These MP Board Class 11th Biology Notes for Chapter 22 Chemical Coordination and Integration help students to get a brief overview of all the concepts.
MP Board Class 11th Biology Notes Chapter 22 Chemical Coordination and Integration
→ Hormones are informational molecules, secreted by endocrine glands into venous blood to regulate the functions of other organs and tissues.
→ If young tadpoles are administered thyroxine, they metamorphosed prematurely and change into tiny frogs. On the other hand, if antithyroid substance like thiourea is given to tadpoles, it delays their metamorphosis.
→ Mexican axolotls which are the larval forms of Ambystoma tigrinum do not metamorphose due to the lack of thyroid hormone and ordinarily exist as axolotl larva and even reproduce in this form, but if thyroid extract is injected, they metamorphose into Ambystoma tigrinum, the adult terrestrial form. Breeding of Axolotl in the larval stage is called neoteny or pedogenesis.
→ Estrogens in human urine, increase twice during the menstrual cycle. Urine of a pregnant woman is a very rich source of estrogen, which appears to be produced by the placenta.
→ Medullary hormones are not essential for life.
→ Glucocorticoids reduce the number of circulating lymphocyte eosinophils (anti-leukaemic property) and have anti-inflammatory and anti-allergic properties. Glucocorticoids are also used in the treatment of rheumatoid arthritis.
→ Certain drugs like thiouracil, thiourea, para-amino benzoic acid, radioactive iodine, carbimazole and methimazole prevent the formation and secretion of thyroxine hormone.
→ Pars tuberalis a part of adenohypophysis of pituitary is rarely found in man.
→ Adrenogenital syndrome (Gallais, 1912) is due to the excess of adrenal cortex androgenic hormones. It is responsible for precocious growth of body “Infant Hercules”. This disease is found in females only.
→ Norepinephrine is known as hormonal secretion of adrenal medulla but it is seldom released as
norepinephrine from gland-what all is released is epinephrine only, not norepinephrine. The latter is secreted at nerve endings only.
→ Night urine usually contains more inactivated ADH than the day urine.
→ Alcohol inhibits ADH secretion.
→ Acromegaly is a kind of malformation of bones due to oversecretion of growth hormones in
adults.
→ Cachexia or Simroonds disease is caused due to undersecretion of growth hormone in adults.
→ Pituitary gland is also known to be as master gland because it controls the secretion of all the endocrine glands.
→ Pheromones or Ectohormones are chemical substances released into the external surroundings by some exocrine glands. The pheromones released by the members of a species are recognized by the other members of the same species. Hence, pheromones serve as means of communication among the members of same species, e.g. The path followed by a worker ant is recognized and followed by the other ants. This is possible because the rest of the ants recognize the pheromones released by the worker ant.
→ Thomas Addison is regarded as the father of Endocrinology.
→ Hyposecretion of thyroid gland results in the production of cretinism, myxoedema, goitre and Hashimoto disease.
→ Hyposecretion of adrenal cortex results in the production of Addisons, Hypoglycemia and Cons disease.
→ Pancreas is a mixed (exocrine as well endocrine) gland.
→ The humoral immune system defends against those pathogens that invade the body fluid (blood and lymph), i.e., extracellular pathogen.
→ Cell mediated immune system defends the body against those pathogens which invade the cells. i.e., intracellular pathogen.