endocrine system

Question 1

Endocrine system=

Answer 1

transports hormones via the bloodstream to mast cells of the body.
Regulated through negative feedback mechanisms

Question 2

Main endocrine glands=

Answer 2

• hypothalamus
• pineal
• thyroid
• pituitary
• parathyroid
• thymus
• adrenals
  -islets of langherns

Question 3

Hypothalamus=

Answer 3

Sits between the cerebrum and brainstem. It regulates:
- temperature
- fluid volume
- growth
- pain and pleasure response
- hunger and thirst

Question 4

Anterior pituitary gland produces=

Answer 4

• growth hormones: promotes growth of bone and muscle
• prolactin: stimulates lactation
• stimulating hormones: TSH (thyroid hormones), FSH (gametes), LH (sex hormones), ACTH (steroid hormones-cortisol)

Question 5

What/ where is the pituitary gland and what does it produce produces=

Answer 5

It sits beneath the hypothalamus and is termed the ‘master’ gland. Is divided into:
- Anterior pituitary gland
- Posterior pituitary gland

Question 6

what do kidneys produce?

Answer 6

dihydroxyvitamin D (stimulated calcium absorption)
Renin (activates the renin-angiotensin system
Erythropoietin (increases red blood cell production)

Question 7

What do ovaries produce?

Answer 7

Estrogen
Progesterone (important in menstrual cycle, maintains pregnancy).

Question 8

What do testes produce?

Answer 8

testosterone (sperm production)

Question 9

What does the thymus produce?

Answer 9

thymosin and thymopoietin

Question 10

What does the adrenal cortex produce?

Answer 10

aldosterone, cortisol and adrenal androgens

Question 11

Adrenal medulla=

Answer 11

In charge of the production of 2 hormones:
- norepinephrine
- epinephrine
These serve as neurotransmitters for sympathetic system and involved in stress response.

Question 12

What are the two major functions of the pancreas?

Answer 12

digestive enzymes and release if two hormones: insulin and glucagon

Question 13

What are the posterior pituitary hormones?

Answer 13

• ADH: acts on kidney and reduces urine output
• Oxytocin: acts on uterus/ breast for milk release

Question 14

What does the thyroid gland produce?

Answer 14

• Produces thyroid hormones (T3 & T4) and calcitonin.
  The hormones: Increase metabolic rate, increase heat production and regulate metabolism.
  Calcitonin: lowers blood Ca2+.
  To produce these, the thyroid needs iodine from blood.

Question 15

What is the parathyroid gland?

Answer 15

• four pea-sized endocrine glands that are embedded within the back side of your thyroid.
• Cells secrete parathyroid hormone
• PTH increases blood calcium levels

Question 16

What do the adrenal gland’s have?

Answer 16

• Capsule
• Cortex
• Medulla
  There are three sections of the adrenal gland hormone: Zona glomerulosa (produces aldosterone), Zona fassiculata (produces glucocorticoids) and Zona reticularis (produces adrenal sex hormones)

Question 17

What is the action of the adrenal hormone cortisol (glucocorticoids) ?

Answer 17

• Regulates metabolism & stress response, raises blood sugar, anti–inflammatory actions and immune suppression.

Question 18

What is the action of the adrenal hormone aldosterone?

Answer 18

Maintains salt/ water balance, acts on kidneys to retain water, regulates blood volume and Bp.

Question 19

Explain aldosterone release (renin- angiotensin-aldosterone mechanism)

Answer 19

1. When Bp falls, kidneys release renin Into bloodstream
2. Renin splits angiotensinogen into pieces I and II.
3. Angiotensinogen I is released first but is inactive, angiotensin II is released next and is an active hormone.
4. Angiotensinogen II causes vasoconstriction of arteries and for adrenal glands to release aldosterone & pituitary gland to release ADH.
5. Aldosterone and ADH cause kidneys to retain sodium- causing salt/ water retention. This increases blood volume and blood pressure.
6. Bp then rises

Question 20

Pancreas=

Answer 20

Located behind stomach between spleen & duodenum.
There are two major functions: digestive enzymes and release of two hormones= insulin and glucagon.
The pancreatic cell islet of lngerhans produces these hormones.

Question 21

What is the homeostatic response to blood glucose levels?

Answer 21

Imbalance- rising blood glucose levels
1. Pancreas will detect levels
2. Pancreas will release insulin
3. This stimulates glycagen formation and glucose uptake by cells
4. Blood glucose falls to the normal range

Question 22

What are the hypothalamus hormones?

Answer 22

They are releasing and inhibiting hormones:
- Corticotropin (releasing)
- Thyrotropin (releasing)
- Growth hormone (releasing)
- Gonadotropin (releasing)
- Somatostatin (inhibits GH and TSH)

Question 23

Pineal gland=

Answer 23

-secretes melatonin
- Role in sleep/ wake cycles, body temperature and sleep
- Ageing and fertility

Question 24

Thyroid gland=

Answer 24

• Produces thyroid hormone & calcitonin
• Takes up iodine from blood
• Thyroid hormones: increase metabolic rate, increase heat production, regulate metabolism
• Calcitonin is a hormone produced, this lowers blood Ca2+

Question 25

Cells of the thyroid=

Answer 25

- follicular cells which excrete triiodothyronine and thyroxine= this increases metabolic rate, heat production and regulates metabolism of nutrients - Thyroid C cells= calcitonin, which lowers blood calcium and phosphate levels

Question 26

What is the role of adrenal androgens?

Answer 26

- Secrete two hormones: epinephrine and norepinephrine. - Serve as neurotransmitters for sympathetic system - Involved in the stress response - Is converted into testosterone in the periphery

Question 27

Pancreatic tissue=

Answer 27

Almost all of the pancreas consists of exocrine tissue that produces pancreatic enzymes for digestion. The remaining tissue consists of endocrine cells called islets of Langerhans. These clusters of cells look like grapes and produce hormones that regulate blood sugar and regulate pancreatic secretions.

Question 28

Insulin=

Answer 28

Is a hormone that the pancreas makes that's essential for allowing your body to use sugar (glucose) for energy. If your pancreas doesn't make enough insulin or your body doesn't use insulin properly, it leads to high blood sugar levels (hyperglycemia).