Chemical Coordination and Integration: Class 11 Biology NCERT Chapter 22
Key Features of NCERT Solutions for Class 11 Biology Chapter 22 – Chemical Coordination and Integration
In chapter 21 of NCERT class 11 Biology: Neural Control and Coordination, you studied about neurons and how it gets controllation by the body. In this chapter: Chemical Coordination and Integration, you will learn about inside and out about this substance coordination and mix of the human body.
What might occur on the off chance that you are incapacitated tomorrow? You won’t have the option to move, talk, run, and so forth. Your body’s inward coordination gets upset. Presently, what might occur in the event that you fallen some time or another during morning get together? What’s going on here? What prompts falling? Therfore these occasions happen because of substance coordination in our bodies.
(Chemical Coordination and Integration: Class 11)
Quick Revision Notes
In creatures, control and coordination is performed by neural framework and endocrine framework mutually. As the nerve strands don’t innervate all cells of the body, henceforth the endocrine framework is required to organize the capacities.
Endocrine Glands
Endocrine organs are ductless organs. They discharge their emission legitimately into blood which is then moved to explicit objective organs to start a specific metabolic change.
The endocrine organs discharge synthetic substances called hormones.
Hormones are non-supplement synthetic substances which go about as intercellular couriers and hence are created in follow sum.
Human Endocrine System
The endocrine organs and hormone creating tissues/cells are situated in various pieces of the body. Gastrointestinal parcel, kidney, liver and heart likewise produce little amount of hormones to control and arrange the capacity of separate organs.
Nerve center contains a few gatherings of neurosecretory cells called cores which produce hormones. Hormones delivered by Hypothalamus manage the combination and emission of pituitary hormones.
Hypothalamus produces two types of Hormones:
The hormones delivered from nerve center arrives at the foremost pituitary through gateway circulatory framework and control its capacity.
The back pituitary is under direct control of nerve center.
Pituitary Gland is situated in sella tursica, a hard pit. It is appended to the nerve center by a tail.
Overabundance emission of Growth Hormone causes over development of the body prompting gigantism and low discharge causes hindered development called dwarfism.
Prolactin invigorates development of mammary organ and creation of milk.
TSH invigorates creation and arrival of thyroid hormone.
LH and FSH invigorate movement of the gonads. In male, LH animates combination and emission of androgen hormone from testis. In female, LH prompts ovulation of completely develop ovum from ovary.
Oxytocin helps in constriction of uterus during labor and milk launch from mammary organs.
Vasopressin invigorates retention of water and electrolyte in kidney.
MSH follows up on the melanocytes and directs skin pigmentation.
The pineal Gland-situated on dorsal side of forebrain and delivery melatonin hormone that assists with directing diurnal musicality of body like rest, wake cycle and internal heat level.
Thyroid Gland-made out of two projections on either side of windpipe associated by isthmus.
Thyroid organ is made of follicles and stromal tissues:
Iodine is fundamental for combination of thyroid hormones. Insufficiency of iodine prompts hypothyroidism (Goiter). During pregnancy, hypothyroidism may cause hindered development of infant and mental hindrance.
Thyroid hormones manage the basal metabolic rate. Therefore, they bolster the procedure of red platelet development. They control the digestion of sugars, proteins and fats. Thyrocalcitonin hormone directs blood calcium levels.
Parathyroid Gland–situated on the rear of thyroid organ, secretes peptide hormone called parathyroid hormone (PTH). PTH controls the calcium particle focus in the blood. It likewise helps in reabsorption of calcium from renal tubules and stomach related plots.
Thymus–situated on the dorsal side of heart and the aorta. This organ discharges peptide hormone thymosins that help in separation of T-Lymphocytes for cell-interceded invulnerability. It additionally elevates creation of antibodies to give humeral invulnerability.
Adrenal Gland – situated on front piece of every kidney, made out of two kinds of tissues focal adrenal medulla and outside adrenal cortex. Adrenal medulla secretes adrenaline and noradrenaline hormone normally called as catecholamines. These hormones are additionally called as crisis hormone. Hence these hormones increment readiness, pupilary widening, perspiring, heart beat, pace of breath, glycogenolysis.
The adrenal cortex secretes glucocorticoids and mineralocorticoids. Glucocorticoids invigorate gluconeogenesis. Mineralocorticoids direct water and electrolyte substance of the body.
Pancreas – goes about as both endocrine and exocrine organ. Endocrine pancreas comprises of “Islets of Langerhans” which contain α-cells and β-cells. The α-cells discharge hormone glucagon and β-cells emit insulin. The two hormones are engaged with support of glucose levels.
Glucagon is a peptide hormone that animates glycogenolysis bringing about expanded glucose (hyperglycemia).
Insulin is a peptide hormone that assume significant job in guideline of glucose homeostasis. It triggers fast development of glucose from blood to hepatocytes and adipocytes bringing about diminished blood glucose levels (hypoglycemia).
Testis – perform double capacities as an essential sex organ just as endocrine organs. Leydig cells or interstitial cells produce androgen for the most part testosterone which manage development of essential sex organs and spermatogenesis.
Ovary – produce two gatherings of steroid hormones called estrogen and progesterone. Estrogen is integrated and emitted by developing ovarian follicles. After ovulation, cracked ovum called corpus luteum, secretes progesterone. Estrogen delivers wide range activities like development of female optional sex organs, improvement of developing ovarian follicles, and guideline of female sexual conduct.
Progesterone manages pregnancy.
Hormones of Heart, Kidney and Gastrointestinal Tract
Atrial mass of heart secretes peptide hormone called atrial natriuretic factor (ANF) which diminishes pulse.
The juxtaglomerular cells of kidney produce erythropoietin hormone which invigorate erythropoiesis.
Gastro-intestinal lot discharge four significant peptide hormones:
- Gastrin animates the discharge of hydrochloric corrosive and pepsinogen.
- Secretin follows up on the exocrine pancreas and invigorates emission of water and bicarbonate particles.
- Cholecystokinin (CCK) animates the discharge of pancreatic chemicals and bile juice
- Gastric inhibitory peptide (GIP) hinders gastric discharge and motility.
Mechanism of Hormone Action
Hormone produce their consequences for target tissues by authoritative to explicit protein called hormone receptors situated in the objective tissue.
Authoritative of hormones to receptor prompts the arrangement of hormone receptor complex. Therefore, this coupling prompts change in target tissue.
According to chemical nature, hormones are grouped as-
Peptide, polypeptide and protein hormones-insulin, glucagon, pituitary hormone, hypothalamic hormones.
Steroids-cortisol, testosterone, progesterone.
Idothyronines-thyroid hormones.
Amino corrosive subsidiaries epinephrine.
Hence, the hormones that quandary with film bound receptors typically don’t enter the objective cells yet produce second courier which therefore manage cell digestion.
The hormones (steroid hormones) which communicate with intracellular receptors generally control quality articulation or chromosome work by association with hormone-receptor complex with the genome. Hence, these biochemical activities brings about physiological and formative impacts.
(Chemical Coordination and Integration: Class 11)