Mastering A and P Exam 2

The following are important steps in the process of endochondral ossification. 1. Enlarged chondrocytes die. 2. Osteoblasts replace calcified cartilage with spongy bone. 3. Chondrocytes enlarge and the surrounding matrix begins to calcify. 4. Blood vessels penetrate the cartilage. 5. Perichondrial cells become osteoblasts and produce a thin shell of bone. What is the correct order for these events?

3, 1, 5, 4, 2

The region of the sarcomere containing the thick and thin filaments is the

A band

In appositional bone growth, how are layers of compact bone added to the bone's outer surface?

Bone is deposited by superficial osteoblasts.

Which statement about excitation-contraction coupling is incorrect? Troponin binds calcium ion and signals tropomyosin to move. Relaxation requires uptake of calcium ions by the sarcoplasmic reticulum. Calcium ion is released from the transverse tubule. Calcium ion is released from the sarcoplasmic reticulum. Tropomyosin moves to expose myosin binding sites on actin.

Calcium ion is released from the transverse tubule.

Which of the following is the intestinal response to PTH stimulation?

Calcium is absorbed quickly.

Which of the following occurs during the relaxation phase of a muscle twitch?

Calcium levels are falling.

________ is a pigment found in vegetables that can make the skin appear orange or yellow.

Carotene

________ are stronger than steel when stretched.

Collagen fibers

________ are cells in the epidermis that are part of the immune system.

Dendritic cells

Ectopic bones may occur in which of the following conditions?

FOP

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

H band.

Bill, age 15, is still growing, but his older sister Andrea, age 19, has stopped. What has changed in Andrea's bones?

Her epiphyseal plates have ossified.

The region of the sarcomere that always contains only thin filaments is the

I band.

Which of the following is a response coordinated by the heat-gain center? The vasomotor center increases blood flow to the dermis. Parasympathetic stimulation of the adrenal medullae releases epinephrine. Shivering decreases body temperature. In children, hypothalamic TRH release increases.

In children, hypothalamic TRH release increases.

Which of the following is a function of the meniscus?

It channels the flow of synovial fluid.

Which statement is correct regarding thick filament structure? It consists of a core of titin, forming a strand that continues across the I band to the Z line on that side. Each long myosin tail is bound to actin molecules within the thick filament. All the myosin molecules are arranged with their tails pointing away from the M line. The free myosin head has three globular protein subunits.

It consists of a core of titin, forming a strand that continues across the I band to the Z line on that side.

Which of the following is not a characteristic of articular cartilage? It is composed of hyaline cartilage. Surfaces are normally slick and smooth. There is no perichondrium. It secretes synovial fluid. The matrix contains more water than other cartilages.

It secretes synovial fluid

How would a drug that blocks acetylcholine 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 acetylcholinesterase from the motor end plate affect skeletal muscle?

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

________ free calcium from bone to maintain blood calcium levels.

Osteoclasts

________ cells are located in the inner cellular layer of the periosteum.

Osteoprogenitor

________ are mesenchymal cells that develop into osteoblasts.

Osteoprogenitor cells

All of the following result in decreased calcium levels in the bloodstream, except: calcitonin inhibition of osteoclasts. PTH stimulation of osteoclasts. decreased PTH or calcitriol levels. increased calcitonin levels.

PTH stimulation of osteoclasts.

Which of the following statements is incorrect? Skeletal muscle contractions help maintain body temperature. Skeletal muscles are responsible for the pumping action of the heart. Skeletal muscles support the weight of some internal organs. Skeletal muscles store nutrient reserves. The contractions of skeletal muscles pull on tendons and move bones of the skeleton.

Skeletal muscles are responsible for the pumping action of the heart.

Which is true regarding skin cancers? Malignant melanomas never metastasize. Skin cancers are the most common types of cancers. The keratin in keratinocytes protects the DNA in epidermal cells against the effects of UV radiation. Basal cell carcinomas are extremely dangerous and metastasize rapidly through the lymphatic system.

Skin cancers are the most common types of cancers

Which of the following statements is/are true regarding human muscles?

Slow fibers are abundant in the calf muscles. Most have both slow and fast fibers. Slow fibers are abundant in the back muscles. Eye muscles are composed entirely of fast fibers.

________ bone reduces the weight of the skeleton and reduces the load on muscles.

Spongy

How would removing hydroxyapatite from bone matrix affect the physical properties of a bone?

The bone would be more flexible.

Why would an elderly person be more prone to skin infections than a younger person?

The epidermis is thinner in the elderly. Skin repairs take longer in the elderly. There are fewer dendritic cells in the skin of the elderly.

What is the result when the zone of overlap is reduced to zero?

The muscle fiber cannot produce any active tension.

What happens immediately after the myosin head binds to the active site on actin?

The myosin head pivots, moving the actin strand.

Which of the following is a response coordinated by the heat-loss center

The respiratory centers are stimulated

Which of the following statements regarding the internal structure of long bones is incorrect?

The wall of the diaphysis consists of a layer of spongy bone

Tetanus is most likely to result from which condition?

a deep puncture wound, such as that from a nail

The skeletal muscle complex known as the triad consists of

a transverse tubule and two terminal cisternae.

A movement away from the midline of the body is termed

abduction.

The intestinal response to PTH secretion when calcium ion levels are low is that calcium is

absorbed quickly.

A myosin head binds to which molecule to form a cross bridge?

actin

Myosin molecules form cross-bridges when they attach to __________.

actin

Which of the following proteins contains the active site involved in cross-bridge formation?

actin

Creatine phosphate

acts as an energy reserve in muscle tissue.

Which process produces the greatest number of twitches, based on initial quantity of energy source in a typical muscle fiber?

aerobic metabolism of glycogen

A slightly movable joint is a(n)

amphiarthrosis.

Decreased blood flow to a muscle could result in all of the following except an oxygen debt. an increase in intracellular lactate. an increase in intracellular glycogen. a shift to anaerobic glycolysis. muscle fatigue.

an increase in intracellular glycogen.

What causes the release of calcium from the terminal cisternae of the sarcoplasmic reticulum within a muscle cell?

arrival of an action potential

The location where two bones meet is called a joint, or an

articulation.

What causes the myosin head to disconnect from actin?

binding of ATP

Which is greater? blood calcium levels when parathyroid hormone is decreased blood calcium levels when parathyroid hormone is increased

blood calcium levels when parathyroid hormone is increased

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.

C cells of the thyroid gland secrete which of the following?

calcitonin

Elevated levels of calcium ion in the blood stimulate the secretion of the hormone ______________

calcitonin.

The most abundant mineral in the human body is

calcium

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

calcium ions

Bone plays a central role in the regulation of blood levels of

calcium.

The narrow passageways that contain cytoplasmic extensions of osteocytes are called

canaliculi.

The primary pigments contained in the epidermis are

carotene and melanin

Endochondral ossification begins with the formation of a(n)

cartilage model.

When a muscle is stimulated repeatedly at a high rate, eliminating a relaxation phase, the amount of tension gradually increases to a steady maximum tension. This is called

complete tetanus.

During which phase of a muscle twitch are active sites on thin filaments exposed, and do cross-bridge interactions occur?

contraction phase

Which of the following is not a property of synovial joints? reinforced by accessory structures freely movable covered by a capsule contain synovial fluid covered by a serous membrane

covered by a serous membrane

The hormone calcitonin functions to

decrease the level of calcium ion in the blood.

Physical evidence that supports the sliding filament theory of muscle contraction includes

decreased width of the H band during contraction.

ATP binding leads to which of the following actions?

detaching and resetting cross-bridges

Synovial joints are classified functionally as:

diarthroses.

A freely movable joint is a(n)

diarthrosis.

The protein that permits stretching and recoiling of the skin is

elastin

The dense layer of connective tissue that surrounds an entire skeletal muscle is the

epimysium.

What structure allows a bone to grow in length?

epiphyseal cartilages

Synaptic vesicles containing neurotransmitters are released by ________ when the action potential arrives.

exocytosis

Which of the following movements is a good example of hyperextension?

extreme backward bending of the head

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

fast fibers.

Which bone is not formed via intramembranous ossification? clavicle patella femur mandible

femur

The movements known as dorsiflexion and plantar flexion involve moving the

foot.

Which type of joint is found between the carpal bones?

gliding

Dense connective tissue is to a suture as a periodontal ligament is to a(n)

gomphosis.

Muscle fibers differ from "typical cells" in that muscle fibers

have many nuclei.

When comparing slow motor units to fast motor units, slow units

have much smaller fiber diameters. are rich in the red protein myoglobin. generate much less tension. take about three times as long to reach peak tension.

A joint that permits only flexion and extension is a ________ joint.

hinge

The elbow joint is an example of a ________ joint.

hinge

In bone, the calcium phosphate forms crystals of

hydroxyapatite.

Movement in the anterior-posterior plane that increases the angle between articulating elements past the anatomical position is called:

hyperextension.

The area of the brain that regulates body temperature is the

hypothalamus.

Which of the following is not a function of synovial fluid? increasing osmotic pressure within joint shock absorption protecting articular cartilages lubrication providing nutrients

increasing osmotic pressure within joint

Parathyroid hormone functions in all of the following ways except that it stimulates osteoclast activity. raises the level of calcium ion in the blood. increases the rate of calcium absorption. inhibits calcitonin secretion. decreases the rate of calcium excretion.

inhibits calcitonin secretion

Elevation of the medial edge of the sole of the foot describes which of the following?

inversion

Polio:

is a viral disease that attacks motor neurons in the spinal cord and brain.

All of the following are true of the hypodermis except it contains many blood vessels. permits independent movement of deeper structures. is attached to the dermis by a basement membrane. contains large amounts of adipose tissue. stores energy reserves.

is attached to the dermis by a basement membrane.

Convection:

is the result of conductive heat loss to the air that overlies the surface of the body.

The type of most cells that form the strata in the epidermis are

keratinocytes.

The space occupied by an osteocyte is called a

lacuna.

Scar tissue is the result of

large numbers of collagen fibers and relatively few blood vessels in the injured area.

The muscle weakness of myasthenia gravis results from

loss of acetylcholine receptors in the end-plate membrane.

Myofibrils are __________.

made of a series of sarcomeres

The most dangerous type of skin cancer is termed

malignant melanoma

The movement of rotating a limb toward the anterior surface of the body is called

medial (internal) rotation

In intramembranous ossification, which cells first cluster together and start to secrete the organic components of the matrix?

mesenchymal cells

When acetylcholine binds to receptors at the motor end plate, the end plate membrane becomes

more permeable to sodium ions.

Each of the following statements concerning sebaceous glands and sebum is true except most sebaceous glands open into hair follicles. sebum can function as an antibiotic. sebum functions to lubricate the hair and skin. acne involves inflammation of sebaceous glands. most sebaceous glands are coiled tubular glands

most sebaceous glands are coiled tubular glands

Receptors for acetylcholine are located on the

motor end plate

The periosteum contains all of the following except: motor nerves. lymphatic vessels. sensory nerves. blood vessels.

motor nerves

A single motor neuron together with all the muscle fibers it innervates is called a(n)

motor unit.

Abduction is a(n):

movement away from the longitudinal axis of the body in the frontal plane.

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

muscle contraction

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

muscles that control the eyes

Determine the correct structural hierarchy of skeletal muscles, from microscopic to gross levels

myofibril - fiber - fascicle - muscle

Which of the following is involved in the power stroke?

myosin

Cross-bridges are portions of

myosin molecules

The narrow region between the head and shaft of a long bone is called the

neck

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

neuromuscular junction

Communication between axons and muscle fibers occurs at specialized synapses called

neuromuscular junctions.

During the process of ________, an existing tissue is replaced by bone.

ossification

Cells of the perichondrium need to take on a new role as ossification begins. They will become __________.

osteoblasts and begin to deposit bone matrix

At puberty:

osteoblasts begin producing bone faster than chondrocytes are producing new epiphyseal cartilage.

Cells that secrete the organic components of the bone matrix are called

osteoblasts.

Which is greater? osteoclast activity when calcitonin is present osteoclast activity when calcitonin is absent

osteoclast activity when calcitonin is absent

The process of osteolysis is performed by which cell population?

osteoclasts

Which component is not present in spongy bone?

osteons

The structural units of mature compact bone are called

osteons.

During anaerobic glycolysis

oxygen is not consumed. pyruvate is produced. ATP is produced.

Cyanosis signifies that a patient has

oxygen-starved skin.

The layer of the skin that contains the blood vessels and nerves that are closest to the surface of the skin is the ________ layer.

papillary

In relationship to the diaphysis of a long bone, the osteons are

parallel.

Which bone-associated structure(s) is/are continuous with the capsule of the joint, adding strength and helping to stabilize the joint?

periosteum

Which foot movement enables a ballerina to stand on her toes?

plantar flexion

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

polio

Which of the following is a recognized function of skeletal muscle?

produce movement maintain posture guard body entrances and exits maintain body temperature

You ________ your jaw when you grasp your upper lip with your lower teeth.

protract

Muscular force can be adjusted to match different loads by

recruiting larger motor units. recruiting more motor units. varying the frequency of action potentials in motor neurons.

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

recruitment.

The smooth but steady increase in muscular tension that is produced by increasing the number of active motor units is called:

recruitment.

Which phase of a muscle twitch is eliminated in complete tetanus?

relaxation phase

What causes the power stroke?

release of ADP and Pi

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.

All of the following are structural classifications of synovial joints except gliding. rolling. saddle. hinge. pivot.

rolling.

The first carpometacarpal joints are examples of which type of synovial joints?

saddle joint

The plasma membrane of skeletal muscle is called the

sarcolemma.

The repeating contractile unit of a skeletal muscle fiber is the

sarcomere.

Z lines define the edges of which of the following?

sarcomeres

Excitation-contraction coupling is the

sequence of processes that links the action potential to contraction.

Bones that develop within tendons are called ________ bones.

sesamoid

The carpal bones are examples of ________ bones.

short

The joint that permits the greatest range of mobility of any joint in the body is the ________ joint.

shoulder

Which of the following is an example of a ball-and-socket joint?

shoulder

A chamber within a bone normally filled with air is a

sinus

The substance called sebum is commonly known as

skin oil

the substance called sebum is commonly known as

skin oil

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

sliding filament theory.

The type of muscle fiber that is most resistant to fatigue is the ________ fiber.

slow

Skin can regenerate effectively even after considerable damage has occurred because

stem cells persist in both epithelial and connective-tissue components of the skin even after injury.

Which of the following best describes the sarcoplasmic reticulum?

storage and release site for calcium ions

Large quantities of keratin are found in the epidermal layer called the

stratum corneum.

The layer of the epidermis that contains abundant desmosomes and dendritic cells is the

stratum spinosum

All of the following are accessory structures of the skin except hair follicles. subcutaneous fat. sweat glands. sebaceous glands. nails.

subcutaneous fat.

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

synaptic cleft.

A suture is an example of a(n)

synarthrosis.

An immovable joint is a(n)

synarthrosis.

Functionally, all of the following are synarthroses except: synostosis synchondrosis gomphosis syndesmosis

syndesmosis

Which of the following is one of the four major types of synarthrotic joints?

synostosis gomphosis synchondrosis suture

What supplies the articular cartilage of long bones with oxygen and nutrients?

synovial fluid

Joints can be classified structurally as

synovial. bony. fibrous. cartilaginous

Exocrine glands do all of the following except __________. assist in thermoregulation lubricate the epidermis excrete wastes synthesize vitamin D3

synthesize vitamin D3

In the stratum basale, which of the following specialized epithelial cells are sensitive to touch?

tactile discs

The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a(n)

tendon.

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

testosterone

Which of the following acts as an ATPase during the contraction cycle of muscle?

the head portion of the myosin molecule

As blood vessels extend into the spaces left by dying chondrocytes, the models begin to ossify internally. Where does internal ossification begin?

the primary ossification center in the diaphysis

Myosin molecules form what part of the sarcomere?

thick filament

The interconnecting tiny arches of bone tissue found in spongy bone are called

trabeculae.

The action potential is conducted deep into a skeletal muscle fiber by

transverse tubules.

The large proximal projection on the femur is termed the

trochanter.

When the sarcomere is at rest, what is covering the active sites on actin?

tropomyosin

At rest, active sites on the actin are blocked by

tropomyosin molecules.

The binding of calcium to which molecule causes the myosin binding sites to be exposed?

troponin

When calcium is released inside a muscle cell, what does it bind to?

troponin

Which thin-filament-associated structure is distinguished by its constituents of three globular subunits, one of which has a receptor that binds two calcium ions?

troponin

Which of the following movements is a good example of supination?

turning the hand palm upward

The rapid rise and fall in force produced by a muscle fiber after a single action potential is a(n)

twitch.

Each thin filament consists of

two protein strands coiled helically around each other.

All of the following are characteristics of the epidermis except that it is serving as UV radiation protection. flexible. vascularized. self-repairing. multilayered.

vascularized

Which of the following bones is classified as "irregular" in shape?

vertebra

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

wave summation

When does a muscle contraction begin?

when stored calcium ions are released from the sarcoplasmic reticulum into the sarcoplasm through gated calcium channels

Which of the following best describes the term "Z line"?

where thin filaments are anchored

Which of the following is not a type of motor unit? red-slow twitch white-slow twitch white-fast twitch pink-fast twitch

white-slow twitch

Osteoprogenitor cells are described by all of the following except: divide to produce daughter cells that differentiate into osteoclasts. important in the repair of a fracture. mesenchymal cells present in small numbers in the inner, cellular layer of the periosteum. present in small numbers in the lining of vascular passageways that penetrate the matrix of compact bone.

divide to produce daughter cells that differentiate into osteoclasts.

The lining of the medullary cavity is called the

endosteum.

The repair of the epidermis after a wound begins as basal cells produce new

epidermal cells.

The terms "thick" and "thin" refer to the relative thickness of which of the following?

epidermis

During wound repair, the activity of which cells leads to the appearance of collagen fibers and typical ground substance?

fibroblasts

A shallow depression on a bone is termed a

fossa

What characteristic may cause life-threatening issues in individuals with Marfan syndrome?

genetic mutation that affects the structure of connective tissue throughout the body

Excessive growth hormone prior to puberty could result in

giantism

All of the following are true of perspiration produced by merocrine sweat glands except that it: is very watery. produces the body odor characteristic of "sweating." helps cool the body when it evaporates. helps to prevent bacteria from colonizing the skin. contains electrolytes and waste products.

produces the body odor characteristic of "sweating."

Each of the following is a function of the integumentary system except: provision of sensation. protection of underlying tissue. synthesis of vitamin C. maintenance of body temperature. excretion of salts and wastes.

synthesis of vitamin C.

Exocrine glands do all of the following except __________. assist in thermoregulation lubricate the epidermis excrete wastes synthesize vitamin D3

synthesize vitamin D3

Which of the following are not components of the skeletal system? tendons ligaments cartilages bones

tendons

The shaft of a long bone is called the

diaphysis.

Perspiration is produced by ________ glands.

merocrine sweat

The following are stages in the regeneration of skin following an injury. 1. blood clot/scab formation 2. cellular migration 3. epidermis covers granulation tissue 4. epidermis covers scar tissue Which of the following places the steps in the correct order?

1, 2, 3, 4

The following are major steps in the process of intramembranous ossification. 1. Clusters of osteoblasts form osteoid that becomes mineralized. 2. Osteoblasts differentiate within mesenchymal connective tissue. 3. Spicules of bone radiate out from the ossification centers. 4. Mesenchymal cells aggregate. What is the correct order for these events?

4, 1, 2, 3

All of the following are characteristics of periosteum except: It is an incomplete cellular layer that lines the medullary cavity. It actively participates in bone growth and repair. It has two layers, an inner layer and an outer layer. It provides a route for the blood and nervous supply.

It is an incomplete cellular layer that lines the medullary cavity.

Which of the following statements about Marfan's syndrome is false? It results in short, stubby fingers. It affects epiphyseal cartilages. It affects connective tissue genes. It results from a mutation. None of the answers is correct.

It results in short, stubby fingers.

Which condition, due to excessive cartilage formation at the epiphyseal cartilages, results in individuals who are very tall, with long, slender limbs?

Marfan syndrome

________ sweat glands are widely distributed across the body surface, ________ glands are located wherever hair follicles exist, and ________ sweat glands are found only in a few areas.

Merocrine; sebaceous; apocrine

If a fair-skinned person is sunburned, why does his or her skin turn red?

The blood flow to the skin increases as part of the inflammatory response.

The effects of aging on the skin include

a decline in the activity of sebaceous glands.

A thickened area of scar tissue that is covered by a shiny, smooth epidermal surface is called

a keloid

A fibrin clot that is formed over a skin wound is called

a scab

Granulation tissue is composed of

an extensive capillary network. clotted blood. fibroblasts.

The ________ glands in the axilla become active at the time of puberty.

apocrine sweat

Melanin is produced by melanocytes within the stratum___________

basale.

Which of the following is a function of the skeletal system?

blood cell production calcium homeostasis body support protection of internal organs

The central canal of an osteon contains

blood vessels.

During appositional growth,

bones grow wider.

Several hours after an injury to the skin and a scab has formed, cells from which integumentary layer undergo rapid divisions and begin to migrate along the edge of the wound?

cells of the stratum basale of the epidermis

Earwax is produced by ________ glands.

ceruminous

Which of the following is not present in bone? hydroxyapatite collagen fibers calcium phosphate chondroitin sulfate calcium carbonate

chondroitin sulfate

To form perforating fibers, osteoblasts from the cellular layer of the periosteum cement collagen fibers from tendons, ligaments, and joint capsules into which structures?

circumferential lamellae

Which primary mechanism of heat transfer is the direct transfer of energy through physical contact?

conduction

On a hot August day at the beach, the lifeguard jumped up and ran into the water, throwing a life-buoy to a troubled swimmer calling for help, and pulling her to safety. He was happy to help the swimmer, and once back on the beach, he realized that being in the water cooled him off a great deal. What form of heat transfer contributed to his feeling more comfortable?

convection

All of the following are true of the pigment melanin except that it: protects DNA from the damaging effects of UV radiation. is usually some shade of brown or black. is released through melanosomes. decreases in concentration within cells during exposure to the sun. is produced by cells called melanocytes.

decreases in concentration within cells during exposure to the sun.

Wrinkles in elderly individuals are the result of

loss of elastic filaments in the reticular layer of the dermis.

The medullary cavity of bones contains

marrow

Immediately after an initial injury to the skin, bleeding and ______ occur.

mast cell activation

Which of the following best matches osteocyte?

mature bone cell

Fat is stored within the

medullary cavity.

The most populous sweat glands are of which glandular type?

merocrine

The layer of the skin that contains bundles of collagen and elastic fibers responsible for the strength of the skin is the ________ layer.

reticular

Sebaceous glands:

secrete a mixture of triglycerides, cholesterol, proteins, and electrolytes that have antibacterial properties.

Which class of bones develops inside tendons and is most commonly located near joints at the knees, the hands, and the feet?

sesamoid bones

All of the following are true of the dermis, except __________. the papillary layer underlies the epidermis the reticular layer of the dermis is dense, irregular fibrous connective tissue The reticular layer of the dermis lies deep to the papillary layer. the hypodermis is part of the dermis

the hypodermis is part of the dermis

In dark-skinned individuals, __________.

the melanosomes are larger