Endocrine System

Question 1

Lipid-soluble hormone

Answer 1

• binds to transport protein
  bind to receptors within target cell (single step process)
  e.g. steroid hormones & thyroid hormones

Question 2

Water soluble Hormones

Answer 2

• circulate freely in blood
• bind to receptors on he exterior surface of the target cell (two step process that requires ATP)
  e. g. peptide hormone & protein Hormone

Question 3

Possible mechanisms of hormone action:

Answer 3

• synthesis of new molecules
• changing permeability of the cell membrane
• stimulating transport of a substance into or our of the cell
  altering the rate of metabolic actions
  causing contraction of smooth or cardiac muscle

Question 4

How a target cell responds to a hormone is based on:

Answer 4

• the hormone concentration in blood
• the number of hormones in the blood
• influence exerted by other hormones
• some hormone work more effectively when a second hormone is present to assist them (synergistic effect)
• some hormones oppose the action of others (antagonistic effect)

Question 5

control of hormone secretion:

Answer 5

hormone are secreted in small bursts when necessary
secretion is regulated by:
- signals from the nervous system
- chemical changes in the blood
- other hormones
most hormone regulation is achieved via negative feedback a few via positive feedback

Question 6

Hypothalamus & Pituitary Gland

Answer 6

The hypothalamus secretes releasing and inhibiting hormones that control the release of hormone by the pituitary gland