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Flashcards in NERVOUS SYSTEM (3) Deck (34):
1

nervous system

specialized for processing info and sending messages from one part of the body to another

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central nervous system (CNS)

consists of the brain and the spinal cord

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peripheral nervous system (PNS)

consists of nerves

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neurons

nerve cells that transmit impulses

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neuroglia

support and nourish the neurons (help neurons)

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neuron structure: cell body

contains nucleus and other organelles

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neuron structure: dendrites

receive signals from sensory receptors or other neurons

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neuron structure: axon (nerve fiber)

conducts nerve impulses away from the cell body

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the myelin sheath

a lipid covering on long axons that acts to increase the speed of nerve impulse conduction, insulation, and regeneration in the PNS

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schwann cells

neuroglia that makes up the myelin sheath in the PNS (helps speed it up)

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saltatory conduction

conduction of the nerve impulse from node to node

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action potential

rapid changes in membrane carried down the axon (allows the nerve impulse to occur)

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depolarization

lets Na+ in

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repolarization

lets K+ out

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synapse

transmission of impulse across a synaptic cleft from the presynaptic membrane to the postsynaptic membrane (GAP)

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integration

is the summation of the inhibitory and excitatory signals received by a postsynaptic neuron (end result of what your body is going to do)

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meniges (CNS)

three membranes covering and protecting the spinal cord and brain

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cerebrospinal fluid (CFS) (CNS)

cushions and protects the CNS

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gray matter (CNS)

cell bodies and short nonmyelinated fibers

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white matter (CNS)

contains myelinated axons

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cerebrum

1. frontal lobe- primary motor area and conscious thought
2. temporal lobe- primary auditory, smell, and speech area
3. parietal lobe- primary somatosensory and taste area
4. occipital lobe- primary visual area

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wernicke`s area

helps us understand both written and spoken word

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broca`s area

adds grammatical refinements and directs the primary motor area to stimulate the appropriate muscles for speaking

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limbic system

emotions

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brainstem (3)

1. midbrain- acts as a relay station for impulses passing between the cerebrum and the spinal cord or cerebellum (also a relax center)
2. pons- regulates breathing rate and has reflex centers concerned with head movements in response to visual and auditory stimuli
3. medulla oblongata- reflex centers for regulating heartbeat, breathing, and blood pressure

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somatic and autonomic

PNS is divided into 2 systems

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autonomic system

regulates activity of the cardiac and smooth muscles and the glands

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sympathetic division

coordinates the body for action "fight or flight"
-speeds up metabolism
-speeds up heart action and breathing

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parasympathetic divison

brings about the responses we associate with a relaxed state
-slows down metabolism
-slows down heart action and breathing

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somatic system

serves the skin, skeletal muscles, and tendons

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reflex arch

-sensory neuron (to spinal cord glands)
-interneuron (spinal cord)
-motor neuron (from spinal cord)
-effector (to muscles)

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resting potential *negative charge

1. Na+ gates open up = depolarized
(cell becomes more +)
2. Na+ gates close = repolarize
(cell becomes more -)
3. K+ gates open
4. K+ gates close
5. Na/K pump

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semantic

skeletal muscle and voluntary

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autonomic

-involuntary, glands, smooth muscle, cardiac muscle
-either sympathetic or parasympathetic