15. Neural Control Flashcards
what is the receptor in homeostasis?
it detects the stimulus
what is the control centre in homeostasis?
its the ‘thermostat’ - the hypothalamus
whats the effector in homeostasis?
the thing that the control centre makes change - ie the ‘heater or air con’
what is the afferent input?
its the sensory input
what is the efferant output?
the motor output
define negative feedback and give an example of a type
buildup of the end product of the sytem then shuts off.
For example thermoregulation - when its to hot or cold the receptor detects the stimulus then the control centre (hypothalamus) makes an adjustment
what is a positive feedback loop and give an example
involves a change in a varable that triggers mecahnisms that amplify the change
for example the sodium potassium pump - the sodium going out stimulates potassium to come in which can then stimulate action potentials
how does the CNS and PNS work togehter?
central nervous system intergrates information recieved from the periferial nervous system and makes an appropriate response
name three things that the nervous system is capable of doing
- detecting change in the internal and external enviornment
- rapid responses of short duration
- voluntary and involunatry responses
where do the cranial nerves originate and go too?
they originate in the brain and terinate mostly in ogans of the head and upper body
where do the spinal nerves originate and where do they go too?
originate in the spinal cod and go to the body below the head
what are the four types of afferent signals
physical (theroreceptors)
chemical (plasma glucose)
mechanical (barroreceptors, pressure on a pen)
photreceptors (in eyes)
what do afferent neurons do?
carry the signals to the central nervous system - internal and external environement
explain the process of afferent signals, intergratin and respoonse
- affrent neurons carry the signal to the CNS
- the CNS and intergrating centre compares the input with a ‘set point’ which compares it wiht hte set value
- the integrating centre (hypothalamus, CNS or endocrine gland) sends a motor signal (efferent) to the effector
- effector changes the condition
what are the two types of motor divisions?
somatic - concious and voluntary but the reflexes are involuntary
autonomic - controls unconsious functions (growth, digestion, breathing)
what are the three divisions of the autonomic nervous system?
- sympathetic
- parasympathetic
- enteric
what do the sypathetic, parasympathetic and entric divison do (from the autonomic system)
sympathetc - control over organs in emergency situations
parasymathetic - recovery - ‘normal situations
entric - digestve tract, gall bladder and pancreas
what is the similarities and differences between the symathetic and parasymathetic division? (1 of each)
similarities: control balance
differences: sympathetic is for excitable and parasympathetic is for ‘normal’
why would the sypathetic divison of the autonmic system inhibit the action of the digestive system, but stimulate the release of glucose from the liver?
because the parasympathetic system acts in opposition to the sypathetic divison. therefore when the sympathetic division is stimulated, it opposes the parasympathetic system, therefore in ‘fight or flight mode’ the sympathetic divisin is activated
