A+P chapter 7 test

The stiffness that occurs at death, when actin and Myosin molecules stay linked to each other in a contracted state, is due to a lack of

ATP

Which of the following is one of the steps that ends contraction

Acetylcholine is broken down by acetylcholinesterase

Upon the nerve impulses arriving at the axon terminal

Acetylcholine is released

The specialized sarcolemma that contains acetylcholine receptors is the

Motor end plate

Neurotransmitters that cause skeletal muscle contraction are normally stored in

Motor neuron exam terminals

the length of time a muscle can continue to contract while supported by mitochondrial activities is referred to as

aerobic endurance

A resting muscle generates most of its ATP by

aerobic respiration

a resting muscle generates most of its ATP by

aerobic respiration

_____ exercise requires oxygen and is of _____ duration than _______ exercise

aerobic; longer; anaerobic

slow fibers are the type of muscle fibers that contain

all of the above

the axial musculature consists of

all of the above

smooth muscle cells

are spindle shaped

when muscles are actively contracting, the process requires large amounts of energy in the form of

atp

tendons are bundles of collagen fibers at the end of a skeletal muscle that

attach muscle to bone

Mitochondrial activities are relatively efficient, but their rate of ATP generation is limited by the:

availability of oxygen

The ________ contains vesicles filled with acetylcholine

axon terminal

from the following selections, choose the one that include only muscles or facial expression

buccinator, orbicularis oris, risorius, frontalis

Active sites on the actin become available for binding when

calcium binds to troponin

in response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases

calcium ions

the names of the muscles of the tongue are readily identified because their descriptive names end in

glossus

during moderate activity, which of the following is true regarding muscle metabolism

glucose and fatty acids are catabolized

regarding muscle fiber elongation

gravity may help lengthen a muscle fiber after elongation

voluntary control over swallowing, defecation, and urination are controlled by skeletal muscles that

guard entrances and exits

the term used to describe muscular growth in response to usage is

hypertrophy

the superficial muscles of the spine are identified by subdivisions that include

iliocostalis, longissimus, and spinalis

which of the following occurs when tension production rises to a peak and very brief periods of relaxation occur

incomplete tetanus

the process of recruitment is the smooth but steady increase in muscle tension produced by

increasing the number of active motor units

Two of the muscles comprising the rotator cuff are the

infraspinatus and teres major

Glycolysis

is an anaerobic process

anaerobic endurance

is exemplified by contractions of fast muscle fibers

which of the following occurs when glycolysis produces pyruvate faster than it can be used by the mitochondria

lactic acid produced

calcium ions are released from the sarcoplasmic reticulum during the _______ phase of contraction

latent

Regarding lactic acid regulation, which cells in the body consume extra oxygen and produce ATP for the conversion of excess lactate absorbed from the blood back to glucose?

liver cells

the ability of skeletal muscles to produce continuous contractions results in the ability of the body to

maintain posture and body position

During a specific action, the insertion is the

more movable end of a muscle

the amount of oxygen used in the recovery period to restore normal pre-exertion conditions is referred to as the

oxygen debt

bundles of muscle fibers called fasicles make up the connective tissue fibers of the

perimysium

the layer of connective tissue that contains blood vessels and nerves is the

perimysium

smooth muscle uses

primarily aerobic metabolism

fast fibers are the type of muscle fibers that

produce powerful contractions but fatigue rapidly

Highly coordinated activities such as swimming, skiing, or typing are examples of the skeletal muscle function of

producing movement

During anaerobic glycolysis

pyruvic acid is produced

the iliac crest is the origin of the

quadratus lumborum

which of the following is an accurate characteristic of slow fibers

resting slow muscle fibers contain oxygen reserves, bound to myoglobin

botulism

results from a bacterial toxin that prevents the release of acetylcholine at the axon terminals

the function of layers of skeletal muscles that comprise the abdominal wall and floor of the pelvic cavity is to

support soft tissues

the endomysium is the layer of connective tissue that

surrounds each skeletal muscle fiber and ties adjacent muscle fibers together

Acetylcholinesterase is found within the

synaptic cleft

in an isometric contraction, the

tension produced never exceeds the resistance and the length of the muscle remains constant

in an isotonic contraction, the

tension rises and the skeletal muscle length changes

the heart has to be able to regulate its contractions. Heart Muscle, unlike skeletal muscle, cannot go into a tetanus. this is because

the heart muscle has to be able to consistently contract and pump blood in a controlled fashion

the final step involved in skeletal contraction is

the muscle cell relaxes and returns passively to its resting length

Which statement regarding isometric contractions is true

the tension produced never exceeds the load

The enzyme acetylcholinesterase causes acetylcholine to

to break down

of the following selections, the one that includes muscles that move the shoulder girdle is the

trapezius, levator scapulae, pectoralis minor, and subclavius

a single stimulus-contraction-relaxation sequence in a muscle fiber is known as a

twitch

the muscular floor of the pelvic cavity is formed by muscles that make up the

urogenital and anal triangle

thin filaments at either end of the sarcomere are attached to interconnecting filaments that make up the

z lines

the origin of the frontalis muscle is the

galea aponeurotica

Steps of muscle contraction

1. Nerve impulse arrives at synapse 2. Acetylcholine is produced 3. Action potential is generated along the sarcolemma 4. Calcium is released into muscle call cytoplasm 5. Actin and myosin molecules continuously cross link, with actin molecules being pulled inward

fast fibers

Have high glycogen reserves

which of the following is true about red muscles

Red muscles are slower than white muscles

athletes training to develop anaerobic endurance perform

frequent, brief, intensive workouts

the command to contract is distributed throughout a muscle fiber by the

T tubules

an example of an activity that requires anaerobic endurance is

a 50-yard dash

choose the correct statement regarding motor units

a motor neuron may control only two or three muscle fibers of the eye muscle

the neurotransmitter released from the synaptic vesicles that initiates an action potential in the sarcolemma is

acetylcholine

skeletal muscle fiber contraction begins when

acetylcholine is released into the neuromuscular junction and binds to receptors on the sarcolemma

the thin filaments of a sarcomere consist of

actin

muscle cells

can only contract

the presence of intercalacted discs is a characteristic unqiue to

cardiac muscle cells

which of the following is characteristic of cardiac muscles

cardiac muscle cells are striated

A muscle that inserts on the body of the mandible is probably involved in

chewing

during which phase is the stimulus frequency so high that the relaxation phase is eliminated

complete tetanus

the primary energy reserve in muscle tissue is

creatine phosphate (CP)

from the following selections, choose the one that includes the muscles that move the upper arm

deltoid, teres major, latissimus dorsi, pectoralis major

the dense layer of collagen fivers that surrounds an entire skeletal muscle is the

epimysium

the three layers of connective tissues comprising each muscle are

epimysium, perimysium, and endomysium

Muscles that insert on the olecranon process of the ulna can act to

extend the forearm

When the gluteus maximus contracts it

extends the thigh backward

in humans, slow fibers are not found in the muscles of the

eyes and hands

when energy reserves in a muscle are exhausted or lactic acid levels increase,

fatigue occurs

during activities requiring aerobic endurance

most of the muscles energy is produced in mitochondria

why do individual muscle twitches have to be added together, as in summation or tetanus

multiple twitches add up to an increase in muscle fiber tension, which increases the strength of the muscle

which statement regarding "heat loss" is true

muscle contractions play an important role in the maintenance of normal body temp

exhaustion of energy reserves or decline in pH due to production and dissociation of lactic acid causes

muscle fatigue

which statement regarding the relaxation phase of a muscle twitch is true

muscle tension falls to resting levels

which of the following occurs as a result of motor units in a particular muscle being always active, even though their contractions do not produce enough movement to cause contraction

muscle tone

After death, rigor mortis lasts until

myofilaments are broken down

the thick filaments of a sarcomere consist of

myosin

The additional oxygen required during the recovery period to restore the normal pre-exertion levels is called the __________.

oxygen debt

the smallest functional unit of the muscle fiber is the

sarcomere

in response to action potentials arriving from the transverse tubules, calcium ions are released from the

sarcoplasmic reticulum

a twitch is the type of contraction represented by a

single stimulus contraction relaxation sequence

a person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more _____ in his or her leg muscles

slow fibers

nonstriated involuntary muscle

smooth

the type of muscle cells that contract either automatically or in response to environmental or hormonal stimulation are

smooth muscle cell

the type of muscle tissue that lacks myofibrils, sarcomeres, and striations is

smooth muscle tissue

As a skeletal muscle contraction is initiated, acetylcholine binding alters the motor end plate membrane's permeability to

sodium ions

creatine phosphate serves to

supply energy for the synthesis of ATP