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40 Cards in this Set
- Front
- Back
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Two major div in nervous system?
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CNS (brain, spinal cord) peripheral (the rest)
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What does a dendrite do?
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Lots of sa to pick up impulse and conduct towards cell body
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What is cell body
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metabolic centre of cell, cellular respiration and protein synth
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Function of myeline sheat
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Made of lipids around axon to insulate
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Schwann cell function
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Produces myelin sheath, tightly packed around forms layers of myelin
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what does nodes of ranvier allow
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more rapid nerve conduction along axon
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What are synaptic endings
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End of axon, vesicles containing neurotransmitters here
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described three types of neurons
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Sensory, motor, interneuron (conveys between parts of system)
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during resting potential w hat is concentration of ions? how is it maintained?
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Na+ more concentrated, K+ inside. Active transport
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Described action potential?
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With stimuli, impulse is generated with voltage change. Upswing (-60->40), membrane is permeable to Na+. They move from outside to inside. this is depolarization.
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Describe recovery phase.
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In b etween nerve impulses, K+ returned inside axon, Na+ back to original position. this requires ATP.
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Why is myelin sheath faster?
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Because the impulse jumps from note to node. nonmyelinated, the impulse must depolarize and repolarize on each point.
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What happens when nerve impulse reaches end of axon?
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Synaptic endings release neurotransmitters that affect potnetial of next neuron.
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Describe structure of axon.
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Synaptic endings are the swollen knobs, presynaptic is before, post synaptic is next neuron. Cleft is between.
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What do excitatory transmitters do?
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Make post synaptic more permeable to Na+
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What doe inhibitory transmitters do?
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Make post synpatic less permeable to Na+
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What are synaptic vesicles?
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They contain neurotransmitters
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summarized synapse in pre synaptic
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impulse reaches synpatic ending (action potential), Ca+2 flows into ending. Ca+2 ions cause contractile proteins to pull synaptic vesicles into inner surface. These fuse with membrane to release neurotransmitters via ATP.
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SUmmarize synapse in cleft and post synaptic (before enzymatic)
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Diffuse accross the cleft to receptors on post synaptic, the post have selective ion channels with lock and key. Ion flux changes voltage to move closer to action potential.
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Summarize synapse in post synaptic after absorption
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The NT are broken down and degraded by enzymes. synaptic ending reabsorbs NT. other enzymes break down after it is absorbed.
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What cell part makes NT?
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Protein (ribosome)
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5 actions of drugs in synapse?
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Stimulates, blocks, combines preventing breakdown, mimics, blocks receptor
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3 types of nerves?
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Sensory, motor, mixed.
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What is the dorsal root?
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Dorsal root ganglion, contains cell bodies of sensory neurons whose dendrites conduct impulse towards spinal cord.
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What is ventral root?
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Each spinal nerves contains axons of motor neurons that conduct impulses away from cord.
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What is somatic nervous system?
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Includes all nerves that serve muscoloskeletal and exterior sense organs.
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Describe a reflex action (5 steps)
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Stimuli, impulse via dorsal root ganglion to spinal cord, synapse with gray matter of spinal cord, interneuron synapses with motor neuron, impulse carried by ventral root to muscle/gland
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What is autonomic nervous system divided into?
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Sympathetic and parasympathetic.
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Describe sympathetic nervous system
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Emergency, fight or flight. Noradrenalin released by postganglionic axon. e.g. bladder constrict
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Describe parasympathetic
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All internal response associated with relaxed state. Include acetylcholine, released by post ganglionic axon. e.g. bladder relax
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CNS contains?
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Brain, spinal cord. Protected by bone, dura mater menignes, arachnoid menings, pia mater meninges. Spaces between filled with spinal fluid.
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Difference between gray and white matter?
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Gray is cell bodies --> synapes, interneurons
White matter ---> mylelinated nerve tracts |
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label
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Medulla oblongata is?
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Primitive brain. Controls heart rate, bp, reflex like vomiting, sneezing
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What is cerebellum?
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Controls balance and movement. Muscle movement.
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What does pons do?
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It relays between forebrain, hindbrain and medulla oblongata
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What does thalamus do, and then hypothalamus?
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Receive sensory info to channel to cerebrum. Thalamus receives sensory impulses except smell and sends to appropriate regions. Hypothalamus --> homeostasis.
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What does corpus callosum do?
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Space between two hemispheres of brain. Transmit impulses between hemispheres.
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Describe cerebrum.
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Largest, conscious brain. Intellect, memory.
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Four parts of consciousness?
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Frontal: movement, higher intellect, parietal: senses and speech, temporal: hearing smell, memory of visual, occipital: vvision, visual experience
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