biopsychology Flashcards
the nervous system
a specialised network of cells in the human body which is our primary internal communication system
- localised on chemical and electrical signals, whereas the endocrine system is based on hormones
functions of the nervous system
- to collect, process and respond to information in the environment
- to co-ordinate the working of different organs and cells in the body
spinal chord
part of the central nervous system, along with the brain
- a bundle of nerve fibres which connects nearly all parts of the body to the brain
peripheral nervous system
transmits messages via millions of neurons , to and from the CNS
somatic nervous system
controls muscle movements and receives information from sensory receptors
- carries commands from the motor cortex and has motor and sensory pathways
autonomic nervous system
controls vital automatic functions in the body
- controlled by the brain stem and only has motor neuron pathways
parasympathetic nervous system
calms you down (the rest and digest response)
- heart rate slows, breathing returns to normal, pupils shrink, digestive system works
sympathetic nervous system
gets you ready for action
- adrenaline, heart rate increases, pupils get wider, breathing deepens, digestive system stops
neurons
cells that make up the nervous system
- they conduct electrical impulses which transmit messages around the body
structure of a neuron
neurons vary in size
- the cell body includes a nucleus which contains genetic material
structure of a neuron (dendrites)
branch-like structures which protrude from the cell body
- they carry nerve impulses from neighbouring neurons towards the cell body
structure of a neuron (axon)
carries impulses away from the cell body down the length of a neuron
structure of a neuron (myelin sheath)
the axon is covered in a fatty layer of myelin sheath which protects the axon and speeds up electrical transmission of the impulse
- it is segmented by gaps called nodes of ranvier
structure of a neuron (terminal buttons)
at the end of an axon are terminal buttons which communicate with the next neuron in the chain across a gap known as the synapse
transmission within a neuron
action potential is how information is transmitted within the neuron
- the dendrites of neurons receive information from sensory receptors
- this excited the neuron causing sodium ions to enter the membrane
- this information is then passed down to the cell body and on to the axon
- once the information has arrived at the axon, it travels down its length as an electrical signal (action potential)
relay neuron
between sensory and relay neurons
- located in the brain and visual system
- dendrite length is short
- axon length is short
sensory neuron
from sensory receptors to CNS
- located in the PNS
- dendrite length is long
- axon length is short
motor neuron
from CNS to effectors to promote movement
- located in the cell body of CNS and in the axons of the PNS
- dendrite length is short
- axon length is long
reflex arc
- receptor in the skin detects a stimulus
- sensory neuron sends electrical impulses to a relay neuron which is located in the spinal cord of the CNS
- relay neurons connect sensory neurons to motor neurons
- motor neurons send electrical impulses to an effector
- the effector produces a response
synaptic transmission
- an electrical impulse travels along the axon of the presynaptic neuron
- this triggers the nerve-ending of the pre-synaptic neuron to release chemical messages called neurotransmitters from vesicles
- ## these chemicals diffuse across the synapse and bind with receptor molecules on the membrane of the next neuron
synaptic transmission
- an electrical impulse travels along the axon of the presynaptic neuron
- this triggers the nerve-ending of the pre-synaptic neuron to release chemical messages called neurotransmitters from vesicles
- these chemicals diffuse across the synapse and bind with receptor molecules on the membrane of the next neuron
- the receptor molecules on the second neuron bind only to the specific chemicals released from the first neuron. This stimulates the second neuron to transmit the electrical impulse
- reuptake: the neurotransmitter is re-absorbed in the vesicles of the pre-synpatic neuron after it has performed its function of transmitting a neural impulse
excitation
neurotransmitter: adrenaline
charge produced: positive
potential produced: exciting
effect: increases the likelihood that the neuron will fire and pass on the electrical impulse to the next neuron
inhibition
neurotransmitter: serotonin
charge produced: negative
potential produced: calming
effect: decreases the likelihood that the neuron will fire
endocrine system
works alongside the nervous system to control vital functions in the body
- regulates cells and organs
- acts more slowly than the nervous system but has very widespread and powerful effects