Homeostasis Flashcards
What is homeostasis?
It is the maintenance of a stable environment whilst adapting to the change in external conditions. It maintains the regulated variables in the internal environment within narrow limits.
What is a negative-feedback System?
This is the planned corrective behaviour of any system that brings it back to the bassline whenever it moves away. keeps it within its narrow limits.
What is a regulated variable?
This is what needs to be maintained to ensure normal bodily functioning.
What is the core body temperature?
It should be 37degreesC for optimal enzyme function. correction of this temperature is called thermoregulation.
What happens when the body temperature gets to hot and what happens when it gets to cold?
Hot - 41degreesC. body will sweat and also an increase in blood flow to the skin to get it closer to the external environment to cool off.
Arterial oxygen pressure and what happens when its too low?
This is the continued supply of oxygen from the blood to all the cells, should be maintained between 75mmHg-100mmHg. When it gets to low, for example, at high altitudes when oxygen is reduced, chemo receptors in the arteries detect this and signal the control centre in the brain which sends a signal to effectors such as respiratory muscles to increase netilation.
Blood glucose, to high and to low?
This is an energy source to all cells. When it is to little (hypoglycaemia) the liver is signalled to secrete more via insulin. When there is too much glucose (hyperglycaemia) the liver is told to stop making and secreting glucose, acting as more of a store instead.
What impairments can the impact of disease cause?
Sensor impairments - cant detect when a regulated system has went past narrow limits. e.g. in T1D, the pancreas (sensor) cant detect when blood glucose is too high and produce insulin)
Control centre impairments - signals cannot be interpreted therefore effectors cannot be signalled for a response.
Effector impairments - response cannot be generated regardless of the rest of the body being aware of a problem.
What are the threats of exercise?
Heat production - cause bodies internal temperature to rise.
Uses oxygen - increasing ventilation is a control system to ensure the replenishment of oxygen to the blood. muscles extract oxygen from the blood for energy.
Produces CO2 - product of metabolism.
Uses blood glucose - more energy is required so more blood glucose is extracted from the blood.
What are the bodies communication systems?
CNS - sends signals through neurones to the CNS (afferent) then from the CNS to the effectors (efferent).
Endocrine system - secreted hormones from glands into the blood which carries them to the appropriate organs.
