midterm #3 practice exam

The term "nerve fiber" refers to a(n) __________

axon

What is the most common type of neuron

multipolar

The __________ division carries signals to the smooth muscle in the large intestine

visceral motor

Conduction of a nerve impulse would be the fastest in which of the following?

A large diameter myelinated fiber

What would be the best explanation for why myelinated fibers conduct signals faster than unmyelinated fibers?

Electrical signals spread faster through insulated (myelinated) regions of axon.

What is the primary site on a neuron for receiving signals from other neurons

The dendrites

A traveling wave of excitation is known as a(n) __________

nerve signal

Which of the following are effectors?

muscles and glands

Where do most local potentials form in a neuron?

dendrites

Some __________ neurons are specialized to detect stimuli, whereas __________ neurons send signals to the effectors of the nervous system.

afferent; efferent

Which glial cell is found wrapped around nerve fibers in the PNS?

Schwann cells

Where are unmyelinated nerve fibers surrounded by Schwann cells?

In the PNS

Which of the following is true regarding unmyelinated nerve fibers in the PNS?

A Schwann cell folds its plasma membrane around several fibers .

What property of neurons allows them to respond to changes in the environment?

Excitability

A myelin sheath is composed primarily of __________.

lipids

If a neuron is prevented from sending a neurotransmitter across a synapse to another cell, which neuron property is being inhibited?

Secretion

Most metabolic and regulatory functions in a neuron happen where?

soma

In which part of a neuron is the postsynaptic membrane usually found?

Dendrite

Local potentials are __________, meaning they vary in magnitude according to the strength of the stimulus.

graded

Which cells form myelin in the spinal cord?

Oligodendrocytes

Local potentials are __________, whereas action potentials are __________.

graded; all or none

Which of the following is an ascending tract of the spinal cord?

lateral spinothalamic tract

A ganglion is a _________.

cluster of neurosomas in the PNS

Which of the following is not a property of reflexes

Reflexes do not require a stimulus.

A __________ is a cordlike organ composed of numerous __________.

nerve; axons

Many upper motor neurons synapse with lower motor neurons in the ___________.

anterior horn

Which of the following fractures would be the least likely to cause a spinal cord injury?

A fracture of vertebra L4

A nurse pricks your finger to type your blood. You flinch at the pain, pulling your hand back. This is called the __________ reflex.

flexor (withdrawal)

Which of the following is not considered a region of the spinal cord?

Pelvic

Which of the following is contained within gray matter?

Neurosomas, dendrites, and proximal parts of axons of neurons

Neurosomas, dendrites, and proximal parts of axons of neurons

posterior horn

Interneurons are located in the __________.

spinal cord

The connective tissue that surrounds a nerve fascicle is called the __________.

perineurium.

You go to the movies after a long day and you begin to nod off as soon as the movie starts. Your head starts to lower a little, but a reflex causes your head to rise. This is called the __________ reflex.

stretch (myotatic)

The middle layer of the meninges is called the __________.

arachnoid mater

In the patellar tendon reflex arc, the patellar ligament is stretched, which stretches the quadriceps femoris muscle of the thigh. This reflex will cause the quadriceps femoris to __________ and the hamstrings to __________.

Contract; relax

The anterior rami of the spinal nerves form nerve plexuses in all regions except the _________ region(s).

Thoracic region

Reflex arcs that only use two neurons are called ____________ reflex arcs.

Monosynaptic

Which one of the following best describes the order of a somatic reflex?

Somatic receptor → afferent nerve fiber → interneuron → efferent nerve fiber → skeletal muscle

Second-order neurons synapse with third-order neurons in the __________.

The thalamus

Which of the following branches of a spinal nerve has the neurosomas of only sensory neurons?

posterior (dorsal) root

A simple spinal reflex typically involves how many neurons?

3

Motor commands are carried by __________ from the brain along the spinal cord.

descending tracts

Which of the following sensory functions involves neurons in the posterior root ganglion?

Touch

The signals that control your handwriting travel down the spinal cord in the _________ tracts.

the corticospinal tracts.

Neurosomas of the anterior root are located in the __________.

gray matter

A reflex in which the sensory input and motor output are on opposite sides of the spinal cord is called __________.

contralateral

Nerve fibers are insulated from one another by __________.

myelin

Which of the following is true regarding the tendon reflex?

It prevents overcontraction of a muscle.

From superficial to deep, the meninges occur in which order?

dura mater, arachnoid, Pia mater,

Loss of equilibrium and motor coordination would most likely be related to a lesion in which structure?

Cerebellum

The right and left cerebral hemispheres are separated from each other by __________.

the longitudinal fissure

The reticular formation is a web of __________ scattered throughout the __________.

gray matter; brainstem

The gray matter of the cerebrum forms a surface layer called the __________ and deeper masses called __________ surrounded by white matter.

cortex; nuclei

The medulla oblongata originates from which structure?

Myencephalon

Which of the following is not a function of CSF?

To provide oxygen and nutrients to the nervous tissue

The blood-brain barrier (BBB) is most permeable to which of the following?

glucose and oxygen

What is the largest part of the hindbrain?

cerebellum

Where are the cardiac, vasomotor, and respiratory centers found?

Medulla Oblongata

The __________ function(s) in visual attention, such as to look and follow the flight of a butterfly.

Superior Colliculi

Where is the third ventricle located?

diencephalon

Cerebrospinal fluid is secreted by choroid plexuses in the ventricles and reabsorbed by arachnoid granulations in the __________.

superior sagittal sinus

Which structures create the blood brain barrier (BBB)?

Tight junctions between endothelial cells that form the capillary walls

Most gray matter of the cerebrum is located in which region?

Neocortex

Which of the following structures does not contain CSF?

Dural sinus

In which structure is the arbor vitae found?

cerebellum

The pons and cerebellum arise from which secondary embryonic vesicle?q

Metencephalon

A lesion in which structure would cause a person to have an erratic waking/sleeping cycle?

Suprachiasmatic nucleus

Which cranial nerve pathway would be used to look cross-eyed at the tip of your nose?

Trochlear nerve IV

The neocortex contains which of the following cells?

Pyramidal and stellate cells

In the cerebral cortex, which cells process information on a local level?

Stellate

Which of the following is not a motor cranial nerve?

vestibulocochlear nerve (VIII)

Destruction of the amygdala would mostly affect which of the following?

Expression of Emotional Feelings

Planning, motivation, and social judgment are functions of the brain associated with which part of the cerebrum?

Frontal lobe

Which cranial nerve innervates most of the viscera in the thoracic and abdominopelvic cavities?

Vagus nerve X

The great majority of which tracts pass through the corpus callosum?

Commissural

What is the largest of the cranial nerves and the most important sensory nerve of the face?

Trigeminal nerve (V)

Why is 90% of the cerebral cortex referred to as the neocortex?

It developed recently evolutionarily when mammals diversified.

Which lobe is deep to the lateral sulcus and can only be seen by removing some of the overlying cerebrum?

Insula

If the cerebrum was no longer able to communicate with the midbrain, what type of tract would you suspect has been damaged?

Projection

The pineal gland is part of which larger region of the brain?

Epithalamus

The thalamus, hypothalamus, and epithalamus are derivatives of which embryonic structure?

Diencephalon

Which of the following is correct regarding the occipital lobe?

it is the principal visual center of the brain

Nearly all the somatosensory input to the cerebrum passes by way of synapses in which region of the brain?

Thalamus

Which of the following cranial nerves is mispaired?

Optic - I

Place the following events in synaptic transmission at a cholinergic synapse in order: A - A postsynaptic potential is produced; B - Voltage gated calcium channels open and calcium enters the cell; C - ACh is released and diffuses across the synaptic cleft; D - A nerve signal arrives at a synaptic knob; E - Ligand gated sodium channels open and sodium enters the cell.

D, B, C, E, A

A cholinergic synapse uses __________ as its neurotransmitter.

acetylcholine

All of the following are typical characteristics of neurotransmitters except __________.

they are released into the bloodstream before reaching the postsynaptic cell.

Some antidepressant drugs act by inhibiting monoamine oxidase (MAO). What is the function of this enzyme?

It breaks down monoamines

Which of these does not contribute to the cessation of the signal in a synaptic transmission?

Synaptic vesicles secrete neurotransmitter by exocytosis.

Which of these happens first in a cholinergic synaptic transmission?

The synaptic vesicles release acetylcholine

What is the most common inhibitory neurotransmitter in the brain?

GABA

Parkinson disease is a progressive loss of motor function due to the degeneration of specific neurons. These neurons secrete an inhibitory neurotransmitter that prevents excessive activity in motor centers of the brain. What neurotransmitter is this?

Dopamine

A predominance of which waves in an electroencephalogram (EEG) might indicate that a person is physically and mentally relaxed?

Alpha waves

Nonfluent aphasia, due to a lesion in the __________, results in slow speech, difficulty in choosing words, or use of words that only approximate the correct word.

Broca area

What type of brain wave is dominant when a person is awake and resting with closed eyes?

Alpha waves

Which of the following occurs during rapid eye movement (REM) sleep?

The muscles are paralyzed, and body temperature, blood pressure, and heart rate and respiratory rate increase.

The __________ association area is responsible for perceiving and attending to stimuli, and the __________ association area is responsible for identifying them.

parietal; temporal

After a stroke, a patient complains about lack of sensitivity in her right hand. The stroke most likely affected which part of the brain?

Postcentral gyrus in the left parietal lobe

Which of the following functions would most likely be controlled by the representational hemisphere of the cerebrum?

Painting a picture