Page 2 - LN-CH-22

• LH and FSH stimulate activity of the gonads. In male, LH stimulates synthesis and
secretion of androgen hormone from testis. In female, LH induces ovulation of fully

mature ovum from ovary.

• Oxycocin helps in contraction of uterus during child birth and milk ejection from
mammary glands.

• Vasopressin stimulates absorption of water and electrolyte in kidney.

• MSH acts on the melanocytes and regulates skin pigmentation.

The pineal Gland-located on dorsal side offorebrain and release melatonin hormone that

helps to regulate diurnal rhythm of body like sleeps wake cycle and body temperature.

Thyroid Gland- composed of two lobes on either side of trachea connected by isthmus.

Thyroid gland is made of follicles and stromal tissues:

• Iodine is essential for synthesis of thyroid hormones. Deficiency of iodine leads to
hypothyroidism (Goitre). During pregnancy, hypothyroidism may cause stunted

growth of baby and mental retardation.

• Thyroid hormones regulate the basal metabolic rate. They support the process of red
blood cell formation. They control the metabolism of carbohydrates, proteins and fats.

Thyrocalcitonin hormone regulates blood calcium levels.

Parathyroid Gland- located on the back side of thyroid gland, secretes peptide hormone

called parathyroid hormone (PTH). PTH regulates the calcium ion concentration in the blood.
It also helps in reabsorption of calcium from renal tubules and digestive tracts.

Thymus- located on the dorsal side of heart and the aorta. This gland releases peptide

hormone thymosins that help in differentiation ofT-Lyrnphocytes for cell-mediated

immunity. It also promotes production of antibodies to provide humeral immunity.

Adrenal Gland- located on anterior part of each kidney, composed of two types of tissues
central adrenal medulla and outside adrenal cortex. Adrenal medulla secretes adrenaline

and noradrenaline hormone commonly called as catecholamines. These hormones are also

called as emergency hormone. These hormones increase alertness, pupilary dilation,
sweating, heart beat, rate of respiration, glycogenolysis.

The adrenal cortex secretes glucocorticoids and mineralocorticoids. Glucocorticoids

stimulate gluconeogenesis. Mineralocorticoids regulate water and electrolyte contents of the

body.