Chapter 12
This type of receptor responds to stimuli from sources and external from body ( the 5 senses)
exteroreceptors
This type of neuron is situated within CNS, is the middle man between cns and periphery
interneurons
if max tension happens
all motor units have been recruited
explain what happens in action potentials when ap is recieved
ap recieved by muscle fiber before 1st twitch response has subsided, tension developed in 2ns twitch sums w/tension of 1st twitch
receptors in deep layws of skin, tendons, etc. that detect touch virbration, change in pressure, change in joint positon
This type of receptors responds to stimuli from sources within the body- deep in body muscle, body detecting tension, muscle cramp
interorecptors
explain the pathway through types of neurons and CNS
Sensory neuron to interneuron to cns to interneuron to motorneuron
the larger number of muscle fibers leads to
explain tetanic contraction
if time between ap is short it occurs, max tension is developed
explain what happens in flexion withdrawal reflex
cutaneous pain receptors detect pain and Pacinian corpuscles detect change in pressure at each end of limb, facilitates flexion of affected limb to protect body
this type of receptor monitors status and position of joints telling us overall position and posture, falling off a chair
proprioceptors
please explain the pathway of impulse for a muscle contraction
1. neural impulse from cns
2. single travels through- if impulse that arrives at neuromuscular junction is strong enough (ACH threshold meet)
3. generates muscle action potential at membrane (sarcolemma) of individual muscle fiber of motor unit
4. all muscle fibers of motor unit contract together, if impulse arrives at neuromuscular juntcion is not strong enough, then none of the fibers will contract
if the smaller # of muscle fibers leads to
more control of muscle
this is the ability to sense orientation and position and movement of your body
proprioception
explain what happens in crossed extensor reflex
combined effec ts of flexor reflex, reciprocal inhibition and extensor thrust,
if pain is detected at end of affected limb response is to..
flexor reflex of limb to withdrawl from cause of pain
reciporcal inhibition to extensor muscle of affected limb to relax
extensor reflex causes extension of other limb to support body
this type of neuron receives external and internal sensory from periphery and sends info to CNS
sensory (afferent)
only a small number of units recruiyed, 1st motor unit are small, stimulation rate low, typically type 1 fibers
this is a single motor neuron and all muscle fiber innervate, <100 >20, ratio of muscle fibers to motor neurons is dependent on control one has over muscle contraction
motor units
what are the 2 types of proprioception
kinesthetic: sense of movement and position of body parts in space
vestibular: provide sense of balance and equilibrium
explain muscle spindles and stretch reflex
proprioceptor detects stretch of muscle and relays changes in length, stretch reflex: helps us not injure ouselves, knee jerk response
this type of neuron conducts impulses from cns, sends to muscles, cell bodies located within spinal cord, terminal endings of axon and dendrites through extremities
motor (efferent)
what happens if large force is needed
more units recruited, large motor units, more type 2 fibers
explain a single twitch response
if single ap generates single contraction in muscle
what are the types of exterorecptor reflexs?
pacinian corpuscles, flexion withdrawal reflex, and crossed extensor reflex
this reflex is a propricoeptor located in tendon, close to muscle, that detects tension ( by stretching or shortening muscle
tendon reflex: protects/prevents rupturing or tearing of muscle
golgi tendon organ