Question | Answer |
Neuron | consists of several dendrites, single axon and cell body |
Dendrites | receive information and transfer it TO CELL body |
Axon | transfers impulses AWAY from cell body |
Glial Cells | produce myelin
· Oligodendrocytes – produce myelin in CNS
· Schwann – produce myelin in PNS |
At rest neuron | is polarized (-70 mV) |
Concentration of K+ higher ____cell // Na+ higher ____cell | inside, outside |
Threshold | level at which action potential is initiated (-50 mV) |
Depolarization | voltage-gated Na+ channels open allowing Na+ to rush in |
Repolarization | voltage-gated K+ channels open so K+ rush out; more negative potential; K+ channels are slow and stay open longer; once cell is repolarized, K+ leak channels open |
Greater diameter & more heavily myelinated axons | will propagate faster impulses |
After Synaptic vesicles fuse w/ presynaptic membrane | neurotransmitter fuses to postsynaptic membrane, Neurotransmitter may be taken back into nerve terminal, degraded by enzymes in synapse, or diffuse out of the synapse |
Acetylcholine | primary neurotransmitter of parasympathetic NS; excitatory and inhibitory on muscles and glands |
Norepinephrine | primary neurotransmitter of sympathetic NS |
Afferent Neurons | carry SENSORY info about enviro TO brain (from A to B / Aff => brain) |
Efferent Neurons | MOTOR commands from BRAIN to BODY |
CNS | consists of the brain and spinal cord |
Brain | grey matter (cell bodies) and inner white matter (axons); forebrain, midbrain, hindbrain |
Forebrain | contains cerebral cortex, olfactory bulb, thalamus ,hypothalamus |
cerebral cortex | processes sensory input / imp for memory and creative thought |
thalamus | relax for cerebral cortex / spinal cord) |
hypothalamus | water balance, blood pressure, and temp regulation |
Midbrain | visual/ auditory impulses; motor control |
Hindbrain | posterior part of brain; cerebellum , pons , medulla |
cerebellum | maintenance of balance, hand-eye coord, timing of rapid movements |
pons | relay center to allow communication b/w cortex and cerebellum |
Medulla | breathing, heart rate, gastrointestinal activity) |
PNS | somatic and autonomic nervous systems |
Somatic | responsible for VOLUNTARY movement |
Autonomic | involuntary movement; innervates cardiac and smooth muscle |
Sympathetic | fight or flight (higher BP and HR) |
Parasympathetic | rest and digest (lower HR / increased gut motility) |
cornea | focuses light |
pupil | diameter controlled by iris (pigmented) |
lens | controlled by cilliary muscles |
Myopia | nearsightedness |
Ear | outer, middle and inner ear; transduces sound energy into impulses |
Outer ear | auricle and auditory canal |
Middle ear | amplifies sound; tympanic membrane (eardrum) vibrates at same frequency as incoming sound => ossicles (malleus, incus, and stapes) |
Inner Ear | vestibular apparatus (equilibrium) and cochlea (vibration of ossicles ecert pressure on fluid stimulating hair cells in basilar membrane => action potential) |