A & P Chapter 9-12

typical spinal cord has how many pairs of spinal nerves, and where does the spinal cord end

31 pairs, lumbar vertebra 1 or 2

the spinal cord continues to elongate until about age

4

where does the simplest processing occur

PNS and the spinal cord

the skeletal muscle complex known as the triad consists of

a transverse tubule and two terminal cisternae

person with polio has lost the use of his leg muscles. in which area of his spinal cord would you expect the virus-infected motor neurons to be

anterior gray horns

sensory input from interoceptors of the body walls and limbs is carried to the spinal nerve via the

anterior rami

which ramus carries sensory information from the limbs

anterior ramus

when comparing slow fibers to fast fibers, slow fibers

appear dark red

all of the following are true of IPSPs except

are graded depolarizations

many meds introduced into the bloodstream cannot directly affect the neurons of the CNS because

astrocytes isolate the CNS by forming a blood-brain barrier

which part of the neuron can conduct an action potential

axon and telodendria

axon is connected to the cell body at the

axon hillock

puffer fish poison blocks voltage gated sodium channels like cork. what effect would this neurotoxin have on the function of neurons

axon would be unable to generate action potentials

in which part of a neuron does wallerian degeneration occur

axons of PNS neurons

action potential travelling along the entire length of an axon demonstrates

continuous propagation

muscle tissue consists chiefly of cells that are highly specialized for

contraction

calcium ions are bound to troponin during which of the following steps

contraction phase

voltage gated channels are present

in the membrane that covers axons

which of the following is not a recognized function of skeletal muscle

controlled involuntarily

suppose that you feel something brushing against your abdomen. the sensory information would be carried to the spinal cord over a _____ ramus

anterior

which kind of neural circuit processes info in a stepwise fashion, one neuron to another

convergent

perikaryon

cytoplasm that surrounds the nucleus of a neuron

inhibitory postsynaptic potential (IPSP)

graded hyperpolarization by the postsynaptic cell

the infraspinatus has its insertion on the

greater tubercle of humerus

explain two key concepts of the sarcomere length-tension relationship

greater zone of overlap, greater tension the muscle can develop there is an optimum range of actin and myosin overlap that will produce the greatest amount of tension

regions of the CNS where neuron cell bodies dominate constitute the _____ matter

grey

area in the center of the A band that contains no thin filaments is the

h band

which of the following terms is used to describe the location of a muscle

hallucis

muscle fibers differ from typical cells in that muscle fibers

have many nuclei

muscles included the term "capitis" would be found within or attached to the

head

which of the following acts as an ATPase during the contraction cycle of muscle

head portion of the myosin molecule

the axial muscle stabilize and position which regions of the body

head, neck, and trunk

greater degree of sustained depolarization at the axon hillock, the _____ (higher or lower) the frequency of action potentials generated

higher

each skeletal muscle fiber contains _______ myofibrils

hundreds to thousands

which of the following muscles has its origin on the hyoid and inserts on the tongue

hyoglossus

if the membrane potential of a neuron is -80 mV, it is

hyperpolarized during the refractory period

a muscle producing tension that peaks but fails to only intermediate stimulus rates is said to be in

incomplete tetanus

decreased blood flow to a muscle could result in all of the following except

increase in intracellular glycogen

muscle hypertrophy

increase in the size of the muscle cells

muscular force can be adjusted to match increased loads by

increasing frequency of action potentials in motor neurons

name the extrinsic eye muscles

inferior rectus, medial rectus, superior rectus, lateral rectus, inferior oblique, superior oblique

the bones, which serve as levers in the body, do not

inhibit movement

which is not true of the spinal cord

interacts with the muscular system by initiating voluntary movement of skeletal mucles

which of the following would not have an effect on synaptic function

interfering with voltage gated sodium channels

muscles located entirely within an organ are called

intrinsic

type of contraction in which the muscle fibers do not shorten is called

isometric

which of the following is not true of the muscular system

it depends upon the cardiovascular system to provide the hemoglobin stored in slow muscle fibesr

summarize the sliding filament theory

it is the process of sarcomere shortening caused by the sliding of thin and thick filaments past another

how would a drug that blocks ACh receptors at the motor end plate affect skeletal muscle

it would cause flaccid paralysis (muscles are relaxed and unable to contract)

how would the loss of acetylcholinerase from the motor end plate affect skeletal muscle

it would cause spastic paralysis (muscles are contracted and unable to relax)

how would the absolute refractory period be affected if voltage-regulated sodium channels failed to inactive

it would last indefinitely

which leg movement would be impaired by injury to the obturator muscles

lateral rotation at the hip

Na+ and K+ both use _____ to passively diffuse across the plasma membrane

leak channels

ion channels that are always open

leak channels

in the patellar reflex, identify the response observed and the effectors involved

leg extension and the effectors are the quadriceps femoris

what sarcomere characteristic affects the amount of tension produced when a skeletal muscle fiber contracts

length of sarcomere

what does the term flexor carpi radialis longus tell you about this muscle

long muscle that lies next to the radius and flexes the wrist

the muscle weakness of myasthenia gravis results from

loss of acetylcholine receptors in the end plate membrane

the _____ originate in the pelvic region and usually insert on the femur

muscles that move the thigh

skeletal muscle fibers are formed from embryonic cells called

myoblasts

when a skeletal muscle fiber contracts, which of the following does not occur

myosin and actin filaments decrease in length

proteins that make up a thick filament

myosin and titin

cross-bridges are portions of

myosin molecules

brachial plexus

network of nerves formed by the branches of spinal nerve segments C5-T1

what accounts for roughly half of the volume of the nervous system

neuroglia

each skeletal muscle fiber is controlled by a motor neuron at a single

neuromuscular joint

communication between axons and muscle fibers occurs at specialized synapses called

neuromuscular junctions

classify neurons based on their structure

neurons are classified structurally as anaxonic, bipolar, unipolar, or multipolar

unipolar neurons

neurons in which dendritic and axonal processes are continuous and the soma lies off to one side

multipolar neurons

neurons that have several dendrites and a single axon

people who are engaged in repetitive hand movements such as typing or playing the piano may suffer wrist pain, especially during palmar flexion. all of the following are true concerning this condition except that it

never causes muscle weakness

which of the following is not contained in the axoplasm of the axon

nissl bodies

the face, head, and cheeks are located in a dermatome supplied by nerves from what spinal cord region

no spinal nerves innervate the dermatome containing the face

in which of the following would the delay between stimulus and response be greater

polysynaptic contralateral reflex

identify the muscle whose origin is on the lateral condyle of the femur

popliteus

which ramus provides sensory and motor innervation to the skin and skeletal muscles of the back

posterior ramus

major peripheral branches of a spinal nerve

posterior ramus, anterior ramus, and rami communicantes

are the wrist extensors located on the anterior surface or the posterior surface of the forearm

posterior surface

gray rami communicans

postganglionic fibers that connect an sympathetic ganglion and carry fibers that innervate glands and smooth muscle of the body wall or limbs

which of the following is an ion that is more concentrated inside the cell than outside

potassium

separation of plus and negative charges across the membrane creates a _____ diference, or voltage

potential

describe components of chemical synapse

presynaptic cell and postsynaptic cell whose plasma membranes are separated by a narrow synaptic cleft

intrinsic muscle of the hand originate

primarily on the carpal and metacarpal bones, and insert on the phalanges

the advantage of having many nuclei in a skeletal muscle fiber is the ability to

produce large amounts of the muscle proteins needed for muscle contraction

action potential

propagated change in membrane potential of an excitable cell

exteroceptors

provide information about the external environment

the adductor brevis has its origin on the

pubis

spinal flexors

quadratus lumborum longus colli longus capitis

which of the following about action potential is false

rapid depolarization phase is caused by the entry of potassium ions

components of reflex arc

receptor, sensory neuron, motor neuron, effector, and sometimes interneurons may be involved

spinal interneurons inhibit antagonist motor neurons in a process called

reciprocal inhibition

the increase in muscle tension that is produced by increasing the number of active motor units is called

recruitment

during abdominal surgery, the surgeon makes a cut lateral to the linea alba. the muscle that would be cut is the

rectus abdominis

the muscle that originates on the superior surface of the pubis around the symphysis is the

rectus abdominis

which axial muscle is often known as the six pack in physically fit people

rectus abdominis

which muscle connects the ribs and sternum to the pubic bones

rectus abdominis

which of the following is not an extrinisic eye muscle

rectus abdominis

all of the following provides flexion of the knee except

rectus femoris

extensive damage to oligodendrocytes in the CNS could result in

reduced speed of nerve impulses

contralateral reflexes

reflexes the activate muscles on the opposite side of they body as the stimulus

explain why the propagation of action potentials along electrically excitable membranes occurs in only one direction

refractory period prevents it from propagating back in the direction from which it began

why is the zone of overlap an important region of the sarcomere

the zone of overlap is important because it is where the myosin heads can interact with the thin filaments

which of the following statements is not true about action potentials

they can travel in two directions

which of the following becoming connected by myosin cross-bridges during muscle contraction

thin and thick filaments

the Na-K ion exchange pump actively transports

3 intracellular sodium ions for 2 extracellular potassium ions

the equilibrium potential for potassium ion occurs at approximately

-90 mV

main steps in generation of action potential

1. a graded depolariztion brings an area of an excitable membrane to threshold. 2. sodium channel activation occurs 3. sodium ions enter the cell and depolarization occurs 4. sodium channels are inactivated. 5. voltage gated potassium channels open and potassium moves out of the cell, initiating repolarization 6. sodium channels regain their normal properties 7. temporary hyperpolarization occurs

steps involved in transmission at a cholinergic synapse

1. action potential depolarizes synaptic knob at the presynaptic membrane 2. calcium ions enter the synaptic knob 3. acetylcholine is released from storage vesicles by exocytosis 4. acetylcholine binds to receptors on the postsynaptic membrane 5. chemically gated sodium channels on the postsynaptic membrane are activated 6. calcium ions are removed from the cytoplasm of the synaptic knob 7. acetylcholinesterase hydrolyzes acetylcholine 8. synaptic knob reabsorbs choline

three types of muscle tissue, where they are found, and functions

1. skeletal muscle, directly or indirectly attached to bones and enables mvmt of the body 2. cardiac muscle forms heart and propels blood 3. smooth muscle is found throughout the body and moves substances through hollow tubes, such as in the digestive tract and regulates diameter of blood vessels

which of the following associations is incorrect

11 thoracic spinal nerves

the cytoplasm of the neuromuscular synaptic terminal contains vesicles filled with molecules of the neurotransmitter

ACh

triggering of the muscle action potential occurs after

ACh binds to chemically gated channels in the motor end plate membrane

what molecule supplies the energy for a muscle fiber contraction

ATP

name pair of spinal nerves that emerges between vertebrae C7 and T1

C8

region of sarcomere that always contains only thin filaments is the

I band

the conus medullaris is found at about

L1

nerve plexus

a complex, interwoven network of nerves

which of the following muscles would contract more forcefully

a muscle recieving 20-25 action potentials per second

why does a pennate muscle generate more tension than does a parallel muscle of the same size

a pennate muscle generates more tension because it contains more muscle fibers

cholinergic synapses release the neurotransmitter

acetylcholine

the most important factor in decreasing the intracellular concentration of calcium ion after contraction is

active transport of calcium back into the sarcoplasmic reticulum

creatine phosphate

acts as an energy reserve in muscle tissue

during the recovery period, the body's need for oxygen is increased because

additional oxygen is required to restore energy reserves consumed during exercise

damage to the pectoralis major would interfere with a person's ability to

adduct the humerus

muscle that adducts the thumb

adductor pollicis

resting muscle generates most of its ATP by

aerobic metabolism of fatty acids

an alternate name for the prime mover in muscle action is

agonist

all or none principle

all stimuli that bring the membrane to threshold will generate identical action potentials

oxygen debt

amount of oxygen intake required to produce the ATP needed to restore the body after strenuous activity

after heavy exercise, if energy reserves in a muscle are depleted, ______ occurs

an oxygen debt

names of the muscles can indicate

angle of the muscle relative to the long axis of the body action of the muscle structural characteristics of the muscle location of the muscle

which muscles flex the knee

biceps femoris, semitendinous, semimembranous, sartorius, politeus

which is not true of voltage gated sodium channels

both have activation gate and inactivation gate that work dependent of each other

each peripheral nerve provides _____ innervation to peripheral structures

both motor and sensory

if the permeability of sodium ions increases in an axon

both the inward movement of sodium ions will increase and the membrane potential will depolarize

in which plexus does the ulnar nerve arise

brachial

which of the following does not move the pectoral girdle

brachialis

which of the following muscles does not have an action that is antagonistic to the action of the brachialis muscle

brachioradialis

state whether the following muscles involve the mouth, eye, nose, ear, scalp, or neck: buccinator, corrugator supercilii, mentalis, nasalis, platysma, procerus, and risorius

buccinator: mouth corrugator supercilii: eye mentalis: mouth nasalis: nose platysma: neck procerus: scapl risorius: scalp

temporal summation

buildup of depolarization when EPSPs arrive in rapid succession

in response to action potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases

calcium ions

what causes calcium to be released from the sarcoplasmic reticulum

calcium is released when an action potential reached the triad

effectors of the ANS

cardiac muscle, smooth muscle, glands, and adipose tissue

composition of gray matter of the spinal cord

cell bodies of neurons, neuroglia, and unmyelinated axons

posterior root ganglia mainly contain

cell bodies of sensory neurons

belly

central body of a muscle

which type of synapse is most common in the nervous system

chemical

which process employs exocytosis

chemical synapse

if you were contracting and relaxing your masseter, what would you probably be doing

chewing or eating

levator ani inserts on the

coccyx

which of the following is the origin of the bulbospongiosus

collagen sheath at the base of the clitoris or penis

branches that may occur along an axon are caled

collateral branches

contrast fast fibers with slow fibers in terms of diameter, glycogen reserves, myoglobin content, and relative abundance of mitochondria

compared with slow fibers, fast fibers have a larger diameter, larger glycogen reserves, less myoglobin, and relatively fewer mitochondria

plexus

complex, interwoven network formed by contributions from the anterior rami of neighboring spinal nerves

describe the action of the external oblique

compresses abdomen, depresses ribs, flexes or bends spine

the epidural space contains

connective tissue and blood vessels

muscle atrophy

decrease in the size of muscle cells

what determines the frequency of action potential generation

degree of sustained depolarization at the axon hillock determines the frequency of action potentials

name the muscle that abducts the arm

deltoid

epimysium

dense layer of connective tissue that surrounds an entire skeletal muscle

during which phase of action potential development does the voltage gated sodium channels open

depolarization

shift of the resting transmembrane potential toward 0 mV is called

depolarization

raising potassium ion concentration in the extracellular fluid surrounding a nerve cell will have which effect

depolarize the membrane potential

wallerian degeneration

deteriorating changes in the distal segment of an axon as a result of a break between it and the soma

all of the following muscles compresses the adomen except

diaphragm

divergent v. convergent neural circuits

divergent: information spreads from one neuron to several neurons convergent: several neuron synapse with one postsynaptic neuron

in a _____ neuronal pool, one neuron synapses on several postsynaptic neurons

diverging

tough, fibrous outermost covering of the spinal cord

dura mater

excitatory postsynaptic potential (EPSP)

graded depolarization by the postsynaptic cell

absolute refractory period v. relative refractory period

during the absolute refractory period the membrane cannot respond to further stimulation during the relative refractory period the membrane can respond only to a larger than normal stimulus

which of the following interactions between electrical and chemical gradients does not lead to the establishment of a neuron's resting potential

electrical forces push sodium ions out of the cell

the delicate connective tissue that surrounds the skeletal muscle fibers and ties adjacent muscle fibers together is the

endomysium

name neuroglia of the CNS

ependymal cells, microglia, astrocytes, oligodendrocytes

structures and spinal coverings that are penetrated during a lumbar puncture procedure

epidermis, dermis, skeletal muscle, dura mater, arachnoid mater, subarachnoid space

connective tissue layers associated with the skeletal muscle tissue

epimysium surrounds entire muscle perimysium divides skeletal muscle into fascicles endomysium surrounds individual muscle fibers

synaptic vesicles containing neurotransmitters are released by______ when the action potential arrives

exocytosis

muscles that insert on the olecranon process of the ulna can act to

extend the forearm

compare f-actin w/ g-actin

f actin is a twisted strand made up of two rows of g actin subunits where myosin heads can bind

convergent

fan shaped muscle with a broad origin and fascicles that attach to a common site

the synchronous contraction of a single motor unit is known as an

fasciculation

large-diameter, densely packed myofibrils, large glycogen reserves, and few mitochondria are characteristics of

fast fibers

which of the following statements is/are not true regarding human muscles?

fast fibers are high in myoglobin

describe the relationship between the number of fibers in a motor unit and the precision of body movements

finer and more precise the movement, the fewer the number of muscle fibers in the motor unit

joint between occipital bone of the skull and first cervical vertebra is which part of which class of lever system

first class lever; fulcrum

which of these is not an intrinsic muscle of the foot

flexor digitorum longus

name the muscles involved in flexing the toes

flexor digitorum longus and flexor hallucis longus

identify the intrinsic muscle that flexes the great toe

flexor hallicus brevis

when opposing the thumb, which muscle is active

flexor pollicis longus

damage to ependymal cells would most likely affect the

formation of cerebrospinal fluid

in the PNS, Schwann cells participate in the repair of damage nerves by

forming a cellular cord that directs axonal regrowth

neuron cell bodies in the PNS are clustered together in masses called

ganglia

integral membrane proteins that connect electrical synapses are called

gap junctions

during the cori cycle, in the liver,

glucose is produced from lactate

which of the following muscles pulls on the iliotibial tract

glutues maximus

the anterior rami form four major plexuses:

lumbar, sacral, cervical, brachial

which intrinsic foot muscles originate on and insert on tendons

lumbricals

in a sarcomere, thick filaments are linked laterally by proteins of the

m line

the Na+/K+ ion pump is responsible for

maintaining the sodium/potassium concentration gradients constant

function of sodium-potassium ion pumps

maintains the resting membrane potential of a cell by exporting three sodium ions out in exchange for two potassium ions entering the cell

how would a torn calcaneal tendon affect movement at the ankle

make extension difficult

the sternocleidomastoid inserts on the

mastoid process

graded potentials

may be either a depolarization or a hyperpolarization

muscles located close to the midline of the body may be called

medialis

which of the following is not involved in creating the resting potential of a neuron

membrane permeability for sodium ions is greater than for potassium ions

which of the following is not a function of the neuroglia

memory

cellular membrane potential is measured in

millivolts

stretch reflex

monosynaptic reflex that provides regulation of skeletal muscle length

when ACh binds to receptors at the motor end plate, the end plate membrane becomes

more permeable to sodium ions

what happens to the lactate produced by skeletal muscle during peak activity?

most of the lactate diffuses into the bloodstream and enters the liver where it is converted to pyruvate

during the activities requiring aerobic endurance,

most of the muscle's energy is produced in mitochondria

what would happen if there were no AChE in the synaptic cleft

motor end plate would be continuously stimulated and continuous muscle contraction would occur

motor unit

motor neuron and all the muscle fibers that it controls

reflexes, controlled by the spinal cord, act by

motor output over spinal nerves to effectors

a single motor neuron together with all the muscle fibers it innervates is called an

motor unit

which of the following motor units would produce the greatest tension

motor unit in a back muscle

most abundant class of neuron in the CNS is

multipolar neuron

neurons and ______ have electrically excitable membranes that propagate action potentials

muscle cells

interactions between actin and myosin filaments of the sarcomere are responsible for

muscle contraction

in the patellar reflex, how does stimulation of the muscle spindle by gamma motor neurons affect sensitivity and reactio ntime

muscle spindles become more sensitive and the reflex response occurs more quickly

in an isotonic contraction

muscle tension exceeds the load and the muscle lifts the load

synergist

muscle that assists the muscle that is primarily responsible for a given action

synergist

muscle that helps the agonist perform its actions more efficiently

in which of the following would motor units have the fewest muscle fibers?

muscles that control the eyes

synaptic fatigue

occurs in an axon terminal when neurotransmitters are released into the synaptic cleft faster than they can be reabsorbed or recycled

which of the following is the insertion of the triceps brachii

olecranon process of the ulna

the myelin sheath that covers many CNS axons is formed by

oligodendrocytes

each of the following muscles is involved in the process of chewing or manipulating food in the mouth except the

omohyoid

at peak levels of muscle exertion, the mitochondria can supply ______ of the energy required by the muscle

only about 1/3

during a withdrawal reflex of the foot, what happens to the limb on the side opposite the stimulus

opposite side is extended. this is called the crossed extensor reflex

3 layers of connective tissue of a spinal nerve

outer epineurium, middle perineurium, and inner endoneurium

horns

outward projections from the central gray matter of the spinal cord

what basic reactants do mitochondria absorb from the cytosol to synthesize ATP

oxygen, ADP, phosphate ions, and organic substrates

which muscles elevate the soft palate

palatal muscles

muscles with fibers that run parallel to the long axis of the body are called

parallel

all of these muscles produce lateral rotation at the hip expect the

pectineus

nerves and blood vessels that service the muscle fibers are located in the connective tissues of the

perimysium

which of the following is not one of the forms of fasicicle organization

perpendicular

the brachial plexus gives rise to all of the following nerves excpet

phrenic

what covers the anterior surface of the neck

platysma

of the following clinical conditions affecting skeletal muscle, which is caused by a virus

polio

names of muscles associated with the thumb frequently include what term

pollicis

which reflex has at least one interneuron placed between the sensory and motor neurons

polysynaptic

fast muscle fibers can adapt to aerobic metabolism by generating more mitochondria in response to

repeated, exhausted stimulation

if potassium channels were blocked, the ______ phase of the action potential would not occur normally

repolarization

zygomaticus major muscle acts to

retract and elevate the corner of the mouth

repolarization

return of the membrane potential to resting

after death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. results in

rigor mortis

the plasma membrane of skeletal muscle is called the

sarcolemma

the repeating contractile unit of a skeletal muscle fiber is teh

sarcomere

identify the neuroglia of the PNS

schwann cells and satellite cells

each of the following nerves originates in the lumbar plexus except the _____ nerve

sciatic

if the posterior root of a spinal nerve is severed

sensory input would be blocked

sensory v. motor nuclei

sensory: receive and relay sensory info from peripheral receptors motor: issue motor commands to peripheral receptors

excitation-contraction coupling is the

sequence of processes that links the action potential to contraction

which of the following is important in emotional states

serotonin

hyperopolarization

shift in membrane potential toward a more negative vlaue

depolarization

shift in membrane potential toward a more positive value

since each myofibril is attached at either end of the muscle fiber, when the sarcomeres shorten, the muscle fiber

shortens

how is skeletal muscle recovery different after moderate activity compared to sustained activity at higher levels

skeletal muscle recovery after moderate activity takes several hours, whereas skeletal muscle recovery at higher levels can take about a week

which of the following statements is incorrect

skeletal muscles are responsible for the pumping action of the heart

pennate muscles

skeletal muscles in which the fascicles form a common angle with the tendon

which muscle types are voluntary and which are involuntary

skeletal: voluntary cardiac: involuntary smooth: involuntary

when an anesthetic blocks the function of the anterior rami of the cervical spinal nerves, which areas of the body will be affected

skin and muscles of the back of the neck and of the shoulders

mentalis muscle inserts on the

skin of the chin

the structural explanation of how a muscle fiber contracts is called the

sliding filament theory

type of muscle fiber that is most resistant to fatigue

slow fiber

which type of muscle fiber predominates in the leg muscles of endurance athletes, such as long distance runners

slow fibers

when cholinergic receptors are stimulated with ACh

sodium ions enter the postsynaptic neuron

what happens at the sodium-potassium exchange pump

sodium potassium exchange pump maintains the resting membrane potential of the cell by ejecting 3 sodium ions for every 2 potassium ions entering cell

spinal meninges

specialized membranes that surround the spinal cord

what extends the neck

spinalis cervicis

which muscles enable you to extend your neck

splenius capitis and spinalis cervicis

what are the functions of the superior and inferior retinacula of the foot

stabilize positions of the tendons descending from the leg

which of the following is an axial muscle

sternocleidomastoid

which of the following does not originate or insert on the hyoid bone

sternothyroid

which of the following best describes the sarcoplasmic reticulum

storage and release site for calcium ions

the myotatic reflex is also known as the

stretch reflex

where is spinal CSF located

subarachnoid space

which muscle originates on the first rib and inserts on the inferior border of the clavicle

subclavius

which muscle originates on the anterior surface of the scapula and inserts on the lesser tubercle of the humerus

subscapularis

which of the following best describes the term titin

substance that accounts for elasticity of resting muscle

electrochemical gradient

sum of the electrical and chemical forces acting on an ion

all of the following originate on the medial epicondyle of the humerus except

supinator

function of the appendicular muscles is to

support, move, and brace the limbs

the narrow space between the synaptic terminal and the muscle fiber is teh

synaptic cleft

axons terminate in a series of fine extensions known as

telodendria

muscles that laterally rotate the thigh include all of the following except the

tensor fasciae latae

muscles that are long and round in cross section are termed

teres

within a resting skeletal muscle fiber, where is the greatest concentration of Ca 2+

terminal cisternae of the sarcoplasmic reticulum

which of the following hormones directly stimulates growth of muscle tissue, leading to increased muscle mass

testosterone

what are the divisions and functions of the muscular system

the axial division support and position the axial skeleton and the appendicular division support and move the limbs

which of the following is greater?

the concentration of calcium ion in the sarcoplasmic reticulum of a resting muscle

insertion

the end of a muscle that is attached to the point that moves when the muscle contracts

if the potassium permeability of a resting neuron increases above the resting permeability, what effect will this have on the transmembrane potential

the inside of the membrane will become more negative

during anaerobic glycolysis, which of the following does not occur

the mitochondria are required

third-class levers

the most common lever systems in the body are those that have the applied force between the fulcrum and the load

if the axon terminal of a motor neuron suddenly became permeable to calcium ions

the motor end plate will be depolarized

what special terms are used to describe the plasma membrane and cytoplasm of a skeletal muscle fiber

the plasma membrane is called the sarcolemma and the cytoplasm is called the sarcoplasm

twitch

the rapid rise and fall in force produced by a muscle fiber after a single action potential

the minimum stimulus required to trigger an action potential is known as the

threshold

which of the following proteins is not found as a part of thin filaments

titin

the muscle whose name ends in the suffix glossus would be found within or attached to teh

tongue

the action potential is conducted into a skeletal muscle fiber by

transverse tubules

muscles with fibers that run perpendicular to the long axis of the body are called

transversus

which muscle forms the deepest layer of the abdominal wall muscles

transversus abdominis

largest of the superficial muscles that position the pectoral girdle

trapezius

the muscle that inserts on the acromion and scapular spine is the

trapezius

the complex of a transverse tubule and two adjacent terminal cisternae is known as

triad

the muscle that extends the arm while doing push-ups is teh

triceps brachii

when calcium ion binds to troponin

tropomyosin moves into the groove between the helical actin strands

transverse tubules

tubular extensions of the sarcolemma that extend deep into the sarcoplasm contacting the terminal cisternae of the sarcoplasmic reticulum

each thin filament consists of

two protein strands coiled helically around each other

membrane potential

unequal charge distribution between the inner and outer surfaces of the plasma membrane

the axial muscles of the head and neck are assigned to one of the following functional groups except the muscles of

vocal expression

which type of membrane channels are found in axons

voltage-gated Na+ and K+ channels

if a second stimulus arrives before the relaxation phase has ended, a second, more powerful contraction occurs. this is called

wave summation

complete tetanus

when a muscle is stimulated repeatedly at a high rate, eliminating a relaxation phase, the amount of tension gradually increases to a steady max tension

depolarization and describe the events that follow it

when the inside of the cell becomes positive due to sodium ions rushing in. after, repolarization occurs when potassium ions rush out of the cell causing the inside of the cell to become negative agian

when do muscle fibers produce lactate

when there is a lack of oxygen

synapse

where one neuron communicates with another cell

reflexes can be classified according to all of the following except

whether they are sensory or motor

which of the following is not a type of motor fiber

white slow twitch

most CNS neurons lack centrioles. this observation explains

why CNS neurons cannot divide

retinaculum

wide band of connective tissue that stabilizes tendons

which of the following describes the action of the corrugator supercilii

wrinkles the brow

can a skeletal muscle contract without shortening? why or why not?

yes because muscles can still contract during an isometric contraction when the muscle tension is equal to the load

the temporalis muscle passes through the

zygomatic arch