Endocrine system

Question 1

What are the 3 main classes of hormones?

Answer 1

• Peptides
• Amino acid derived
• Steroids

Question 2

How are peptide hormones synthesised?

Answer 2

From amino acids

Question 3

How are amino acid derived hormones synthesised?

Answer 3

• Derivatives of tyrosine

- Requires specific enzymes

Question 4

How are steroid hormones synthesised?

Answer 4

• Metabolites of cholesterol

- Requires specific enzymes

Question 5

How are peptide hormones secreted?

Answer 5

• Dense-core secretory granules

- Exocytosis

Question 6

How are amino acid derived hormones secreted?

Answer 6

• Synaptic vesicles
• Exocytosis
  (Exception for thyroid hormones)

Question 7

What kind of hormone are thyroid hormones?

Answer 7

Amino acid derived

Question 8

How are thyroid hormones secreted?

Answer 8

Facilitated diffusion

Question 9

How are steroid hormones secreted?

Answer 9

Diffusion (lipid soluble)

Question 10

Where are the receptors for peptide hormones?

Answer 10

Cell surface

Question 11

Where are the receptors for amino acid derived hormones?

Answer 11

Cell surface
(Thyroid hormone receptors are intracellular because they travel via facilitated diffusion)

Question 12

Where are the receptors for steroid hormones?

Answer 12

Intracellular

Question 13

Which is the fastest acting class of hormones?

Answer 13

Peptide/(amino acid derived)

Question 14

Which is the slowest acting class of hormones?

Answer 14

Steroids

Question 15

What are the 7 classic endocrine glands?

Answer 15

• Pituitary gland (anterior and posterior)
• Thyroid gland
• Parathyroid glands
• Adrenal glands (cortex and medulla)
• Ovaries
• Testes
• Endocrine pancreas

Question 16

How many parathyroid glands are there?

Answer 16

4

Question 17

What other endocrine tissues are there (not classical glands)? (6)

Answer 17

• Hypothalamus
• Kidneys
• GI tract
• Heart
• Liver
• Adipose tissue

Question 18

Where is the thyroid gland located?

Answer 18

Around the trachea

Question 19

What is the structure of the thyroid tissue?

Answer 19

• Made up of follicles

- Follicles made of follicular cells and contain colloid

Question 20

What do follicles in the thyroid contain?

Answer 20

Colloid

Question 21

Which element do thyroid follicular cells need?

Answer 21

Iodine

Question 22

What is iodine needed for in the thyroid?

Answer 22

To make a prohormone (precursor)

Question 23

Where is prohormone stored?

Answer 23

• Colloid

- Produced by follicular cells

Question 24

How are hormones T3 and T4 secreted?

Answer 24

• Prohormone taken back up into follicular cells and converted into thyroid hormones
• Secreted from follicular cells into interstitial fluid and bloodstream via facilitated diffusion

Question 25

What is hypothyroidism?

Answer 25

Low levels of thyroid hormones

Question 26

Which receptors do thyroid hormones activate?

Answer 26

Nuclear receptors

Question 27

What are the actions of thyroid hormones?

Answer 27

- Regulate transcription via nuclear receptors | - Regulate development, growth and metabolism

Question 28

What kind of hormone is parathyroid hormone?

Answer 28

Peptide

Question 29

Which cells in the parathyroid glands release parathyroid hormone?

Answer 29

Chief cells

Question 30

What are the actions of parathyroid hormone? (3)

Answer 30

- Increases calcium absorption in intestines - Increases calcium reabsorption in kidneys - Increases calcium reabsorption from bones into plasma

Question 31

What are the 3 main targets of parathyroid hormone?

Answer 31

- Intestines - Kidneys - Bones

Question 32

What does parathyroid hormone do?

Answer 32

- Regulates plasma Ca2+ and phosphate | - Negative feedback loop (high Ca2+ causes reduced release of parathyroid hormone)

Question 33

Which type of hormone is released from the adrenal cortex?

Answer 33

Steroid

Question 34

Which types of steroid hormones are released from the adrenal cortex?

Answer 34

- Mineralocorticoids - Glucocorticoids - Androgens

Question 35

What is an example of a mineralocorticoid?

Answer 35

Aldosterone

Question 36

What kind of steroid hormone is aldosterone?

Answer 36

Mineralocorticoid

Question 37

What does aldosterone do?

Answer 37

Regulates Na+ in the bloodstream

Question 38

What is an example of a glucocorticoid?

Answer 38

Cortisol

Question 39

What do glucocorticoids do?

Answer 39

Regulate glucose

Question 40

What kind of steroid hormone is cortisol?

Answer 40

Glucocorticoid

Question 41

What causes release of cortisol?

Answer 41

Stressful situations

Question 42

What does cortisol do?

Answer 42

- Increases blood glucose | - Stimulates chromaffin cells to release adrenaline

Question 43

What is released from the adrenal medulla?

Answer 43

- Adrenaline from chromaffin cells | - Catecholamines (adrenaline, noradrenaline)

Question 44

What does oestrogen do?

Answer 44

Stimulates cellular proliferation of the endometrium

Question 45

What does progesterone do?

Answer 45

Stimulates secretions and maturation of tissues

Question 46

Which cells in the testes produce testosterone?

Answer 46

Leydig cells

Question 47

What kind of hormone are oestrogen, progesterone and testosterone?

Answer 47

Steroid

Question 48

What does testosterone do?

Answer 48

Stimulates protein synthesis

Question 49

What is the exocrine pancreas?

Answer 49

Secretes digestive enzymes

Question 50

What is the endocrine pancreas?

Answer 50

Secretes insulin and glucagon (hormones)

Question 51

Which cells release insulin?

Answer 51

Beta cells

Question 52

Which cells release glucagon?

Answer 52

Alpha cells

Question 53

Where are alpha and beta cells located?

Answer 53

In Islets of Langerhans in the pancreas

Question 54

What is a portal blood system?

Answer 54

- When a blood vessel to one organ goes straight onto another organ without returning to the heart/lungs first - Carrying deoxygenated blood

Question 55

How do insulin and glucagon travel to the liver?

Answer 55

Via a portal blood system

Question 56

Which organ is the target of insulin and glucagon?

Answer 56

Liver

Question 57

What is the adenohypophysis?

Answer 57

Anterior lobe of the pituitary gland

Question 58

What is the neurohypophysis?

Answer 58

Posterior lobe of the pituitary gland

Question 59

Where does the adenohypophysis develop from?

Answer 59

Upward projection of the pharynx

Question 60

Where does the neurohypophysis develop from?

Answer 60

Downward projection of the brain

Question 61

What are the 2 sections of the pituitary gland?

Answer 61

- Adenohypophysis | - Neurohypophysis

Question 62

What does the adenohypophysis do?

Answer 62

- Receives releasing hormones from small diameter neurones of the hypothalamus - Stimulates Troph cells to release hormones which enter the circulation

Question 63

What are the cells in the adenohypophysis called?

Answer 63

Troph cells

Question 64

What does the neurohypophysis do?

Answer 64

- Receives hormones from large diameter neurones of the hypothalamus - Releases the hormones directly into systemic circulation

Question 65

Which 2 main hormones are released by the neurohypophysis?

Answer 65

- ADH (vasopressin) | - Oxytocin

Question 66

Which hormones are released from the adenohypophysis as a result of Releasing Hormones?

Answer 66

- Growth hormone - Prolactin Trophic hormones: - Adrenocorticotrophic hormone - Thyroid stimulating hormone - Gonadotrophic hormones

Question 67

What does adrenocorticotrophic hormone do?

Answer 67

Stimulates adrenal cortex to release cortisol

Question 68

What does thyroid stimulating hormone do?

Answer 68

Stimulates the thyroid gland to release thyroid hormones

Question 69

What are gonadotrophic hormones? (2)

Answer 69

- LH | - FSH