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111 terms

lecture exam 3

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The muscular system of humans contributes approximately what percentage to the adult body weight?
44%
A muscle that controls the diameter of an opening is a ________ muscle
circular
The most common lever systems in the body are those that have the applied force between the fulcrum and the load. These are called ________ levers.
third-class
A skeletal muscle fiber can contract until it has shortened by about
30%
Muscles with fibers that run at an angle to the long axis of the body are called
oblique
Deep muscles are called
profundus
The "kissing muscle" that purses the lips is the
orbicularis oris
The ________ covers the anterior surface of the neck
platysma
Which eye muscle sends its tendon of origin through a pulley or trochlea before inserting on the globe?
superior oblique
The sternocleidomastoid inserts on the
mastoid process
In assessing a stroke patient, you ask her to stick out (protract) her tongue. You note that it deviates to one side. You suspect that damage to the neural control of the ________ muscle has occurred
genioglossus
The entire length of longissimus muscle extends from the mastoid process of the temporal bone to the __________.
sacrum
The external intercostals elevate the rib cage during __________.
inspiration
The origin of the external obliques includes ribs __________.
five through twelve
_____ have their origin on the transverse and costal processes of cervical vertebrae.
the scalenes
collagen sheath at the base of the clitoris or penis is the origin of the?
bulbospongiosus
The following muscles: ischiocavernosus, coccyges, deep transverse perineal, and bulbospongiosus are found within the?
pelvic floor
Skeletal muscles in which the fascicles form a common angle with the tendon are ________ muscles.
pennate
Muscles with fibers that run parallel to the long axis of the body are called
rectus
A muscle that assists the muscle that is primarily responsible for a given action is a
synergist
Muscles with fibers that run perpendicular to the long axis of the body are called
transversus
Which of the following describes the action of the corrugator supercilii?
wrinkles the brow
The temporalis muscle passes through the
zygomatic arch
The muscle that elevates the tongue is the
palatoglossus
The insertions of the semispinatus capitus are on the __________.
occipital bone
The actions of the internal intercostals are most important during __________.
forced expiration
The actions of the __________ include compression of the abdomen to assist in forced expiration
internal obliques
The origins of the rectus abdominus muscle are on the __________.
pubic bone
During abdominal surgery, the surgeon makes a cut lateral to the linea alba. The muscle that would be cut is the
rectus abdominis
The two heads of the biceps brachii combine to insert on the __________.
radial tuberosity
All fibers of the triceps brachii are innervated by the __________.
radial nerve
Muscles of the rotator cuff include all of the following, except the
rhomboid
The trapezius muscle may be separated into all of the following groups, except __________.
lateral
The latissimus dorsi inserts on the __________ of the humerus
intertubercular groove
One of the actions of the latissimus dorsi muscle is to __________.
adduct the arm
To keep the humeral head centered within the glenoidal cavity the rotator cuff muscles must be located __________.
in the same plane
The location of the rotator cuff muscles in relation to the glenohumoral joint minimizes the upward pressure against the __________ of the scapula.
acromion
Which muscle is not part of the rotator cuff?
trees major muscle
Downward dislocation of the humerus from the glenohumeral joint when carrying weight is prevented by the __________.
supraspinatus muscle
The angle of which muscle prevents the humeral head from sliding upward out of the joint as the arm is raised?
subscapularis
The rotator cuff is a term used to describe the group of muscles and tendons that stabilize and reinforce the __________.
glenohumeral joint
All the tendons of the rotator cuff muscles combine at which location?
humeral head
Damage to the pectoralis major would interfere with a person's ability to
adduct the humerus
To allow movement of the tendons within the carpal tunnel zone, each tendon is encased in a __________.
sheath
Carpal tunnel syndrome is characterized by inflammation of the __________.
flexor retinaculum and/or tendon sheaths
Of all the flexor muscles of the forearm, the __________ is the shortest.
pronator teres
The muscle that extends the arm while doing push-ups is the
triceps
The insertion of the extensor digitorum branches into __________.
four tendons
At the completion of supinator action, the palm is turned __________.
anteriorly
Of the intrinsic muscles of the hand, which one originates on the hamate bone?
flexor digiti minimi brevis muscle
All fibers of the trapezius muscle are innervated by the __________.
spinal accessory nerve
The prime mover of hip extension is the __________.
gluteus maximus
The tensor fascia latae is involved in hip __________.
abduction
Which of the following muscles pulls on the iliotibial tract?
gluteus maximus
The band of collagen fibers that laterally braces the knee is the
iliotibial tract
Both heads of the biceps femurs muscle flex the leg at the __________.
knee
The long head of the biceps femoris muscle originates on the __________.
ischial tuberosity
The biceps femoris is located in the __________.
posterior thigh
All fibers of the semimembranosus muscle converge to insert on the __________.
posterior tibia
The semimembranosus __________ the thigh at the hip and __________ the leg at the knee.
extends; flexes
The semitendinosus muscle lies ______________ to the semimembranosus muscle.
posterior
The semitendinosus muscle is innervated by the tibial portion of the __________ nerve.
sciatic
Which of the following is a flexor of the knee?
biceps femoris, semitendinosus, and semimembranosus
The main action of the fibularis longus is to __________.
evert the foot
The soleus muscle shares an insertion with the __________ muscle.
gastrocnemius
The soleus muscle __________ the foot at the ankle and is innervated by the __________.
flexes; tibial nerve
Which muscle is found in the superficial posterior compartment of the calf region?
gastrocnemius muscle
If the anterior compartment of the lower limb was suffering from "compartment syndrome," which of these muscles would be at risk of injury?
tibialis anterior, extensor hallucis longus, and extensor digitorum longus
The ________ nervous system controls the skeletal muscles.
somatic
The axon is connected to the cell body at the
axon hillock
Most CNS neurons lack centrioles. This observation explains why CNS neurons
cannot regenerate
Sensory neurons of the PNS are
unipolar
The myelin sheath that covers many CNS axons is formed by
oligodendrocytes
Small, wandering cells that engulf cell debris and pathogens in the CNS are called
microglia
________ account for roughly half of the volume of the nervous system.
neuroglia
Many medications introduced into the bloodstream cannot directly affect the neurons of the CNS because the astrocytes isolate the CNS by forming
a blood-brain barrier
After a stroke, what type of glial cell accumulates within the affected brain region?
microglia
The neurilemma of axons in the peripheral nervous system is formed by
schwann cells
Ion channels that are always open are called ________ channels.
leak
Puffer fish poison blocks voltage-gated sodium channels like a cork. What effect would this neurotoxin have on the function of neurons?
The axon would be unable to generate action potentials.
If the sodium-potassium pumps in the plasma membrane fail to function, all of the following occur, except the intracellular concentration of potassium
ions will increase.
In the peripheral nervous system, Schwann cells participate in the repair of damaged nerves by forming a cellular cord that
directs axonal regrowth
In a typical undisturbed cell, the extracellular fluid (ECF) contains high concentrations of sodium ions and chloride ions, whereas the cytosol contains high concentrations of______ and negatively ______.
potassium ions; charged proteins
Chemically gated channels include receptors that bind
ACh at the neuromuscular junction
What prevents the Na+ and K+ gradients from dissipating?
Na+ K+ ATPase
The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors
The presence of concentration gradients and leak channels
The plasma membrane is much more permeable to K+ than to Na+. Why?
There are many more K+ leak channels than Na+ leak channels in the plasma membrane.
On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you?
The inside surface of the plasma membrane is much more negatively charged than the outside surface.
Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel?
leak channels
Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference?
resting membrane potential
Ions can move across the plasma membrane in which of the following ways?
through voltage-gated channels as in the action potential, through passive or leak channels by ATP-dependent ion pumps like the sodium-potassium exchange pump, through chemically-gated channels as in neuromuscular transmission
all of the above
Which type of membrane channels are found at label "3"?
voltage-gated Na+ channels, voltage-gated K+ channels
The dorsal root ganglia mainly contain
cell bodies of sensory neurons
Spinal nerves are
both sensory and motor
After age ________ the vertebral column continues to elongate, but the spinal cord itself does not.
4
In an adult, the conus medullaris is found at about
L1
What is the function of denticulate ligaments?
They prevent lateral movement of the spinal cord
Samples of CSF for diagnostic purposes are normally obtained by placing the tip of a needle in the
subarachnoid space
Cerebrospinal fluid flows within the
subarachnoid space
The tough, fibrous, outermost covering of the spinal cord is the
dura mater
Which spinal cord structure contains somatic motor nuclei?
anterior gray horn
The white matter of the spinal cord contains
bundles of axons with common origins, destinations, and functions.
Nerve tracts or fasciculi make up the
anterior white columns
A viral disease that destroys the cells of the anterior gray horn will
lead to muscle weakness or paralysis
Spinal nerves from the sacral region of the cord innervate the ________ muscles.
leg
Each peripheral nerve provides ________ innervation to peripheral structures.
motor AND sensory
The dorsal root of a spinal nerve contains
axons of sensory neurons
The ________ of each spinal nerve innervates the skin and muscles of the back.
dorsal ramus
If the dorsal root of a spinal nerve is severed,
sensory input would be blocked
The complex, interwoven network formed by contributions from the ventral rami of neighboring spinal nerves is termed a
plexus
The ________ nerve, which arises in the cervical plexus, innervates the diaphragm.
phrenic