Endocrine Glands

Question 1

What are the functions of the hypothalamus

Answer 1

• thermoregulation
• hormone secretion
• circadian rhythms
• motivation
• emotions

Question 2

What are the two pituitary glands called

Answer 2

The posterior and anterior pituitary gland

Question 3

What connects the two pituitary glands

Answer 3

The infundibulum

Question 4

Describe the role of the pituitary glands in thermoregulation

Answer 4

Thermoreceptors in the hypothalamus compare the body temperature to a set point and act accordingly to reach the set point

Question 5

What is a circadian rhythm

Answer 5

One example is Body temperature follows a circadian rhythm over 24hours

Question 6

When does temperature peak

Answer 6

After meals

Question 7

What can affect the circadian rhythm of body temperature

Answer 7

Night shifts

Question 8

Describe how hormone secretion is triggered from the anterior pituitary gland

Answer 8

• hypothalamus produces releasing hormones, these pass to the anterior pituitary via blood vessels which triggers the secretion of hormones from the anterior pituitary

Question 9

Describe hormones produced in the posterior pituitary gland

Answer 9

Hormones produced in hypothalamus pass to posterior pituitary along nerve axons, released into circulation in posterior pituitary

Question 10

What hormones are produced by the hypothalamus

Answer 10

• corticotropin releasing hormone
• gonadotropin releasing hormone
• thyrotropin releasing hormone
• growth hormone releasing hormone
• somatostatin
• prolactin releasing hormone
• dopamine

Question 11

What are the anterior pituitary hormones

Answer 11

• adrenocorticotropic hormone
• follicle stimulating hormone
• luteinising hormone
• thyroid stimulating hormone
• growth hormone
• prolactin

Question 12

Describe the regulation by feedback on hormone secretion by the hypothalamus

Answer 12

Hormones are released by the hypothalamus when a stimulus occurs, the target organ will then produce a hormone that can inhibit the hypothalamus and stop the releasing hormone secretion

Question 13

Describe how thyroid hormones are stimulated

Answer 13

A stimulus causes the hypothalamus to produce thyrotropin RH which in turn stimulates the anterior pituitary gland to produce thyroid stimulating hormone hence acting on the thyroid gland and release in thyroid hormones

Question 14

Where is the thyroid gland

Answer 14

Situated in the neck anterior to the trachea

Question 15

What hormones are produced by the thyroid gland

Answer 15

• thyroid hormone
• T3, T4
• calcitonin (regulates calcium levels)

Question 16

What cells produce calcitonin

Answer 16

Para follicular c cells

Question 17

What are the functions of hormones T3 and T4

Answer 17

• increases metabolic rate of all cells
• determines basal metabolic rate
• essential for normal fetal and childhood rate
• permissive effect on action of adrenaline by upregulating adrenoreceptors

Question 18

What can undersecretion of thyroid hormones cause

Answer 18

• hypothyroidism
• cretinism, myoedema

Question 19

What can oversecretion of thyroid hormone cause

Answer 19

• hyperthyroidism
• Graves’ disease

Question 20

What is goitre

Answer 20

Thyroid swelling associated with iodine deficiency, low levels of thyroxine result in increased secretion of TSH

Question 21

Where are the parathyroid hormones situated

Answer 21

The 4-5 parathyroid gland lie on the deep surface of the thyroid gland
They produce parathyroid hormone which is involved in regulation of blood calcium levels

Question 22

What hormones does the islets of langerhans in the pancreas produce

Answer 22

• insulin
• glucagon
• somatostatin

Question 23

How much of the pancreas is occupied by the islets of langerhans

Answer 23

Occupy 1-2% of pancreatic tissue

Question 24

When is insulin produced

Answer 24

Released in response to raised blood glucose, acts to lower blood glucose

Facilitates glucose entry into -
- muscle cells
Promotes formation of -
- glycogen
- triglycerides
- facilitates protein synthesis

Question 25

What does insulin inhibit

Answer 25

The secretion of adrenaline, sympathetic nerves, somatostatin

Question 26

When is glucagon produced

Answer 26

In response to low blood glucose concentration, acts to raise blood glucose

Question 27

What are the actions of glucagon

Answer 27

Glycogenolysis in liver Glucogenesis in liver Lipolysis and ketone synthesis

Question 28

Where are the adrenal glands located

Answer 28

They lie on top of the kidneys

Question 29

What cortex hormones do adrenal glands produce

Answer 29

- aldosterone - cortisol - androgens

Question 30

What are the actions of cortisol

Answer 30

- metabolic effects - permissive effects - anti-inflammatory, immunosuppressant

Question 31

What are the functions of aldosterone

Answer 31

Promotes re absorption of Na+ and H2O in kidney Increases excretion of H+ and K+

Question 32

Describe androgens

Answer 32

The main hormones are androgens which contributes to growth and 2 percent of sexual characteristics in boys and girls Pubertal growth spurts

Question 33

Describe the adrenal medulla

Answer 33

This is a modified sympathetic ganglion Controlled by pre ganglionic sympathetic nerves The cells mostly produce adrenaline

Question 34

What can adrenal insufficiency lead to

Answer 34

Addison’s disease, decreased adrenal function and reduced levels of adrenal hormones