Anatomy quiz 2
Mike falls off his skateboard and sprains his ankle. Which of the following most likely occurs with this type of accident?
A ligament is stretched and collagen fibers in the ligament are damaged.
he characteristic muscle stiffness associated with rigor mortis is due to the inability of myosin filaments to detach from the active site on actin filaments. What molecule is essential for this detachment?
ATP
How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle?
It would cause muscles to stay contracted.
Which of the following occurs when the articular cartilage is damaged?
Normal synovial joint function is unable to continue. The exposed surface appears rough. Friction in the joint increases. The matrix begins to break down.
Which of the following explains the occurrence of a hip fracture rather than a hip dislocation?
Stress gets transferred from head of femur to the diaphysis via the thin neck.
Identify the incorrect statement about a single motor unit.
The more neurons involved, the more powerful the contraction.
The soleus muscle is very red in color. Which of these statements about soleus muscle fibers is FALSE?
They are large in diameter.
Why do the disease tetanus and the normal sustained muscle contraction called tetanus share the same name?
They both eliminate the relaxation phase in the affected muscle fibers.
The flava ligament is
a paired ligament that connect the laminae of adjacent vertebrae.
Which of the following is important to increasing efficiency in tension production?
a shortened relaxation phase
The cytoplasm of the neuromuscular terminal contains vesicles filled with molecules of the neurotransmitter
acetylcholine.
Which of the following situations could contribute to prolonged muscle contraction?
acetylcholinesterase not being produced
In the knee joint, the medial and lateral menisci
act as cushions between the articulating surfaces.
The most important factor in decreasing the intracellular concentration of calcium ion after contraction is
active transport of calcium into the sarcoplasmic reticulum.
Creatine phosphate
acts as an energy reserve in muscle tissue.
When a skeletal muscle fiber is at rest, its ATP demands are met by __________.
aerobic metabolism of fatty acids
A resting muscle generates most of its ATP by
aerobic metabolism of fatty acids.
The fibrocartilage outer layer of the intervertebral disc is called the
annulus fibrosus.
Within an intervertebral disc, which structure provides the tough outer layer of fibrocartilage and which structure provides the soft inner core for resiliency and shock absorption?
anulus fibrosus; nucleus pulposus
What structure covers the bony surfaces of a synovial joint to prevent the surfaces from touching?
articular cartilage
Which of the following athletes are at greatest risk of developing a rotator cuff injury?
baseball pitchers
The surface of articular cartilage is
both slick and smooth.
Small pockets of synovial fluid that reduce friction and act as a shock absorber where ligaments and tendons rub against other tissues are called
bursae.
Triads in skeletal muscle fibers function in __________.
calcium ion release
In response to action potentials arriving along the transverse tubules, the sarcoplasmic reticulum releases
calcium ions
Interactions between the thick and thin filaments are prevented by tropomyosin. To make the active sites accessible, __________ ions must bind to __________.
calcium, troponin
Smooth muscle contracts when calcium binds to __________ and activates __________.
calmodulin; myosin light chain kinase
Structurally, the pubic symphysis is classified as a ________ articulation.
cartilaginous
A muscle producing its maximum tension for a prolonged period is in __________.
complete tetanus
The ligaments that limit the anterior-posterior movement of the tibia and maintain the alignment of the femoral and tibial condyles are the ________ ligaments.
cruciate
Fatigued muscles signify __________.
decreased pH
A freely movable joint is a(n)
diarthrosis.
A synovial joint is an example of a(n)
diarthrosis.
What is the function of the structure indicated by the arrows?
distribute action potentials throughout the interior of the skeletal muscle cell
Lifting a stone with the tip of foot is
dorsiflexion.
Muscle fibers are directly surrounded by which thin layer of connective tissue?
endomysium
The capillaries that wrap around each muscle fiber are located within the __________.
endomysium
Nerves and blood vessels that service a muscle fiber are located in the connective tissues of its
endomysium.
The origin of the frontalis muscle is the
epicranial aponeurosis.
The thick, flat sheet of tendon deep to the scalp is called the
epicranial aponeurosis.
The dense layer of connective tissue that surrounds an entire skeletal muscle is the
epimysium.
A twisting motion of the foot that turns the sole of the foot outward is known as
eversion.
Synaptic vesicles contain neurotransmitters that are released by ________ when the action potential arrives.
exocytosis
The stylohyoid is innervated by which nerve?
facial
Muscles that move the eyeball have ________ fibers.
fast
The structures that assist the bursae in reducing friction between the patella and other tissues are the
fat pads
Usually found outside the capsule, ________ protect the articular cartilages and act as packing material for the joint.
fat pads
The movements known as dorsiflexion and plantar flexion involve moving the
foot.
The glenoid fossa is rimmed by the fibrocartilaginous
glenoid labrum.
Dense fibrous connective tissue is to a suture as a periodontal ligament is to a(n)
gomphosis.
The synarthrosis that binds the teeth to the bony sockets is a
gomphosis.
Which of the following allows muscles to return to their original shape during relaxation?
gravity, opposing muscle contractions, and elastic forces
A fascicle is a
group of muscle fibers that are encased in the perimysium
Cardiac muscles cells have a sarcolemma that is more permeable to calcium, which causes them to __________.
have contractions that last longer than skeletal muscle fibers
Muscles including the term capitis would be found within or attached to the
head
What is the function of the structure indicated by the arrow?
houses the genetic material (DNA) of the cell
What can the nervous system do to increase muscle tension?
increase stimulation frequency recruit larger motor units increase the number of active motor units
Which of the following is not a function of synovial fluid?
increases osmotic pressure within joint
A weight-lifter strains to lift a heavy weight and there is no movement of the person's arms holding on to the weight. This type of contraction is called a(n) ________ contraction.
isometric
The type of contraction where the tension exceeds the load is called
isotonic concentric contraction.
The type of contraction where the tension is less than the load is called The type of contraction where the tension is less than the load is called
isotonic eccentric contraction.
The three functions of synovial fluid are nutrient distribution, shock absorption, and
lubrication.
What is the function of the structure indicated by the arrow?
making of energy (ATP); "power house" of the cell
The ________ muscle is the strongest jaw muscle.
masseter
The sternocleidomastoid inserts on the
mastoid process of the temporal bone
The most common athletic knee injury produces damage to the
medial meniscus.
Bacteria that cause tetanus release a neurotoxin. Which of the following components of the neuromuscular junction (NMJ) does this neurotoxin affect directly?
motor neurons
Interactions between actin and myosin filaments of the sarcomere are responsible for
muscle contraction.
During the recovery period following exercise, all of the following are true except
muscle fibers are unable to contract.
In an isotonic contraction,
muscle tension exceeds the load and the muscle lifts the load.
In which of the following would the motor units have the fewest muscle fibers?
muscles that control the eyes
The gelatinous core of an intervertebral disc is called the
nucleus pulposus.
To pinch with a thumb and finger involves a movement called
opposition.
The "kissing muscle" that purses the lips is the
orbicularis oris.
During anaerobic glycolysis,
oxygen is not consumed. carbohydrate is metabolized. pyruvic acid is produced. ATP is produced.
The ligament that provides support to the front of the knee joint is the ________ ligament.
patellar
Which muscle is named for either shape or size?
pectoralis major deltoid latissimus dorsi vastus lateralis All of the above are named for shape or size.
The atlantoaxial joint is an example of a ________ joint.
pivot
Which foot movement enables the ballerina to stand on her toes?
plantar flexion
The back of the knee joint is reinforced by ________ ligaments.
popliteal
The iliac crest is the origin of the
quadratus lumborum.
The increase in muscle tension that is produced by increasing the number of active motor units is called
recruitment.
Muscles with fibers that run parallel to the long axis of the body are called
rectus
Which of the following best describes the term sarcomere?
repeating unit of striated myofibrils
After death, muscle fibers run out of ATP and calcium begins to leak from the sarcoplasmic reticulum into the sarcoplasm. This results in a condition known as
rigor mortis.
The coxal bones articulate with the sacrum at the ________ joint.
sacroiliac
In response to an action potential along the transverse tubules, the __________ release(s) calcium ions into the sarcoplasm.
sarcoplasmic reticulum
The joint that permits the greatest range of mobility of any joint in the body is the ________ joint.
shoulder
Which of the following joints is an example of a ball-and-socket joint?
shoulder
The type of muscle fiber that is most resistant to fatigue is the ________ fiber.
slow
What type of muscle fibers has the longest endurance?
slow
Which skeletal muscle fiber typeslow or fastcontains more mitochondria?
slow
What is the function of the structure indicated by the arrow?
storage of calcium
Factors that increase the stability of the hip joint include
supporting ligaments. strong muscular padding. almost complete bony socket. tough capsule.
Which of the following is not a type of synovial joint?
symphysis
An immovable joint is a(n)
synarthrosis
A suture is an example of a(n)
synarthrosis.
Joints can be classified structurally as
synovial. fibrous. bony. cartilaginous.
At each end of the muscle, the collagen fibers of the epimysium, perimysium, and endomysium, come together to form a
tendon
Tom, a trumpet player, asks you which muscles he should develop in order to be a better trumpeter. What would you tell him?
the buccinator and orbicularis oris
Complete dislocation of the knee is rare because
the knee contains seven major ligaments
In rigor mortis
the myosin heads are attached to actin. calcium ions keep binding to troponin. sustained contractions occur. ATP is depleted.
The muscle action potential penetrates deep into a fiber along the __________.
transverse tubules
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.
At rest, active sites on the actin are blocked by
tropomyosin molecules.
When calcium ion binds to troponin
tropomyosin rolls away from the active site
A single contraction-relaxation cycle in a muscle fiber produces a(n)
twitch
Increased muscle fiber endurance can be produced by __________
type of activity preformed
The muscle that raises the corners of the mouth as when smiling is the ________ muscle.
zygomaticus major