Homeostasis Flashcards
What is homeostasis
The maintenance of a constant internal environmental despite internal and/or external changes by adjusting physical processes
What systems are responsible for homeostasis and what do they do ?
The nervous system and the endocrine system (hormones) are responsible for this. The nervous system maintains homeostasis by controlling and regulating parts of the body.
What function of the body is important for homeostasis to occur?
The ability of the body to change the rate of flow of blood to various body tissues is important in achieving homeostasis.
How does homeostasis occur?
A change from a normal set point acts as a stimulus that is detected by a receptor and sends nerve impulses to a regulating centre in the brain.
The brain then directs an effector to act in such a way that an adaptive response takes place.
What is Vasoconstriction?
Narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, in particular the large arteries and small arterioles.
What is Vasodilation?
The widening of the blood vessels
What are Receptors?
receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems
What do receptors do?
Sensory receptors allow the body to respond to different stimuli
What is a stimulus
any physical or chemical change in the environment which can cause a response in an organism
Why are stimulus important
an organism must respond to stimuli in order to survive
What is feedback mechanism
self-regulating mechanism that maintains a balance (in water level, body temperature, etc). • Circular system in which information about something is continually fed back to central control.
Fluctuations from a set point activate the control system, which returns the parameter to its normal level.
What is the hypothalamus
part of the brain that serves as the coordinating centre. It receives messages from the receptors and initiates a hormonal/ nervous response.
What is positive feedback
physiological control mechanism in which a change in some variable triggers mechanisms which amplify the change.
What triggers positive feedback
The response triggered by changing conditions serves to move the variable even further away from cits steady state
What is negative feedback
A change that reverses a particular trend
