Slides in this set
The Endocrine System
Uses blood circulation to send signal around the body, signals released by the
endocrine system are molecules called hormones.
Two types of glands:
·Consist of groups of cells that produce and release hormones directly into the
·Do not release hormones.
·Has a duct which carries secretion to where it's needed, e.g. salivary glands.…read more
Have specific complementary receptors which binds to the specific hormone,
grouped to form the target tissue.
Two types of hormones:
Protein and peptide hormones e.g. Insulin, glucagon, adrenaline
·They are not phospholipid membrane soluble.
Steroid hormones e.g. Sex hormones
·They are membrane soluble and can enter the cell effecting the DNA in the
The action of adrenaline
Adrenaline amino acid derivative, it causes an effect without entering the cell
Adrenal glands (above the kidneys) divided into:
The adrenal medulla:
·centre of the gland.
·Release adrenaline hormone in response to pain or shock.
·Prepares body for activity, Effects; increase heart rate, relax smooth muscle,
dilate pupils, erect body hair, increase mental awareness etc..
The Adrenal cortex:
·Uses cholesterol to produce steroid hormones
·E.g. Aldosterone controls the conc. of NA and K in the blood.
·E.g. Cortisol controls the metabolism of carbohydrates and proteins in the
1. The adrenaline molecule ( first messenger) binds to the
complementary shape of the adrenaline receptor on the cell surface
membrane. Adrenaline-receptor complex formed.
2. Activates enzyme adenyl cyclase which converts;
cAMP (second messenger) 3. Effects cell by activating enzymes.…read more