Assignment 7 (Lesson 8) - WILEY Muscles and Muscular System

Which ion is required for exocytosis of ACh? H+1 Cl-1 Na+1 Ca+2 K+1

Calcium

What causes actin to slide toward the center of the sarcomere? An increase in pressure on the distal end of actin from the transverse tubule forces the actin to move toward the center of the sarcomere. Due to the sudden release of ATP from the sarcolemma, spring-like titan molecules pull actin toward the center of the sarcomere. The sarcoplasmic reticulum coils to pull the actin toward the center of the sarcomere. Myosin heads form a cross-bridge with actin. When the myosin head bends it moves the actin toward the center of the sarcomere.

Myosin heads form a cross-bridge with actin. When the myosin head bends it moves the actin toward the center of the sarcomere.

A large motor unit would control which body part? a muscle required for back support a muscle of the finger a muscle involved in facial features all of these

a muscle required for back support

Which functions as a motor protein in all three types of muscle tissue? myosin titin actin troponin tropomyosin

myosin

Which muscles have a triangular fascicle arrangement that spreads over a broad area and converges at a thick central tendon? Select all that apply. pectoralis major rectus femoris deltoid pectoralis minor lattisimus dorsi orbicularis oris digastric

pectoralis major pectoralis minor lattisimus dorsi

Skeletal muscle is covered, surrounded and protected by various layers of connective tissue. Which layer of connective tissue would surround a bundle of muscle fibers (muscle cells)? perimysium epimysium hypodermis endomysium fascia

perimysium

Muscles of the ____ assist in urination, defecation, erection of the penis or clitoris, and ejaculation. thorax abdomen perineum vertebral column none of these choices

perineum

Exercise can produce a fashionable "six pack" of toned muscles. Which of the following muscles is involved in giving the appearance of this defined pack of muscles? external oblique internal oblique transversus abdominis rectus abdominis serratus anterior

rectus abdominis

Which of these muscles flexes the thigh at the hip joint alone, but extends the knee working in a group? biceps femoris rectus femoris semitendinosus semimembranosus vastus lateralis

rectus femoris

Most of the strength in the shoulder joint comes from the ______________. glenohumeral ligaments rotator cuff muscles articular capsule coracohumeral ligament

rotator cuff muscles

The muscle cell's contracting unit is known as the sarcolemma. sarcomere. transverse tubule. lobule.

sarcomere.

In the muscle cell, calcium ions are stored in the sarcoplasmic reticulum. sarcolemma. sarcomere. transverse tubules.

sarcoplasmic reticulum.

Which of the following muscles act to stabilize the scapula, and would also, when contracted, pull the shoulders back (like a soldier at attention)? 1. trapezius 2. levator scapulae 3. rhomboid major and minor 1 only 2 only 3 only 1 & 2 2 & 4

3 only

At the end of contraction, the sarcomere returns to its relaxed position when The hormone relaxin is released to cause the contraction to stop. There is a chemical breakdown of the myosin head. The pressure inside the sarcomere drops below a specific level required to maintain contraction. Calcium pumps remove calcium ions from the sarcomere and put them back into storage in the sarcoplasmic reticulum.

Calcium pumps remove calcium ions from the sarcomere and put them back into storage in the sarcoplasmic reticulum.

For crossbridges to occur, what events must happen? Select all that apply. calcium ions be present in the sarcoplasm. Acetylcholine be present in the synaptic cleft myosin binding sites be exposed. high amounts of sodium be present in the synaptic cleft ATPase breaks down ATP.

calcium ions be present in the sarcoplasm. myosin binding sites be exposed. ATPase breaks down ATP.

In a hiatus hernia, the stomach protrudes through which opening of the diaphragm? the caval opening the esophageal hiatus the mediastinum the aortic hiatus the inguinal hiatus

the esophageal hiatus

Skeletal muscle fibers are classified as "fast" or "slow" based upon what factor? the number of mitochondria present the amount of myoglobin present the speed of the myosin ATPase the ability of the muscle fiber to respond anaerobically

the speed of the myosin ATPase

Which of the following muscles have an insertion on the xiphoid process? 1. rectus abdominis 2. internal and external obliques 3. transversus abdominis 1 only 2 only 3 only 1 and 3 2 and 3

1 and 3

Asynchronous recruitment allows for An increase in ATP levels. Possible relaxation of one or more motor units. Sustained contraction in a muscle. All of these

All of these

What activates the sarcomere to contract? Transverse tubules produce contractile proteins Calcium ions are released from the sarcoplasmic reticulum ATP is released from the sarcolemma Pressure builds up within the myofibril

Calcium ions are released from the sarcoplasmic reticulum

How are binding sites on actin exposed? Contractile proteins from the transverse tubules attach to the binding sites on actin to fold them into their active configuration. Calcium ions attach to troponin which slides tropomyosin off binding sites on actin. A pressure build up within the myofibril squeezes the binding sites into the active position. ATP attaches to the binding sites to rotate them into the active position.

Calcium ions attach to troponin which slides tropomyosin off binding sites on actin.

The sheet or broad band of fibrous connective tissue that supports and surrounds muscles and other organs of the body is called Hypodermis Tendon Ligament Fascia Endomysium

Fascia

______: wraps around groups of muscles ______: encircles muscle ______: encircles fascicles ______: separates muscle fibers

Fascia Epimysium Perimysium Endomysium

A woman complains of problems going up steps. Tests reveal hip extension weakness but no issues with hip flexion or knee flexion or extension. What muscle is most likely damaged? Adductor magnus Gluteus maximus Gluteus medius Semitendinosus Sartorius

Gluteus maximus

Which of the following statements is INCORRECT? Concentric isotonic contractions result in muscle shortening. Eccentric isotonic contractions result in controlled lengthening of the muscle. Isometric contractions result in lengthening or shortening of the muscle and moving a load E large motor unit. In isometric contractions, the tension generated is not great enough to move the load.

Isometric contractions result in lengthening or shortening of the muscle and moving a load E large motor unit.

What happens to the neurotransmitter once an action potential is propagated on the muscle sarcolemma? It decomposes on its own within 30 seconds. It is immediately broken down by an enzyme. It enters the muscle cell where it is used to produce ATP. It remains attached to the muscle cell until it eventually wears away.

It is immediately broken down by an enzyme.

By what process does the motor neuron stimulate the muscle cell? The motor neuron changes shape putting pressure on the muscle cell to trigger contraction. The motor neuron creates a magnetic resonance which stimulates myofibrils to react. The action potential skips directly from the motor neuron onto the muscle cell. Neurotransmitter is released into the synaptic cleft to cause an action potential in the muscle cell.

Neurotransmitter is released into the synaptic cleft to cause an action potential in the muscle cell.

Which of the following in INCORRECT? The aortic hiatus is a passageway through the diaphragm for the aorta, thoracic duct and azygous vein. The esophageal hiatus is a passageway through the diaphragm for the esophagus and the vagus nerve. The caval opening is a passageway through the diaphragm for the vena cava. The foramen ovale is a passageway through the diaphragm for the inferior vena cava.

The foramen ovale is a passageway through the diaphragm for the inferior vena cava.

The knee (tibiofemoral) joint can be described by what statements? Select all that apply. The force is applied between the fulcrum and the resistance. The resistance is between the fulcrum and the force. The fulcrum is between the force and resistance. Produces a mechanical disadvantage. Produces a mechanical advantage. first-class lever second-class lever third-class lever

The force is applied between the fulcrum and the resistance. Produces a mechanical disadvantage. third-class lever

An action potential depolarizes the synaptic end bulb, which causes openings of ___________. The influx of _____________ causes exocytosis of _______. The neurotransmitter attaches to _____________. Opening of the channel allows an influx of ___________.

Voltage Gates Calcium Ions Acetylcholine Ligand Gates Sodium Ions

Wave summation is when the release of bound phosphate leads to the powerstroke. rapid stimulations affect a muscle without any relaxation, leading to a sustained contraction. successive stimulations at the same frequency produce a series of rapid contractions. a second stimulus excites a partially relaxed muscle.

a second stimulus excites a partially relaxed muscle.

Which of the following is directly responsible for transmitting an action potential from a motor neuron to a skeletal muscle fiber? intercalated discs creatine phosphate myofibrils acetylcholine gap junctions

acetylcholine

The motor end plate differs from the rest of the sarcolemma in that it contains large numbers of _________. acetylcholine receptors synaptic vesicles ATP calcium

acetylcholine receptors

The neurotransmitter released by the motor neuron to cause muscle contraction is epinephrine. dopamine. serotonin. acetylcholine.

acetylcholine.

During the downswing, a right-handed batter's right shoulder ___________ as the left shoulder __________________. abducts and flexes; adducts and flexes adducts and flexes; abducts and flexes adducts and extends ; abducts and extends abducts and extends ; adducts and extends

adducts and extends ; abducts and extends

When the electrical impulse of the motor neuron reaches the synapse, the release of neurotransmitter is caused by the electrical activation of pumps in the synaptic cleft. the opening of electrically sensitive pores in the motor neuron. the temporary electrical breakdown of the neuromuscular junction. an increase in intra-cellular calcium when voltage-gated calcium channels open.

an increase in intra-cellular calcium when voltage-gated calcium channels open.

Which correctly lists the sequence of structures that action potentials must move through to excite skeletal muscle contraction? T tubules, sarcolemma, myofilament axon of neuron, sarcolemma, T tubules myofibrils, myofilaments, mitochondria sarcolemma, axon of neuron, T tubules muscle fiber, axon of neuron, myofibrils

axon of neuron, sarcolemma, T tubules

Which of the following pairs of muscles are agonist-antagonists (that is, one flexes and the other extends) the forearm? biceps brachii and brachioradialis brachialis and brachioradialis triceps brachii and anconeus biceps brachii and triceps brachii anconeus and supinator

biceps brachii and triceps brachii

Your friend nods back and forth to you, making the "yes" motion. What muscles are involved in this 'yes' motion? Select all that apply. bilaterally sternocleidomastoid bilaterally splenius capitis unilaterally splenius capitis bilaterally longissimus capitis unilaterally longissimus capitis spinalis capitis unilaterally sternocleidomastoid bilaterally semispinalis capitis unilaterally semispinalis capitis

bilaterally sternocleidomastoid bilaterally splenius capitis bilaterally longissimus capitis spinalis capitis bilaterally semispinalis capitis

The impulses that initiate muscle contraction originates in the joint associated with the specific muscle. tendons attached to the ends of the muscle. muscle itself. brain or spinal cord.

brain or spinal cord.

Forcefully blowing through a trumpet would require contraction of which muscle? buccinator zygomaticus major levator labii superioris risorius occipitofrontalis

buccinator

At the neuromuscular junction, _______must enter the synaptic end bulb to stimulate the release of ____________, which binds to ligand gates so ________can enter the muscle fiber. calcium ions; ACh, sodium ions calcium ions, sodium ions, ACh sodium ions, calcium ions, ACh ACh, calcium ions, sodium ions sodium ions, ACh, calcium ions

calcium ions; ACh, sodium ions

The pectoralis major and _____________ are the prime movers of shoulder adduction. supraspinatus coracobrachialis deltoid supraspinatus

coracobrachialis

The deltoid muscle inserts on the ___________ of the humerus. head greater tubercle deltoid tuberosity lesser tubercle

deltoid tuberosity

Which of the following muscles would be involved in writing and serve primarily as flexors? a) Flexor carpi radialis b) Palmaris longus c) Abductor pollicis longus d) Extensor pollicis longus e) a and b only

e) a and b only

Which of the following muscle groups would be more likely to have many small motor units (one motor neuron, and just a few muscle fibers under its control)? a) the muscles that control eye movement b) the postural muscles that control standing c) the muscles that control the many movements of the hands d) all of these choices would have many small motor units e) only a and c would have many small motor units

e) only a and c would have many small motor units

The properties of muscle tissue include: electrical excitability, contractility, extensibility and elasticity. extensibility and elasticity only. contractility and electrical excitability only. contractility, elasticity and extensibility only.

electrical excitability, contractility, extensibility and elasticity.

The __________ muscle(s) is (are) the primary extensor muscle(s) of the vertebral column. transversospinales erector spinae spinalis thoracis scalene group rotators

erector spinae

The ______ are the synergist muscles to the diaphragm during inspiration. external intercostals external obliques rectus abdominis internal intercostals internal obliques

external intercostals

During inhalation, _____ muscles contract to elevate the ribs. During forced exhalation, ______ muscles contract to depress the ribs. external intercostals; internal intercostals transverse abdominis; diaphragm diaphragm; transverse abdominis internal intercostals; external intercostals rectus abdominis; external obliques

external intercostals; internal intercostals

What type of skeletal muscle fiber would an Olympic quality weight lifter specifically be developing during training, to enhance his or her weight lifting power? slow oxidative fibers fast oxidative-glycolytic fibers fast glycolytic fibers all of these choices none of these choices

fast glycolytic fibers

If the person receives a series of multiple stimuli in a short period of time, the wave of muscle activity that will be recorded will show a sustained contraction with no period of relaxation in between the periods when they receive the stimuli. The myograms has recorded: an incomplete twitch fused (complete) tentanus incomplete tetanus an extended muscle spasm a fused (complete) twitch

fused (complete) tentanus

When all rotator cuff muscles are activated at the same time they act to hold the head of the humerus in the _______________. coracoid process acetabulum acromion glenoid cavity

glenoid cavity

The ___________ is a rim of fibrocartilage that slightly deepens the glenoid cavity. rotator cuff glenoid labrum coracoid process bursa

glenoid labrum

The teres major and __________ act synergistically to extend the shoulder. pectoralis major supraspinatus latissimus dorsi coracobrachialis

latissimus dorsi

Which term describes a somatic motor neuron and all the skeletal muscle fibers it stimulates? neuromuscular junction synapse motor unit motor end plate

motor unit

A group of muscle cells stimulated by a single motor neuron is known as a contractile structure. myofibril. neuron divergence. motor unit.

motor unit.

During a muscle twitch, all of the following happen during the latent phase except crossbridge formation myosin contraction of actin filaments titin is stretched calcium release

myosin contraction of actin filaments

If you are an endurance athlete, you especially rely on which type of skeletal muscle fiber to perform your sport? slow oxidative fibers fast oxidative-glycolytic fibers fast glycolytic fibers all of these choices are correct none of these choices is correct

slow oxidative fibers

Smooth muscle fibers do not have striations like skeletal and cardiac muscle cells do. This is because: the sarcomeres are smaller than in cardiac muscle cells and skeletal fibers, and aren't visible even when smooth muscle fibers are examined microscopically smooth muscle fibers contain only intermediate filaments, which aren't arranged in sarcomeres smooth muscle fibers contain thin and thick filaments, as well as intermediate filaments, but none of them are arranged in sarcomeres visceral smooth muscle fibers don't have striations, but multiunit smooth muscle cells do, but these cells are more rare, and so we rarely have a chance to view them with a microscope smooth muscle fibers contain only intermediate filaments, which aren't arranged in sarcomeres and visceral smooth muscle fibers don't have striations, but multiunit smooth muscle cells do, but these cells are more rare, and so we rarely have a chance to view them with a microscope

smooth muscle fibers contain thin and thick filaments, as well as intermediate filaments, but none of them are arranged in sarcomeres

Which rotator cuff muscle originates on the subscapular fossa of the scapula and inserts on the lesser tubercle of the humerus? supraspinatus teres minor infraspinatus subscapularis

subscapularis

Which of the following is NOT a rotator cuff muscle? teres major teres minor subscapularis supraspinatus

teres major

Skeletal muscle contraction is triggered to begin when calcium is released from T-tubules mitochondria myofibrils terminal cisterns of sarcoplasmic reticulum

terminal cisterns of sarcoplasmic reticulum

Thick filaments differ from thin filaments in that thin filaments possess: a titin binding site located on the myosin head. an actin binding site located on the myosin head. thin filaments are composed of myosin while thick filaments are composed of actin. thin filaments contain actin and thick filaments contain myosin.

thin filaments contain actin and thick filaments contain myosin.

Binding sites on actin are covered by tropomyosin. transverse tubules. troponin. fibronectin.

tropomyosin.