?

Answer 21

Zona glomerulosa

Question 22

What is the main function of aldosterone?

Answer 22

Increase sodium retention in the kidney

Question 23

What type of receptors do aldosterone and cortisol bind to and why?

Answer 23

Intracellular receptors as they are steroid hormones they can diffuse through the cell surface membrane.

Question 24

What causes cushings syndrome?

Answer 24

Overproduction of ACTH or a tumour in the adrenal gland which leads to excessive cortisol production.

Question 25

What are the symptoms of cushings syndrome?

Answer 25

``` Obesity Diabetes due to cortisol raising blood glucose levels Hypertension Thin skin Muscle weakness ```

Question 26

What is Addisons disease and how is it caused?

Answer 26

Hypoadrenalism caused by autoimmune destruction of the adrenal gland.

Question 27

What are the symptoms of Addisons disease?

Answer 27

Weight loss Dizziness Weakened immune system Strange pigmentation of the skin

Question 28

What controls ACTH production?

Answer 28

CRH

Question 29

Where does CRH act?

Answer 29

Corticotrophs in the anterior pituitary

Question 30

What is the leptin feedback loop?

Answer 30

1. Fat cells produce leptin 2. Leptin decrease food intake 3. Less food intake means fat levels decrease 4. Decreased fat levels means less leptin produced 5. Less leptin produced = eat more, fat levels increase

Question 31

Define diurnal

Answer 31

During the day

Question 32

Was is goitre?

Answer 32

Swelling of the neck due to enlargement of the thyroid.