Cortex of adrenal gland secretes Glucocorticoids and Mineralocorticoids:
Function of adrenal hormones:
1. Glucocorticoids stimulate gluconeogenesis, lipolysis and proteolysis (the life saving activity).
2. Cortisol is a glucocorticoid involved in maintaining cardiovascular and kidney functions. It produces anti-inflammatory reactions and suppresses the immune response. It stimulates the RBC production. It is also known as stress combat hormone.
3. Mineralocorticoids regulates water and electrolyte balance' of our body. Aldosterone stimulates thereabsorption of sodium and water and eliminates potassium and phosphate ions through excretion, thus it helps in maintaining electrolytes, osmotic pressure and blood pressure. Adrenal androgen plays a role in hair growth in the axial region, pubis and face during puberty.
4. The adrenal medulla secretes the hormones adrenalin and noradrenalin and are referred as "3F hormone" (fight, flight and fright hormone).
5. Adrenalin increases liver glycogen breakdown into glucose and increases the release of fatty acids from fat cells.
6. During emergency it increases heart beat rate and blood pressure. It stimulates the smooth muscles of cutaneous and visceral arteries to decrease blood flow .
7. It increases blood flow to the skeletal muscles thereby increases the metabolic rate of skeletal muscles, cardiac muscles and nervous tissue.

S.No. Hyperglycaemia Hypoglycaemia 1. It is a disorder caused due to lower secretion of insulin hormone It is a disorder caused due to increased secretion of insulin
hormone 2. Hyperglycemia is otherwise known as Diabetes mellitus Hypoglycemia is otherwise known as
Diabetes insipidus 3. Blood glucose level is increases Blood glucose level is decreases 4. Different types are seen. Like Type
I - Insulin dependent diabetes.
Type II-Non Insulin dependent
diabetes. Symptoms are glucose
level increase like polyurea [excessive urination] polyphagia [excessive intake of food] polydipsia [excusive fluid intake due to thirst] ketosis etc. Symptoms are Glucose level lowers than normal fasting index, increased heart beat, weakness, nervousness, brain defects like epilepsy,coma etc.

(i) A pair of adrenal glands are located at the anterior end of the kidneys. The outer region is the cortex and the inner region is the medulla.
(ii) The adrenal cortex has three distinct zones, they are 1. Zona glomerulosa 2. Zona fasciculata and 3. Zona reticularis.
(iii) Zona glomerulosa an outer thin layer constitutes about 15% of adrenal cortex and its secretes mineralocorticoids.
(iv) Zona fasiculata, the middle layer constitutes about 75% of adrenal cortex and secretes glucocorticoids such as cortisol, corticosterone and trace amounts of adrenal androgen and oestrogen.
(v) Zona Reticularis, an inner zone of adrenal cortex constitute about 10% of adrenal cortex and secretes the adrenal cortex androgen, trace amount of oestrogen and glycocorticoids.

Structure of thyroid gland:
Thyroid gland is the largest endocrine gland in the body.


1. It is a butterfly shaped, bilobed gland located below the larynx on either side of upper trachea.
2. The two lateral lobes are connected by a median tissue mass called isthmus.
3. Each lobe is made up of many lobules. The lobules consist of follicles called acini.
4. Each acinus is lined with glandular, cuboidal or squamous epithelial cells. The lumen of acinus is filled with colloid, a thick glycoprotein mixture consisting of thyroglobulin molecules.
5. It secretes two hormones namely tri-iodothyronine [T₃] and thyroxine or tetra- iodothyronine [T₄].
6. The parafollicular cells or 'C' cells of thyroid gland secrete a hormone called thyrocalcitonin.
7. Iodine is essential for the normal synthesis of thyroid hormone.
8. Thyroid hormones shows a negative feedback effect on the hypothalamus and pituitary.

Diabetes mellitus:
1. It is otherwise known as hyperglycaemia.
2. It is caused due to lower secretion of insulin. By this process blood glucose level is elevated. There are two types of diabetes mellitus. Types I and Type II.
3. Type I diabetes is known Insulin dependent diabetes, caused by the lack of insulin secretion due to illness or some viral infections.
4. Type II diabetes is also known as Non-Insulin dependent diabetes, caused due to lower secretion of insulin.
5. The half life period of insulin [in plasma] is only 6 minutes.
6. Symptoms of diabetes includes polyurea, polyphagia, polydipsia [excessive consumption of liquid due to thirst] ketosis [Breakdown of fat into glucose result in accumulation of ketone bodies in blood.]
Diabetes insipidus:
1. Diabetes insipidus is caused due to hypo secretion of vasopressin [ADH] from neuro hypophysis
2. The symptom includes frequent urination [Polyurea] and excessive consumption of liquid due to thirst [polydipsia]