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.
