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Ley dig cells produces hormones called androgens mainly testosterone.

Functions:

• Androgens regulate the development, maturation and functions of male accessory sex organs.
• They play a major stimulatory role in the process of spermatogenesis.

Hormones of adrenal gland, adrenaline and nor adrenaline are collectively called as catecholamines.

Thymus gland degenerates with age.

Glycogen concentration decreases.

Cholecystokinin

Thyroid Stimulating Hormone.

Gets affected by diabetes mellitus which causes loss of glucose through urine and formation of harmful ketone bodies.

Hormones of Pars distalis :

It may be due to the hyposecretion of parathyroid hormone. Damage in parathyroid gland may have lead to this condition. PTH plays an important role in absorption of calcium from the digested food and reabsorption of calcium by the renal tubules. Hence, hyposecretion of PTH results in calcium deficiency in spite of taking calcium rich diet.

(a) Parathyroid:

• Parathyroid hormone (PTH)

(b) Adrenal: 

• Adrenaline/epinephrine
• Noradrenaline/Norepinephrine
• Corticcids
• Cortisol
• Aldosterone

(c) Pancreas:

• Glucagon
• Insulin 

(d) Testis:

• Testosterone

Endocrine Glands: Endocrine glands do not have ducts. They directly secrete their secretions.

Adrenocorticotrophic hormone.

Through hypothalamic neurons control anterior pituitary gland. Through neural regulation controls posterior pituitary gland.

Two portions of pituitary gland are:

• Adeno hypophysis: Hormones secreted are Prolactin (PRL) Thyroid stimulating hormone (TSH) etc.
• Neurohypophysis: Hormones secreted are oxytocin and vasopressin.

Thymus gland is located on the dorsal side of the heart and aorta. Thymus gland secretes hormone thymosins which play a major role in the development of the immune system.Thymosins play a major role in the differentiation of T- lymphocytes, which provide cell-mediated immunity and also promote production of antibodies to provide humoral immunity.

Thymus gland is located on the dorsal side of the heart and aorta.

The adrenal glands are small glands located on top of each kidney. They produce hormones that you can't live without, including sex hormones and cortisol. Present at anterior part of each kidney.

Has two parts- outer cortex & central- medulla.

• Oxytocin acts on the smooth muscles of our body and stimulates their contraction.
• In females, it stimulates a vigorous contraction of uterus at the time of child birth, and milk ejection from the mammary gland.

The pituitary gland.

The pituitary gland produces a totally 9 hormones; 6 of them from the anterior lobe, 1 from the intermediate lobe and 2 from the posterior lobe. The list with one function each is given below.

(1) Growth hormone (GH) or Somototrophin:

The basic function of this hormone is to stimulate body weight and rate of growth of the body in terms of muscle, bone structure, cartilage etc.

(2) Thyroid stimulating hormone (STH):

regulates the growth of the thyroid gland and increase in thyroid activity. 

(3) Adrenocortlcotrophic hormone (ACTH):

Regulates the hormonal secretions of the Adrenal cortex (Steroid hormones) and Increase Adrenocortical activity.

(4) Gonadotrophic hormones:

Stimulating the growth and activity of gonads

• Follicle stimulating hormone (FSH):

stimulates ovarian follicular growth in female (Ovary) and stimulates the increased production of sperms in male (Testis – semiferous tubules)

• Luteinizing hormones (LH):

Stimulates final maturation of graafian follicle in the ovary. Along with FSH it also stimulates production of progesterone in females. ICSH- in males, it stimulates the testis to produce androgens.

(5) Prolactin (PRL):

Stimulates growth of mammary glands and production of milk in females.

(6) Melanocyte – stimulating hormone:

Stimulates the increased production of Melanin pigment and its dispersal in mammalian skin.

(7) Vasopressin (or Antidiuretic hormone – ADH):

Acts on kidney tubules and controls the water (metabplism) balance, i.e. increases reabsorption of water in kidney tubules (distal part) whenever the body faces a deficit in water.

Pineal gland functions as a biological clock in our body. It is located on the dorsal side of forebrain. Pineal secretes a hormone called melatonin.

Cortisol in our body.

Thyrocalcitonin (TCT) and parathyroid hormone (PTH).

Glucocorticoid - Cortisol; Mineralocorticoid - Aldosterone. 

By dilation of the blood vessels.

Follicle stimulating hormone (FSH)

The Melanocyte – stimulating hormone (or M.S.H.)

(a) Function of Parathyroid Hormone: Parathyroid hormone (PTH) increases the Ca²⁺ levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/ demineralisation). PTH also stimulates reabsorption of Ca²⁺ by the renal tubules and increases Ca²⁺ absorption from the digested food. It is, thus, clear that PTH is a hypercalcemic hormone, i.e., it increases the blood Ca²⁺ levels. Along with TCT, it plays a significant role in calcium balance in the body

(b) Functions of Thyroid Hormones: Thyroid hormones play an important role in the regulation of the basal metabolic rate. These hormones also support the process of red blood cell formation. Thyroid hormones control the metabolism of carbohydrates, proteins and fats. Maintenance of water and electrolyte balance is also influenced by thyroid hormones. Thyroid gland also secretes a protein hormone called thyrocalcitonin (TCT) which regulates the blood calcium levels.

(c) Functions of Thymosins: Thymosins play a major role in the differentiation of T-lymphocytes, which provide cell-mediated immunity. In addition, thymosins also promote production of antibodies to provide humoral immunity.

(d) Functions of Androgen: Androgens regulate the development, maturation and functions of the male accessory sex organs like epididymis, vas deferens, seminal vesicles, prostate gland, urethra etc. These hormones stimulate muscular growth, growth of facial and axillary hair, aggressiveness, low pitch of voice etc. Androgens play a major stimulatory role in the process of spermatogenesis (formation of spermatozoa). Androgens act on the central neural system and influence the male sexual behaviour (libido). These hormones produce anabolic (synthetic) effects on protein and carbohydrate metabolism.

(e) Functions of Estrogen: Estrogens produce wide ranging actions such as stimulation of growth and activities of female secondary sex organs, development of growing ovarian follicles, appearance of female secondary sex characters (e.g., high pitch of voice, etc.), mammary gland development. Estrogens also regulate female sexual behaviour.

(f) Functions of Insulin and Glucagon: Glucagon is a peptide hormone, and plays an important role in maintaining the normal blood glucose levels. Glucagon acts mainly on the liver cells (hepatocytes) and stimulates glycogenolysis resulting in an increased blood sugar (hyperglycemia). In addition, this hormone stimulates the process of gluconeogenesis which also contributes to hyperglycemia. Glucagon reduces the cellular glucose uptake and utilisation. Thus, glucagon is a hyperglycemic hormone.

Insulin is a peptide hormone, which plays a major role in the regulation of glucose homeostasis. Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue), and enhances cellular glucose uptake and utilisation. As a result, there is a rapid movement of glucose from blood to hepatocytes and adipocytes resulting in decreased blood glucose levels (hypoglycemia). Insulin also stimulates conversion of glucose to glycogen (glycogenesis) in the target cells. The glucose homeostasis in blood is thus maintained jointly by the two – insulin and glucagons.

Melatonin is hormone of pineal gland.

The Pineal Gland: On dorsal side of brain.

Two lobes in gland joined with isthmus. Present on either side of trachea. Deficiency disease: Goitre. Hyper secretion-Exoopthalamia

Thyroid gland is composed of follicles and stromal tissues.

Deficiency of iodine results in enlargement of the thyroid gland, condition know as goitre.

Thyrocalcitonin

(a) Glucagon and insulin

(b) Parathyroid hormone

(c) LH and FSH (d) Progesterone

(e) Atrial Natriuretic Factor (ANF)

(f) Testosterone and estradiol

• Gastrin
• Secretin
• Cholecystokinin
• Gastric inhibitory peptide.

Adenohypophysis and neurohypophysis.

Pars  nervosa.

• Prolactin (PRL): Regulates the growth of mammary gland and formation of milk in them
• Thyroid stimulating hormone (TSH): It stimulates the synthesis of secretion of thyraid hormones from the thyroid gland.
• Follicle stimulating hormone (FSH): It regulates growth and development of the ovarian follicles in females.

(a) Pituitary

(b) Thyroid

(c) Adrenal Cortex

(d) Testis and Ovaries

(e) Pineal gland

The volume of urine decreases.

Hormones can be divided into four groups on basis of their chemical nature.

• Peptide, polypeptide, protein hormones

Eg: insulin, glucagon

• Steroids

Eg: cortisol, testosterone

• Lodothyronines

Eg: thyroid hormones

• Amino – acid derivatives

Eg: epinephrine

Non-nutrient chemicals, synthesised in trace amounts, acts as intracellular messengers and are specific in their action.

Hypothalamus : 

• It is basal part of diencephalon. 

• Has neurosecretory cells called nuclei which produce hormones to regulate the synthesis and secretion of pituitary gland hormones. 

• Two types of hormones released are :

Releasing hormones : Stimulate secretion of pituitary hormones, e.g., Gonadotropin releasing hormone stimulates pituitary gland to synthesise gonadotrophins. 

Inhibiting hormones : Inhibit secretions of pituitary hormones, e.g., Somatostatin inhibits secretion of growth hormone.

Releasing hormones and inhibiting hormones.

Sella  turcica

Pars distalis and pars inter media