Term
| The nervous system is divided into 2 sections. What are they? |
|
Definition
central nervous system (CNS)
peripheral nervous system (PNS) |
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Term
| What does the CNS consist of? |
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Definition
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Term
What does the PNS consist of?
What are the two divisions of the PNS? |
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Definition
all neurons outside the CNS
sensory
motor |
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Term
| What is the sensory division of the PNS? |
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Definition
| afferent fibers transmit impulses from receptos to CNS |
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Term
| What is the motor division of the PNS? |
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Definition
| efferent fibers transmit impulses from CNS to effectos organs |
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Term
| What does the motor division play a role in? |
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Definition
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Term
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Definition
| a neuron from the CNS to a muscle |
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Term
| T/F The postganglionic axon in the parasympathetic nervous system is long, but short in the sympathetic nervous system. |
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Definition
False
the postganglionic axon is shot in the parasympathetic nervous system and long in the sympathetic system. |
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Term
| What is the length of postganglionic axon in the sympathetic nervous system? |
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Definition
|
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Term
| What are the effector organs of the sympathetic nervous system? |
|
Definition
smooth muscle
cardiac muscle
glands |
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Term
| What is the neurotransmitter and receptor type of the sympathetic nervous system? |
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Definition
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Term
| What is the neurotransmitter in the effector organs of the sympathetic nervous system? |
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Definition
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Term
| What are the receptor types in the effector organs of the sympathetic nervous system? |
|
Definition
|
|
Term
| What are the effector organs of the parasympathetic nervous system? |
|
Definition
smooth muscle
cardiac muscle
glands |
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Term
| T/F The preganglionic axon is short in the sympathetic nervous system, but long in the parasympathetic nervous system. |
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Definition
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Term
| T/F ACh is the neurotransmitter for both the pre and postganglionic axon for the parasympathetic nervous system. |
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Definition
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Term
| T/F The receptor type in the ganglion is the same in the parasympathetic and sympathetic nervous system. |
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Definition
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Term
| What is the receptor in the effector organs of the parasympathetic nervous system? |
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Definition
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Term
| The somatic nervous system deals with what type of neurons? |
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Definition
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Term
| What are the effector organs of the somatic nervous system? |
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Definition
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Term
| T/F The somatic nervous system has both a pre and post ganglionic axon. |
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Definition
False
the somatic nervous system has no ganglion |
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Term
| What is the neurotransmitter of the somatic nervous system? |
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Definition
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Term
| What is the receptor in the effector organ of the somatic nervous system? |
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Definition
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Term
| What is the difference between neurons and nerves? |
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Definition
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Term
| When are neurons called nerves? |
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Definition
| when they are bundled in the periphery |
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Term
Do nerve cells need energy?
What is their primary source of energy? |
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Definition
|
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Term
| T/F Nerves can contain only sensory or motor neurons. |
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Definition
False
nerves can also contain both sensory or motor neurons |
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|
Term
How many regions can the neuron be divided into?
What are these regions called? |
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Definition
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Term
| The cell body of the neuron contains what? |
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Definition
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Term
| What is the role of the dendrites? |
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Definition
conduct impulses toward the cell body
take information into the cell body |
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Term
What is the role of the axon?
How many axons can a neuron have? |
|
Definition
carries electrical impulses away from the cell body to effector organs
one |
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Term
| What is the axon covered in? |
|
Definition
Schawnn cells
form the discontinuous myelin sheath |
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Term
|
Definition
| contact points between avon of one neuron and dendrite of another neuron |
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Term
| What is the surface of the axon, smooth or rough? |
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Definition
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Term
| T/F A neuron can have more the one axon. |
|
Definition
False
ONLY ONE AXON PER CELL, but it can be divided into collateral branches |
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Term
| What does the myelin sheath do? |
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Definition
|
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Term
| What is the surface of the dendrite, smooth or rough? |
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Definition
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Term
| T/F Usually many dendrites per cell. |
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Definition
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Term
| T/F Dendrites have a myelin sheath. |
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Definition
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Term
| T/F Usually the larger diameter or the axon, the greater the speed of neural transmission. |
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Definition
|
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Term
| T/F Axons with smaller myelin sheaths conduct impulses more rapidly. |
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Definition
False
axons with larger myelin sheaths conduct impulses more rapidly |
|
|
Term
| what is the longest cell in the body? |
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Definition
|
|
Term
| what is the oldest cell in the body? |
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Definition
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|
Term
| What is the disadvantage of nerve cells? |
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Definition
| When damaged or die they cannot be replaced |
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Term
| What happens when there is damage to the myelin sheath? |
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Definition
| slows down the speed of neural transmission |
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Term
| What is multiple sclerosis? |
|
Definition
neurological disease that destroys myelin sheath axons
autoimmune disease |
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|
Term
| Can exercise treat multiple sclerosis? |
|
Definition
| No, but there are some studies the suggest exercise can influence cellular and immune parameters |
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|
Term
| What kind of tissue are neurons? |
|
Definition
|
|
Term
|
Definition
| ability to respond to a stimulus and convert it to a neural impulse |
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|
Term
|
Definition
| transmission of the impulse along the axon |
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|
Term
| What is resting membrane potential? |
|
Definition
the potential difference that exists across the membrane of excitable cells such as nerve and muscle cells
when all these ion forces balance out |
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Term
| Can our cells be activated all the time? |
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Definition
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|
Term
| To activate a muscle cell we must increase or decrease the membrane potential? |
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Definition
|
|
Term
| At rest, the membrane potential is positive or negative? |
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Definition
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|
Term
What is the resting membrane potential?
What does this mean? |
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Definition
-70mV
inside the cells has 70mV less than outside the cell |
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Term
| The process of making the inside of the cell more positive to activate is called what? |
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Definition
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|
Term
| T/F the negative charge inside the cell CANNOT cross the membrane and attract positive charges from the extracellular fluid. |
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Definition
|
|
Term
| At rest which two ions can pass easily across the membrane? |
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Definition
|
|
Term
| What is the -70mV resting membrane potential determined by? |
|
Definition
the permeability of membrane to different ions
ion concentration |
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|
Term
| What are the major regulators of membrane potential? |
|
Definition
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|
Term
| T/F K+ is highest inside the cell, Na+ is highest outside the cell |
|
Definition
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|
Term
At rest almost all Na+ channels are (open/closed), but few K+ channel gates are still (open/closed).
What does this result in? |
|
Definition
closed
open
a net loss of positive charges |
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|
Term
| How can NE/E regulate Ca levels? |
|
Definition
beta receptors open Ca channels to bring Ca into the cell
alpha receptors break down glucose |
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|
Term
| How do you prevent a net loss of positive charges? |
|
Definition
| the cell membrane has a Na+/K+ pump using ATP to maintain both Na+ and K+ intracellular and extracellular concentrations and resting membrane potential |
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Term
| How much Na+ to K+ does the Na+/K+ pump? |
|
Definition
| 3 Na+ out per 2 K+ in for each cycle of the Na+/K+ ATPase |
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|
Term
| What hormone regulates K+ concentration? |
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Definition
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|
Term
| Occurs when a stimulus or sufficient strength depolarizes the cell. |
|
Definition
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|
Term
| Returns to resting membrane potential, gains negative charge. |
|
Definition
|
|
Term
| What happens during depolarization? |
|
Definition
open Na+ channels and Na+ diffuses into the cell
K+ channels closed
inside becomes more positive |
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|
Term
| What happens during repolarization? |
|
Definition
open K+ channels, K+ leaves the cell rapidly
Na+ channels closed |
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Term
| Once a nerve impulse is initiated, it will travel the length of one neuron without a decrease in voltage. |
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Definition
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|
Term
| At 30mV what position are the Na+ channel gates in? |
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Definition
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|
Term
| Before the impulse the Na+ gates are? |
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Definition
|
|
Term
| After the impulse the K+ gates are open or closed? |
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Definition
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|
Term
| T/F Repolarization immediately follows depolarization. |
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Definition
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|
Term
| Small gap between presynaptic neuron and postsynaptic neuron. |
|
Definition
|
|
Term
| What is a neurotransmitter? |
|
Definition
chemical messenger released from presynaptic membrane
binds to a receptor in postsynaptic membrane
causes depolarization of postsynaptic membrane |
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|
Term
| What happens after the muscle is depolarized? |
|
Definition
Ca is released from the sarcoplasmic reticulum
requires an action potential
binds to triponin C |
|
|
Term
| What are the steps of synaptic transmission? |
|
Definition
Step 1: action potential travels down the motor neuron to the presynaptic terminal
Step 2&3: depolarization of the presynaptic terminal opens Ca2+ channels and flows into the presynaptic terminal, which causes ACh to be released by exocytosis.
Step 4&5: The ACh diffuses across the the synaptic cleft and binds to nicotinic receptors on the postsynaptic membrane, opening Na+ channels. Allowing Na+ to enter and cause the depolarization (excitatory postsynaptic potentials)
Step 6: the depolarization of the postsynaptic membrane spread by local currents to muscle fibers to reach action potential
Step 7: to prevent chronic depolarization of the postsynaptic neuron, the ACh must be degraded. The postsynaptic neuron becomes repolarized |
|
|
Term
|
Definition
detaches from the receptor
broken down by AChE to choline
almost 50% of choline is pumped back into the presynaptic neuron to be used to make ACh |
|
|
Term
| Why is calcium required for muscle contraction? |
|
Definition
| Ca uptake needed to release ACh |
|
|
Term
| T/F all neurotransmitters are excitatory. |
|
Definition
False
NOT ALL neurotransmitters are excitatory some are inhibitory |
|
|
Term
|
Definition
excitatory postsynaptic potentials
cause depolarization |
|
|
Term
|
Definition
inhibitory postsynaptic potentials
causes hyperpolarization
more negative |
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|
Term
What is hyper polarization?
What causes it? |
|
Definition
more negative than resting membrane potential
causes by the efflux of K+ or influx of Cl- |
|
|
Term
| T/F ACh has inhibitory abilities, but not excitatory. |
|
Definition
|
|
Term
| How do EPSPs bring a neuron to threshold? |
|
Definition
Temporal summation
spatial summation |
|
|
Term
| What is temporal summation? |
|
Definition
| to sum several EPSPs from a single presynaptic input over a short time |
|
|
Term
| What is spatial summation? |
|
Definition
| to sum EPSPs from several different presynaptic inputs |
|
|
Term
|
Definition
| posture and movement depend on a combination of involuntary reflexes coordinated by the spinal cord |
|
|
Term
|
Definition
| one motor neuron and the muscle fibers it innervates |
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|
Term
| How is the amount of muscle fibers being innervated determined? |
|
Definition
| the nature of the motor activity |
|
|
Term
| what is a motor neuron pool? |
|
Definition
| the set of motor neurons innervating fibers with the same muscle |
|
|
Term
| what are the two types of motor neurons? |
|
Definition
|
|
Term
| alpha motor neurons have small or large diameters? |
|
Definition
|
|
Term
| what do alpha motor neurons innervate? |
|
Definition
| normal muscle fiber (extrafusal) that generate tension by contracting to allow skeletal movement |
|
|
Term
| gamma motor neuron have smalle or large diameters? |
|
Definition
|
|
Term
| what do gamma motor neurons innervate? |
|
Definition
| thin muscle fiber (intrafusal), a component of muscle spindles that provides sensory information about changes in muscle length |
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|
Term
what are extrafusal fibers?
innervated by?
what are the used for? |
|
Definition
normal muscle fibers
innervated by alpha motor neurons
used to generate force |
|
|
Term
what are intrafusal fibers?
innervated by? |
|
Definition
thin muscle fibers
innervated by gamma motor neurons
too small to generate significant force
muscle spindle composed of several intrafusal fibers |
|
|
Term
| What is the muscle spindle? |
|
Definition
| insert into the connective tissue within the muscle |
|
|
Term
| what does the muscle spindle consist of? |
|
Definition
intrafusal fiber
sensory neuron
gamma motor neuron |
|
|
Term
| what do primary nerve fibers detect? |
|
Definition
| velocity of length changes |
|
|
Term
| what do secondary nerve fibers detect? |
|
Definition
| length of the muscle fiber |
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|
Term
| T/F alpha and gamma motor neurons are activated simultaneously. |
|
Definition
|
|
Term
| what is the stretch reflex? |
|
Definition
| stretch on muscle causes reflex contraction |
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|
Term
| step by step function of the muscle spindle. |
|
Definition
Step 1: when a muscle is stretched, the extrafusal and intrafusal muscle fibers are lengthened
Step 2: this increase in length of intrafusal fibers is detected by and activate the sensory nerve fibers
Step 3: activations of sensory nerve fibers stimulate alpha motor neuron in the spinal cord
Step 4: then this alpha motor neuron innervates extrafusal fibers in the same muscle resulting in (1) the muscle contracts and (2) resisting being stretched thereby decreasing stretch on the muscle spindle which returns to original length |
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|
Term
| When the extrafusal fiber is activated what happens to synergistic and antagonistic muscles? |
|
Definition
synergistic are activated
antagonistic relax |
|
|
Term
| what is the Golgi Tendon Organ? |
|
Definition
| a stretch receptor found in tendons |
|
|
Term
|
Definition
Step 1: when the muscle contracts, the extrafusal muscle fibers become shorter, activation GTOs
Step 2: when activated, the GTO sends information to the spinal cord via sensory neuron that synapse on inhibitory interneuron in spinal cord
Step 3: when the inhibitory interneuron is activated, it inhibits the alpha motor neuron, producing relaxation of the contracting muscle |
|
|
Term
| During exercise training, why can you lift more weight? |
|
Definition
|
|
Term
| What happens at the same time as the relaxation of the synergistic muscles in the GTO? |
|
Definition
| the contraction of antagonistic muscles |
|
|
Term
| What is the crossed extensor reflex? |
|
Definition
| occurs in response to painful stimulus |
|
|
Term
| How does the crossed extensor reflex work? |
|
Definition
Step 1: when your right hand touches are hot stove, a sensory neuron is activates to synapse on multiple interneurons in the spinal cord, which then innervate alpha motor neurons
Step 2: then, the reflex is activated to cause flexor muscles to contract and extensor muscles to relax (reciprocal inhibition)
Step 3: however, on your left hand this reflex causes flexor muscles to relax and extensor muscles to contract to maintain balance |
|
|
Term
| What is reciprocal inhibition? |
|
Definition
| simultaneous excitatory and inhibitory activity |
|
|
Term
How many synapses do each reflex have?
stretch?
GTO?
crossed-extensor? |
|
Definition
strech:1
GTO:2
crossed-extensor: many |
|
|
Term
| what is the stimulus for the stretch reflex? |
|
Definition
|
|
Term
| what is the stimulus of the GTO? |
|
Definition
| contraction of the muscle |
|
|
Term
| what is the stimulus of the crossed-extensor reflex? |
|
Definition
|
|
Term
| what is the response of the stretch reflex? |
|
Definition
| contraction of the muscle |
|
|
Term
| what is the response of the GTO? |
|
Definition
|
|
Term
| what is the response of the crossed-extensor reflex? |
|
Definition
| flexion on ipsilateral side; extension on contralateral side |
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