Topic Homeostasis Essay - Main Points!

Q) Explain what is meant by an endocrine gland

Main points
Key idea:	What is endocrine gland + features
· Group of cells, secrete small amount of hormones (chemical messengers) · Ductless, secretes hormones directly into bloodstream · Ref to transport of hormones to specific target cells/tissues, affect their activities · Ref to integration, coordination, control of physiological activities of organism
Key idea:	Named example : Islets of Langerhans, pancreas
· Made up of α cells + β cells - secrete glucagon + insulin, respectively · Ref to a rich network of bl capillaries in direct contact w secretory cells · Direct release of hormones into bl · E.g. of target cells of insulin and glucagon are liver cells
Key idea:	Control of secretion of hormones
· Rel of either homones - determined by changes of level of bl glucose (stimulus/input) · If bl glucose level is above norm, receptors on surface of β cells detect change,  insulin released · If bl glucose level is below norm, receptors on surface of α cells detect change, glucagon released · Hence, endocrine gland ensures homeostatic level of blood glucose · Via negative feedback mechanism · When homeostatic level is achieved, the gland stops secreting hormones
Comments: (i) Visualize the answer with the aid of a labelled diagram. (ii) Verbalize the answer + write down the main points w/o referring to the answer (use abbreviations) (iii) Read again within the next 24h & once more within 72h (do not spend more than 10min)