Anatomy - Muscular

B. Increased accumulation of acetylcholine in the synapse

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

B. Gluteus medius

A common site for injections is the ________.

A. Complete tetanus

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

B. Is surrounded by perimysium

A fasciculus _________.

A. Threshold

A muscle fiber will respond to a stimulus when that stimulus reaches the ________ level.

A. Constant tension produced by muscles for long periods of time

A proper definition of muscle tone is _________.

A. One Z disk to an adjacent Z disk.

A sarcomere extends from __________.

A. Tetanus

A sustained muscle contraction is known as ________

C. Lactic acid

A waste product of anaerobic respiration in muscle cells is _____________.

C. Myosin heads.

ATPase is found in ___________.

B. Depolarization

Acetylcholine binds to a membrane bound receptor and causes ligand-gated sodium channels to open and results in ____________.

D. Contain strands of fibrous actin.

Actin myofilaments _____________.

E. all of these choices are correct

Aerobic exercise

B. Yields as many as 38 ATP per glucose molecule metabolized

Aerobic respiration __________.

D. Sodium ions

Depolarization of the cell membrane occurs when there is a rapid influx (inflow) of __________.

B. Creatine phosphate

During resting conditions, _________ is synthesized to store energy.

E. both aerobic respiration and anaerobic respiration

During short periods of intense exercise, energy in muscles is primarily derived from _________.

C. Actin-myosin cross-bridges form.

During the contraction phase of a muscle twitch, _____________.

A. Contractions cannot occur

If sodium ions cannot enter a muscle fiber in response to a stimulus, ___________.

A. Back muscles are strong to maintain erect posture.

In humans, ____________.

C. The active sites on actin must be blocked

In order for muscle relaxation to occur, _____________.

A. A relaxed muscle fiber

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

B. The nervous systems ability to recruit a large number of motor units simultaneously

Increased strength of a trained muscle is due to ___________.

C. Occipitofrontalis

Raising the eyebrows is the action of the _________ muscle.

D. Deltoid.

Raising your arm to shoulder level is accomplished almost entirely by the __________.

A. Cross bridges form but can't release

Rigor Mortis occurs after death because

C. Helps raise body temperature

Shivering _________.

A. Possess striations

Skeletal muscle fibers ________.

D. Extend from one bone to another bone

Skeletal muscles _____________.

A. Are under involuntary control

Smooth muscle and cardiac muscle are similar in that they both _______.

C. Acetylcholine

Synaptic vesicles in the neuromuscular junction contain _____________

E. sarcolemma

T tubules are invaginations of the ___________.

A. High calcium ions concentrations in the sarcoplasm.

Tetanus of a muscle is thought to be caused by _________.

A. Rectus abdominis

The abdominal muscle that has its origin at the pubic crest and symphysis pubis is the __________.

E. myosin myofilaments

The active sites to which cross-bridges attach are found on the _____________.

E. function and size

The adductor Mingus is named for its ______ and ________.

D. Latissimus dorsi and pectoralis major

The arm is attached to the thorax by the __________.

A. Hamstrings

The biceps femoris is part of the __________.

B. Origin and insertion

The brachioradialis is named for its ____ and _____.

B. Gastrocnemius and soleus

The bulge of the calf is caused by the _______ and _______ muscles.

A. Contractility

The capacity of a muscle cell to shorten forcefully is known as __________.

A. Cramps

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

B. Accounts for a sprinters stance

The gluteus Maximus ____________.

B. Adducts and laterally rotates the arm.

The infraspinatus _____________.

C. Gluteus Maximus

The largest buttocks muscle is the _______.

A. Longer than the length of a contracted sarcomere

The length of a resting sarcomere is _______________.

B. Diaphragm

The major movement produced during quiet breathing is accomplished by the _________.

C. Sliding filament model.

The model that describes the contraction of the muscle is called the ____________.

B. Parallel

The muscle shape that has the capacity to shorten to the greatest degree is __________.

A. Sartorius

The muscle that is used to cross the legs is the __________

A. Positively charged

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

D. Hold the head of the humerus in the glenoid fossa of the scapula.

The rotator cuff muscles ___________.

A. Stores calcium ions.

The sarcoplasmic reticulum ____________.

A. Neuromuscular junctions

The sites where a chemical substance is transmitted from the presynaptic terminal of an axon to the postsynaptic membrane of a muscle fiber are called _____________.

Insertion.

The sternocleidomastoid muscle extends from the mastoid process of the temporal bone to the sternum and medial clavicle. When both sternocleidomastoid muscles contract, the head is flexed. The end of the muscle that connects to the sternum is the __________.

B. Adduction of the arm.

The teres major and teres minor are not involved in _________.

B. Stress fractures of the fibula 2 to 5 cm distal to the knee

The term "shin splints" is applied to __________.

C. Latent or lag

The time between application of the stimulus to a motor neuron and the beginning of contraction is called the __________ phase.

D. The emotional state of an individual

The type of muscle fatigue known as "phychological fatigue" is the result of ____________.

C. Convergent

The type of muscle that can contract with the greatest force is the _________.

C. Circular

The type of muscle that functions as a sphincter is___________.

B. Rapid degradation of acetylcholine

Too much acetylcholinesterase causes ________.

E. all of these choices are correct

Treppe

B. Insertion

When a skeletal muscle contracts to cause a given movement, the more movable end of attachment of the muscle is termed its ___________.

A. Calcium ions diffuse into the presynaptic terminal through voltage-gated ions channels.

When an action potential reaches the presynaptic terminal, ______________.

C. Rectus femoris

When an intramuscular injection is given in the anterior aspect of the thigh, the injection is in the ____________.

B. The myofilaments in smooth muscle do not form sarcomeres.

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

C. Cell no longer has a potential difference across its membrane.

When repolarization of the cell membrane is complete, the _________.

B. Synergists

When you "pull your tummy in" and compress your abdomen, you use the texture abdominis, external abdominal oblique, internal abdominal oblique, and transversus abdominis muscles. This is an example of muscles working as __________.

B. Moving your feet in walking.

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

D. Increased permeability of the membrane to sodium ions and increased intracellular concentration of potassium ions

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

C. Epimysium

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

C. Acts as a reservoir for oxygen

Which of the following correctly describes myoglobins special function in muscle tissue?

D. Neurotransmitter combines with a receptor molecule

Which of the following events occurs on the postsynaptic membrane?

D. Increased cardiovascular fitness

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

C. Vastus lateralis

Which of the following is a part of the quadriceps femoris muscle group?

A. Thick myofilaments

Which of the following is composed of myosin molecules?

E. gastrocnemius

Which of the following is inserted on the calcaneus by the Achilles' tendon?

B. A threshold stimulus will cause contraction of a muscle fiber?

Which of the following is true?

B. Smooth muscle is found in the walls of hollow organs

Which of the following is true?

D. Internal intercostals

Which of the following muscles contracts during forced expiration?

C. Triceps brachii

Which of the following muscles extends the forearm and has its insertion on the ulna?

E. flexor Carpi radialis

Which of the following muscles flexes the wrist?

A. Masseter

Which of the following muscles is involved in chewing gum?

B. Quadriceps femoris

Which of the following muscles is named for its location?

D. Trapezius

Which of the following muscles is named for its shape?

C. Infraspinatus

Which of the following muscles is part of the rotator cuff?

A. Gastrocnemius

Which of the following muscles is used when walking on your tiptoes?

A. Trapezius

Which of the following muscles moves the scapula?

A. Pectoralis major

Which of the following muscles of the chest has its insertion on the humerus?

B. Biceps femoris

Which of the following muscles would be considered an antagonist to the rectus femoris?

C. Conversion of excess lactic acid to glucose

Which of the following occurs during recovery from oxygen debt?

C. Depolarization causes voltage-gated sodium ion channels to open

Which of the following situations occurs in electrically excitable cells?

A. They split ATP rapidly

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

B. Both actin and myosin myofilaments shorten during contraction.

Which of the following statements regarding the sliding filament model is false?

D. Neuromuscular junction

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

D. A single muscle fiber and a single motor unit

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

B. Depletion of ATP reserves

Which of the following would contribute to muscular fatigue in the muscle fiber?

D. Twitch

Which of the following would occur as a result of a single muscle contraction?

A.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 cells undergoing contractions?

D. Deltoid

All of the following muscles are rotators of the arm. Which is a lateral rotator of the arm?

A. Occurs when the local potential reaches threshold level

An action potential ______________.

B. Results from the heat produced when muscles contract

Body temperature __________.

B. Orbicularis oris

Closing or puckering the lips is the action of the _______ muscle.

D. Rotate the head toward the left

Contracting the right sternocleidomastoid muscle would ________.

D. Inability of the muscle fiber to respond to nervous stimulation

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

E. it is responsible for locomotion

Identify the statement concerning skeletal muscle that is true.

E. all of these choices are correct

Electric signals called action potentials ________________.

A. Surrounds each muscle fiber.

Endomysium is a delicate network of loose connective tissue that _________.

E. all of these choices are correct

If abdominal muscles are contracted while the vertebral column is fixed this will aid in _________.

B. Insert and sometimes originate on skin and connective tissue.

Facial muscles are unusual in that they ___________.

A. Surrounds individual muscles

Fascia _____________.

B. Size of muscle fibers.

Hypertrophy of skeletal muscles from weight lifting is caused by an increase in the _________.

A. Muscle tissue shortens forcefully but lengthens passively.

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

B. Continuous stimulation of the postsynaptic membrane

Lack of acetylcholinesterase in the synaptic cleft would result in _________.

B. Motor units contract out of phase at their own particular rates.

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

B. Is characterized by a decrease in muscle size.

Muscle atrophy _______.

B. Muscle fibers

Muscle hypertrophy results from increased numbers of ___________.

C. Contain myosin and actin myofilaments

Muscle myofibrils _____________.

D. Responds to stimulation by the nervous system.

Muscles exhibit the property of excitability. This means that the muscle _____.

D. Masseter and medial pterygoid

Muscles that elevate the jaw and close the mouth include the __________.

A. Pennate

Muscles that have their fasciculi arranged like barbs of a feather along a common tendon are called ___________.

D. Replacement of muscle cells by connective tissue.

Muscular dystrophy is characterized by _____________.

C. Orbicularis oculi

Of the following muscles of the head, which one wraps around the orbits?

C. Tibialis anterior

Of the following muscles of the leg, which one is on the anterior side of the leg?

A. Biceps femoris

Of the following muscles of the thigh, which one does NOT pull the leg forward?

A. Biceps femoris

Of the following muscles of the thigh, which one is NOT part of the quadriceps group?

D. Biceps femoris

Of the following muscles of the thigh, which one is on the posterior side?

C. Inhibition of acetylcholinesterase

One cause of spastic paralysis might be ______.

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

Oxygen debt represents ___________.