ANATOMY AND PHYSIOLOGY:
7. ENDOCRINE SYSTEM
GLANDS
The endocrine system comprises glands that secrete hormones, regulating various bodily
functions. Here's an overview of major endocrine glands and their functions:
1. Pituitary Gland: Often referred to as the "master gland," it controls the function of other
glands. It secretes hormones like growth hormone (GH), thyroid-stimulating hormone
(TSH), and adrenocorticotropic hormone (ACTH), among others, influencing growth,
metabolism, and stress response.
2. Thyroid Gland: Produces hormones (thyroxine - T4 and triiodothyronine - T3) that
regulate metabolism, energy production, and growth. It also influences body temperature
and heart rate.
3. Parathyroid Glands: Situated behind the thyroid, they produce parathyroid hormone
(PTH), which regulates calcium and phosphorus levels in the body, crucial for bone
health and nerve function.
4. Adrenal Glands: Divided into two parts, the adrenal cortex and adrenal medulla. The
cortex produces cortisol (regulates metabolism and stress response) and aldosterone
(regulates blood pressure and electrolyte balance). The medulla secretes adrenaline
(epinephrine) and noradrenaline (norepinephrine), involved in the "fight or flight"
response.
5. Pancreas: Functions as an endocrine and exocrine gland. The endocrine part releases
insulin (lowers blood sugar), glucagon (raises blood sugar), somatostatin, and pancreatic
polypeptide, regulating blood glucose levels.
6. Thymus Gland: Crucial for the development of the immune system, producing
hormones like thymosin, which assists in the maturation of T lymphocytes (T cells) that
play a role in immune responses.
7. Pineal Gland: Secretes melatonin, which regulates sleep-wake cycles (circadian
rhythms) and influences reproductive hormones.
8. Reproductive Glands:
• Ovaries: In females, produce estrogen and progesterone, regulating the menstrual cycle,
pregnancy, and secondary sexual characteristics.
• Testes: In males, testosterone, is necessary for sperm production, sex drive, and
secondary sexual characteristics.
1. Hypothalamus: Though not a gland itself, it plays a crucial role by producing hormones
that stimulate or inhibit the release of hormones from the pituitary gland, thereby
controlling various bodily functions.
The endocrine system functions via feedback mechanisms, maintaining hormonal balance.
Imbalances in hormone levels can lead to various disorders, like diabetes, thyroid dysfunction,
7. ENDOCRINE SYSTEM
GLANDS
The endocrine system comprises glands that secrete hormones, regulating various bodily
functions. Here's an overview of major endocrine glands and their functions:
1. Pituitary Gland: Often referred to as the "master gland," it controls the function of other
glands. It secretes hormones like growth hormone (GH), thyroid-stimulating hormone
(TSH), and adrenocorticotropic hormone (ACTH), among others, influencing growth,
metabolism, and stress response.
2. Thyroid Gland: Produces hormones (thyroxine - T4 and triiodothyronine - T3) that
regulate metabolism, energy production, and growth. It also influences body temperature
and heart rate.
3. Parathyroid Glands: Situated behind the thyroid, they produce parathyroid hormone
(PTH), which regulates calcium and phosphorus levels in the body, crucial for bone
health and nerve function.
4. Adrenal Glands: Divided into two parts, the adrenal cortex and adrenal medulla. The
cortex produces cortisol (regulates metabolism and stress response) and aldosterone
(regulates blood pressure and electrolyte balance). The medulla secretes adrenaline
(epinephrine) and noradrenaline (norepinephrine), involved in the "fight or flight"
response.
5. Pancreas: Functions as an endocrine and exocrine gland. The endocrine part releases
insulin (lowers blood sugar), glucagon (raises blood sugar), somatostatin, and pancreatic
polypeptide, regulating blood glucose levels.
6. Thymus Gland: Crucial for the development of the immune system, producing
hormones like thymosin, which assists in the maturation of T lymphocytes (T cells) that
play a role in immune responses.
7. Pineal Gland: Secretes melatonin, which regulates sleep-wake cycles (circadian
rhythms) and influences reproductive hormones.
8. Reproductive Glands:
• Ovaries: In females, produce estrogen and progesterone, regulating the menstrual cycle,
pregnancy, and secondary sexual characteristics.
• Testes: In males, testosterone, is necessary for sperm production, sex drive, and
secondary sexual characteristics.
1. Hypothalamus: Though not a gland itself, it plays a crucial role by producing hormones
that stimulate or inhibit the release of hormones from the pituitary gland, thereby
controlling various bodily functions.
The endocrine system functions via feedback mechanisms, maintaining hormonal balance.
Imbalances in hormone levels can lead to various disorders, like diabetes, thyroid dysfunction,
