Hormonal control - The adrenal gland

what are hormones ?

Hormones are primary massagers. They travel in the blood and release by glands. They act on target cells.  

what are the 2 types of hormones ?

steroids hormones or non-steroids hormones.  

example of Steroids hormones

Steroids hormones E.g. Oestrogen & testosterone are structurally based on and similar to cholesterol.  

example of Non- Steroids hormones

proteins.  

The Adrenal gland 

where is the adrenal gland placed ? 

The Adrenal gland located on top of the kidney.

what are the 2 areas of the adrenal gland 

2 areas of the adrenal gland; adrenal cortex – adrenal medulla 

 

what does the adrenal cortex do ? 

The cortex releases the hormone cortisol  

what does the adrenal medulla do ? 

The medulla releases the hormone adrenaline (ST flight or fight)  

what is the functions of Cortisol (glucocorticoid) ?

• Controls metabolism of carbohydrates, fats and proteins in the liver.  

• Released in the response or low BGL. Blood glucose 

• Stimulates glycogenolysis. Splitting of glycogen to release glucose.  

what is the functions of Mineralocorticoids ?

• E.g. aldosterone  

• Release from the adrenal cortex.  

• Helps to control Na+ and K+ concentrations in the blood.  

• Acts as cells of the DCT to increase absorption of Na+ and decrease absorption of K+.  

• In turn, this contributes to maintain blood pressure. 

 

what is the functions of Adrenaline   

 

• Release from the adrenal medulla.  

• Polar molecules made from the amino acids' tyrosine.  

• Travels easily in the blood and acts on many cell types.  

• Target cells express a receptor glycoprotein on the cell surface and a response a generated via a second messenger pathway.  

 

what are the actions of adrenaline ?

 

• Increase heart rate. 

• Increase stroke volume of the heart. 

• Dilate smooth muscle in bronchioles.  

• Dilate pupils.  

• Converts glycogen to glucose (glycogenolysis) 

• Causes hair erector muscle to contract (hair stands up)  

what is a secondary messenger ? and its functions

Cyclic AMP (cAMP)

Adrenaline is a polar non steroid hormone.  

Target cells express glycoprotein receptors on the cell surface membrane.  

Effects are induced in the cell using a second messenger molecule.