Endocrine 1

Question 1

what glands/organs make up the endocrine system?

Answer 1

• hypothalamus
• pituitary gland
• pineal gland
• thyroid gland
• parathyroid gland
• adrenal gland (on top of the kidneys)
• testes (male)
• ovaries (female)
• pancreas
• thymus
• stomach
• kidneys
• liver

Question 2

what endocrine gland is the control centre for the release of many other hormones (central coordintating hub for the endocrine system)

Answer 2

• hypothalamus

Question 3

explain how hypothalamus pituitary axis (negative feedback loop) works using low levels of thyroid hormone as an example

Answer 3

• the hypothalamus detects low levels of the thyroid hormone in the blood stream , it secretes TRH (thyrotropin releasing hormone)
• TRH stimulates the anterior pituitary gland to secrete thyroid stimulating hormone (TSH)
• TSH then binds to receptors on the thyroid gland, stimulating the increase secretion of T3 and T4
• when levels return to normal, this signals to the hypothalamus and the anterior pituitary gland to stop production of TRH and TSH

Question 4

Endocrine dysfunction can be divided into primary and secondary dysfunction: what is primary?

Answer 4

Dysfunction in the secreting gland
(hypothalamus and anterior pituitary functioning normally)
resulting in either:
- over production (autoimmune disease, exocrine gland tumours)
- underproduction (autoimmune disease, drug SE)

Question 5

Endocrine dysfunction can be divided into primary and secondary dysfunction: what is secondary?

Answer 5

secondary dysfunction is failure of the HP control (either the hypothalamus or the anterior pituitary), target endocrine gland is functionally normally
examples
- pituitary tumours (excessive stimulating hormone production)
- hypothalamic dysfunction (brain tumours, previous brain surgery, radiotherapy, traumatic brain injuries, congenital disorder)

Question 6

what are the 2 types of pituitary hormones?

Answer 6

functional - tumour promotes secretion of an active hormone
non-functional - consists of tissue that has no hormone secreting ability, but if they groow large enough they can create a pressure effect on the pituitary gland or tissue, which can prevent production of stimulating hormones

Question 7

what is an adenoma?

Answer 7

a tumour of epithelial tissue with glandular origin

Question 8

what surgery approach is taken to remove tumours from the pituitary gland?

Answer 8

trans-sphenoidal approach
- access through nasal passage to sphenoid sinus

Question 9

What regulates the release of growth hormone (GH)

Answer 9

the hypothalamus releases GHRH which stimulates the pituitary gland to release GH