Table of Contents
Chemical coordination and Integration – Involve two independent integration systems. i.e. nervous system and endocrine system.
Endocrinology is the study of endocrine glands and its secretions (hormones).
Grave’s disease or hyperthyroidism is caused due to the secretion of the excessive amount of thyroid hormone by the thyroid gland, i.e. hyperthyroidism (NEET- II 2016).
Insulin is the peptide hormone which enhances the uptake of glucose molecules by liver cells (hepatocytes) and fat cells (adipocytes) for its cellular utilization (NEET-II 2016).
High levels of estrogen and progesterone give negative feedback to hypothalamus for the release of GnRH. Thus inhibiting the gonadotropin release (NEET-I 2016).
Inhibin is produced by granulosa cells of ovarian follicles in the ovary and has a negative feedback effect on the secretion of FSH (NEET-I 2016).
Some hormones that are insoluble in lipids do not affect a physiological process directly. They activate secondary messenger that convey the information to the target cells. On the other hand, glucocorticoids are steroid hormones, that can directly affect the gene expression (EAMCET 2015).
Gluconeogenesis is the synthesis of the glucose molecule and mainly controlled by glucagon. Insulin stimulates the conversion of glucose to glycogen, i.e. glycogenesis (KCET 2015)
The pineal gland secretes a hormone called melatonin. It involved in the regulation of a diurnal (24 hours) rhythm of our body. It also influences metabolism, pigmentation and menstrual cycle as well as our defense capability (WB JEE 2015).
Ectopic transplantation of pituitary is done in the kidney capsule, anterior eye chamber or third cerebral ventricle. It secretes prolactin (PRL) abundantly (Chattisgarh PMT 2015)
The adrenocorticotropic hormone is a polypeptide, which promotes the release of glucocorticoids and androgens from the adrenal cortex. Rest all hormones give are steroids (AMU 2015)
Pregnancy Hormones – Chemical coordination and Integration
During pregnancy, the human body secretes human Placental Lactogen (hPL), Human Chorionic Gonadotropin (hCG) and Relaxin. hCG promotes maintenance of the corpus luteum during the beginning of pregnancy. It is used for testing pregnancy. hPL produced by the placenta facilitates the energy supply of the fetus by modifying the metabolic state of the mother during pregnancy. Relaxin is to relax the joints in the pelvis so, as to make a room for the baby to pass through the birth canal (AMU 2015).
Thyroxine or tetraiodothyronine (T4) is the hormone produced by follicular cells of the thyroid gland (KCET 2015).
The zona glomerulosa of the adrenal gland produces a mineralocorticoid called Aldosterone. It plays a central role in the regulation of blood pressure mainly by acting on the distal tubules and collecting ducts of the nephron, increasing reabsorption of ions and water in the kidney, to cause the conservation of sodium, secretion of potassium, increase in water retention and decrease in blood pressure and blood volume (CBSE AIPMT 2015).
Leydig cells are present in the testes of mammals. These produce androgens (testosterone). These hormones control the development of secondary sexual characters as well as gametogenesis (spermatogenesis) in males (WB JEE 2015).
Pheromones are the intraspecific chemical messenger that triggers a social response in members of the same species. These are chemicals capable of acting outside the body of the secreting individual to impact the behavior of the receiving individual (WB JEE 2015).
Phenylalanine-n-methyl Transferase (PNMT) is an enzyme present in the adrenal medulla that converts norepinephrine (noradrenaline) to epinephrine (adrenaline). PNMT catalyzes the transfer of a methyl group from SAM (S-adenosyl-l-methionine) which is a factor to norepinephrine, converting it into epinephrine (WBJEE 2015).