ANSC 230 Exam 3 Practice MC

Which of the following is NOT a function of the skeletal system?

a. Support

b. Storage of minerals and lipids

c. regulation of body temperature

d. blood cell production

regulation of body temperature

Yellow bone marrow primarily functions in:

a. blood cell production

b. lipid storage for energy reserves

c. calcium regulation

d. formation of synovial fluid

lipid storage for energy reserves

Which skeletal function allows bones to act as levers for movement?

a. protection

b. support

c. leverage

d. mineral storage

leverage

A ligament connects:

a. muscle to bone

b. bone to bone

c. tendon to cartilage

d. bone to muscle

bone to bone

Which connective tissue covers the ends of bones and joints to reduce friction?

a. ligament

b. tendon

c. articular cartilage

d. periosteum

articular cartilage

The structural frame made of bones and joints is called the:

a. skeleton

b. periosteum

c. endosteum

d. trabeculae

skeleton

Tendons connect:

a. bone to bone

b. muscle to bone

c. cartilage to cartilage

d. joint to joint

muscle to bone

The femur is classified as a:

a. flat bone

b. irregular bone

c. long bone

d. sesamoid bone

long bone

The patella is an example of a:

a. short bone

b. flat bone

c. irregular bone

d. sesamoid bone

sesamoid bone

Vertebrae are classified as:

a. long bones

b. flat bones

c. irregular bones

d. sesamoid bones

irregular bones

Which is part of the axial skeleton?

a. femur

b. radius

c. sternum

d. metacarpal

sternum

The neurocranium houses:

a. the digestive tract

b. the brain

c. the lungs

d. the pelvic organs

the brain

Vertebrae separated by intervertebral discs for what type of joint?

a. synovial

b. symphysis (slightly movable)

c. immovable fibrous

d. hinge

symphysis

The annulus fibrosus of an intervertebral disc is composed of:

a. collagen only

b. fibrocartilage

c. hyaline cartilage

d. elastic cartilage

fibrocartilage

Ribs that do not attach to the sternum at all are called:

a. true ribs

b. false ribs

c. floating ribs

d. accessory ribs

floating ribs

Which domestic mammal has a clavicle?

a. horse

b. dog

c. cat

d. cow

cat

The os coxae is formed by the fusion of which bones?

a. Ilium, ischium, and sacrum

b. ilium, ischium, and pubic

c. sacrum, pubis, and coccyx

d. femur, tibia, and fibula

ilium, ischium, and pubis

In horses, the main metacarpal/metatarsal bone is called the:

a. splint bone

b. cannon bone

c. pastern bone

d. coffin bone

cannon bone

The acetabulum is found in the:

a. scapula

b. pelvis

c. femur

d. tibia

pelvis

The human wrist and quadruped forelimb "knee" joint contains which bones?

a. metacarpals

b. carpals

c. tarsals

d. phalanges

carpals

The cylindrical shaft of a long bone is the:

a. epiphysis

b. metaphysis

c. diaphysis

d. periosteium

diaphysis

Compact (cortical) bone makes up approximately what percentage of bone tissue?

a. 20%

b. 50%

c. 70%

d. 80%

80%

Spongy bone contains a scaffold of mineralized tissue called:

a. osteons

b. lamellae

c. trabeculae

d. canaliculi

trabeculae

The periosteum contains:

a. only blood vessels

b. an outer fibrous layer and an inner cellular layer

c. cartilage and synovial fluid

d. osteons exclusively

an outer fibrous layer and an inner cellular layer

The Haversian system consists of concentric lamellae surrounding a:

a. trabecula

b. Haversian canal

c. canaliculus.

d. Lacuna

Haversian canal

Which bone cells are most abundant and maintain bone structure?

a. osteoblasts

b. osteocytes

c. osteoclasts

d. chondrocytes

osteocytes

Osteoblasts are responsible for:

a. bone resorption

b. ossification

c. producing cartilage

d. forming marrow

ossification

Osteoclasts function by:

a. producing osteoid

b. recycling calcium salts

c. dissolving bone matrix

d. creating trabeculae

dissolving bone matrix

Approximately what percentage of bone is mineral by composition?

a. 25%

b. 30%

c. 45%

d. 60%

45%

The vascular inner lining of bone is the:

a. Endosteum

b. Periosteum

c. Epiphysis

d. metaphysis

endosteum

Which process replaces hyaline cartilage with bone during fetal development?

a. intramembranous ossification

b. endochondral ossification

c. appositional growth

d. bone remodeling

endochondral ossification

The epiphyseal growth plate is the site of:

a. Post-natal longitudinal growth

b. bone width increase

c. compact bone remodeling only

d. bone resorption exclusively

post-natal longitudinal growth

Which hormone primarily stimulates IGF-1 production for longitudinal bone growth?

a. Calcitonin

b. Parathyroid hormone

c. growth hormone

d. estrogen

growth hormone

Closure of the growth plate at puberty is mediated largely by:

a. testosterone

b. estrogen

c. parathyroid hormone

d. cortisol

estrogen

In the zone of proliferation, chondrocytes:

a. die in a calcified matrix

b. divide and push the epiphysis away from the diaphysis

c. hypertrophy and enlarge lacunae

d. are replaced by osteoblasts

divide and push the epiphysis away from the diaphysis

Apposition growth refers to:

a. bone lengthening

b. cartilage replacement by bone

c. bone fracture repair

d. bone widening

bone widening

Which cells are quiescent stem cells in the periosteum that differentiate into osteoblasts?

a. osteogenic progenitor cells

b. osteoclasts

c. chondrocytes

d. osteocytes

osteogenic progenitor cells

Which process enlarges the medullary cavity during appositional growth?

a. osteoblast deposition from periosteum

b. osteoclast resorption from endosteum

c. osteocyte entrapment

d. calcitonin activity

osteoclast resorption from endosteum

The first stage of bone fracture repair involves formation of a:

a. spongy bone callus

b. compact bone matrix

c. hematoma

d. osteon

hematoma

During bone repair, the cartilage callus is converted into bone by:

a. intramembranous ossification

b. calcitonin

c. periosteal ossification

d. endochondral ossification

endochondral ossiication

Which vitamin-derived hormone increases intestinal calcium absorption?

a. calcitonin

b. calcitriol

c. parathyroid hormone

d. aldosterone

calcitriol

Which hormone is released when blood calcium is too low?

a. parathyroid hormone

b. calcitonin

c. growth hormone

d. cortisol

parathyroid hormone

Which hormone reduces osteoclast activity to lower blood calcium levels?

a. parathyroid hormone

b. calcitriol

c. calcitonin

d. vitamin D3

calcitonin

Which muscle type is voluntary and striated?

a. skeletal

b. cardiac

c. smooth

d. all of the above

skeletal

Cardiac muscle cells are distinguished by:

a. multinucleation at the periphery

b. intercalated discs

c. spindle-shaped fibers

d. lack of striations

intercalated discs

Smooth muscle is primarily responsible for:

a. voluntary body movement

b. blood vessel constriction

c. shivering thermogenesis

d. postural control

blood vessel constriction

The connective tissue surrounding an entire muscle is the:

a. endomysium

b. perimysium

c. epimysium

d. sarcolemma

epimysium

The contractile organelle of skeletal muscle is the:

a. sarcolemma

b. myofilament

c. sarcoplasmic reticulum

d. myofibril

myofibril

The basic contractile unit of striated muscle is the:

a. sarcomere

b. myofiber

c. fascicle

d. Z-line

sarcomere

Which protein blocks myosin binding sites on actin?

a. troponin

b. tropomyosin

c. titin

d. dystrophin

tropomyosin

Which protein binds calcium during contraction?

a. actin

b. tropomyosin

c. troponin

d. myosin

troponin

The sarcoplasmic reticulum's primary role is to:

a. store glycogen

b. store and release calcium

c. transmit nerve impulses

d. form cross-bridges

store and release calcium

The site where a motor neuron communicates with a muscle fiber is the:

a. sarcomere

b. T-tubule

c. Myofibril

d. Neuromuscular junction

Neuromuscular junction

Which neurotransmitter is released at the neuromuscular junction?

a. norepinephrine

b. acetylcholine

c. dopamine

d. serotonin

acetylcholine

What enzyme degrades acetylcholine in the synaptic cleft?

a. acetylcholinesterase

b. monoamine oxidase

c. lactate dehydrogenase

d. create kinase

acetylcholinesterase

According to the sliding filament theory, which band remands the same length during contraction?

a. I-band

b. A-band

c. H-zone

d. Z-line

A-band

Which structure moves closer together during contraction?

a. A-bands

b. M-lines

c. Z-lines

d. H-zones

Z-lines

Cross-bridge detachment requires binding of:

a. Calcium

b. ADP

c. ATP

d. Phosphate

ATP

Hydrolysis of ATP during muscle contraction serves to:

a. Release calcium from SR

b. expose actin binding site

c. detach acetylcholine

d. re-cock the myosin head

re-cock the myosin head

During relaxation, calcium is returned to the SR by:

a. passive diffusion

b. sarcoplasmic reticulum Ca2+-ATPase pump

c. voltage-gated Na+ channels

d. Troponin-tropomyosin

Sarcoplasmic reticulum Ca2+-ATPase pump

A muscle twitch is defined as:

a. continuous contraction of a whole muscle

b. a contraction from a single action potential in one motor unit

c. tetanus caused by bacterial toxins

d. multiple motor units firing together

a contraction from a single action potential in one motor unit

The latent phase of a muscle twitch corresponds to:

a. immediate contraction after stimulation

b. passive relaxation fibers

c. ATP depletion

d. Time for Ca2+ to diffuse from SR and bind to troponin

Time for Ca2+ to diffuse from SR and bind to troponin

During the contraction phase of a twitch:

a. Cross-bridge cycling actively generates force

b. troponin releases Ca2+

c. the muscle lengthens passively

d. no ATP is required

cross-bridge cycling actively generates force

The relaxation phase occurs when:

a. ATP stores are depleted

b. the muscle continues force generation

c. Ca2+ returns to the SR and muscle returns to resting length

d. troponin is permanently bound to calcium

Ca2+ returns to the SR and muscle returns to resting length

Wave summation occurs when:

a. a second action potential arrives before relaxation of the first twitch

b. multiple motor units fire at the same time

c. Ca2+ is completely removed from cytosol

d. ATP is exhausted

A second action potential arrives before relaxation of the first twitch

Tetanus (not the disease) refers to:

a. sudden random spasms

b. fusion of individual twitches into a sustained contraction

c. a bacterial infection of the muscles

d. loss of neuromuscular junction function

fusion of individual twitches into a sustained contraction

In tetanus, force reaches:

a. zero tension

b. only half the normal force

c. below twitch levels

d. a plateau at maximal contraction

a plateau at maximal contraction

Red skeletal muscle fibers are specialized for:

a. endurance

b. power

c. rapid fatigue

d. low oxygen usage

endurance

White skeletal muscle fibers are specialized for:

a. endurance

b. strength and power

c. fatigue resistance

d. slow contraction

strength and power

Red muscle has high levels of:

a. glycolytic enzymes

b. fast twitch isoforms

c. myoglobin and mitochondria

d. fatigability

myoglobin and mitochondria

White muscle fibers have:

a. few mitochondria, high glycolytic activity

b. high oxidative enzyme levels

c. abundant myoglobin

d. slow contraction

few mitochondria, high glycolytic activity

Which factor primarily determines red vs. white muscle color?

a. collagen

b. capillary density

c. myoglobin concentration

d. ATP concentration

myoglobin concentration

The number of muscle fibers in an individual is:

a. fixed at birth

b. increased by training

c. doubled after puberty

d. controlled only by diet

fixed at birth

Postnatal skeletal muscle growth occurs by:

a. hyperplasia (increase in fiber number)

b. hypertrophy (increase in fiber size0

c. addition of new stem cells

d. none of the above

hypertrophy (increase in fiber size)

Muscle wasting from disuse or disease is due to:

a. hyperplasia

b. atrophy of existing fibers

c. loss of muscle cell nuclei

d. formation of new small fibers

atrophy of existing fibers

Which twitch phase corresponds to Ca2+ binding troponin?

a. latent

b. relaxation

c. recovery

d. contraction

contraction

A marathon runner would rely more heavily on:

a. red fibers

b. white fibers

c. equal mix

d. neither

red fibers

A sprinter would rely primarily on:

a. Red fibers

b. white fibers

c. slow twitch only

d. none of the above

white fibers

Increased mitochondrial density is most associated with:

a. White fibers

b. atrophied muscle

c. hyperplasia

d. red fibers

red fibers

A key reason white fibers fatigue quickly is:

a. lack of ATP production

b. reliance on glycolytic metabolism

c. poor neuromuscular junctions

d. weak cross-bridge

reliance on glycolytic metabolism

Disuse atrophy occurs because:

a. existing fibers shrink

b. muscle cells die

c. myoglobin is lost

d. fiber number decreases

existing fibers shrink

Tetanus provides greater force than a twitch because:

a. Ca2+ accumulates, maintaining cross-bridge cycling

b. ATP is more abundant

c. fibers become longer

d. myosin heads detach more rapidly

Ca2+ accumulates, maintaining cross-bridge cycling

What is A on the diagram?

A-band

What is B on the diagram?

H-zone

What is C on the diagram?

I-band

What is D on the diagram?

M-line

What is E on the diagram?

Z-line