Lecture 15: 10/2 - Reflexes pt 1 Flashcards
Test 2
What are the 4 reflex pathways?
Stretch reflex
Tendon reflex
Withdrawal reflex
Crossed extensor reflex
What 2 reflex pathways are responses to pain?
Withdrawal reflex
Crossed extensor reflex
All reflexes have a ______ and ______ component
Sensory
Skeletal
What is the Alpha motor neuron?
Neuron thats stimulated that produces an AP down its axon to the skeletal muscle to produce a reflex
What’s an interneuron?
If the stimulation is not strong enough, body uses interneurons to communicate with the Alpha neuron.
Can be excitatory or inhibitory
What reflex can bypass an interneuron?
Stretch reflex
Where are pain/pressure sensors located?
Peripheries
Can tension cause a reflex? Why?
Yes
Pressure/pain sensors found in tendons therefore when stretched too wide –> reflex
T/F: Reflexes stay within the cord and are not communicated to the brain
F
The brain is communicated that the reflex happened but doesnt make the decision for it to happen.
Where does crosstalk happen in reflexes?
Interneuron
Describe the Stretch reflex
Someone pushes you on the forehead
- Sensory information fed in from the muscle spindle through dorsal horn
- Alpha motor neuron stimulated
- Effector muscle (quadricepts) contracts
If there is an interneuron used, it is inhibitory –> inhibits flexor muscle (hamstring) causing relaxation
What is the goal of the Stretch reflex
Keep muscles a constant length
Keep posture constant on weight bearing muscles
What does the interneuron do in the Stretch reflex?
inhibits flexor muscle
What is the stretch sensor in the Stretch Reflex?
Muscle spindle
Describe the muscle spindle
A spring in muscle
Senses how much tension is in the hamstrings
How do you elicit the Stretch reflex?
- Tap on ligament right under patella w/ mallet
- Patella will drop down
- Quadricept muscle will length
- This causes the foot to twitch forward
What is the most simple reflex?
Stretch reflex
What is the goal of the Tendon reflex?
Protective in nature
Prevents muscles from being torn from insertion points in bone when lifting heavy loads