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