BB wk 1- Peripheral Nervous System

Question 1

the perineurium is continuous with what structure?

Answer 1

the arachnoid membrane

Question 2

what are normal values for glucose and RBC’s its the CSF?

Answer 2

glucose = 4.onM, RBCs = 0

Question 3

what are abnormal values for protein and WBC?

Answer 3

protein = 3.5 G/L
WBC = 10/mm cubed

Question 4

what does the axon of an alpha motor neuron generate?

Answer 4

the CMAP waveform, the compound muscle action potential is a summation of the APs from several muscle fibers. if nerves suppling the muscle become demyelinated, can have problems with conduction, or CMAP amplitude

Question 5

what are the clinical signs of LMN lesion?

Answer 5

fibrillations, muscle weakness, muscle wasting, decreased reflexes ( hyporeflexia),, no clonus, babinski or bing signs

Question 6

pacinian corpuscles do what?

Answer 6

perceive deep pressure, and are an example of mechano receptors because they need mechanical deformation of the receptor to open ion channels and depolarize

Question 7

what nerve does sensory ( mostly) to the head?

Answer 7

CN V

Question 8

efferent activity to the intrafusal muscle fibers is carried in:

Answer 8

axons of the gamma-motor neurons

Question 9

what is generator potential and what is the typical generator potential of a mechanoreceptor?

Answer 9

generator potential is the change in potential needed to activate the receptor. it can be a stretch that depolarizes the receptor, as in mechanoreceptors, or it can be light that hyperpolarizes you like in photoreceptors.

Question 10

what do meissners corpuscles react to?

Answer 10

light touch

Question 11

what does a normal CMAP, with decreased conduction velocity mean on EMG study?

Answer 11

the neuropathy is promarily affecting the myelin sheath, as its just conduction speed thats off

Question 12

which axons are myelinated by schwann cells?

Answer 12

“axons transmitting the dynamic signal fro muscle spindles”. primary myelination cell of the PNS. recall this week was guillan barre

Question 13

the sensory innervation of muscle spindle is primarily detect what?

Answer 13

changes in muscle length

Question 14

name 4 features of guillian barre syndrome

Answer 14

Increased CSF potein, proximal weakness, reduced conduction velocities on peripheral nerve conduction studies, diffuse arreflexia, with peak deficits within 3 weeks of onset

Question 15

while attending a hockey game, person is hit in the temple with a stray puck. The middle meningeal artery is lacerated. blood from the laceration will go where?

Answer 15

epidural space. they will wake up the next morning with a headache, and they will go unconcious relatively late after the headache because the blood takes alot of time to rip the dura off the skull, its very tightly adherent

Question 16

infections of the scalp can spread to the meninges via

Answer 16

the emissary veins

Question 17

the fourth ventricle is located where?

Answer 17

between the pons and cerebellum

Question 18

what are structures of the brainstem?

Answer 18

the midbrain, pons and medulla make up the brainstem, NOT the basal ganglia

Question 19

what are the components of the central nervous system?

Answer 19

the cerebellum, medulla and midbrain are parts of the CNS, but NOT the cranial nerves. The cranial nerves are analagous ot the spinal nerves and are part o fthe peripheral nervous sysmte

Question 20

in what space does the CSF flow?

Answer 20

the subarachnoid space

Question 21

what do the cerebral peduncles contain, information-wise?

Answer 21

descending motor informatino. these are prominent on the ventral surface of the midbrain.

Question 22

a typical example of a pseudo-unipolar neuron is

Answer 22

a neuron in the dorsal root ganglion. this is opposed to options such as the alpha or gamma motor neurons

Question 23

how do you get from the lateral ventricles to the third ventricle?

Answer 23

either called the foramen of monroe, or the interventricular foramen

Question 24

white matter appears white because of the presence of what substance?

Answer 24

myelin

Question 25

what type of fibers is the corpus callosum

Answer 25

comissural fibers

Question 26

if you were to poke someone from the outside of their skull into their brain, what layers would you hit?

Answer 26

hair, skin, scalp, skull, dura, subdural space, arachnoid, subarachnoid space, pia, cortex

Question 27

what induces the neural plate to form?

Answer 27

the notochord

Question 28

cells in the basal plates of the developing spinal cord give rise to what kind of neuron>

Answer 28

motor neurons.

Question 29

the cell bodies of spinal motor nerves develop in the:

Answer 29

basal plate

Question 30

what does the telencephalon give rise to, in the adult

Answer 30

the cerebral hemisphers

Question 31

sympathetic postganglionic neurons are derived from:

Answer 31

neural crest