The adrenal glands are endocrine glands that produce a wide variety of hormones.
The adrenal glands are encased in a connective tissue capsule that extends septae into the substance of the gland.
The organ is richly vascularised and capsular blood vessels, nerves and lymphatic penetrate along with the connective tissue septae.
LOCATION OF ADRENAL GLAND
Adrenal glands are found on the top of the kidneys and consist of a number of different layers that directly influence the structure and functions of the glands.
STRUCTURE OF ADRENAL GLAND
- Adrenal glands are located on the top of the kidney.
- They are composed of two parts.
- Adrenal cortex
- Adrenal medulla
Adrenal cortex is divided into three zones of layers.
- Zona glomerulosa.
- Zona fasciculate.
- Zona reticularis.
- Hormones secreted by all three layers called corticoids.
- Zona glomerulosa-pyramidal cells are arranged in closely packed. It secrets mineralocorticoids (aldosteron).
- Zona fasciculate-polyhedral cells arranged in straight cords. It secrets glucocorticoids (cortisone and cortisol) and androgens.
- Zona reticularis-cells disposed in irregular cords that forms anatomozing network. It secrets glucocorticoids and androgens.
- Adrenal medulla is the center of each adrenal gland. It is surrounded by adrenal cortex.
- Spherical chromaffin cells are modified postganglionic sympathetic neurons.
- Chromaffin cells receive direct innervations from sympathetic nervous system.
- It produces epinephrine and norepinephrine hormones, which are sympathomimetic.
- Acetylcholine increase hormone secretion by adrenal medulla.
FUNCTIONS OF ADRENAL GLAND
ADRENAL CORTEX FUNCTIONS
- MINARAL CORTICOIDS-regulates sodium retention and potassium loss and body fluid.
- GLUCOCORDICOIDS-acts as anti-inflammatory agents, affect metabolism.
- ANDROGEN-it regulates growth and developments of genitalia and puberty.
ADRENAL MEDULLA FUNCTIONS
- ADRENALINE (EPINEPHRINE)-increase heart rate and blood pressure.
- NOR ADRENALINE (NOR EPINEPHRINE)-constricts arterioles.
ADRENAL GLAND DISORDERS
Hypersecretion of cortisol causes include a tumor of the adrenal gland or a tumor that secrets ACTH, which is turns stimulates the secretion of cortisol.
Adrenal tumors are commonly found as incidentalomas. Unexpected tumors are found in medical imaging and in most case they are benign adenomas. Adrenal carcinomas are very rare. Adrenal cancer is the presence of malignant adrenal tumors and includes neuroblastoma, adrenocortical carcinoma.
Characterized by breakdown of muscle proteins and redistribution of body fat.Resultiong in spindly arms and legs accompanied by rounded ‘moon face’ ‘buffalo hump’.
Adrenal adenoma is the benign tumor of the glandular type (adenoma) in the adrenal gland. Sometimes it does not secrete hormones. Some secrets cortisol (causes Cushing’s syndrome), aldosteron (causes Conn’s syndrome), androgens (causes hyperandrogenism).
ADRENAL GLAND SYMPTOMS
- Adrenal fatigue.
- Facial puffiness.
- Facial hair in women.
- High blood pressure.
- Muscle weakness.
- Aches and pains, particularly back pain.
- Periods may become irregular or stop in women.
- Lack of sex drive.
This is the general notes on Adrenal Glands and It’s Structure, Functions and Disorders.
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