Chapter 13 Flashcards
Nonencapsulated (free) nerve ending receptors
everywhere in body- adbundant in epi c.t.
thermoreceptors, and nociceptors
tactile discs- light touch receptors
hair follicle receptors- detect bending od hairs. light touch receptors
Encapsulated dendritic endings - most are mechanoreceptors
tactile corpuscles- in dermal papillae . discriminative touch
lamerllar corpuscles- deep in dermirs. deep pressure
bulbous corsuples (ruffini)- -dermins/hypo similar to tendon (stretch)
muscle spindles - proprio’s that respond to muscle stretch
(golgi) tendon- detect stretch
joint kinesthetic receptors- monitor joint position/motion
somatosensory system gets input from receptors in body walls and limbs. explain the 3 main levels of processing in this sys
- receptor lvl- sensor receptors 2. circuit level- ascending pathways 3. perceptual lvl- neuron processing in cortical sensory areas
Neural processing at receptor levl
stimulus-> GP in afferent neuron -> AP at first mylein gap
sensory recepots can adapt to unchaning stimuls and AP declines. name fast adapting receptors and slow (non) adapting
fast- touch/smell receptors
slow (non)- interoceptors/prioprioceptors and pain receptors
explain what happens at perecpetual level of neural processing
thalamus projects fivers to cerebral cortex- somatosensory (in post central gyrus) and sensory association areas
perception takes pace by determining location and magnitude of stimuli
what fibers are associated with sharp pain? burning pain?
sharp- small mylein fibers
burning- small unmylein
what is the pathway of pain perception?
fibers (myelin/nonmyelin)-> release glutamate and substance P -> activating second-order sensory neurons -> spinothalamic pathways
explain the regeneration of nerve fibers in peripheral
if soma of damaged neuron is intact - regeneration can happen
1. axons becoming fragmented @ injury site 2. macrophages clean out debris 3. axon sprouts/filaments grow through a regeneration tube 4. axon regeneration and new myeline forms
spinal nerves have 2 roots - explain ventral and dorsal roots
ventral r.- has motor (efferent) fibers that innervate skeletal
Dorsalr. has sensory (afferent) fibers
what does the dorsal root ganglion have?
cell bodies of sensory fibers
spinal nerves are short, when they emerge from foramen they divide into rami - explain dorsal, ventral ramus
dorsal rami supply- skin and muscles of dorsal trunk (posterior)
ventral- supply rest of trunk and limbs (intercostal nerve in thoracic region only)
rami communicators
have autonomic nerve fibers (sympatheic) attach to base of ventral rami of thoracic spinal nerves
rami vs. roots
- roots lie medial to and for the spinal nerves. each root is either sensory or motor
- rami lie distal to and are lateral branches of spinal nerves. carry sensory and motor as well
what part forms the nerve plexus?
ONLY ventral rami
lumbar plexus is in which muscle and what is the major nerve?
psoas major
femoral nerve
what is dermatome?
area of skin that is innervated by cutaneous branches of single spinal nerve.
5 parts of reflex arc pathway
- receptor: site of stimulation 2. sensory neuron : transmit info to CNS 3. Integration center: can be monosynpathic of poly 4: motor neuron: conduct efferent impulse fro integration 5. effector: muscle fibers or gland cells repsond
stretch and tedon reflexes help with coordination of muscle activity. which sensory receptors activate them? and how?
Proprioceptors: muscle spindles - activated by stretch
and tendon organs - tension in muscles and tendons
Stretch reflex is?
monosynap and ipsilateral
tendon reflex is?
poly and ipsilateral
