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75 Cards in this Set
- Front
- Back
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What is the main purpose of a nerve's ability to be excitable?
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So that it can create an action potential
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What are the 3 structural characteristics of a nerve?
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1. cell body
2. dendrites 3. axon |
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What is the function of the cell body/soma?
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To process information it receives from other cells
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What is the function of the dendrite?
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to collect information and send it toward the axon
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What is the function of the axon?
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to pass on information if there is a large enough stimulus
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What is the function of the axon hillock?
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to process information
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What is the longest nerve in the body?
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The sciatic nerve
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Define Synapse
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Junction between neurons and/or target cells (muscle cells)
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Define Axon terminal
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Where the nerve meets the muscle cells at the post-synaptic gap
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Define myelin sheath
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Substance that insulates the nerve to block the action potential to force it to jump over to each node of Ranvier
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What is the resting membrane potential in mV?
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-70 mV
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when does an action potential occur?
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when the voltage reaches -55mV
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Where in the nerve is the action potential generated?
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at the axon hillock
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What happens when the action potential reaches threshold?
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depolarization opens more sodium channels
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What is the meaning of an absolute refractory period?
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the nerve cannot refire again because the sodium gates are open
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What is the meaning of a relative refractory period?
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Sodium gates are closed so the cell CAN refire but only with a large stimulus
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Define Graded potential
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Action potential not strong enough to depolarize the cell
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Define Depolarization
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inside of the cell is less negative than the outside and is caused by change or permeability
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All_____ potentials begin as ______potentials
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action; graded
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Define Resting Membrane Potential
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The difference between the electrical charges inside and outside a cell, caused by separation of charges across the cell membrane
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At resting membrane potential there is a high concentration of ___ ions on the ___of the cell and a high concentration of ____ ions on the outside of the cell
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K; inside
Na; outside |
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What are some foods that contain potassium?
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tomatoes, bananas, potatoes, milk
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Why do larger-diameter neurons conduct nerve impulses faster?
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because there is less resistance to the current flow
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What are the 4 major regions of the CNS?
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1. Cerebrum
2. Diencephalon 3. Cerebellum 4. Brainstem |
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Which part of the cerebrum is in charge of motor response?
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pre-central gyrus
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Which part of the cerebrum is in charge of sensory response?
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post-central gyrus
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what connects the precentral gyrus to the postcentral gyrus?
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corpus colossum
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What is said to be the area of mind and intellect?
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cerebrum
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what is the center of homeostasis and thermal regulation?
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diencephalon
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What is the center of motor memory?
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cerebellum
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what is an engram?
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something that memorizes motor pattern
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What is the regulator of the respiratory and cardiovascular systems?
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The brainstem
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Muscles controlling ______ movements have more muscle fibers per motor unit.
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gross
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Where do afferent neurons enter the spinal nerve?
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through the posterior root
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Where to efferent neurons enter the spinal nerve?
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they LEAVE through the ventral root of the spinal nerve
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what is the term used to describe what takes advantage of the spinal reflex?
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plyometrics
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Where does the lateral corticospinal tract begin?
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the precentral gyrus
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what structure carries a majority of the motor impulses from the precentral gyrus of the motor cortex to the peripheral nerves?
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lateral corticospinal tract
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what do mechanoreceptors respond to?
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pressure, touch, stretch
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Where are mechanoreceptors integrated?
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medulla
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what do thermoreceptors respond to?
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changes in temperature
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Where are thermoreceptors integrated?
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in the hypothalamus
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What do nociceptors respond to?
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pain
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What do chemoreceptors respond to?
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chemical stimuli and changes in blood concentration
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where are chemorecptors found (mostly) if they are responding to changes in the blood?
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carotid arteries and arch of aorta
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Give 2 examples of propioceptors
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1. muscle spindle fibers
2. golgi tendon organ |
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Which part of the muscle spindle fibers are alpha motor neurons?
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extrafusal
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Which part of the muscle spindle fibers are beta motor neurons?
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intrafusal
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Why does one's leg bounce when hit at the patellar tendon?
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because it stretches the tendon so that the muscle spindle fiber shortens in an attempt to prevent overstretching of the tendon
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What does the golgi tendon organ detect?
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tension of a muscle on its tendon
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What does a kinesthetic receptor sense and where is it found?
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it senses position and movement of joints and it is found in joint capsules.
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How much energy do you lose to heat?
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about 60% is lost as heat
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what goes up in arterial blood when you stop breathing?
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CO2
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Which receptors tell you to breathe when you stop breathing?
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chemoreceptors
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Why does carbon monoxide kill you soundlessly?
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the oxygen binds to it instead of getting to your lungs/blood
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What are 3 of the best stretching techniques for flexibility?
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1. Proprioceptic neuromuscular facilitation
2. static stretch 3. plymetric stretch |
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Which nervous system is in charge of housekeeping?
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parasympathetic nervous system
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Define Direct calorimetry
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measures body's heat production to estimate energy expenditure
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Define indirect calorimetry
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calculates energy expenditure from the ratio of CO2 produced to oxygen consumed
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What does Haldane transformation allow us to do?
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calculate Vi from Ve because the nitrogen concentration is constant
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The respiratory exchange ratio occurs in the _____ while the Respiratory quotient occurs in the _____.
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body; cell
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What is the equation for the respiratory exchange ratio?
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VCO2/VO2
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What is a normal RER at rest?
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.78-.80
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If you are burning pure CHO what is your RER?
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1.0
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If you are burning pure fat, what is your RER?
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.70
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What can be used to determine metabolic rate over long periods of time?
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isotopes
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What is the recommended amount of time one should spend in moderate aerobic activity per week?
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150 minutes
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What is the recommended amount of time one should spend in vigorous aerobic activity per week?
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60 minutes
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What does METS stand for?
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metabolic equivalency
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What does 1 METS equal?
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RMR per min or 3.5 ml/kg/min
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Define Resting Metabolic Rate
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Minimum amount of energy required by the body to sustain basic cellular function.
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What are 2 factors that effect resting metabolic rate?
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1. Fat-free mass
2. Body surface area |
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what 3 word phrase answers why trained athletes have a higher lactate threshold than untrained people?
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higher cardiac output
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What are 4 reasons for fatigue?
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1. energy delivery
2. accumulation of metabolic by-products, such as lactate and H+ 3. Failure of the muscle's contractile mechanism 4. alteration in the nervous system |
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Define Lactate Threshold
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the point at which blood lactate begins to accumulate substantially above resting concentrations during exercise of increasing intensity
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