Homeostasis lecture 1

winniesmith1's version from 2017-02-22 15:47

Section 1

Question Answer
What does homeo meanunchanging, the same
What does stasis meanstanding
What is homeostasisThe maintenance (or tendency towards of) a relatively constant internal environment
What does failure to maintain internal conditions result indisease, malfunction, death

Section 2

Question Answer
What are the two types of regulationAutoregulation/intrinsic regulation and Extrinsic regulation
What is autoregulation/intrinsic an automatic response by a cell, tissue, organ or organ system to a change in its environment
What is extrinsic regulation Changes regulated by the nervous system or the endocrine system
In extrinsic regulation how does the nervous system respond to external stimuliThe nervous system responds to external stimuli with rapid, short term and very specific nerve responses.
In extrinsic regulation how does the endocrine system respond to internal conditionswith long term chemical controls (hormones). Can persist for days or weeks.

Section 3

Question Answer
What are the 3 parts of the homeostatic regulatory mechanismReceptor, control centre (or integration centre) and effectors.
What is a receptorSensors that are sensitive to a particular environmental change or stimulus.
What is a control centreReceives and processes the info from the sensors and sends out a command
What is an effectorA cell or organ that responds to the commands of the control centre and carry out instructions (opposing or enhancing stimuli).

Section 4

Question Answer
What is negative feedbackThe response of the effector negates the stimulus. Response which corrects the situation (back to normal ranges). Tends to minimize change keeping variation within the limits that are compatible to our long-term survival.
What is positive feedback stimulus produces a response that exaggerates or enhances the change in the original condition, rather than opposing it. (blood clotting or childbirth)
What happens when blood glucose level is too lowAlpha cells of pancreas stimulated to release glucagon into blood--> liver breaks down glucagon and releases glucose into the blood.
What happens when blood glucose is too highBeta cells of pancreas stimulate to release insulin into blood. This causes body cells and the liver to take up more glucose. Liver stores it as glycogen.

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