Feedback, regulation and hormones

Question 1

Glands

Two types

Answer 1

1. Exocrine glands (outside)
   - secrete products into ducts e.g. sweat,, digestion
2. Endocrine Gland (inside)
   - secrete hormones into the blood e.g. insulin

Question 2

Regulation of calcium blood levels

Answer 2

high or low blood levels of ca2+ stimulate the release of different hormones

• parathyroid hormone or calcitonin

Question 3

blood glucose regulation

Answer 3

regulation of glucagon and insulin secretion is via negative feedback mechanisms which do not involve the hypothalamus or pituitary gland

• low blood glucose stimulates release of glucagon
• high blood glucose stimulates secretion of insulin

Question 4

hormones

Answer 4

travel in the blood throughout the body

2. affect only specific target cells
3. target cells have specific receptors to which hormones bind
4. receptors are constantly being synthesised and broken down

Question 5

when a hormone

Answer 5

is excess
-regulation (a decrease in the number of receptors may occur)
is deficient
- op-regulation (an increase in the number of receptors) may occur

Question 6

anterior pituitary gland

Answer 6

hormones secreted by the hypothalamus travel through the hypophyseal portal veins

Question 7

blood calcium

Answer 7

directly controls the secretion of calcitonin and parathyroid hormone via negative feedback loops that do not involve the hypothalamus or the pituitary gland

Question 8

positive feedback

Answer 8

a response increases or enhances the original stimulus, contractions, during labour

Question 9

feedback loop components

Answer 9

receptor
- monitors changes in a controlled condition
control center
- analyse and determines next action
effector
- receives directions from the control centre
- produces a response that changes the controlled condition

Question 10

negative feedback

Answer 10

a response reverses or eliminates the original stimulus

deceases: blood glucose levels, blood calcium levels and metabolic rate

Question 11

anterior pituitary gland

Answer 11

hormones secreted by the hypothalamus travel through the hypophyseal portal veins
- stimulates the release of anterior pituitary hormones

Question 12

hypothalamus and pituitary gland

Answer 12

the hypothalamus and the pituitary gland regulate virtually all aspects of growth, development, metabolism and homeostasis