A&P chapter 10: Muscle tissue

True or False: Playing the paino with your fingers uses very small motor units.

True

True or false: A single myofibril runs the length of the muscle fiber.

True

True or false: Postural muscles contract continuously when a person is awake to prevent collapse of the body.

True

In sarcomere, the _______ zone (or band) is the light, central region of the A band. A. H B. Z C. M D. I

A. H

Parts of the sarcoplasmic reticulum that appear as blind sacs perpendicular to the fiber's length are called ___. A. Terminal cisternae B. Alveoli C. Triads D. Terminal tubules

A. Terminal cisternae

Under the light microscope, the dark (A) bands observed in skeletal muscle contain ___ filaments. A. Thick and thin B. Only thick C. Only thin D. Titin

A. Thick and thin

A tropomyosin molecule is a short, thin, twisted filament that covers small sections of the ____ strand. A. actin B. collagen C. elastin D. myosin

A. actin

Smooth muscle shows a different length-tension relationship than skeletal muscle because _______. A. the lack of sarcomeres prevents actin and myosin from interacting in sliding filament mechanism. B. the arrangement of the thick and thin filaments allows for contraction even when stretched. C. it lack Z discs but has dense bodies.

B C

Multiunit smooth muscle is found in which of the following locations? A. around small blood vessels B. iris of the eye C. Uterine wall D. wall of the small intenstine E. arrector pili muscles in the skin

B E

Place the stages of cross-bridge cycling in order: Reset of myosin head Power stroke Calcium binds troponin; myosin binding sites uncovered Release of myosin head by ATP Cross-bridge formation

Calcium binds troponin; myosin binding site uncovered Cross-bridge formation Power stroke Release of myosin head by ATP Reset of myosin head

Select all that are true when a muscle fiber is at rest: There is a charge difference across the sarcolemma Sodium-potassium pumps are active Calcium is stored in the sarcoplasm ACh receptors are open

Calcium is stored in the sarcoplasm

Autonomic motor neurons that control smooth muscle contraction have bulbous swellings called ____ that contain synaptic vesicles. A. dense bodies B. caveolae C. axonal terminals D. varicosities

D

The synaptic knob of the neuron is a(n) _____ of an axon. A. beginning B. narrowed end C. midpoint D. expanded tip

D

The Z-disc is a thin transverse protein structure in the center of the ______ band in sarcomere.

I

A- Sarcomere B- Titin C- Thin filament D- Thick filament

Identify each structure in the diagram: Sarcomere Thick filament Titin Thin filament

A- 4 B-3 C-1 D-2

Identify the molecules pictured in the neuromuscular junction: A. moves into the axonal terminal B. moves into the sarcoplasm C. moves across the synaptic gap D. moves out of the sarcoplasm 1. acetylcholine 2. potassium ions 3. sodium ions 4. calcium ions

A- myosin B- tropomyosin C- G-actin D- troponin

Identify the myofilament proteins in the picture. B is pointing to a green structure. Myosin G-actin Troponin Tropomyosin

The ____ line is a thin transverse protein meshwork structure in the center of the H zone of a sarcomere. A. A B. M C. I D.Z

M

The _____ line is a thin, transverse, protein meshwork structure in the center of the H zone of sarcomere.

M

In a motor unit, a single ____ neuron typically controls numerous muscle fibers in a muscle.

Motor

ACh is an acronym for

acetylcholine

What protein is found in thin filament?

actin

Smooth muscle cells generally generate ATP through which mechanism? A. aerobic respiration B. Glycolysis C. anaerobic respiration

aerobic respiration

A term that describes the change in muscle following a lack of exercise is:

atrophy

Smooth muscle contraction is under _____ control of the nervous system.

autonomic

The type of muscle fibers that are striated, form a Y-shaped branches, and are joined by intercalated discs are:

cardiac

The enzyme acetylcholinesterase resides in the synaptic _____.

cleft

The enzyme acetylcholinesterase resides in the synaptic _______.

cleft

The property of muscle tissue that allows an impulse to travel down the entire length of the cell membrane is ________. extensibility contractility conductivity responsibility elasticity

conductivity

The shortening of muscle cells is called ________.

contracting

What are characteristics of oxidative fibers? White or dark red fatigue-resistant or fatigable low myoglobin or high myoglobin supply Use for aerobic respiration or anaerobic respiration

dark red fatigue-resistant high myoglobin supply aerobic respiration

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

disc

After a contraction, muscle returns to its original relaxed position due to it's natural _______.

elasticity

Muscles of the eye and hand have a high percentage of _______ fibers. fast-twitch slow-twitch

fast-twitch

Each myosin strand has a free _____ and an attached ____.

head, tail

The ______ mechanism allows smooth muscle to maintain muscle contraction without the use of additional ATP.

latchbridge

A graph of a muscle twitch contains three periods. The period during which there is no change in external muscle tension (and no change in muscle length) is the ________ period.

latent

Although muscle fibers obey the all-or-none principle, the force of muscle contraction can be varied depending on how many______ units are used.

motor

Skeletal muscle contraction is controlled by _______ neurons.

motor

although muscle fibers obey the all-or-none principle, the force of muscle contraction can be varied depending on how many ______ units are used.

motor

When someone engages in exercise that requires more oxygen than is available, they develop a(n) ______ _______ (2 words), which results in heavy breathing for several minutes after the exercise is complete.

oxygen debt

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

sarcolemma

Within a myofibril each _______ shortens as the muscle fiber contracts.

sarcomere

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

sarcomeres

Within a myofibril, Z discs sperate the functional contractile unit known as ________.

sarcomeres

The cytoplasm of a skeletal muscle cell has a specific name and is known as _____.

sarcoplasm

The length-tension relationship of ____ muscle cells is limited by the Z-discs which are lacking in ____ muscle cells.

skeletal, smooth

The length-tension relationship of ____ muscle cells is limited by the z-discs which are lacking in ____ muscle cells.

skeletal, smooth

Smooth muscle contraction is ______, resistant to ______, and usually sustained for an extended period of time.

slow, fatigue

The motor end plate has folds and indentations to increase the membrane surface area adjacent to the ________.

synaptic knob

A cord like structure that attaches a muscle to a bone is a _______.

tendon

At the ends of muscles, the connective tissues merge to form a _______, which attaches the muscle to other structures.

tendon

What are characteristics of glycolytic fibers? White or dark red fatigue-resistant or fatigable low myoglobin or high myoglobin supply Use for aerobic respiration or anaerobic respiration

white fatigable low myoglobin anaerobic respiration

Single unit muscle cells contract _____. A. in pairs B. together C. individually

B

The motor end plate is a specialized region of the ______. A. sarcomere B. myofilament C. sarcolemma D. motor neuron

C. sarcolemma

A nerve impulse travels through an axon to its ______. A. dendritic zone B. sarcoplasm C. synaptic knob D. axon hillock

C. synaptic knob

The sodium-potassium pump moves_______ sodium ions out of the cell for every _____ potassium ions it brings in. 1;3 2;3 3;1 3;2

3;2

A neuromuscular junction contains a(n) _____. A. motor end plate B. postsynaptic neuron C. Synaptic cleft D. Intercalated disk E. Tight junction F. Synaptic knob G. Desmosome

A C F

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

Calcium

Match each protein with its function: A. MLCK 1. Dephosphorylates myosin B. Calmodulin 2. Phosphorylates myosin C. MLCP 3. Binds Calcium

A-2 MLCK: phosphorylates myosin B-3 Calmodulin: binds calcium C-1 MLCP: dephosphorylates myosin

Match the name of the component of a muscle fiber with its description: A. Sarcolemma B. Muscle fiber C. Sarcoplasm D. Sarcoplasmic reticulum E. T-tubule 1. A muscle cell 2, Narrow, tubular extensions of the sarcolemma into sarcoplasm 3. Cytoplasm of a muscle fiber 4. Plasma membrane of a muscle fiber 4. Smooth endoplasmic reticulum in a muscle fiber

A-4 B-1 C-3 D-4 E- 2

Multiunit smooth muscle cells are stimulated _____. A. individually B. in pairs C. as a group

A.

Acetylcholinesterase in the synaptic cleft is needed so that ____ will not continuously stimulare the cell the contract. A. ACh B. dopamine C. AChE D. norepinephrine

A. ACh

While observing skeletal muscle tissue under the microscope you note it appears striated. You tell your lab partner because: A. of the arrangement of myofilaments in each sarcomere B. of alternating rough and smooth surfaces on the sarcolemma C. different organelles within muscle fibers take up stain differently

A. of the arrangement of myofilaments in each sarcomere

Inside a muscle cell, the sacs of the SR where calcium is stored and released from are the ________. A. terminal cisternae B. transverse tubules C. axon terminals D. sarcomeres

A. terminal cisternae

In a muscle cell at rest, the myosin heads of a thick filament point ______ the sarcomere. A. towards the ends of B. towards the center of

A. towards the ends of

Which of the following proteins are found within a sarcomere? Actin Elastin Connectin Collagen Keratin

Actin and Connectin

A muscle cell obtains ATP in the short term via what process? Electron transport chain Krebs cycle Aerobic respiration Anaerobic respiration

Anaerobic respiration

In each helical strand of F-actin, many small, spherical molecules are connected to form a long filament resembling a string of beads. Each spherical molecule is called ___________. A. J-actin B. G-actin C. I-actin D. H-actin

B. G-actin

In a muscle contraction, as increasing numbers of motor units are recruited _____ force is exerted. A. A consistent B. Greater C. Less

B. Greater

The narrow space separating the synaptic knob and the motor end plate is called the _______. A. Sarcolemma B. Synaptic cleft C. sarcoplasm D. intracellular cleft

B. Synaptic cleft

Skeletal muscle fibers are _____. A. uninucleate B. multinucleate C. binucleate D. anucleate

B. multinucleate

The motor end plate is a specialized region of the ______. A. sarcomere B. sarcolemma C. myofilament D. motor neuron

B. sarcolemma

Match each function of skeletal muscle with it's description Body movement Posture Temperature regulation Storage and movement of materials Contraction of specific skeletal muscles stabilizes joints Muscles contract and pull on the tendons that attach the muscles to the bones. Heat is produced as a waste product of energy usage. Voluntary sphincter muscles of the gastrointestinal and urinary tracts can be kept closed or opened.

Body movement: Muscles contract and pull on the tendons that attach the muscles to the bones. Posture: Contraction of specific skeletal muscles stabilizes joints. Temperature regulation: Heat is produced as a waste product of energy. Storage and movement of materials: voluntary sphincter muscles of the gastrointestinal and urinary tracts can be kept closed or opened.

Thin filaments in smooth muscle cells contain which proteins? A. elastin B. troponin C. tropomyosin D. actin E. collagen

C D

When smooth muscle is stretched, it responds by ______. A. contracting as much as possible B. relaxing then contracting C. contracting the relaxing D. relaxing as much as possible

C. contracting then relaxing

When a muscle relaxes, A. crossbridges form and muscle extensibility returns the muscle to rest length. B. crossbridges form and muscle elasticity returns the muscle to rest length. C. crossbridges stop forming and muscle elasticity returns the muscle to rest length. D. crossbridges stop forming and muscle extensibility returns the muscle to rest length

C. cross bridges stop forming and muscle elasticity return the muscle to rest length

A motor unit is composed of a single _______ and all of the muscle fibers it controls. A. interneuron B. association neuron C. motor neuron D. sensory neuron

C. motor neuron

What part of myosin molecules does ATP bind to? A. Neck B. Tail C. Middle D. Head

D. Head

During development, many groups of _____ fuse to form single skeletal muscle fibers. A. Fibroblasts B. Chondroblasts C. Neuroblasts D. Myoblasts

D. Myoblasts

The functional contractile unit of a skeletal muscle fiber is known as a ___. A. Sarcolemma B. Sarcoplasm C. Sarcoplasmic reticulum D. Sarcomere

D. Sarcomere

Myofibrils are made of _____. A. sarcolemma B. fascicles C. transverse tubules D. myofilaments E. sarcoplasmic reticulum

D. myofilaments

The motor end plate has folds and indentations tp increase the membrane surface area adjacent to the _____. A. sarcoplasmic reticulum B. sarcoplasm C. sarcomere D. synaptic knob

D. synaptic knob

Under the light microscope, the dark (A) bands observed in skeletal muscle contain _______ filaments. A. only thin B. only thick C. titin D. thick and thin

D. thick and thin

Within a myofibril, each __ shortens as the muscle fiber contracts. A. M-line B. Z-disc C. H-zone D. Myofilament E. Sarcomere

E. Sarcomere

Match the structure with its description: H-zone M-line Z-disc I-band A. Lighter region in the middle of an A band B. Appears as a dark protein disc in the center of H-zone C. Light band containing thing filaments only D. Made of dark proteins that create a zig-zag line

H-zone: A M-line: B Z-disc: D I-band: C

Match each muscle unit with the connective tissue layer that surrounds it. Muscle Fascicle Muscle cell Epimysium Endomysium Perimysium

Muscle: Epimysium Fascicle: Perimysium Muscle cell: Endomysium

Place events in the order that they happen ACh binds receptors on the motor end plate Ca2+ enters and binds synaptic vesicles Nerve impulse arrives at synaptic knob ACh is released into synaptic cleft

Nerve impulse arrives at synaptic knob Ca+ enters and binds synaptic vesicles ACh is released into synaptic cleft ACh binds receptors on the motor end plate

The skeletal muscle arranged in layers along the walls of the abdominal cavity and the floor of the pelvic cavity preform what function? Protection Support Contraction Insulation

Protection, Support, Contraction

What two types of muscle would you expect to find in the cardiovascular system?

Smooth and cardiac

Match the muscle tissue with its appearance or shape. Skeletal Cardiac Smooth Fusiform-shaped cell Long, cylindrical fiber Short, branched cell

Skeletal: Long, cylindrical fiber Cardiac: Short, branched cell Smooth: Fusiform-shaped cell

The sodium-potassium exchange pump maintains a higher concentration of which ion outside the sarcolemma?

Sodium

The narrow space separating the synaptic knob and motor end plate is called the _____.

Synaptic cleft

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

Thick

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

isometric

Which contraction occurs when you try (unsuccessfully) to move a wall? isotonic isometric

isometric

Muscle cells store oxygen bound to a _______ molecule.

myoglobin

Thick filaments are assembled from bundles of the protein called _____.

myosin

Thick myofilaments are composed of bundles of ________ protein molecules.

myosin

The point where a motor neuron meets a skeletal muscle fiber is called the _____ junction.

neuromuscular

The point where a motor neuron meets a skeletal muscle fiber is called the ______ junction.

neuromuscular