biopsychology- systems Flashcards
what are the two nervous systems
central nervous system (cns)
peripheral nervous system (pns)
what are the two main sub divisions of the pns ?
somatic and autonomic
what movement is somatic associated with ?
voluntary movement across sensory and motor neurones
what movements is the autonomic nervous system ?
involuntary movement
what are the sub divisions of autonomic system ?
sympathetic and parasympathetic
what is the sympathetic role ?
prepares body for stress - heart + breathing rate increase , dilated pupils, stomach stops digesting, lung capacity increases, muscles contract
what is the parasympathetic role ?
returning body to routine - decrease heart rate , dilate pupils
what makes up the CNS?
spinal cord and brain
difference between nervous system and endocrine system?
nervous is faster
nervous = electrical impulses but endocrine = hormones
nervous = collection of neuron cells
glands and organs operate the endocrine system
what is the charge of a resting neuron ?
negative inside the cell
when does neuron cell become positive inside the cell?
when it has been activated by a stimulus
what is a sensory neuron?
short axon long dendrites info towards
the brain
what is a motor neuron?
short dendrites long axon info away from brain
what is a relay neuron?
between sensory and motor neurons allowing them to communicate
what percentage of neurons are in the brain ?
80%
what are dendrites ?
branch like structures that receive nerve impulses from neighboring neurons
what is the soma?
cell body
what does the cell body include ?
nucleus which contains genetic material
what does the axon do ?
carries impulses known as action potential away from cell body down neuron to axon terminal
what is myelin sheath ?
protects axon and speeds electrical impulse
what would happen if myelin sheath was continuous ?
electrical impulse would be slower therefor it is segmented so impulse has to jump
what are the gaps in myelin sheath called
gaps of Ranvier
what are axon terminals?
responsible for communicating with next neuron
what is the basic structure of a neuron?
- cell body or ‘soma’ - which contains nucleus of DNA
- branch structures named dendrites protrude from the cell body which carry nerve impulses
- axon carries impulses away from cell body to the end of the neuron
- axon is insulated by myelin sheath which protects cell and speeds up travel of impulse through the nodes of ranvier
- at the end of the axon is terminals which allow synpatic transmission
what is a vesicle ?
holds neurotransmitters until it needs to be released
why can electrical impulses only be transmitted in one direction ?
because neurotransmitters are released from pre-synaptic neuron and binds to postsynaptic cell. there is no vesicles on the postsynaptic cell to release the chemical.
what is synaptic transmission?
impulse arrives at presynaptic cell. neurotransmitter released from vesicle. diffuses across synapse, binds to receptor sites on postsynaptic neuron. chemical message is converted back into electrical impulse . neurotransmitters are broke down and reabsorbed into presynaptic cell.
what is a neurotransmitter ?
chemical that diffuses across the synapse to the next neuron
what is the lock and key mechanism in a neuron?
the postsynaptic site has specific receptor sites for different neurotransmitters
what is excitation ?
when a neurotransmitter causes neighboring neurons to become more positively charged and more likely to fire
what is inhibition ?
when a neurotransmitter causes neighboring neurons to become more negatively charged and less likely to fire
structure of a relay neuron ?
short dendrites and varied axons
structure of a motor neuron ?
short dendrites and long axon
structure of a sensory neuron ?
long dendrites and short axon
what is the function of the endocrine system ?
to secrete hormones from glands into the bloodstream which bind to certain receptors to regulate cells and organs. e.g adrenaline released from the adrenal gland for flight or fight. imbalance in hormones might lead to dysfunctions
