Exam 1 - Chapter 14

___ binds to ligand-regulated gates, and is the most common inhibitory neurotransmitter in the brain.

-aminobutyric acid (GABA)

How many muscle fibers stimulate one somatic motor neuron?

0

There are __ pairs of spinal nerves.

31

Aerobic respiration produces approximately _________ more ATPs per glucose molecule than glycolysis does.

36

During muscle contraction, a single myosin head consumes ATP at a rate of about __________ ATP per second.

5

___ excites skeletal muscle and inhibits cardiac muscle.

Acetylcholine

__________ show MORE lateralization than __________.

Adult males; adult females

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

Alpha

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

This figure shows a dermatome map. A patient with no sensation in the left thumb would probably have a nerve damaged in

C6

The cerebellum is __________ to the cerebrum.

Caudal

In which structure is the arbor vitae found?

Cerebellum

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

Cerebellum

The following are all major components of the brainstem except the _________.

Cerebellum

There are no cranial nerves associated with which part of the brain?

Cerebellum

What is the largest part of the hindbrain?

Cerebellum

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

Commissural

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

Cortex;nuclei

____ are the primary site for receiving signals from other neurons.

Dendrites

___ carry motor commands from the brain along the spinal cord

Descending tracts

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

Diencephalon

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

Dura mater, arachnoid, pia mater

Which of the following is a property of collagen?

Elasticity

___ keep(s) nerve fibers insulated from one another.

Endoneurium

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

Epithalamus

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

Expression of emotional feelings

A nerve fiber is enclosed in its own fibrous sleeve called perineurium

False

Acetylcholine triggers the synthesis of the second messenger cAMP only in neurons of the PNS.

False

All cranial nerves lead to structures in the head and neck.

False

Any two EPSPs will override one IPSP.

False

In a myelinated fiber only the initial segment in the trigger zone have voltage-regulated channels.

False

In the brain, neurons are more abundant than neuroglia.

False

Most nerves are motor nerves.

False

Motor signals typically begin in an upper motor neuron in the thalamus.

False

Neurons move material away from the soma by retrograde transport.

False

Oligodendrocytes serve the same purpose in the CNS that satellite cells do in the PNS

False

Somatic reflexes are responses of skeletal, smooth and cardiac muscles.

False

Spinal cord conducts signals up and down the body passing through gray and white matter, respectively.

False

Structures in the midbrain control homeostasis and relay sensory signals to specific regions of the cerebral cortex.

False

The blood-CSF barrier is composed of dense regular connective tissue lining the ventricles.

False

The blood-brain barrier (BBB) helps prevent hemorrhages in the nervous tissue of the brain.

False

The cerebellum is the largest part of the brain.

False

The epidural space is filled with cerebrospinal fluid (CSF).

False

The medulla oblongata is the most rostral part of the brain.

False

The nervous system employs exclusively electrical means to send messages, whereas the endocrine system communicates by means of chemical messengers.

False

The stretch reflex is a tendency of a muscle to stretch when it is overcontracted.

False

The tendon reflex is the inhibition of a muscle contraction that occurs when its tendon is excessively stretched.

False

The vision association area resides primarily in the temporal lobe.

False

There are three cranial nerves involved in eye movement and two in the sense of taste.

False

When a neuron is stimulated, Na+ gates open and allow Na+ to exit the cell.

False

Which body region is controlled by the largest area of the motor cortex?

Fingers

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

Frontal lobe

Which of these happens first in an adrenergic synaptic transmission?

G protein dissociates from the NE receptor

___ are examples of effectors of the nervous system.

Glands

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

Glucose and oxygen

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

Gray matter; brainstem

Short-term memory is associated with the __________, whereas long-term memory is associated with the __________.

Hippocampus; cerebral cortex

Sex drive, body temperature, and food and water intake are regulated by which part of the brain?

Hypothalamus

Which structure forms the floor and part of the walls of the third ventricle?

Hypothalamus

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

Insula

Which of the following is correct regarding the occipital lobe?

It is the principal visual center of the brain.

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

Lateral, third, and fourth; superior sagittal sinus

Where are the hippocampus and amygdala found?

Limbic system

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

Medulla oblongata

A patient is experiencing a high fever, stiff neck, drowsiness, and intense headaches. A spinal tap showed bacteria and white blood cells in the cerebrospinal fluid (CSF). This individual most likely has what condition?

Meningitis

The pons and cerebellum arise from which secondary embryonic vesicle?

Metencephalon

___ neurons are the most common type of neurons.

Multipolar

The medulla oblongata originates from which structure?

Myelencephalon

Which of the following is not associated with the pons?

Neck movements

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

Neocortex

___ form myelin in the spinal cord.

Oligodendrocytes

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

Painting a picture

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

Parietal; temporal

Which of the following structures appears as a large bulge just rostral to the medulla?

Pons

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

___ has the greatest influence on the resting membrane potential

Potassium

This image shows a representative neuron. What does "5" represent?

Schwann cells

___ fibers innervate eyes and ears.

Special

Degeneration of the neurons in which of the following structures leads to the muscle tremors associated with Parkinson disease?

Substantia nigra

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

Superior colliculi

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

Suprachiasmatic nucleus

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

Thalamus

Which of the following best describes the resting membrane potential (RMP)?

The intracellular environment is negatively charged.

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

The longitudinal fissure

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.

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

There are no internodes in unmyelinated fibers.

Which structures create the blood brain barrier (BBB)?

Tight junctions between endothelial cells that form the capillary walls

Which of the following is not a purpose of the excess postexercise oxygen consumption (EPOC) in muscle?

To neutralize carbon dioxide buildup

Which of the following is not a function of CSF?

To provide oxygen and nutrients to the nervous tissue

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

Trigeminal nerve (V)

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

Trochlear (IV)

A dermatome is a nerve innervating a specific region in the skin.

True

A ganglion is a swelling along a nerve containing cell bodies of peripheral neurons.

True

A stretch reflex is often accompanied by reciprocal inhibition.

True

Action potential never occurs in dendrites.

True

Both cerebrum and cerebellum have gray matter in their surface cortex and deeper nuclei, and white matter deep to the cortex.

True

Cervical and lumbar enlargements are wide points in the cord marking the emergence of motor nerves.

True

Each portion of the spinal cord served by a spinal nerve is called a segment of the cord.

True

Ependymal cells line the inner cavities of the CNS.

True

Memories are formed by neural pathways of modified synapses.

True

Most neurons have multiple dendrites

True

Nerve fibers in a given tract in the white matter are similar in origin, destination, and function.

True

Nitric oxide (NO) acts as a neuromodulator by altering synaptic function.

True

Norepinephrine is a monoamine.

True

Posterior root ganglia contain somas of unipolar neurons

True

Purkinje cells are unusually large neurons found in the cerebellum.

True

The Wernicke area recognizes spoken and written language.

True

The amygdala, hippocampus and hypothalamus are involved in such feelings as love, anger, fear, pleasure, and pain.

True

The cerebellum exhibits folds called gyri separated by grooves called sulci.

True

The cross extension reflex is the contraction of the extensors on one side of the body when the flexors are contracted on the other side

True

The forebrain consists of the cerebrum and the diencephalon.

True

Unipolar neurons have only a single process leading away from the soma.

True

Which fibers are primarily responsible for producing lactate?

Type IIB fast glycolytic fibers

The pyramidal cells of the PRECENTRAL gyrus are called __________ neurons.

Upper motor

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

Vagus nerve (X)

Which of the following is not a motor cranial nerve?

Vestibulocochlear nerve (VIII)

____ division carries signals to the smooth muscle in the large intestine.

Visceral motor

Which of the following individuals would have more mitochondria in her skeletal muscle?

a 22-year-old soccer player

Which of the following contains overlapping thick and thin filaments?

a band

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

a fracture of vertebra L4

A traveling wave of excitation is what we know as

a nerve signal.

The best type of neural pool for producing a prolonged output is

a reverberating circuit

This image shows an action potential. What does "1" represent?

a rising local potential

Which of these is an example of an EPSP in a typical neuron?

a voltage change from -70 mV to -69.5 mV

A cholinergic synapse employs ___ as its neurotransmitter.

acetylcholine

A mixed nerve consists of both

afferent and efferent fibers

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

afferent; efferent

The fibers that carry action potentials to cause skeletal muscle to contract are

alpha motor neurons.

Nerve fiber refers to

an axon.

A myofilament that runs throught the core of a thick filament and anchors it to a Z disc is called a(n) __________.

an elastic filament.

If a bee sting on the right thigh causes a quick involuntary reaction of the right arm, this would be an example of

an intersegmental reflex.

This figure shows a cross section of the spinal cord. What does "3" represent?

anterior horn

This figure shows a detail of the spinal cord, meninges and spinal nerves. What does "4" represent?

arachnoid mater

Cerebrospinal fluid fills in the space between

arachnoid mater and pia mater.

About 90% of the neurons in the nervous system are ___ neurons.

association

Loss of muscle mass from lack of activity is called _____

atrophy

Where is dystrophin, the protein that is defective in muscular dystrophy, normally found?

between the outmost myofilaments and the sarcolemma of a muscle fiber

This figure shows the posterior aspect of spinal nerve roots and plexuses. What does "3" represent?

brachial plexus

Which of the following has the largest mitochondria?

cardiac muscle

The bundle of nerve roots that occupy the vertebral canal from L2 to S5 is called the

cauda equina.

Nerves are ___ of the nervous system.

cells

The myelin sheath is formed by

cells

Opening of __ gates produces an ___.

chloride; IPSP

A ganglion is a

cluster of neurosomas in the PNS.

Even though all action potentials are the same, the brain can differentiate a variety of stimuli by source and intensity. The mechanism by which the nervous system converts these action potentials into meaningful information is called neural

coding

When a skeletal muscle lengthens, its __________ helps resist excessive stretching and subsequent injury to the muscle.

collagen

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

contract and the antagonist muscles, the hamstrings, to relax.

Which of the following is an accurate comparison of skeletal muscle to smooth muscle?

contracts and relaxes more slowly.

A reflex where the sensory input and motor output are on opposite sides of the spinal cord is called a(n) _____ reflex arc.

contralateral

The transfer of phosphate from CP to ADP is catalyzed by ________

creatine kinase

Most local potentials happen at the

dendrites

This image shows a representative neuron. What does "1" represent?

dendrites

Opening of sodium gates typically leads to

depolarization of the plasma membrane.

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. This neurotransmitter is

dopamine

Epidural anesthesia is introduced in the epidural space between ___ to block pain signals during pregnancy.

dural sheath and vertebral bones

All muscle types will respond to an electrical stimulus because all muscle cells are _________.

excitable

Presynaptic inhibition is the opposite of

facilitation

A dark band formed by parallel thick filaments that partly overlap the thin filaments is known as an H band.

false

The sliding filament theory of muscle contraction has emerged from research only in the last 10 to 15 years.

false

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

flexor (withdrawal) reflex.

The sensitivity of the muscle spindle is maintained by

gamma motor neurons.

Which of the following would be caused by a contraction of smooth muscle?

goose bumps

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

graded

Inhibitory postsynaptic potentials (IPSPs) are associated with

hyperpolarization of the cell membrane.

This image shows an action potential. What does "6" represent?

hyperpolarization of the membrane

An inhibitory local potential

hyperpolarizes the plasma membrane.

If one nerve stimulus arrives at a muscle fiber so soon that the fiber does NOT relax at all from the previous twitch, the most likely result will be __________. This can only be achieved in the laboratory.

incomplete tetanus

If one nerve stimulus arrives at a muscle fiber so soon that the fiber has only partially relaxed from the previous twitch, the most likely result will be __________.

incomplete tetanus

The training regimen of a competitive weight lifter is designed partly to _______

increase the average number of myofibrils per muscle fiber

Which of the following will cause the plasma membrane to hyperpolarize when at its RMP?

inflow of chloride

Where would you expect to find numerous gap junctions in muscular tissue?

intercalated discs of cardiac muscle`

Shortening a muscle while it maintains constant tension is called __________.

isotonic contraction.

Why is the contraction strength of smooth muscle relatively independent of its resting length?

it does not have sarcomeres.

80% of the lactate produced by skeletal muscle is converted to pyruvate by the __________.

kidneys

Conduction speed of a nerve fiber would be the fastest in a

large myelinated fiber

Most of the myelin sheath is composed of

lipids

Athletes who train at high altitudes increase their red blood cell count, which increases their oxygen supply during exercise. Increased oxygen supply results in __________.

longer aerobic respiration

The quickest reflex arcs involve only two neurons, thus forming __ reflex arcs.

monosynaptic

A muscle spindle contains mostly

muscle fibers.

Which of the following groups of muscles have the most muscle spindles?

muscles of the hand

In order for muscle to continue contracting during anaerobic fermentation, which of the following is essential?

myokinase

A ___ is a cordlike organ composed of numerous ___.

nerve; axons

Gray matter contains

neurosomas, dendrites, and proximal parts of axons of neurons.

Exposure to the bacterium Clostridium tetani causes continuous release of acetylcholine. What effect does this have on smooth muscle?

no effect

During the absolute refractory period

no stimulus of any strength will trigger a new action potential.

Local potentials are ___, whereas action potential are ___.

nondecremental; decremental

The flexor (withdrawal) reflex employs a ____, which maintains a sustained contraction.

parallel after-discharge circuit

A skeletal muscle generates the greatest tension when it is __________.

partially stretched before being stimulated.

The spinal cord is divided into all of the following regions except

pelvic.

This figure shows the anatomy of a nerve. What does "3" represent?

perineurium

The cervical plexus gives origin to the ___ nerve(s

phrenic

Which of the following is not a characteristic of a muscle cell?

plasticity

Which of the following branches of a spinal nerve have somas of solely sensory neurons?

posterior (dorsal) root

Neurosomas of the posterior root are located in the ___, whereas neurosomas of the anterior root are located in the ___.

posterior root ganglion; gray matter

This figure shows a detail of the spinal cord, meninges and spinal nerves. What does "1" represent?

posterior root of a spinal nerve

During hyperpolarization (or afterpotential

potassium ions are leaving the cell.

The sarcolemma of a resting muscle fiber is most permeable to __________

potassium.

Drugs called calcium channel blockers may be used to lower blood pressure by causing arteries to vasodilate. How do you suppose these drugs work?

prevent calcium from entering smooth muscle, thus allowing the muscle to relax

The tendon reflex

prevents overcontraction of a muscle.

Tendon organs are

proprioceptors

As you are lifting a box, someone places extra weight on top of it. For your muscle to continue contracting and lifting the box, the muscle must __________.

recruit more muscle fibers

The process of engaging more motor units to increase the strength of a muscle contraction is called __________.

recruitment

These are all properties of reflexes except

reflexes are spontaneous actions of the nervous system.

When acetylcholinesterase outlasts the release of acetylcholine from the synaptic vesicles, the skeletal muscle __________.

relaxes

When the voltage of a plasma membrane shifts from +35mV towards 0 mV, we say the cell is

repolarizing

Cardiac muscle has very little capacity for regeneration because it lacks __________.

satellite cells

Which of the following nerves originates in the coccygeal plexus?

sciatic

Which muscle type depends solely on the sarcoplasmic reticulum as its calcium source?

skeletal muscle

Which muscle(s) can contract without the need for nervous stimulation?

smooth and cardiac muscle

While the membrane is depolarizing its

sodium gates are fully open

Most metabolic and regulatory functions in a neuron happen at the

soma

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

somatic receptor afferent nerve fiber interneuron efferent nerve fiber skeletal muscle

A neuron can receive thousands of EPSPs from different neurons, and responds by triggering or not triggering an action potential. This addition and response to the net effect of postsynaptic potentials is called

spatial summation

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 this reflex causes your head to rise. This is called the

stretch (myotatic) reflex.

In skeletal muscle, the term that describes the alternating light and dark bands is ___________.

striations

The ___ division tends to prepare the body for action

sympathetic

Accumulation of Ca2+ in the synaptic knob is called ___, and probably plays an important role in ___.

synaptic facilitation; short-term memory

To stimulate muscle contraction, acetylcholine is released from the ___________ into the synaptic cleft.

synaptic vesicles

Which of these happens first in an cholinergic synaptic transmission?

synaptic vesicles release ACh

All of these contribute to the cessation of the signal in a synaptic transmission except

synaptic vesicles secrete neurotransmitter by exocytosis

This reflex shows the least synaptic delay.

tendon reflex

The absence or inhibition of acetylcholinesterase at a synapse would lead to __________.

tetanus

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

thalamus.

Some antidepressant drugs act by inhibiting monoamine oxidase (MAO), which is an enzyme

that breaks down monoamines.

Many upper motor neurons synapse with lower motor neurons in

the anterior horns.

This figure shows the posterior aspect of spinal nerve roots and plexuses. What does "2" represent?

the cervical enlargement

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

the corticospinal tract.

Why does one continue to breathe heavy after rigorous physical activity has stopped?

the diaphragm is waiting for its acetylcholine to run out

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

the gracile fasciculus

Which of the following is true concerning isotonic eccentric contraction?

the muscle lengthens but tension remains constant

What happens when acetylcholine stimulates its receptors in the neuromuscular junction?

the permeability of the sarcolemma to Na+ increases

which of the following systems would provide energy for a racquetball player, while playing a point?

the phosphagen system

The upper motor neurons that control skeletal muscles begin with a soma in

the precentral gyrus of the cerebrum.

In order for a peripheral nerve fiber to regenerate it must have

the soma and at least some neurilemma intact.

Which of the following is predominately made up of myosin?

the thick filament

The ventral rami of the spinal nerves form nerve plexuses in all regions except

the thoracic region

What is the purpose of the triad?

the triad allows for Ca2+ release when a muscle fiber is excited.

Somatosensory refers to these sensory signals except the sensory signals from

the viscera.

All of the following are typical characteristics of neurotransmitters except

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

A volleyball player depends on the gastrocnemius muscles for plantar flexion, whereas a marathon runner depends more on the soleus muscles for the same action. What characteristic of the soleus muscles makes this so?

they make more use of aerobic respiration

What is the purpose of motor nerve varicosities as they relate to smooth muscle?

they release neurotransmitter onto smooth muscle cells

The minimum stimulus needed to cause muscle contraction is called the _________

threshold

Which statement best describes the goal of medications used to treat myasthenia gravis?

to inhibit the function of cholinesterase

The following are all functions associated with the spinal cord except

to protect neurons in both the ascending and descending tract.

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

touch

he protein that acts as a calcium receptor in skeletal muscle is __________.

troponin

A deficiency of acetylcholine receptors leads to muscle paralysis in myasthenia gravis.

true

An isometric contraction does not change muscle length.

true

Clinically, dystrophin is the most important noncontractile protein to occur in muscle fibers.

true

Extensibility refers to the ability of a muscle to stretch.

true

Some smooth muscle is autorhythmic

true

The sarcoplasmic reticulum is the smooth endoplasmic reticulum of a muscle fiber.

true

The triads of a muscle fiber consist of ________

two terminal cisternae and one T tubule

The autonomic nervous system is also called the

visceral motor division.

Skeletal muscle is called ___________, because it is usually subject to conscious control.

voluntary

Michael Jordan was arguably the best player in professional basketball history. Scientifically, one would expect him to have highly developed __________ fibers.

white

Which of the following structures is the richest in lipid content?

white matter

Which of the following marks the boundaries of a sarcomere?

z discs