Neuro Exam 1 questions Flashcards
A patient reports loss of pain and temperature in the right leg. Lesion of which of the following structures will best explain this sensory loss?
Left spinothalamic tract
Pick the correct statement about group 1 fibers
They process proprioception sensation from muscles spindles and golgi tendon organs
Plasticity occurs in the adult somatosensory cortex following?
Amputation of a limb or digit
Repetitive behavior/ overuse of particular digits
Cell bodies of the first order neurons processing proprioception information from the facial area are located in the:
Mesencephalic nucleus of the trigeminal complex
Which of the following nerves process somatosensory information from the posterior 1/3 third of the tongue?
Glossopharyngeal nerve
Which of the following pathways carriers mechanosensory information from the legs?
Dorsal column medial lemniscal pathway
Which of the following sensory fibers has the slowest conduction velocity?
C fibers= Slowest conduction
A fibers= Fastest
B fibers= intermediate
Which of the following skin areas has the smallest two-point discrimination threshold?
Finger tips
** The hand has one of the greatest receptor densities. Remember; the smaller the two point discrimination, the greater the receptor density in the body (smaller two point discrimination)
Receptor potential in a Pacinian corpuscle is generated predominantly by the influx of:
Na+
What statement is true about sensory transduction?
Generator potential of a critical threshold initiates action potential
Which of the following mechanoreceptors are most helpful in processing fine tactile sensations?
Merkel discs
Where does CSF flow?
In subarachnoid space
Blood supply to the brain is more reliable than other organs because:
Circle of willis (arterial anastomosis) creates redundancy in circulation
A 62 year old women is admitted to the hospital after suffering an embolic stroke secondary to previously undiagnosed arterial fibrillation
Middle cerebral artery
A 21 year old college student is brought to the ER by his roommate. He started feeling sick last night with a headache and fever. In the morning, he vomitted and complained of a stiff neck before becoming lethargic. CT of the brain revealed no lesions of bleeding. The physician prepares to perform a lumber puncture. What is true about this procedure?
The correct intervertebral space can be found by drawing a line connecting the posterior superior lilac crest
Efferent division:
Motor pathways
Preganglionic neuron:
Cell body located in the CNS
Neurons emerge from the brain stem or spinal cord
Form synapse at the ganglia
What is a ganglia:
Collection of nerve bodies
Postganglionic neurons:
Cell body located in the ganglia
Non-mylelinate neurons
Terminates on effector organs> smooth muscles, cardiac muscles, exocrine glands
T/F: Sympathetic preganglionic fiber will be long
False. Sympathetic preganglionic fiber will be short
*Remember: SSL (Sympathetic; short (pre), long (post)
where are sympathetic preganglionic neurons located?
T1-L3 spinal cord
Where are sympathetic postganglionic neurons located?
paravertebral or preortic ganglion
Tizanidine:
MOA:
Agonist alpha 2 adrenoreceptors in spinal cord> Bind to Upper motor neuron
-Tone deceased by blocking the release of excitatory neurons (i.e. epi, NE, glu)
-increasing the inhibition of presynaptic motor neurons> leads to reduced release of excitatory amino acids from the spinal interneurons
