Bio-chapter 10: LS

Skeletal muscle contraction involves the physiologic events that occur:

1. Nerve impulse arrives at synaptic knob 2. Ca2+ enters and binds synaptic vesicles 3. ACh is released into synaptic cleft 4. ACh binds receptors on the motor end plate (340)

Identify the metabolic components/ processes of generating ATP.

A. Glycolysis B. Decarboxylation of pyruvate to Acetyl CoA C. Citric acid cycle D. Electron transport chain (351)

In a neuromuscular junction, what enzyme breaks down acetylcholine?

Acetylcholinesterase (340)

Contraction of a muscle fiber requires that the myosin heads in the think filament bind to active sites on ____ molecules within the thin filaments.

Actin (344)

For longer contractions, muscle cells obtain ATP by which process?

Aerobic respiration (351)

A muscle cell obtains ATP in the short term via what process?

Anaerobic Respiration (350)

Match each function of skeletal muscle with its description.

Body movement- muscle contract and pull on the tendons that attach the muscles to the bone Posture- contraction of specific skeletal muscles stabilizes joints Temperature regulation- he is produced as a waste product of energy usage Storage and movement of materials- voluntary sphincter muscles of the gastrointestinal and urinary tracts can be kept closed or opened (332)

The sarcolemma of smooth muscle cells has small invagination a called____.

Caveolae (361)

The amount of additional oxygen that must be inhaled in order to restore pre-exercise levels is called oxygen ____.

Debt (352)

Place that event at a neuromuscular junction in order:

1. Arrival of nerve signal at synaptic knob 2. Calcium entry into synaptic knob 3. Exocytosis of ACh into synaptic cleft 4. Binding of ACh to motor end plate (341)

Place the steps of cross-bridge cycling in order:

1. Cross-bridge formation 2. Power stroke 3. Release of myosin head 4. Reset myosin head (344)

In a muscle contraction, as increasing numbers of motor units are recruited ____ force is exerted.

Greater (339)

Slow muscle fibers are about ____ the diameter of fast muscle fibers.

Half (353)

What part of a myosin molecule does ATP bind to?

Head (336)

During development, many groups of ____ fuse to form single skeletal muscle fibers.

Myoblasts (334)

Approximately 40-50% of your body weight is ____ muscle.

Skeletal

The H-band (or H-zone) is more lighty shaded because only ______ filaments are present.

Thick (337)

A "step-wise" increase in the force of contraction of a single muscle fiber or single motor unit due to repeated stimulation without an increase in intensity of frequency of stimulation is called ____.

Treppe (355)

Calcium ions bind to what protein in a thin myofilament?

Troponin (344)

Single contraction and relaxation of a muscle fiber is referred to as a muscle ____.

Twitch. (354)

The stages of cross-bridge cycling in order:

1. Calcium blinds troponin; myosin binding site uncovered 2. Cross-bridge formation 3. Power stroke 4. Release of myosin head by ATP 5. Reset of myosin head (345)

Identify neuromuscular junction:

A. Moves into the atonal terminal: calcium ion (Ca2+) B. Moves into the sarcoplasm: sodium ions (Na+) C. Moves across the synaptic gap: acetylcholine (ACh) D. Moves out of the sarcoplasm: potassium ions (K+) (339)

Energy to drive the myosin movement in the sliding filament process is provided in the form of ____.

ATP. (350)

The arrival of a nerve impulse that is the synaptic knob of a motor neuron causes synaptic vesicles to release ____ into the synaptic cleft.

Acetylcholine (341)

The connective tissue layers in muscle provide: protection, distribution sites for blood vessels and nerves, and a means of ____ to the skeleton.

Attachment

The sarcoplasmic reticulum stores ___ ions needed to initiate muscle contraction.

Calcium (335)

In smooth muscle cells, thin filaments are attached to ____.

Dense bodies (361)

Myosin head attachment and pivoting do not require energy, and ATP is needed for the myosin head cross bridge to ____ from actin and re-cock.

Detach.

Acetylcholine moves across the synaptic cleft by _____.

Diffusion (341)

A sarcomere is defined as the distance from one Z _____ to the next.

Disc (337)

The epimysium of a muscle surrounds the ____.

Entire skeletal muscle (333)

Smooth muscle is composed of short cells that have a ____ shape.

Fusiform (360)

Upon release of the synaptic knob, acetylcholine attaches to receptors on the _____.

Motor end plate

Match the muscle component with its description.

Muscle- multiple bundles housing many muscle fiber Fascicles- abundle of muscle fiber Muscle fiber- elongate, multinucleated, cylindrical cell Myofibril- long, cylindrical contractile element within muscle cell Myofilament- short contractile proteins of two types: thick and thin (333)

The immediate supply of ATP for use in muscle contraction is generated by the ____ system.

Phosphagen (350)

ATP is generated when the enzyme creatine kinase transfers Pi from creatine to ADP.

Phosphate (350)

Match the name of the component of a muscle fiber with its description:

Sarcolemma- plasma membrane of muscle fiber Muscle fiber- a muscle cell Sarcoplasm- cytoplasm of a muscle fiber Sarcoplasmic reticulum- smooth endoplasmic reticulum in a muscle fiber T-tubule- narrow, tubular extensions of the sercolemma into the sarcoplasm. (335)

The cytoplasm of a skeletal muscle cell is referred to as ____.

Sarcoplasm (334)

Match the muscle tissue with its appearance or shape.

Skeletal- long, cylindrical fiber Cardiac- short, branched cell Smooth- fusiform-shaped cell (359)

Mash the muscle tissue with its condition speed.

Skeletal-fast Cardiac-moderate Smooth-slow (359)

What type of muscle forms the majority of the walls of the digestive tract?

Smooth (332)

In addition to skeletal muscle, two other types of muscle are found in the body: ____ muscle and ____ muscle.

Smooth and Cardiac ( 359-360)

The muscle that surrounds the opening to your esophagus and opens reflexively to allow you to swallow food is what type of muscle?

Sphincter (332)

Single unit muscle cells contract ____.

Together (363)

The motor neuron transmits the effect of a nerve impulse to the muscle fiber at a neuromuscular ____.

Junction (339)

Which can cause muscle fatigue?

-build up of intracellular P1 - insufficient Ca2+ - Na+ or K+ imbalances (357)

The skeletal muscles arranged in layers along the walls of the abdominal cavity and the floor of the pelvic cavity perform what function?

-protection -compression -support -contraction (332)

Which are characteristics of oxidative fibers?

-red -good for endurance - high concentration of myoglobin - use aerobic respiration (352)

A neuromuscular junction contains a(n) ____.

-synaptic knob -motor end plate -synaptic cleft (339)

In a muscle there are concentric layers of connective tissue. From deep to superficial these connective tissue layer are the ____, the ____, and the _____.

Endomysium, perimysium, and epimysium (333)

Which are characteristics of glycolytic fibers?

-white -good for a burst of power -low concentration of myoglobin -use anaerobic respiration (352)

Place the following events in the correct order of occurrence once ACh diffuses across the synaptic cleft of a NMJ:

1. ACh binds to receptors on the motor end plate 2. The resulting action potential moves down the sarcolemma 3. The action potential moves down the t-tubules 4. The action potential reaches the terminal cisternae of the SR. 5. Calcium ions are released into the sarcoplasm (342)

When smooth muscle is stretched, it responds by _____.

Contracting then relaxing (363)

The majority of skeletal muscle fiber in the body are _____ fibers.

Fast glycolytic (353)

Match the duration of a single muscle contraction with the source of ATP:

Immediate-creatine phosphate Short term-anaerobic respiration Long term-aerobic respiration (350)

If you strain to push on a wall that does not move, your muscles are in what type of contraction?

Isometric (356)

In order to predict how much tension a muscle can produce when contracting, it is important to consider the ____ they should ship of the thick and thin filaments.

Length-tension (357)

Skeletal muscle contraction is controlled by _____ neurons.

Motor (333)

Myofibrils are made of _____.

Myofilaments (336)

The point where a motor neuron meets a skeletal muscle fibber is called the ____ junction.

Neuromuscular (339)

As you hold a barbell and begin to flex your arm in a curl, your biceps brachii slowly lifts the weight by using more and more units. This phenomenon, which increases the strength of the contraction, is referred to as _____.

Recruitment. (355)

Thick and thin filaments maintain their ____, whether the muscle is relaxed or contracted.

Same length (340)

The plasma membrane of a skeletal muscle fiber is called the ___.

Sarcolemma (334)

Moto and play is specialized region of the _____.

Sarcolemma (340)

Within a myofibril, Z discs separate the functional units known as _____.

Sarcomeres (336)

Slow-twitch and fast-twitch muscle fibers differ primarily in:

Their ATPase which splits ATP (352)

Thin filaments in smooth muscle cells contain which proteins?

-tropomyosin -actin (361)

Which proteins are found in a thin filaments?

- actin - tropomyosin - troponin (336)

Smooth muscle is found in which of the following location?

- in the wall of the small intestine - in wall of the uteruse - around the blood vessel (360)