Give the full form of the abbreviation ACTH. Which gland secretes this hormone?
Important Points to Remember in Chapter -1 - Endocrine System from Dr. K.K. Aggarwal A New Approach to Biology Solutions
1. Endocrine glands and Hormones:
(i) The endocrine system consists of endocrine glands that secrete chemical messengers called hormones.
(ii) Endocrine glands are ductless glands whose secretions are poured directly into the blood.
(iii) Exocrine glands pour their secretions (enzymes) through ducts.
2. Endocrine glands in humans:
(i) Hypothalamus is a part of the brain that controls the function of the anterior pituitary gland by secreting 'releasing hormones'.
(ii) The pituitary gland is called the master gland because it controls the secretion of other glands.
(iii) The anterior pituitary releases six hormones, which are Thyroid Stimulating Hormone (TSH), Adrenocorticotrophic hormone (ACTH), Follicle Stimulating Hormone (FSH), Luteinising Hormone (LH), Prolactin (PRL), and Growth Hormone (GH).
(iv) The posterior pituitary secretes two hormones called Antidiuretic Hormone (ADH) and Oxytocin.
(v) The pancreas is a mixed gland that has both exocrine and endocrine functions.
(vi) The pancreas consists of small clusters of cells called islets of Langerhans that secrete hormones such as insulin and glucagon.
(vii) Insulin lowers the blood sugar level.
(viii) Deficiency of insulin causes diabetes mellitus.
(ix) Glucagon increases the blood sugar level.
(x) The thyroid gland produces and secretes three hormones, such as thyroxine, triiodothyronine, and calcitonin.
(xi) The adrenal gland has two distinct regions: Adrenal cortex and Adrenal medulla.
(xii) The adrenal cortex secretes mineralocorticoids and glucocorticoids, and adrenal medulla secretes adrenaline and nor-adrenaline.
(xiii) The adrenaline and nor-adrenaline prepare the body for emergency conditions.
(xiv) Examples of glands with dual functions are pancreas, ovary and testes.
