bio 201 exam 3
The plexus that travels through the axillary region is the
Brachial
The central nervous system or CNS of vertebrate animals consists of
Brain and Spinal cord
A given neurotransmitter can produce either excitatory or inhibitory effects on postsynaptic neurons depending on the specific receptor type it binds.
True
Which of the following is NOT a neurotransmitter
atropine
Which of the following does NOT increase the strength of contraction?
availability of iron
which of the following does not increase the strength of a contraction
availability of iron
Which of the following is NOT a spinal cord region
axial
Which nerve supplies muscles of the rotator cuff?
axillary
Which part of the neuron is responsible for propagating action potentials?
axon
When a resting muscle is stimulated, its electrical potential:
becomes more positive
This plexus is formed by the ventral rami of nerves C4 to T2. It innervates the upper limb and some muscles of the neck and shoulder.
brachial
A ganglion is a
bundle of axons in the CNS
The epineurium
bundles fascicles into nerves
All of the following events occur when a nerve signal reaches a synaptic knob. The one that occurs first is
calcium ions enter the synaptic knob
The sarcoplasmic reticulum stores ____ ions and forms dilated sacs alongside transverse (T) tubules called the _____.
calcium; terminal cisternae
why is blockage of a coronary artery such a serious threat to cardiac muscle
cardiocytes have abundant mitochondria and rely on a constant supply of oxygen
quadriplegia would result if the spinal cord was severed at
C2
All of the following statements about initiation and transmission of action potentials in neurons are correct EXCEPT:
Information about the intensity of a stimulus is conveyed by changes in the size of the action potential generated.
The nerves projecting inferiorly from the spinal cord are collectively called the
cauda equina
A threshold stimulus applied to an excitable membrane is one that is just sufficient to cause a change in membrane potential depolarize a dendrite be conducted to the axon hillock cause a net inward movement of positive charge through the membrane
cause a net inward movement of positive charge through the membrane
A reflex arc in which both the receptor and effector organs of the reflex are on the same side of the spinal cord is
Ipsilateral
During an isometric contraction of a skeletal muscle
Isometric contractions involve sarcomere shortening and increasing muscle tension, but do not move a load, as the force produced cannot overcome the resistance provided by the load
Identify the statement concerning skeletal muscle that is true.
It is responsible for locomotion.
Which of the following is an autoimmune disease in which antibodies attack the neuromuscular junctions and bind Ach receptors together in clusters?
Myasthenia Gravis
A nerve impulse travels fastest along ________ axons of ______ diameter.
Myelinated; large
During the rising phase of an action potential, voltage-gated
Na+ channels open
This viral infestation can remain viable with the dorsal root ganglia for many years.
chickenpox
Which does not cause smooth muscle contraction
collagen
T tubules
conduct action potentials deep into the muscle cell.
Which of the following is NOT part of the thin filaments of striated muscle?
connectin
Which of the following is NOT a function of skeletal muscle?
constriction of organs
lack of acetylcholinesterase in the synaptic cleft would result in
continuous stimulation of postsynaptic membrane
Lack of acetylcholinesterase in the synaptic cleft would result in
continuous stimulation of the post-synaptic membrane
The capacity of a muscle cell to shorten forcefully is known as
contractility
If sodium ions cannot enter a muscle fiber in response to a stimulus,
contraction cannot occur
In comparison to skeletal muscle, smooth muscle
contracts and relaxes more slowly
If the origin of a motor signal is the left side of the brain, but the destination of that signal is the right hand, we say that the spinal tract relaying the information is
contralateral
Nissl bodies are ________ and are located in the __________ of a neuron
endoplasmic reticulum; soma
The glial cell that helps to form cerebrospinal fluid is the
ependymal cell
Anesthetics and anti-inflammatory drugs are introduced into this space in the vertebral column.
epidural
action potential transmission in the PNS is decreased if which cells are damaged?
Schwann Cells
Remembering the three things that you need to pick up at the grocery store on your way home is an example of
Short-term memory
The type of muscle fibers that have only a single nucleus, both thick and thin filaments, but no Z discs
Smooth
Which of the following statements is FALSE?
Smooth muscle does not have actin & myosin.
___ nerve fibers are those that innervate the skin and skeletal muscles.
Somatic
A muscle whose name has "superficialis" in it is located On the front Parallel to the midline Superficially Deep On the side
Superficially
At the distal end of a nerve fiber, action potentials have the same voltage as they had at the beginning. This means that they are
nondecremental
lumborum means ____ while brachii means _____
of the lower back; of the arm
The glial cell that helps to form the myelin sheath in the CNS is the
oligodendrocyte
A sarcomere extends from
one Z disk to an adjacent Z disk
Which of these happens first in an cholinergic synaptic transmission?
Synaptic vesicles release ACh
Endurance is determind by the supply of
oxygen, glucose, fatty acids, amino acids (all of the above)
__________ are straplike muscles of uniform width whose fascicles all fun in the same direction
parallel muscles
The spinal cord is divided into all of the following regions except
pelvic
The connective tissue wrapping that surronds bundles (fascicles) of axons is the
perineurium
The connective tissue wrapping that surrounds bundles (fascicles) of axons is the
perineurium
A neuron innervating your bicep muscle would be considered part of the
peripheral nervous system
A neuron innervating your bicep muscle would be consisdered part of the
peripheral nervous system
From deep to superficial, the meninges occur in the order
pia mater, arachnoid, dura mater
The bladder's ability to greatly distend and return to normal tension is due to the ___ of smooth muscles.
plasticity
Which is NOT a universal characteristic of all muscles?
plasticity
Which of the following is NOT a characteristic of a muscle cell?
plasticity
Which of the following disease of the central nervous system can be prevented by a vaccine?
poliomyelitis
The phenomemon of __________ enables frequently used synapses to transmit signals more easily in long-term memory
post-tetanic potentiation
The phenomenon of __________ enbables frequently used synapses to transmit signals more easily in long-term memory
post-tetanic potentiation
the adaptive significance of the crossed extensor reflex when a person steps on a tack is to
prevent the person from falling down
A muscle which does most of the work during a specific action is called the
prime mover
After contraction has occured, the calcium is
released from troponin.
The charge difference across the plasma membrane in relaxed muscles and nerve cells is called the ______ .
resting potential
Stiffening of the body following death is called
rigor mortis
The plexus formed from the anterior rami of L4-S4 is the __________ plexus
sacral
T tubules are extensions of the ______________ in skeletal muscle.
sarcolemma
The contractile unit of a muscle fiber is called a
sarcomere
The functional unit of a skeletal muscle fiber is the
sarcomere
The distance from one Z disc to the next is called the ________ and it __________ during contraction
sarcomere; shortens
In skeletal muscle fibers, a network of calcium storage sacs is called
sarcoplasmic reticulum
what structure stores calcium ions that trigger contraction
sarcoplasmic reticulum
Which of the following is mismatched?
schwann cells- secrete nerve growth factors
The largest and longest nerve in the body is the _________ nerve.
sciatic
When a person sits on a hard surface for a period of time, his foot or leg may "go to sleep." This sensation is the result of compressing the _____ nerve.
sciatic
The afferent division of the nervous system is also known as the _____ division.
sensory
The peripheral nervous system includes the
sensory nerves and motor nerves
each of the following terms is a descriptive term for a muscle's action except
serratus
Which of the following characteristics would establish conclusively that muscle tissue being examined was skeletal muscle tissue?
several nuclei per cell
Which type of muscle has fibers as long as 30cm?
skeletal
Which of the following is voluntary muscle?
skeletal muscle
Which of the following is NOT an example of procedural long term memory
skiing
The type of fibers specialized to continue contracting for extended periods of time, as would be required in running a marathon, for example, are ________ fibers
slow
Posture is maintained mainly by _____ fibers.
slow oxidative (SO)
Which muscle(s) can contract without the need for nervous stimulation?
smooth and cardiac muscle
gap junctions are characteristic of
smooth muscle
Identify the incorrect statement
smooth muscle is voluntary
In resting muscle or nerve cell, there are excess _______ ions in the extracellular fluid and excess ________ ions in the intracelluar fluid
sodium; potassium
Exposure to Clostridium tetani causes continuous release of ach. What effect does this have on skeletal muscle? myocardial atrophy spastic paralyis treppe flaccid paralysis
spastic paralysis
which does not belong to the peripheral nervous system
spinal cord
which does not belong to the peripheral nervous system?
spinal cord
In a lumbar puncture (spinal tap), fluid is extracted from the
subarachnoid space
The majority of cerebrospinal fluid in the spinal cord is found in the
subarachnoid space.
All of these contribute to the cessation of the signal in a synaptic transmission except
synaptic vesicles secrete neurotransmitter by exocytosis
Muscles that work together to cause movement are called insertions antagonists origins prime movers (wrong) synergists
synergists
The region of a sarcomere where actin and myosin overlap is
the A band
Action potentials are propagated from the surface to the interior of a muscle fiber by way of
the T tubules
In order for muscle relaxation to occur,
the active sites on actin must be blocked.
To treat some of the symptoms of Myasthenia gravis, physicians sometimes prescribe the anticholinesterase drug neostigmine. Why does this drug help with the symptoms of muscle weakness and fatigue?
The drug inhibits the activity of acetylcholinesterase, which prevents the breakdown of ACh. Consequently, ACh levels in the synapse remain elevated, thereby increasing the stimulation of the reduced number of functional ACh receptors.
Which of these spinal nerve counts is incorrect?
Thoracic nerves = 8 pairs
Which is not a function of the motor division of the nervous system?
Transmits impulses from the viscera
Arrange the following list of biochemical events in the correct sequence. (1) An action potential is conducted deep into the muscle fiber by the T tubule. (2) Calcium ions bind to troponin. (3) The membranes of the sarcoplasmic reticulum become more permeable to calcium ions. (4) Calcium ions diffuse into the sarcoplasm around the myofibril. (5) The troponin-tropomyosin complex moves exposing active sites.
(1) An action potential is conducted deep into the muscle fiber by the T tubule (3) The membranes of the sarcoplasmic reticulum become more permeable to calcium ions. (4) Calcium ions diffuse into the sarcoplasm around the myofibril. (2) Calcium ions bind to troponin. (5) The troponin-tropomyosin complex moves exposing active sites.
The resting potential across a sarcolemma of a skeletal muscle cell is about _______ millivolts (mV)
-90
One muscle fiber is stimulated by how many somatic motor neurons?
1
Due to overlap of dermatomes, a total loss of sensation requires anesthesia of _________ successive spinal nerves?
3
Put the following events in chronological order. (1) Ca++ floods into the pre-synaptic neuron. (2) Ach (Acetylcholine) binds to ACh receptors in the sarcolemma. (3) Na+ floods into the post-synaptic muscle cell. (4) The action potential arrives at the pre-synaptic terminal causing Ca++ channels to open. (5) Ach from the synaptic vesicles spills into the pre-synaptic cleft. (6) A post-synaptic action potential results in the muscle fiber (depolarization).
4, 1, 5, 2, 3, 6
Arrange the events of synaptic transmission in correct sequence. (1) Na+ diffuses into the cell and cause a local potential (2) Neurotransmitter binds with receptor on postsynaptic cell (3) Neurotransmitter diffuses across the synaptic cleft (4) Membrane permeability to Na+ on postsynaptic cell increases (5) Action potential causes release of neurotransmitter
5, 3, 2, 4, 1
Action potentials would be conducted most rapidly by all action potentials are conducted at the same rate. a 5 mm diameter unmyelinated axon. a 5 mm diameter myelinated axon. a 55 mm diameter unmyelinated axon. a 55 mm diameter myelinated axon
55 mm diameter myelinated axon (large myelinated are fastest)
Which of the following fractures would be the least likely to cause a spinal cord injury
A fracture of vertebra L4
Choose the answer that correctly lists, in chronological order, the events involved in synaptic transmission: A: a nerve impulse reaches the synaptic knob B: Neurotransmitter molecules diffuse across the synaptic cleft C: A nerve impulse begins in the postsynaptic cell D: Neurotransmitter molecules bind to receptors in the postsynaptic cell E: A voltage change occurs in the postsynaptic cell
A: a nerve impulse reaches the synaptic knob B: Neurotransmitter molecules diffuse across the synaptic cleft D: Neurotransmitter molecules bind to receptors in the postsynaptic cell E: A voltage change occurs in the postsynaptic cell C: A nerve impulse begins in the postsynaptic cell
________ is required for muscle relaxation
ATP
Which of the following is not found in the thin filaments of striated muscle? F actin ATPase troponin Ca2+ receptors
ATPase
Which ions are important for establishing the resting potential in neurons?
All of the choices other than H+ are correct (Na, K, intracellular anions)
Which of the following statements best describes the membrane situation in the resting state of the neuron?
All of the voltage-gated Na and K channels are closed
Aerobic exercise develops fatigue-resistant fast-twitch fibers. increases vascularity of muscle. All of these choices are correct. can increase the number of mitochondria in muscle cells. can increase the efficiency of slow-twitch fibers
All of these choices are correct.
Which of the following statements is FALSE?
At rest, the concentration of Na+ is higher inside the cell than outside
The plexus that supplies the upper limbs is the _________ plexus.
Brachial
Rising intracellular levels of which ion are necessary for neurotransmitter release from a neuron?
Ca2+
The type of muscle fibers that are striated, form Y-shaped branches, and have junctions called intercalated discs are
Cardiac
What is the correct order for the parts of the spinal cord, from superior to inferior?
Cervical - thoracic - lumbar - sacral - coccygeal
There are two types of synapses, based on mode of communication. What are they?
Chemical and Electrical
A reflex arc in which the receptor and effector organs of the reflex are on the opposite side of the spinal cord is
Contralateral
____ are the primary site for receiving signals from other neurons.
Dendrites
___ carry motor commands from the brain along the spinal cord.
Descending tracts
_______ carry motor commands from the brain along the spinal cord
Descending tracts
___ keep(s) nerve fibers insulated from one another.
Endoneurium
Which of the following is true about skeletal muscle?
Every muscle fiber receives a branch of an axon from the nerve.
A neurotransmitter that was inhibitory would produce an ______ that would ____ a neuron.
IPSP, hyperpolarize
Which of the following is true?
In saltatory conduction, electrical charges jump from node to node
Curare is a poison used by south american indians. It is known to bind to ACh receptors preventing the binding of ACh. What effect would it have on muscle function?
The muscle fibers would not contract because the Na+ channels which cause depolarization of the muscle fiber membrane are never signaled to open
When comparing smooth and skeletal muscle cells, which of the following statements is true?
The myofilaments in smooth muscle do not form sarcomeres.
____ division carries signals to the smooth muscle in the large intestine.
Visceral motor
The gangster movies call a dead person a stiff, rigor mortis is the proper name. How does this occur?
Without ATP, muscles remain fixed in their last state of contraction.
Which of these processes occurs during the contraction of skeletal muscle
Z discs move closer together
Which of the follwoing individuals would have more mitochondria in his skeletal muscle
a 22 year old football player
Which are the locations of neuron cell bodies? a: peripheral ganglia b: gray matter c: white matter d: meninges e: central canal of spinal cord
a and b
which of the following is an effector?
a gland
In contrast to skeletal muscle, smooth muscle has all of the following properties except
a more extensive sarcoplasmic reticulum
Choose the answer that correctly lists, in chronological order, the events involved in synaptic transmission. a: A nerve impulse reaches the synaptic knob b: Neurotransmitter molecules diffuse across the synaptic cleft c: A nerve impulse begins in the postsynaptic cell d: Neurotransmitter molecules bind to receptors in the postsynaptic cell e: A voltage change occurs in the postsynaptic cell
a, b, d, e, c
Which is the correct order of the connective tissue layers of a skeletal muscle, beginning with the innermost first? a: endomysium b: epimysium c: perimysium
a, c, b
Which are considered specific functions of the spinal cord? a: conductivity b: extensibility c: locomotion d: emotion e: reflexes
a, c, e
Which is a correct listing of the hierarchy of a skeletal muscle's components beginning with the smallest? a: myofibrils b: muscle fiber c: fascicle d: skeletal muscle
a,b,c,d
which is the correct order of the connective tissue layers of a skeletal muscle, beginning with the innermost first? a:endomysium b:epimysium c:perimysium
a,c,b
___________ is a neurotransmitter that triggers muscle contraction
acetylcholine
In the neuromuscular junction, ACh released into the synaptic cleft is rapidly destroyed by
acetylcholinesterase
Which protein makes up the thin filaments?
actin
During the contraction phase of a muscle twitch,
actin-myosin cross-bridges form
Cross-bridges form between _______ and ________ during muscular contraction
actin; myosin
The epidural space in the spinal column is occupied by
adipose tissue
_________ neurons are specialized to detect stimuli, whereas ___________ send signals to the effectors of the nervous system
afferent; efferent
endurance is determined by the supply of
all of the above
The straiations observed in skeletal and cardiac muscles are produced by
alternating A bands and I bands
Nerve fiber refers to
an axon
A long-distance runner asks her coach why it is so difficult to have a "finishing kick" (sprinting the last hundred yards to the finish line) Her coach should reply
anaerobic activities like sprinting are limitied by available glucose and rate of buildup of lactic acid
The biceps brachii muscle and the triceps brachii muscle
are antagonists
smooth muscles
are innervated by somatic nerve fibers only
calcium ions
are released from the T tubules by active transport
A condition known as flaccid paralysis
arises because the muscle is incapable of contracting in response to nervous stimulation
When there is not enough oxygen to create ATP by aerobic respiration, a muscle fiber can produce ATP by borrowing phosphate groups from
creatine phosphate
when there is not enough oxygen to create ATP by aerobic respiration, a muscle fiber can produce ATP by borrowing phosphate groups from
creatine phosphate
Sarcoplasm is the
cytoplasm of muscle cells
The posterior ramus of a typical spinal nerve innervates the
deep muscles of the back and the skin of the back
In a neuron, __________ receive signals from sensory receptors
dendrites
In a neuron, __________ receive signals from sensory receptors.
dendrites
The effect of increasing the flow of Na+ ions into a neuron at rest (-70 mV initially) would be termed
depolarization
****An increase in the extracellular concentration of K+ above normal would result in (not 100% sure)
depolarization of resting nerve cells
Opening of sodium gates typically leads to
depolarization of the plasma membrane
The cutaneous regions innervated by specific spinal nerves are each called a
dermatome
The cutaneous sensory distribution of a spinal nerve can be mapped as a
dermatome
Damage to the phrenic nerve would result in
difficulty breathing
A deficiency of ACh receptors in a motor endplate would cause ____ and is called _____.
difficulty firing muscle fibers; myasthenia gravis
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
The thicket of the meninges is the
dura mater
From superficial to deep, the meninges occur in the order
dura mater, arachnoid, pia mater
Motor nerves are known as_________ nerves and sensory nerves are known as _________ nerves
efferent; afferent
There are ________ cervical spinal nerves.
eight
The ability of the muscle cell to return to its initial length after being stretched is
elasticity
Which is a connective tissue sheath that surrounds an individual muscle fiber?
endomysium
You were going to have a spinal tap to remove some cerebrospinal fluid for analysis. Starting from outside of the spinal cord, what would be the correct order of spaces and meninges through which the syringe would pass?
epidural space, dura mater, arachnoid mater, subarachnoid space
Which of the follwoing would occupy lumen of a transverese tubule
extracellular fluid
_______ are examples of muscles under fine motor control
eye muscles
Gray matter tracts of the spinal cord carry sensory information up to the brain and motor information down from the brain
false
Regeneration of axons occurs more readily in the CNS that in the PNS
false
The fat and connective tissue that enciricle a beef steak from the endomysium
false
In skeletal muscle, Indiviudal muscle cells are called _______ and are surrounded by a connective tissue sheath called the _____
fascicles, endomysium
In skeletal muscle, groups of muscle cells are called _______ and are surrounded by a connective tissue sheath called the _____
fascicles, perimysium (this is right!!)
You would expect a body-builder to have more __________ muscle fiber than a long-distance marathon runner
fast glycolytic
The movement of your fingers is controlled by muscles which have a greater proportion of
fast glycolytic fibers with small motor units
The names of the muscles can indicate all of the following except
fat content of the muscle
In contrast to red muscle fibers, white fibers
fatigue more quickly
The thin strand of pia mater that helps to anchor the spinal cord to the coccyx is the
filum terminale
Which of the following describes an appearance of red muscular tissue emerging directly from bone rather than being separated from it by an obvious tendon?
fleshy attachment
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
___________ are muscles which are widest in the middle and then taper at the ends
fusiform muscles
Outside the CNS, groups of neuronal cell bodies that are clustered together to perform basic functions are termed
ganglia.
In cardiac muscle and single-unit smooth muscle, ions can flow directly from one cell into an adjacent cell through
gap junctions
A brief activity using maximum muscular effort (weight-lifting) is commonly fueled by the
glycogen-lactic acid system (anaerobic)
Local potentials are _______, meaning they vary in magnitude according to the strength of the stimulus
graded
Slow-twitch muscle fibers
have a richer blood supply than fast twitch fibers, and contain myoglobin
Which cellular organelle is not functioning properly in order to allow for the accumulation of a glycolipid in the myelin sheath of those with Tay-Sach's disease?
lysosomes
Shivering
helps raise body temperature
shivering
helps raise body temperature
Inhibitory postsynaptic potentials (IPSPs) are associated with
hyperpolarization of the cell membrane
which of the following would NOT contribute to muscular fatigue in the fiber?
increased level of serotonin
Which of the following would not contribute to muscular fatigue in the muscle fiber? blocked receptors in the postsynaptic membrane increased levels of serotonin the inability of the motor neuron to produce sufficient quantities of ach depletion of neurotransmitter
increased levels of serotonin
Which of the following would you expect to find in skeletal muscle cells of endurance trained athletes?
increased number of mitochondria
A neurotransmitter, such as glycine, attaches to a receptor and causes hyperpolarization. This neurotransmitter would most likely cause an
inhibitory local potential
The _______ of a muscle is located on the bone that moves
insertion
several genetic disorders including Tay Sach's disease strip in the myelin sheath from nerve cells. The myelin sheath serves to ____ the axon
insulate
Muscle tone
is a constant tension produced by muscles
Which contraction occurs when you try (unsuccessfully) to move a wall?
isometric
When a muscle develops increased tension, but does not change in length, it is said to exhibit
isometric contraction.
Conduction speed of a nerve fiber would be the fastest in a
large myelinated fiber
A volleyball player depends on the gastrocnemius muscles for plantar flexion, whereas a marathon runner depends more on the soleus muscles for the same reaction. This is because the soleus muscles
make more use of aerobic respiration
A synergist
may stabilize a joint or modify direction of movement at the joint
which of the following is NOT an example of procedural long term memory
moderate
The efferent division of the nervous system is also known as the _____ division.
motor
The neurons that stimulate muscle contraction are called ________ neurons
motor
A depression in a muscle fiber where it has synaptic contact with a nerve fiber and a high density of neurotransmitter receptors is a
motor endplate
A motor neuron and the muscle fibers it innevates is called a
motor unit
If the ventral root of a spinal nerve were cut, the regions innervated by that spinal nerve would experience complete loss of
movement
which of the following is not primarily associated with skeletal muscle
moving contents through the digestive tract
The disease ______________ is characterized by destruction of CNS myelin sheaths and the formation of hardened scars.
multiple sclerosis
This condition involves progressive demyelination of neurons in the CNS accompanied by the destruction of oligodendrocytes. Ad a result, the conduction of nerve impulses is disrupted, leading to impaired sensory perception and motor coordination
multiple sclerosis
The brachial plexus supplies nerves that function to contract which of the following?
muscles of the arm and forearm
A 35 year old woman complains of drooping eyelids, weakness in her limbs and poor physical endurance. What is a likely cause of her symptoms
myasthenia gravis
White matter is
myelinated axons in the CNS
From largest to smallest, which of the following is the correct order?
myofilament, myofibril, myofiber
The bright red color of skeletal muscle is due mainly to its
myoglobin
Slow oxidative (SO) fibers (slow-twitch fibers) have more ________ and less _________ than fast glycolytic (FG) fibers (fast twitch fibers)
myoglobin, lactic acid
slow oxidative (SO) fibers (slow twitch fibers) have more _____ and less ______ than fast glycolytic (FG) fibers (fast twitch fibers)
myoglobin, lactic acid
which of the following is the correct sequence of events in cross bridge cycling
myosin cross-bridge binds to actin, the powerstroke moves the thin filament relative to the thick filament, ATP binds to myosin and cross-bridge detatchment occurs, ATP is hydrolyzed and the myosin head is "cocked"
Nervous tissue consists mainly of what two major types of cells?
neuroglial cells and neurons
Barry asked his physician why tentanus shots were necessary. The doctor explained that ______
the bacterium Clostridium tetani can cause the muscles to tentay and stay contracted causing death
the burning sensation that you feel in your muscles when you are lifting weights is presumably caused by
the build-up of lactic acid
Otto Loewi performed an experiment in which he electrically stimulated the vagus nerve connected to one frog heart and let the fluid bathing his first heart pass to a second chamber containing second frog hear not connected to a nerve. What did Loewi observe?
the first heart showed a decrease in beat rate and so did the second heart
when comparing smooth and skeletal muscle cells, which of the following statements is true?
the myofilaments in smooth muscle do not form sarcomeres
The right brachial plexus primarily supplies
the right arm
Synaptic vesicles are found in
the synaptic knob
A neuron fires only when its membrane reaches
the threshold potential
Nerve fibers that stimulate the skeletal muscles of your foot have their somas in
the ventral horn of the spinal cord.
Local potentials exhibit all of the following charchteristics except
they obey the all or none law
Which of the following is composed of myosin molecules?
thick myofilaments
In which body region would you expect to find a muscle whose name included the word "pollicis" ?
thumb
Which of the following is not a purpose of the excess postexercise oxygen consumption (EPOC) in muscle?
to neutralize carbon dioxide buildup
a threshold stimulus applied to an excitable membrane is one that is just sufficient to
trigger an action potential
When calcium ions are released from the sarcoplasmic reticulum, they combine with the protein ______
troponin
Which of the following would occur as a result of a single muscle contraction
twitch
There are _____ enlargements of the spinal cord where nerves supplying the extremities enter and leave.
two
You are examining a cross-sectional slide of a muscle, and you noticed the following characteristics in most of the muscle fibers: smaller diameter, abundant mitochondria and myoglobin, and low levels of gylcogen reserves. This muscle is predominantly made up of fibers that are
type 1 and slow oxidative
you are examining a cross-sectional slide of a muscle, and you noticed the following characteristics in most of the muscle fibers: smaller diameter, abundant mitochondria, abundant myoglobin, and low levels of glycogen reserves. This muscle is predominantly made up of fibers that
type I and slow oxidative
The motor root of a spinal nerve is also referred to as the
ventral root.
Which of the following does NOT apply to cardiac muscle?
voluntary
Stepping on a piece of glass would most likely invoke a _____ reflex.
withdrawal
