5: Adrenal Glands

How many Adrenal Glands are there in the body?

• 2

Where are the Adrenal Glands located?

• Superior Pole on each Kidney

The adrenal gland is composed of the?

• Adrenal Cortex & Adrenal Medulla

The Adrenal Cortex & Adrenal Medulla are structurally and functionally?

• Different

The adrenal cortex secretes?

• corticosteroids which are

• Steroid hormones that control Mineral & Energy Balance.

The adrenal medulla secretes the?

• Catecholamine Hormones (Adrenaline & Noradrenaline).

• which complement the SNS flight-orfight response

Steroids act via?

• Nuclear receptors on target tissues.

The Adrenal Cortex has 3 Zones called?

• Zona glomerulosa

• Zona fasciculata

• Zona reticularis

The 3 Adrenal Cortex zones are structurally and functionally…?

• Different

Zona Glomerulosa produces?

• Aldosterone

• the most potent mineralocorticoid

Mineralocorticoids are the important regulators of?

• Na + and K+ Balance.

Aldosterone acts to by stimulating the kidney to retain?

• Na+ and secrete K+

The actions of Aldosterone function to?

• promote increases in blood volume and maintain electrolyte balance.

Angiotensin II also stimulates the secretion of?

• Aldosterone

The zona fasciculata produces?

• Cortisol

• the predominant glucocorticoid

Glucocorticoids act to regulate?

• Glucose & Other Organic Molecules

Cortisol production is stimulated by?

• ACTH

Cortisol production effects on the body include…?

• Degradation of Proteins

• Stimulation of gluconeogenesis

• Inhibition of glucose utilisation
  - Raise BGL

• Stimulates lipolysis
  - Breakdown of Fat

The actions of cortisol result in an increase of?

• Increased BGL

• And Fatty Acids in the blood.

The zona reticularis can also produce?

• Cortisol

However, the zona reticularis is better known for the production of?

• Adrenal Androgens

Androgens supplement the major … Hormones?

• Sex Hormones

Androgens are ana?

• Anabolic Steroids

What is Cushing Syndrome?

• Develops due to chronically elevated levels of Glucocorticoids.

• Occurs mainly in patients prescribed high doses of glucocorticoid medication

• or by a tumour of the pituitary / Adrenal Gland

What are the Common S&S of Cushing Syndrome?

• Hyperglycaemia

• Hypertension

• Buffalo Hump / Fat pad at the back of the neck

• Rounded Face

What is Addisons disease?

• Also known as Adrenal Insufficiency.

• caused by inadequate production of corticosteroids.

Insufficient levels of cortisol results in?

• Hypoglycaemia

The cells of the adrenal medulla are modified sympathetic postganglionic neurons called?

• Chromafin Cells.

The chromaffin cells are innervated by?

• Preganglionic Sympathetic Axons

Chromaffin cells release adrenaline and noradrenaline into the blood at a ratio of about ?:?

• 4:1

The effects of systemic catecholamine release is similar effects to local SNS stimulation but the effects last?

• 10x Longer

The catecholamine hormones result in?

• Increased Cardiac Output

• Dilate Coronary Vessel

• Increased Alertness

• Increased Respirations

• Increased BGL & Fatty Acids.

A tumour of the adrenal medulla is referred to as a?

• Pheochromocytoma

The Tumor of the Adrenal Medulla causes hypersecretion of?

• Epinephrine & Noradrenaline

• which produces an effect similar to continuous sympathetic nerve stimulation

Symptoms of Phaeochromocytoma include?

• The symptoms of this condition are

• hypertension,

• elevated metabolism,

• hyperglycaemia