divisions of the NS Flashcards
what does the NS divide into
central NS: spinal cord + brain
peripheral NS: neurones that connect CNS to rest of body
role of the CNS
Life functions / psychological processes
higher mental functions
spinal cord transmits info to the brain
controls reflex behaviours
what does the peripheral NS divide into
autonomic NS
somatic NS
role of the autonomic NS
controls unconscious activities for example breathing, HR, digestive system
Role of the somatic NS
Controls conscious activities for example muscle movement and transmits info to and from the CNS
What does the automatic NS divide into
Sympathetic NS
parasympathetic NS
role of the parasympathetic NS
calms the body to restore to its resting state
role of the sympathetic NS
FLIGHT OR FIGHT
sympathetic NS effect HR
incr. HR
more blood flow to organs –> spread adrenaline around the body
more blood + glc pumped to muscles for respiration
sympathetic NS: physical changes on the body during flight or fight
incr HR
- more blood flow to organs –> spread adrenaline around the body
- more blood + glc pumped to muscles for respiration
Pupils dialate
- improve vision
digestive system halts
- conserve + release stored energy
sweat
- facilitate temp regulation
outline the NS pathway
stimulus Receptor Sensory neurone CNS Motor neurone Effector Response
What are dendrites
Receive information from other neurones
Passes information along an axon to form an electrical impulse that ends at the synaptic knob
What is the role of the myelin sheath
Too late of the axon to increase the speed of nervous transmission
What are neurotransmitters
Chemicals which are released from the presynaptic knob, diffuse across the signups to initiate the next impulse on the following you around to continue the signal
What is the charge of the neurone like in the resting state
Negatively charge compared to the outside
What is the charge of the neurone like in an activated state
Positively charged compared to outside
Generate an action potential, this creates an electrical impulse travels down the axon
what is a synapse
Specialised gap between the neurons through which electrical impulses are transmitted
Outline the structure of a synapse
Presynaptic membrane - cell membrane acts on terminal that faces the receiving cell
Postsynaptic membrane is separated by the presynaptic membrane by synapse
Outline synaptic transmission
Neurotransmitters found inside vesicles in the presynaptic knob
When stimulated by nerve impulse at the presynaptic knob, vesicles fuse with presynaptic membrane and neurotransmitters are released into the synapse
Neurotransmitters diffused across the synapse and bind with postsynaptic receptors
This causes iron channels to be inflicted into the postsynaptic membrane and ions flow into the postsynaptic membrane, effects are excitatory or inhibitory
exitatory = AP triggered inhibitpry= AP not triggered
