Safrans exams

in the condition called __, a virus that is dormant in anterior horns of the spinal cord reactivated and attack neurons in the posterior roots, causing a painful skin rash as seen in the dermatome supplied by the affected spinal nerve

shingles

which of the following statements about the potential is FALSE

the rapid depolarization phase is caused by the entry of potassium ions into the cell

Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?

The axon would be unable to generate action potentials.

reflex that results in a motor response on opposite side of the stimulus and complements the response produced on the same side of the stimulus

crossed extensor reflex

which of the following is NOT true regarding the establishment of a resting potential for neurons

ion pumps in the plasma membrane force sodium ions into the cell and eject potassium ion out of the cell

Reflexes that activate muscles on the same side of the body as the stimulus are called

ipsilateral

motor neurons that control skeletal muscles typically have multiple dendrites and a single axon and are classified as

multipolar

the period during which an excitable membrane cannot respond to any further stimulation is the __ period and is due to inactivation of __

absolute refractory; voltage-gated sodium channels

The sum of the electrical and chemical forces acting on an ion is known as its

electrochemical gradient

area between the dura mater and the vertebral wall, containing fat and small blood vessels

epidural space

which of the following is NOT true about the cerebrum

it derives from the mesencephalon (midbrain)

Axons cross from one side of the spinal cord to the other through the

lateral white column

the anterior root of the spinal cord contains

motor neurons

The white matter of the spinal cord is mainly

myelinated axons

which of the following neurotransmitters is a dissolved gas which has an indirect effect on ion channels

nitric oxide

the myelin sheath that covers many CNS axons is formed by

oligodendrocytes

innermost protective layer of the CNS that is in direct contact with either the spinal cord or brain tissue

pia mater

the tracts that connect the cerebellum to the brain stem are located in the

pons

sensory function of the hand is by the 3 following peripheral nerves

radial, ulnar, and median

Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the

subarachnoid space

When a second EPSP arrives at a single synapse before the effects of the first have disappeared, what occurs?

temporal summation

incoming sensory information is processed and relayed to the cerebrum by the

thalamus

the purpose of the blood brain barrier is

to isolate neural tissue in the CNS from the general circulation, to protect the brain from toxins or pathogens that circulate in the blood

at the brachial plexus, the anterior rami of several spinal nerves converge into large bundles of axons that are termed

trunks

sensory neurons of the PNS that display a single elongated process with a cell body that lies off to the side are classified as

unipolar

The passageway between the lateral ventricles and the third ventricle is the

2 interventricular foramens

method used by clinicians that test for CNS damage and which results in the bending back of toes following stimulation at the lateral sole of an adult foot

Babinski reflex

the following are the main steps in the generation of an action potential

a graded depolarization brings an area of an excitable membrane to threshold, voltage-gated sodium channel activation occurs, sodium ions enter the cell and depolarization occurs, voltage-gated sodium channels are inactivated, voltage gated potassium channels open and potassium moves out of the cell, initiating repolarization, voltage gated sodium channels regain their normal resting properties, a temporary hyper-polarization occurs

in which of the following would the rate of impulse conduction be the greatest

a myelinated fiber of a 10-um diameter

the following steps involved in transmission at a cholinergic synapse

an action potential depolarizes the synaptic terminal at the presynaptic membrane, calcium ions enter the synaptic terminal, acetylcholine is released from storage vesicles by exocytosis acetylcholine binds to receptors on the postsynaptic membrane, chemically-gated sodium channels on the postsynaptic membrane are activated, acetylcholinesterase hydrolyzes acetylcholine, the pre-synaptic terminal reabsorbs choline.

all of the following are true of muscle spindles EXCEPT they

are found in tendons

Mary is in an automobile accident and suffers a spinal cord injury. She has lost feeling in her lower body. Her doctor tells her that swelling is compressing a portion of her spinal cord. Which part of her cord is likely to be compressed?

ascending tracts

spinal nerves conduct

both afferent and efferent signals, both sensory and motor info

an example of function of the PNS is

carrying motor commands to skeletal, smooth, and cardiac muscles, bringing sensory input to the CNS

the posterior root ganglia mainly contain

cell bodies of sensory neurons

which main region of your brain coordinates complex somatic motor pattern that involved voluntary movements such as posture and balance and can fail when intoxicated with alcohol

cerebellum

a postsynaptic neuron will develop an EPSP when

chemically regulated sodium channels open and sodium is diffusing into the cell

a threshold stimulus is the

depolarization necessary to cause an action potential

area of the skin that a single nerve innervates

dermatome

place the following events in the correct order starting where the CSF is mad an ENDING at the site where the CSF is absorbed into the general circualtion

ependymal cell layers which are modified epithelia with tight junctions produces CSF at the choroid plexus, the CSF moves from the choroid plexus into the ventricles and fills the spinal cord central canal, the CSF enters the subarachnoid space through small apertures located by the 4th ventricle, the CSF flows around the entire periphery of the brain and of the spinal cord providing cushioning against physical trauma, the CSF is absorbed into the venous sinuses at the arachnoid villi and eventually regains the general circulation through the jugular veins

injections of analgesics that alleviate severe back pain such as pain experienced during child laber is usually administered in the __ of the lower spinal segments

epidural space

dense layer of connective tissue composed of collage fibers that surrounds the exterior of peripheral nerves

epineurium

an action potential develops if simultaneous stimuli produce postsynaptic graded potentials as follows: 3 EPSPs that each corresponds to +10mV and 1 IPSP that corresponds to -10mV? To answer this question consider a resting potential of -70mV and a threshold potential of -60mV

true