Nervous system (ch 11) Flashcards
4 lobes in the cerebrum and their jobs
- Frontal: voluntary movement (muscles), memory, intelligence, personality
- Temporal: sound and smell (2s)
- Parietal: Touch, pain/ pressure, Temp, Taste (3T)
- Occipital: vision
Cerebellum job
co-ordinates muscle movements: balance/ coordination (muscle memory)
Pons job
bridge for sensory info between cerebellum & medulla oblongata
medulla oblongata job
autonomic brain control:
involuntary muscle movement (heart/breathing rate, digestion control, blood vessel diameters, etc)
hypothalamus job
- send signal to medulla oblongata or pituitary gland
- maintains homeostasis
spinal chord job
controls reflexes
nerve highway: nerves go to brain and leave brain through the spinal chord (2-way communication)
5 steps of reflex arc
- stimulus
- sensory neuron: reception/ action potential
- interneuron: integrate; send signal to brain & motor neuron
- motor neuron
- effector organ: response
Which 2 things are included in the central nervous system (CNS)?
brain and spinal cord
2 branches of the peripheral nervous system
- autonomic (involuntary)
2. somatic (voluntary)
2 branches of the autonomic nervous system (ANS)
- involuntary
1. sympathetic (ON switch- fight or flight) excitatoty
2. parasympathetic (OFF switch- rest and digest) inhibitory
2 branches of the somatic (voluntary) nervous system
- sensory somatic (afferent- bring info in)
2. motor somatic (efferent- bring info out)
dendrite
short branches that receive incoming impulses/ neurotransmitters. conduct impulse to cell body
cell body
bridge between dendrite and axon; grouped together to form ganglia when along spinal cord or nuclei within CNS. contains organelles and nucleus
axon
conduct impulse away form the cell body. large dendrite
neurilemma
membrane around myelinated (white matter) neurons, promotes regeneration of damaged neurons
myelin sheath
white, fatty insulator that prevents ion loss and increases impulse speed. produced by schwann cells
node of ranvier
gaps between neighboring schwann cells; allows ions to enter axon from external environment
axon bulbs
end of axon; contains synapitic vesicles that release neurotransmitters (acetylcholine or norepinepherine) into synapse
synaptic cleft (synapse)
space between one neuron and the next
resting potential
- when a fibre is not transmitting a signal (POLARIZED)
- maintains a charge of -70mV
- Na/K pump: 3Na out for every 2 K in
- neg proteins in axon/cell
- K building up inside diffuses out the K leak channels
action potential
- sending a signal in response to stimuli that exceeds threshold level (DEPOLARIZATION)
- charge inside neuron jumps to +40mV
- na gates open, na floods in
- k leak channels remain open
repolarization
end of signal transmission, beginning steps to regain polarization
- -80mV (hyperpolariztaion- very negative)
- Na gates close, K gates open and too much K leaves
refractory period
neuron cannot re-fire until na is returned to outside, so pumping na/ k starts again to regain polariztaion (-70mV inside, positive outside)
drugs “do their thing” at the _____
synapse
