Simple reflex arcs:
- 1. Receptor (stimulus hits skin)
- 2. Sensory neuron
- 3. Integration center (in the spinal cord/CNS, the interneuron)
- 4. Motor neuron (from spinal cord to muscle)
- 5. Effector
What is the difference between a monosynaptic reflex and a Polysynaptic reflex?
- Monosynaptic reflex: uses the same muscle so the reflex is much quicker.
- Polysynaptic reflex: uses a different muscles so relex is much slower.
Events of the stretch reflex by which muscle stretch is damped.
- 1. stretching of the muscle activates a muscle spindle --> transmitted by afferent fibers from muscle spindle to alpha motor neurons in the spinal cord.
- 2. stimulated alpha motor neurons activate the stretched muscle, causing it to contract.
- 3. impulses transmitted by afferent fibers from muscle spindle to interneurons in the spinal cord result in reciprocal inhibition of the antagonist muscle (muscle underneith)
In a stretch reflex, the inhibition of those interneurons and the antagonist muscles that follows causes them to relax and prevents them from resisting the contraction of the stretched muscle caused by the main reflex arc is...
When are stretch reflexes hypoactive?
- peripheral nerve damage
- ventral horn disease
When are stretch reflexes hyperactive?
corticospinal tract lesions
pupals dilated --> fight/flight
pupals constricted --> rest/digest
reflexes when distracting person more or less vigorous?
reflexes when pulling up on desk more or less vigourous?
less vigorous becaus they are engaging their spine
reflex more or less vigourous when fatigued?
consists of a flexor, or withdrawl, reflex followed by extension of the opposite limb.
When sitting on bench and someone is unexpectedly pricked in the index finger the subject will...
- jerk away with whole body
- (but the reflex is slower since it must go through multiple synapses)
Archilles tendon refelx:
makes person kick down
The superficial cord reflex:
pain/ temperature changes
on bottom of foot --> toes flex and move closer together
What is Babinksi's sign?
an abnormal response in which the toes flare and the great toe move in an upward direction
mediated through the trigeminal nerve
When subjects eye is touched to test the corneal reflex...
- the subject will blink --> somatic
- reflex used to protect eye
tests the somatic motor responses of cranial nerves
When subjects uvula is touched to test the gag reflex...
subject will gag --> somatic
- include pupillary, ciliospinal, and salivary reflexes
- smooth motor
When a light is shinned in the right eye what will occur?
- right eye will constrict
- so will left eye due to consensual response
The consensual response, or any reflex observed on one side of the body when the other side has been stimulated, is called?
The pupillary light response, or reflex occuring on the same side stimulated, is called?
another example of pupillary response.
When neck was stroked the left and right pupals are...
- left is dialated
- right stays the same
- (sympathetic nervous system)
- the effectors are glands not muscles
- secrete saliva when reflexed
- automatic/ parasympathetic