Anatomy and function of the organs of the endocrine system

Question 1

where does the nervous and endocrine system interact?

Answer 1

Pituitary Gland and Hypothalamus

Question 2

what does the hypothalamus regulate?

Answer 2

Hypothalamus regulates

secretions of anterior pituitary

Question 3

what is an extension of the hypothalamus?

Answer 3

Posterior pituitary is an
extension of the
hypothalamus

Question 4

anterior pituitary produces nine major hormones that…

Answer 4

◦ Regulate body functions

◦ Regulate the secretions
of other endocrine glands

Question 5

examples of hormones the anterior pituitary produces?

Answer 5

 Leptin secreted by adipose tissue (endocrine organ)

 Leptin acts to stimulate satiety and inhibit hunger

 Leptin binds to receptors on hypothalamus, inhibiting feeding behaviour

Question 6

anterior pituitary gland: Growth hormone influences what and is secretion is controlled through what?

Answer 6

 Influences growth of all
tissues

 Secretion controlled through hypothalamus

Question 7

what are the actions of growth hormone?

Answer 7

 Actions:

◦ Increases tissue uptake of amino acids

◦ Synthesises new protein

◦ Stimulates long bone growth

Question 8

growth hormone spares what and mobilises what?

Answer 8

 Spares plasma glucose and mobilises fatty acids

Question 9

posterior pituitary gland-Antidiuretic Hormone (ADH) does what?

Answer 9

 Reduces water loss

Question 10

Antidiuretic hormone is stimulated through what?

Answer 10

 Stimulated through low water concentration (osmoreceptors in hypothalamus) or low plasma volume (stretch receptors in right atria)

Question 11

Antidiuretic hormone during exercise does what?

Answer 11

 During exercise, plasma volume will decrease and

osmolality increases

Question 12

Antidiuretic hormone during exercise above 60% max will increase ADH to do what?

Answer 12

 Exercise above 60 % max will show increased ADH to maintain plasma volume.

Question 13

Thyroid has what?

Answer 13

◦ T3 and T4 (metabolic rate or presence of themselves, inhibitory to their presence)
◦ Calcitonin (controls calcium level in blood)

Question 14

Parathyroid releases what?

Answer 14

◦ PTH

Question 15

what does PTH do? Effects of PTH on Bone

Answer 15

inhibits osteoblasts

stimulates osteoclasts

bone is broken down, releasing calcium ions into bloodstream

Question 16

what does PTH do? Effects of PTH on kidneys

Answer 16

PTH stimulates kidney tubule cells to recover waste calcium from the urine.

PTH stimulated kidneys tubule cells and releases calcitonin

Question 17

what does PTH do? Effect of Calcitonin on intestine

Answer 17

stimulates intestines to absorb calcium from digesting food

Question 18

Calcitonin release does what?

Answer 18

High concentrations of calcium stimulate parafollicular cells in the thyroid to release calcitonin

Question 19

what are the effects of Calcitonin on bone?

Answer 19

stimulates osteoblasts

inhibits osteoclasts

calcium is removed from blood and used to build bone.

Question 20

Adrenal Glands-Adrenal Medulla, what are Epinephrine and Norepinephrine used for?

Answer 20

used to be called adrenalin

◦ ↑ metabolic rate
◦ ↑ rate and force of heart contraction
◦ ↑ blood pressure
◦ ↑ muscle blood flow
◦ maintain plasma glucose concentration

Question 21

what is the Adrenal Medulla?

Answer 21

 The adrenal medulla is part of the sympathetic
nervous system so hormones released from it
affect a large number of systems

Question 22

what is the Adrenal Cortex?

Answer 22

 Secretes over 30 different steroid hormones -
corticosteroids such as:

◦ Mineralocorticoids (e.g. aldosterone)

◦ Glucocorticoids (e.g. cortisol)

◦ Gonadocorticoids (e.g. androgens and oestrogens)

Question 23

what is Cortisol?

Answer 23

• Maintains plasma glucose during fasting and exercise
• Makes amino acids available for tissue repair
• Released in response to hypoglycaemia, exercise and stress

Question 24

Pancreas-insulin does what?

Answer 24

 Stimulates uptake of nutrients and storage of
glycogen, proteins and fats

 Facilitates glucose diffusion across membranes

 A lack of insulin can cause glucose to be lost in urine
(diabetes mellitus)

 Insulin secretion is influenced by blood glucose
concentrations

Question 25

Pancreas-Glucagon is what?

Answer 25

 Stimulates mobilisation of glucose and fatty acids

 Increased secretion in response to low plasma
glucose concentration

Question 26

Testes and Ovaries-Testosterone is what?

Answer 26

 Both anabolic (tissue building) and androgenic
(promoter of masculinity)

 Key hormone responsible for muscle growth

 Primary parameter to assess anabolic status of
the body

Question 27

what are the effects of testosterone?

Answer 27

 Effects of Testosterone:

◦ Influence protein synthesis

◦ Mineralisation of skeleton

◦ Growth plate maturation and function