6.3 Nervous System

Question 1

purpose of endogenous pain suppression

Answer 1

we have built in pathways that are activated during stress that can help diminish the perception of pain for a breif period of time

Question 2

define stress induced analgesia

Answer 2

specific, powerful mechanisms for pain control, utilizing enkephalins and endorphins

Question 3

purpose of B-endorphin in stress-induced analgesia? path of action?

Answer 3

• released from hypothelamus and binds to 3rdventricle
• binds to pre-synaptic terminal to open up Cl- channels, which causes a hyperpolarization so it is hard for internueron to become active enough to release NT
• descending pain suppression pathway nihibit the interneuron by pre-synaptic inhibition; this decreases transmission of ascening pain-inducing neural impulses

Question 4

pain is mediated by group ____?

Answer 4

group 3 (A-delta) nerve fibers AND C-fibers

Question 5

periodontal ligament is richly supplied by group ___?

Answer 5

1 (A-alpha) nerve fibers

Question 6

PDL sensory mechanoreceptors are exquisitly senstive to ?

Answer 6

directionality of applied forces

Question 7

PDL neurons have cell bodies in either?

Answer 7

trigeminal ganglion or mesoencephalic nucleus

Question 8

forces excerted on PDL cause?

Answer 8

sensation perception and reflex jaw movement and relfex salivation

Question 9

more than ___% of the motor cortex is dedicated to vocalization and the control of the hands

Answer 9

50%

Question 10

neither the cerebellum nor the basal nuclei can initiate______, yet both are needed for the?

Answer 10

initiate motor function

*both are needed for the control of normal motor activites

Question 11

cerebelum function in?

Answer 11

timing motor acitivaties like fast typing!

**injury leads to incoordination (loss of timing, intention tremor)

Question 12

1) basal nuclei function in control of?
2) recieves input from?
3) houses?
4) what type of tumor

Answer 12

1) voluntary SMOOTH movement
2) input from cerebral cortex, sends output back to cerebral cortex via thalamus
3) houses substania nigra (and others)
4) relaxation tremor

Question 13

intention vs relaxation tremor caused by what areas of brain?

Answer 13

• intention= cerebellar injury; overshoot; intentional movement
• relaxation= basal ganglia/substania nigra; EARLY parkinsons

Question 14

what area the muscle sensory receptors?

Answer 14

1) muscle spindles- senses muscle stratching (afferent stretch receptors and GAMMA efferent motor neuron)
2) golgi tendon orgen- sense tension

Question 15

1) gamma efferent motor neuron found where?

2) what does it cause?

Answer 15

at the ends of muscle spindle fibers

2) causes contraction of the muscle spindle; keeps intrafusal fibers same length as extrafusal fibers

Question 16

muscle spindles are found where?

Answer 16

intrafusal muscle fibers
-wrap around muscle fibers centrally
does not generate tension

Question 17

sensory afferent neuron senses?

Answer 17

magnitude and rate of stretch

Question 18

reciprocal inhibition and reciprocal activation

Answer 18

inhibition= activation of movement agonist is paired with inhibition of the movement antagonist

activation= inhibition of a movement agonist is paired with activation of the movement antagonist