Exam 4 A&P

The proper sequence of events in bone repair is

Hematoma formation, callus formation, callus ossification, remodeling of bone

In a laboratory experiment, the resting membrane potential of a muscle is measured and is found to be more negative. Which of the following has occurred?

Hyperpolarization

Which of the following statements concerning types of muscle contractions is false?

In isometric contractions, the amount of tension produced by the muscle is constant.

Atrophy at the neuromuscular junction that naturally occurs with age would have what effect on muscles?

It would decrease the number of action potentials sent to the muscle fiber.

Identify the statement concerning general functional characteristics of muscle that is true.

Muscle tissue shortens forcefully but lengthens passively.

Functionally, smooth muscle

exhibits autorhythmic contractions

Acetylcholine is released from the presynaptic terminal by the process of

exocytosis.

True or False? The two types of bone development formation include endochondral and endosteal bone.

false

Which type of muscle tissue causes peristalsis?

Smooth muscle

Which type of muscle tissue has spindle-shaped cells?

Smooth muscle

Which of the following events occurs during the lag phase of a muscle twitch?

The action potential is propagated from presynaptic to postsynaptic membrane.

True or False? The application of pressure creates a slight electrical charge on osteoblasts.

True

Which fibers are primarily responsible for producing lactate?

Type IIB fast fibers

Synaptic vesicles in the neuromuscular junction contain

acetylcholine.

Heather is watching a movie. Which type of chemical pathway does her muscles depend on at this time?

aerobic respiration

When skeletal muscle is producing CO2 and water while making ATP, which chemical processes could be active at this time?

aerobic respiration

A stimulus either causes an action potential or it doesn't. This is called

an all-or-none response.

Osteons or haversian systems

are the basic units in compact bone tissue

Smooth muscle and cardiac muscle are similar in that they both

are under involuntary control.

You would look for concentric lamellae

around the central canal of an osteon

Increase in epiphysis size is the result of bone growth at the __________.

articular cartilage

Osteoclasts and osteoblasts that travel through or across the bone surface removing and replacing old bone matrix are collectively called a(n) __________.

basic multicellular unit

Collagen and calcium hydroxyapatite are the primary constituents of __________.

bone matrix

Ligaments attach

bone to bone

In smooth muscle, cross-bridging occurs due to

both Ca2+ binding to calmodulin and myosin kinase adding a phosphate to myosin heads.

Which type of muscle tissue is autorhythmic?

both cardiac and smooth muscle

Which type of muscle tissue possesses striations?

both skeletal and cardiac muscle

When an action potential reaches the presynaptic terminal,

calcium ions diffuse into the presynaptic terminal through voltage-gated ion channels.

A passageway connecting neighboring osteocytes in an osteon is a __________.

canaliculus

Chondroblasts produce

cartilage matrix

If Na+ cannot enter a muscle fiber in response to a stimulus,

contraction cannot occur.

Inflammation of the fibrous connective tissue resulting in stiffness and soreness is

fibrositis.

The flat bones of the skull develop from __________.

fibrous connective tissue

Bones are classified as one of four types, based on their shapes. The bones of the cranium are examples of ______ bones.

flat

Bones that are thin and have a broad curved shape are classified as ______ bones.

flat

The spaces between developing skull bones that have not ossified are called

fontanels

One ATP molecule is required for

formation of the cross-bridge, for movement of the cross-bridge, and for release of the cross-bridge.

A drug that interferes with the active transport of Ca2+ from the sarcoplasm back into the sarcoplasmic reticulum would result in

contraction with no relaxation.

The condition of painful, spasmodic contractions of muscles is referred to as

cramps.

During resting conditions, _________ is synthesized to store energy.

creatine phosphate

Rigor mortis occurs after death because

cross-bridges form but can't release.

intramembranous ossification

forms the bones of the roof of the skull

Intramembranous ossification

forms the bones of the roof of the skull.

The most common bone disease is osteoporosis. The most common consequence of this disease is

fractures

The spaces between developing skull bones that have not ossified are called _________

frontals

Proteoglycan molecules in the matrix of cartilage

give cartilage its resilient nature

Which of the following would be caused by a contraction of smooth muscle?

goose bumps

Betsy took a fall and broke her arm, which required that she wear a cast for a prolonged period of time. When she took the cast off, she was alarmed to see that her muscles

had undergone atrophy.

Woven bone

has its collagen fibers randomly oriented

Intense exercise that results in a great deal of anaerobic activity

increases muscular strength and mass.

One cause of spastic paralysis might be

inhibition of acetylcholinesterase

Which structure forms between the ends of a broken bone as well as the marrow cavity?

internal callus

The type of lamellae found between osteons (haversian systems) is __________.

interstitial

The electrical properties of cells are the result of

ion concentration differences across the plasma membrane.

Muscle tone

is a constant tension produced by muscles for long periods of time.

muscle tone

is a constant tension produced by muscles for long periods of time.

Calcitonin

is associated with decreased osteoclast activity.

Lamellar bone

is organized into thin sheets of tissue.

A fascicle

is surrounded by perimysium.

Complete tetanus

is the condition in which stimuli occur so rapidly that there are no intervening relaxations.

Incomplete tetanus

is the condition in which the muscle fiber only partially relaxes between contractions.

Movements of the body are usually smooth and occur at differing rates because

motor units contract out of phase at their own particular rates.

Calcium ion blocking agents would most likely affect

movement of the tropomyosin molecule.

The stretch of elastic components of a muscle adds to the increased tension during

multiple wave summation.

Skeletal muscle develops from cells called

myoblasts.

ATPase is found in

myosin heads

appositional growth of cartilage

new chondrocytes and new matrix are added on the outside of the tissue.

visceral smooth muscle

occurs in sheets and exhibits numerous gap junctions.

Appositional growth deposits a new layer of bone tissue

on the surface of the bone.

When repolarization of the plasma membrane is complete, the

original polarity of the cell is restored.

Brittle bone disorder is another name for __________.

osteogenesis imperfecta

Osteoclast activity is increased by __________.

parathyroid hormone

A skeletal muscle generates the greatest tension when it is

partially stretched before being stimulated.

A connective tissue sheath around cartilage is the __________

perichondrium

The sarcolemma is the

plasma membrane of a muscle fiber.

The outside of the resting plasma membrane is __________ relative to the inside of the resting plasma membrane.

positively charged

When the myosin head flexes into a bend, pulling the actin filament along with it, this is called the

power stroke.

The sequence of events that produces growth at the epiphyseal plate is

proliferation, hypertrophy, calcification, cell death, ossification, and remodeling.

Too much acetylcholinesterase causes

rapid degradation of acetycholine.

As you are lifting a box, someone places extra weight on top of it. For your muscle to continue contracting and lifting the box, the muscle must

recruit more muscle fibers.

After contraction has occurred, the Ca2+ are

released from troponin.

Myosin phosphatase

removes phosphate from myosin.

Muscular dystrophy is characterized by

replacement of muscle tissue by connective tissue

Diseases that affect the ability of skeletal muscle to contract are considered life threatening because

respiratory movements depend on skeletal muscle contractions.

Multiple wave summation

results in complete and incomplete tetanus.

Osteoclasts have projections called __________ that cause bone reabsorption.

ruffled boarders

T tubules are invaginations of the

sarcolemma

The growth spurt seen in puberty is triggered by __________.

sex hormones

These collagen fibers help to connect ligaments and tendons to the periosteum of the bone.

sharpey fibers

Some flat and irregular bones of the skull have air-filled spaces called __________.

sinuses

Which type of muscle tissue is multinucleated?

skeletal muscle

Which type of muscle tissue causes vasoconstriction?

smooth muscle

The sarcoplasmic reticulum

stores Ca2+

The proportion of collagen to hydroxyapatite in bone determines the

strength of the bone.

A sarcomere is the

structural and functional unit of the skeletal muscle fiber.

Endomysium is a delicate network of loose connective tissue that

surrounds each muscle fiber.

Epimysium

surrounds individual muscles.

Interconnecting rods of bone are ___________.

trabeculae

The diffusion of Ca2+ into a smooth muscle cell does not depolarize the membrane so no action potential occurs. True or False

true

Which chemical, ingested or synthesized by the body, is necessary for calcium absorption from the intestines?

vitamin d

Multiunit smooth muscle is located in the

wall of blood vessels

Which of the following individuals would have more mitochondria in her skeletal muscle?

A 22-year-old soccer player

Which of the following correctly describes myoglobin's special function in muscle tissue?

Acts as a reservoir for O2

A lack of mitochondria within skeletal muscle fibers would impair which ATP-yielding chemical process?

Aerobic respiration

What is an oxygen deficit?

After exercise, the O2 taken in that exceeds the O2 required for resting metabolism

Treppe

All of these choices are correct.

Arrange the following list of biochemical events in the correct sequence. (1) An action potential is conducted deep into the muscle fiber by the T tubule. (2) Calcium ions bind to troponin. (3) The membranes of the sarcoplasmic reticulum become more permeable to calcium ions. (4) Calcium ions diffuse into the sarcoplasm around the myofibril. (5) The troponin-tropomyosin complex moves exposing active sites.

1, 3, 4, 2, 5

List the following structures in order from smallest to largest. (1) Muscle fiber (2) Myofilament (3) Myofibril (4) Muscle fascicle

2, 3, 1, 4

Which of the following is true?

A threshold stimulus will cause contraction of a muscle fiber.

You are hired to work in a laboratory to measure the rate of human muscle contraction. Which of the following might decrease in quantity in muscle fibers undergoing contractions?

ATP

you are hired to work in a laboratory to measure the rate of human muscle contraction. Which of the following might decrease in quantity in muscle fibers undergoing contractions?

ATP

Which of the following statements best predicts the effect of a substance that blocks creatine kinase activity?

ATP production from creatine phosphate would decrease.

Randy is participating in a strong man competition and is required to pull a yacht as far as he can. Which type of chemical process will his skeletal muscles rely on during this competition?

Anaerobic respiration

Which type of tissue covers the ends of long bones?

Articular cartilage

Name the process that changes the shapes of bones to adjust to bone stress, replaces old bone matrix and facilitates the repair of broken bones.

Bone remodeling

Canaliculi are found in this type of bone tissue.

Both "spongy bone" and "compact bone" are correct.

In which type of bone tissue are osteoblasts and osteoclasts present?

Both "spongy bone" and "compact bone" are correct.

Which of the following will respond to a threshold stimulus with an all-or-none contraction?

Both a single muscle fiber and a single motor unit are correct.

A lack of glycolytic enzymes within skeletal muscle fibers would impair which type of ATP-yielding process?

Both anaerobic respiration and aerobic respiration are correct.

Alex is participating in a 50-meter dash. Predict the most important chemical process his muscles will rely on during this race.

Both anaerobic respiration and creatine phosphate breakdown are correct.

In which type of bone tissue are osteons present?

Compact bone

Which type of bone tissue is considered dense bone?

Compact bone

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

Constriction of organs

Which of the following occurs during recovery from oxygen deficit?

Conversion of excess lactate to glucose

Which of the following conditions in muscle fibers would contribute to muscle fatigue?

Depletion of ATP reserves

Which of the following situations occurs in electrically excitable cells?

Depolarization causes voltage-gated sodium ion channels to open.

Which of the following is not an important function of calcium ions in skeletal muscle activity?

Depolarization of the sarcolemma

Which of the following connective tissue layers is outside all the others?

Epimysium

What is the site of longitudinal growth in long bones?

Epiphyseal plate

Substance A is found to be a competitor with acetylcholine. Which step of muscle contraction physiology would be directly affected by this substance?

Exposure of the active sites on G actin

In a contracted muscle, the A bands narrow because the length of the myosin myofilaments changes. T OR F

False

The type of neurotransmitter or hormone that binds to receptors on smooth muscle plasma membranes determines the response of the muscle. True or False

False

True or False? The two types of bone development formation include endochondral and endosteal bone.

False

Consider the following four phrases and select the one that does not belong with the others.

Fuels runner in a marathon

Which of the following is part of a thin myofilament?

Globular (G) actin

Which chemical stimulates interstitial cartilage and appositional bone growth?

Growth hormone

If one nerve stimulus arrives at a muscle fiber so soon that the fiber has only partially relaxed from the previous twitch, the most likely result will be __________.

Incomplete tetanus

A child ingested an organophosphate poison used to kill insects. Soon the child's muscles began spastic contractions. Predict what occurred at the synaptic cleft.

Increased accumulation of acetylcholine in the synapse

Which of the following is NOT a known effect of illegal use of anabolic steroids in large dosages?

Increased cardiovascular fitness

Which of the following changes have the potential to dramatically affect the potential difference across the plasma membrane?

Increased permeability of the membrane to Na+ and increased intracellular concentration of K+

What is the type of ossification that forms the flat bones of the skull?

Intramembranous ossification

Why is the contraction strength of smooth muscle relatively independent of its resting length?

It does not have sarcomeres.

Which of the following is NOT true of muscular atrophy?

It is irreversible.

Which of the following actions is caused by contraction of skeletal muscle?

Moving your feet in walking

Which of the following causes an unequal ion concentration across the resting plasma membrane?

Negatively charged proteins not readily diffusing across the plasma membrane

Which of the following structures contains the other four items listed?

Neuromuscular junction

Which of the following events occurs on the postsynaptic membrane?

Neurotransmitter combines with a receptor molecule

Which type of bone cell combines hydroxyapatite and collagen to form extracellular bone matrix?

Osteoblast

Which type of bone cell incorporates calcium and phosphate ions into bone tissue?

Osteoblast

Which type of bone cell possesses extensive ER and ribosomes?

Osteoblast

Which of the following cell types is responsible for breaking down bone matrix?

Osteoclast

Which type of bone cell has a ruffled border and secretes acids?

Osteoclast

Which type of bone cell is a large cell that forms from fusion of several precursor cells?

Osteoclast

Which of the following is correctly matched?

Osteoclast - responsible for reabsorption

Which type of bone cell has processes that lie in canaliculi?

Osteocyte

Which substance causes an increase in the blood calcium level?

Parathyroid hormone

Which of the following substance is mismatched with its role in the body?

Parathyroid hormone - increases calcium loss in the kidneys

Which of the following membranes covers the surface of a mature bone?

Periosteum

Which of the following is true during the resting membrane potential

Potassium is concentrated primarily inside the cell.

Which of the following is true during the resting membrane potential?

Potassium is concentrated primarily inside the cell.

Which of the following matrix molecules in cartilage tends to trap large quantities of water?

Proteoglycan

Which of the following is true concerning isotonic concentric contraction?

The muscle shortens, but tension remains constant.

Arrange these structures as they participate in excitation-contraction.

Sarcolemma, T tubules, sarcoplasmic reticulum, Ca2+

Which of the following correctly matches the bone type with an example?

Short bone - carpal bone

Which type of muscle tissue has neuromuscular junctions?

Skeletal muscle

Whales are air-breathing aquatic mammals, and some species can remain underwater for long periods of time. Which type of skeletal muscle fibers are most likely dominant in these deep diving whales?

Slow fibers

Which type of bone tissue appears porous?

Spongy bone

Susan slipped on the ice and was unable to be fully mobile for several days. What disruption to homeostasis would you predict she experienced during her immobile period in terms of her muscular system?

Susan was more cold than usual because her inactivity prevented her muscles from helping to regulate her body temperature.

What would result from a lack of extracellular Ca2+ at the neuromuscular junction?

Synaptic vesicles would fail to fuse and ACh would not be released

Which of the following statements best distinguishes between tetanus and treppe?

Tetanus occurs when stimulation of muscle occurs frequently with little to no relaxation between stimuli; treppe occurs when stimulation of muscle occurs frequently, but complete relaxation occurs between stimuli.

Which of the following descriptions best represents the appearance of the sarcomere during peak contraction?

The H zone is eliminated, and the I bands are very thin.

A cancer patient is told by their physician that their colon is lacking smooth muscle tone. What does this mean?

The colon is unable to maintain constant tension for sustained periods of time.

What is the power stroke?

The movement of myosin head while attached to actin myofilament

Which of the following is true concerning isotonic eccentric contraction?

The muscle lengthens, but tension remains constant.

Consider a chemical that blocks the action of acetylcholinesterase. What effect does this have on muscles?

The muscle would have no way to relax, and spastic contractions would result.

When comparing smooth and skeletal muscle cells, which of the following statements is true?

The myofilaments in smooth muscle do not form sarcomeres.

Which of the following statements does not accurately describe factors that determine the amount of force generated during a muscle contraction?

The number of cross-bridges that can form is higher in a short muscle fiber compared to longer fibers.

Why does muscle activity affect the temperature of the body?

The rate of chemical reactions increases in muscle fibers during contraction, so the rate of heat production also increases.

An antibody test on smooth muscle reveals fewer dense bodies and intermediate filaments in a patient with a colon disorder. What is the purpose of these structures?

They are part of the intracellular cytoskeleton.

Callie is a world class marathon runner. Which of the descriptions about her dominant type of skeletal muscle is FALSE?

They are well adapted to anaerobic activity.

Which of the following is NOT a property of the myosin head?

They bind to troponin.

A volleyball player depends on the gastrocnemius muscles for plantar flexion, whereas a marathon runner depends more on the soleus muscles for the same action. What characteristic of the soleus muscles makes this so?

They make more use of aerobic respiration.

Drugs called calcium channel blockers may be used to lower blood pressure by causing arteries to vasodilate. How do you suppose these drugs work?

They prevent calcium from entering smooth muscle, thus allowing the muscle to relax.

What is the role of pacemaker cells?

They rapidly develop action potentials.

Which of the following statements concerning fast-twitch muscle fibers is true?

They split ATP rapidly.

Which of the following is composed of myosin molecules?

Thick myofilaments

What is the role of myosin phosphatase?

To serve as an enzyme that removes phosphate from myosin

The diffusion of Ca2+ into a smooth muscle cell does not depolarize the membrane so no action potential occurs. T/F

True

What is a triad?

a T tubule and two adjacent terminal cisternae

Rickets is

a disease in children characterized by soft, bowed, and swollen bones.

An isotonic contraction is described as

a muscle produces constant tension during contraction.

An eccentric contraction is described as

a muscle produces tension, but the length of the muscle is increasing.

In which of the following situations does a resting membrane potential exist?

a relaxed muscle fiber

The type of lamellae that forms the outside surface of compact bone is __________.

circumferential

Osteogenesis imperfecta can be caused by abnormally formed __________.

collagen

If one nerve stimulus arrives at a muscle fiber so soon that the fiber does NOT relax at all from the previous twitch, the most likely result will be __________.

complete tetanus

A condition in which stimuli occur so rapidly that there are no intervening relaxations between contractions is called

complete tetanus.

he type of lamellae found in osteons (Hhaversian systems) is __________.

concentric

T tubules

conduct action potentials deep into the muscle fiber.

Osteoblasts involved in bone growth in length come primarily from

connective tissue surrounding blood vessels of the endosteum.

Actin myofilaments

contain strands of fibrous actin.

Cartilage

contains chondrocytes located in lacunae.

Spongy bone tissue

contains interconnecting plates called trabeculae.

The H zone

contains only myosin myofilaments.

A myofibril is the

contractile thread that extends the length of the muscle fiber

When blood vessels become surrounded by concentric lamella forming osteons, the bone will grow in __________.

diameter

Ossification that involves replacing cartilage with bone is __________.

endochondral

What is the membrane that lines the medullary cavity?

endosteum

Cardiac muscle cells are like skeletal muscle cells in that they both

have striations.

Tetanus of a muscle is thought to be caused by

high Ca2+ ion concentrations in the sarcoplasm

the type of cartilage associated with bone function and development is __________.

hyaline cartilage

The compression (weight-bearing) strength of bone matrix is due to the presence of __________.

hydroxyapatite crystals

Which of the following is NOT a function of bone?

immunity

Curare blocks acetylcholine receptors at the motor end plate. This would result in

inability of the muscle fiber to respond to nervous stimulation.

The training regimen of a competitive weight lifter is designed partly to

increase the average number of myofibrils per muscle fiber.

Anabolic steroids can do all of the following except

increase the number of muscle fibers.

Parathyroid hormone (PTH) causes

increased RANKL and decreased OPG.

Select the phrase that does not belong with the others.

increased vascularity

The refractory period

is the time during which the tissue cannot respond again.

Spaces in the bone matrix that are occupied by osteocytes are __________.

lacunae

The primary function of osteoblasts is to

lay down bone matrix

The medullary cavity is

lined with endosteum.

medullary cavity

lined with endosteum.

Bones that are longer than they are wide and generally have enlarged ends for articulations are classified as ______ bones.

long

Athletes who train at high altitudes increase their red blood cell count, which increases their oxygen supply during exercise. Increased oxygen supply results in

longer aerobic respiration.

Some marrow of long bones is termed "red" marrow. The function of red marrow is to

manufacture blood cells.

What is the area where marrow is located?

medullary cavity

A band of connective tissue that attaches a muscle to a bone is a/an __________.

tendon

A sustained muscle contraction is known as __________.

tetanus

Oxygen deficit represents

the amount of oxygen that cells need to replenish ATP supplies after exercise.

What is a cross-bridge?

the combination of myosin heads with active sites on actin molecules

The type of muscle fatigue known as "psychological fatigue" is the result of

the emotional state of an individual.

The longitudinal growth of long bones ceases when

the epiphyseal plate is completely replaced with bone tissue.

Excitation-contraction coupling begins with

the production of an action potential in the sarcolemma

Smooth muscle is regulated by all of the following except

the somatic nervous system.

Due to the pattern of innervation of skeletal muscle, one would expect that

there are fewer motor neurons than skeletal muscle fiber

Michael Jordan was arguably the best player in professional basketball history. Scientifically, one would expect him to have highly developed __________ fibers.

white

Aerobic respiration

yields as many as 36 ATP per glucose molecule metabolized.