Reflexes Flashcards
true reflexes
- fast. fewer synapses the quicker
- involuntary. e.g. visceral
- stereotyped = same every time
- has source
somatic reflexes
integrated in spinal cord, not involved with brain. hand and hot stove
cranial reflexes
in brainstem, eye movement for reading
Reflex arc somatic
- somatic receptors (skin, muscles or tendons)
- sensory neuron (d. horn up spinal cord/brainstem) not higher
- integrating center (grey matter in spinal cord/brain) response
- efferent fiber (V. root)
- effector (ex: muscle)
Receptors involved in somatic reflex
Proprioceptors (body position and movement)
- Golgi tendon organs
- muscle spendile fibers
Golgi tendon organs (GTO)
receptor in tendon monitoring stretch.
what does tendon connect
muscle -> bone
tendon stretches means?
why should it stop?
how to stop (goal of GTO)?
- muscle is contracting
- so they don’t tear
- inhibit motor neuron, cause muscle to relax
Muscle spindle fibers
goal?
provide
purpose
1.+ by muscle stretch
2.contract muscle
3. muscle length and stretch
4 reduce potential injury
muscle spindle fibers location
areas of fine movement (eyeballs)
muscle spindle stretch reflex
reciprocal innervation of two antagonistic muscles
ctxn of one muscle and inhib of other
muscle spindle fibers axn potential.
- receptors in muscle + (muscle stretch)
- response = ctx
- axn pot sent to D. root of spinal cord
- synapses in two places (neuron and interneuron)
- ctx agonist and inhib ctxn of antagonist
flexor reflex & cross extension reflex (2 diferent reflexes)
how?
+ via pain.
- stimulate pain receptors
- sensory neurons
- ipsilateral pthwy: contract flexors (inhib extensor)
- contralateral pthwy: Inhib flexors (contract extensor)
visceral reflexes
ctxn of smooth, cardiac muscle or glands
