Topic Cell Signalling Essay - Main Points!

Q) Using a named example, discuss the basis of homeostatic control

Main points
Key idea:	What is homeostasis
· Maintenance of a constant internal environment, for organism to achieve a degree of independence fr ext environmental factors
Key idea:	Homeostasis achieved via endocrine + nervous system
· Multicellular organisms - communication b/w diff groups of cells of endocrine & nervous sys control + coordinate activities to maintain homeostasis
Key idea:	Principles of negative feedback + self-regulation
· Any deviation from normal level triggers a series of events that restores the normal level · The entity to be regulated.triggers the corrective mechanism if deviation occurs
Key idea:	Named example : Control of blood glucose level in human
· Detector (e.g. α cells and β cells, Islets of Langerhans in the pancreas) sense any deviation from norm (100mg/100ml blood) · The cells also act as regulators, coordinate signals, secrete appropriate hormones into blood · Blood transport hormones to target cells (e.g. liver cells) which act to restore homeostatic level of the blood glucose level. · The regulation of blood glucose level is triggered by same entity.
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)