Nervous system Flashcards
(19 cards)
nervous system
consists of central and peripheral nervous system. a specialised network of cells in the human body and is our primary internal communication system. Has 2 main functions 1)collect,process and respond from information in the environment 2)coordinate the working of different organs and cells in the body
the 2 functions of the nervous system
1)collect,process and respond from information in the environment
2)coordinate the working of different organs and cells in the body
central nervous system (CNS)
consists of brain and spinal cord and is the origin of all complex commands and decision.
peripheral nervous system (PNS)
all he nerves out side of he CNS.send information to the CNS from the outside world and transmit messages from CNS to muscles and glands.
somatic nervous system
transmits info from receptor cells in sense organs to CNS . also recieves info from CNS that directs muscles to act.
autonomic nervous system
transmits info from bodily organs. its automatic as system operate involuntarily. has 2 main divisions sympathetic and parasympathetic nervous systems .
2 main divisions of the autonomic nervous system
sympathetic and parasympathetic
2 main functions of CNS and what does it need to do this?
controls behaviour and regulation of body’s physiological prcoesses.
to do this brain need to be able to receive info from sensory receptors and send messages muscles and glands. this involves, the spinal cord a collection of nerve cells that are attched to the brain and run the lengths of the spinal cord.
sensory receptors
eyes ears skin etc
brain
-centre of all conscious awareness
-recieves sensory input from sensory recpetors
-sesnory info carries through sensory neurons and goes up spinal cord to brain
-brains outer layer =cerebral corex which in humans is highly devloped which separates out higher cognitive functions from animals.
spinal cord
-main function is to relay info between brain and rest of body
-allow brain to monitor and regulate bodily processes e.g digestion and to coordinate voluntary movements.
-spinal cord connected to diff parts of body by spinal nerves,which connect to with specific muscles and glands
-contains circuits of nerve cells enabling us to perform simple reflexes without direct involvement of brain
-if spinal cord damaged areas supplied by spinal nerves below damaged site will be cut off from brain and stop funcioning
2 main division of PNS
somatic and autonomic
function of PNS
relay nerve impulses from CNS to rest of body and from body back to CNS.
somatic nervous system
-transmitts signals from CNS to skeletal muscles and responsible for voluntary and involunary movements
-made up of 12 pairs of cranial nerves
-and 31 pairs spinal nerves
–these nerves jave boh sensory and motor neurons.
-sensory neorons relay message to CNS and motor neurons relay info from CNS to the rest of the body .
-also invloves reflex actions without invlovemn of CNS allows it to occur very quickly.
cranial nerves
nerves that emerge directly from underside of the brain
spinal nerves
nerves that emerge from the spinal cord.
function of autonomic system
carries out actions without conscious awareness e.g heart beating and digesting food. involuntary actions like these recgulated by ANS. the system is necessary as body wouldn’t work as efficiently if we had to think about them.
sympathetic nervous system
-usually used neurotransmitter noradreline which has stimulating effects
-active when fight or flight system aroused
e.g sympathetic nervous system cuases body to release stored energy,pupils to dialate and hair to stand on end,slows bodily processes that are less important in emergancies e.g digestion and uranation
parasympathetic nervous system
-opposite effect to sympathetic
-generally uses neurotransmitter acetylcholine which has inhibiting effects
-e.g slow heartrate and reduces blood pressure
-as invloved in energy conservation and digestion it’s sometimes refeered to as the body’s rest and digest system.
