Biology Exam Study Material: Reflex Arc and Neural Processes - Safran Exam #4

Dense layer of connective tissue composed of collagen fibers that surrounds the exterior of peripheral nerves

epineurium

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

epidural space

Area of the skin that a single nerve innervates

dermatome

Region of the spinal cord that contains the cell bodies of somatic motor neurons

anterior horn

Innermost protective layer of the central nervous system that is in direct contact with either the spinal cord or brain tissue

pia mater

The effect observed when multiple stimuli arrive from various neurons at nearby locations to depolarize the post-synaptic membrane

spatial summation

Method used by clinicians that test for CNS damage and in which results in the bending back of toes (spreading like a fan) following stimulation at the lateral sole of adult foot

barbinski reflex

Method used by clinicians that overemphasize a spinal reflex by inhibiting mental awareness

jendrassik maneuver

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

crossed extensor reflex

An example of function of the peripheral nervous system is _________ (multiple answers)

- carrying motor commands to skeletal smooth and cardiac muscles

- integrating information from both inside and outside the body

Sensory neurons of the CNS that duo lay over a single elongated process with a cell body that lies off to the side are classified as

unipolar

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

multipolar

The myelin sheath that covers many CNS axon is formed by

oligodendrocytes

Although the satellite cells in the peripheral nervous system perform similar functions as astrocytes do in the central nervous system, which of the following describes a technique to astrocytes

establish the bbb

Put the following steps in order for the transmission at a cholinergic synapse:

1) chemically gated sodium channels in the postsynaptic membrane are activated

2) calcium ions enter the synaptic terminal

3) acetylcholinesterase hydrolyzes ACh

4) an action potential depolarizes the synaptic terminal at the presynaptic membrane

5) the presynaptic terminal reabsorbs choline

6) acetylcholine is released from storage vesicles by exocytosis

7) acetylcholine binds to receptors on the post synaptic membrane

4, 2, 6, 7, 1, 3, 5

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

- ACh

- dopamine

- norepinephrine

- glutamate

- nitric oxide

nitric oxide

IPSP

are localized hyperpolarization

When a second EPSP (excitatory postsynaptic potential) arrives at a single synapse before the effects of the first have disappeared, what occurs?

hyperpolarization

A postsynaptic neuron will develop an excitatory postsynaptic potential when

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

True or false: an action potential develops if simultaneous stimuli produce post synaptic graded potentials as follows : 3 EPSP that each correspond to a +10 mV and 1 IPSP that corresponds to a -10mV ?

true

A threshold stimulus is the

depolarization necessary to cause an action potential

The sun of an electrical and chemical forces acting on an ion is known as

electrochemical gradient

Which is not true regarding the establishment of a resting membrane potential for neurons:

- negatively charged proteins tend to accumulate on the internal portion of the membrane

- the chemical gradient for potassium ions tends to drive them out of the cell

- ion links in the plasma membrane force sodium ions into the cell and eject potassium ions out of the cells

- sodium ions are forced to remain outside of the cell she to a very limited number of sodium leak channels

negatively charged proteins tend to accumulate in the internal portion of the membrane

Put in correct order the generation of a action potential:

1) voltage gated sodium channels are in activated

2) voltage gated channels old. Abs list assign moves out of the cell initiating repolarization

3) voltage gated sodium channels regain their normal resting properties

4) a graded depolarization brings an area of an exits left membrane to threshold

5) a temporary hyperpolarization

6) voltage gated sodium channel activation occurs

7) sodium enter the cell and depolarization occurs

4, 6, 7, 1, 2, 3, 5

Puffer fish poison blocked 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 potential

Which of the following statements about the action portentously is false:

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

- during the repolarization phase voltage gated sodium channels become inactive and voltage gated potassium channels open

- during the depolarization phase voltage gated sodium channels open and the membrane potentially becomes rapidly positive

- during the hyperpolarization phase the ion pump reestablish the sodium and potassium concentrations across the cell membrane

- repolarization occurs as more potassium ions leave the axon

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

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

a non myelinated fiber of 10 um diameter

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

absolute refractory; voltage gated sodium channels

Injection of analgesics that alleviate severe back pain such as pain experienced during child labor is usually administered in the ______ of the lower spinal segments

epidural space

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

subarachnoid space

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

anterior white commissure

The white matter of the spinal cord is mainly

myelinated axons

The anterior root of a spinal nerve contains

axons of motor neurons

The posterior root ganglion mainly contain

cell bodies of sensory neurons

Spinal nerves conduct ______ (multiple answers)

- both afferent and efferent signals

- both sensory abs motor information

At the brachial plexus the anterior rank of several spinal nerves converge into large bundles of axons that are terms

trunks

Sensory function of the band is served by the three following peripheral nerves

radial, ulnar, and median

In the condition called ______ a virus that is for ant in the anterior horns of the spinal cord activated and attacks neurons in the posterior root cause a painful skin rash as seen in the dermatome supplies by the affected spinal nerve

shingles

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?

acending tracts

Place in correct order of the reflex arc:

1) motor neuron activation

2) sensory neuron activation

3) sensory receptor activation

4) information processing

5) effector Response

3, 2, 4, 1, 5

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

ipsilateral

All of the following are true about neural reflexes except:

- cannot be modified by the brain

- involved at least two neurons

- are automatic motor responses

- are the simplest form of behavior

cannot be modified by the brain

All of the following are true of muscle spindles except:

- are surrounded in tendons

- are surrounded by extrafusal muscle fiber

- are the receptor for the stretch reflex

- consist of socialized fibers called intrafusal fibers

- are innervated internally by gamma motor neurons

are found in tendons

The passageway between the lateral ventricles and the third ventricle is

interventricular foramen

The purpose of the bbb is _________ (multiple answers)

- to protect the brain from toxins or pathogens that circulate in the blood

- to isolate neural tissue in the CNS from the general circulation

Place events in order starting where the CSF is made and ending with the site where the CSF is absorbed:

1) the CSF flows around the entire periphery of the brain and of the spinal cord providing cushions against physical trauma

2) ependymal cell layers which are medicines epithelia with tight junctions produce CSF at the choroid plexus

3) the CSF enters the subarachnoid space through small aperture's lovage by the 4th ventricle

4) the CSF is absorbed into the venous sinuses at the arachnoid villi and eventually regains the general circulation through the jugular veins

5) the CSF moves from the choroid plexus in the ventricles and sulked the spinal cord central canal

2, 5, 3, 1, 4

Which is not the of the cerebrum:

- it's made of a large pair of cerebral hemispheres

- it derives from the mesencephalon (midbrain)

- it is the largest areas of the adult brain

- it's is involved in higher level processing consciousness and intellectual functions

- it's surface area is increased by rounded elevations called gyri

it derives from the mesencephalon (midbrain)

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

pons

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

cerebellum

Incoming sensory information is processed and relayed to the cerebellum by the

thalamus

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

lateral white column