chapter 9 a&p

within a sarcomere, the ? band includes the area of overlap between actin (thin) filaments and myosin (thick) filaments

A

myosin and actin filaments

A band (dark band)

myosin (thick) filaments only

H zone

within a sarcomere, the region within the A band that lacks thin filaments is called the ?

H zone

the ? region of a sarcomere is composed primarily of actin

I band

a sarcomere extends from one ? to the next

Z line

the sarcomere extends from one ? to the next

Z line

what is a muscle fiber?

a muscle cell

the frequency of stimulation and number of fibers stimulated are factors that influence what characteristic of whole muscle contraction

amount of force generated by the muscle

the process of glycolysis is ?

anaerobic

what are myofibrils?

bundles of proteins in a muscle cell

the type of muscle called ? muscle is found in the walls of the heart

cardiac

transverse abdominis

deepest layer

describe the Z line that is seen within striations of skeletal muscle

direct attachment for the thin filaments; bisects the I band

the major action of the muscles of the homstring group is ? of the knee

flexion

the quadriceps femoris has ? heads

four

dorsiflexion

front of leg

the muscles of the ? group are located on the posterior thigh

hamstring

the biceps femoris, semitendinosus, and semimembranosus are part of what muscle group?

hamstring group

what structures within cardiac muscle tissue allows the entire cardiac muscle network to contract in unison

intercalated discs

eversion

lateral side of leg

inversion

medial side of leg

piriformis gluteus maximus

move the thigh and are located posteriorly

gastrocnemius soleus flexor digitorum longus

moves foot downward

what is the meaning of the root word myo-?

muscle

vastus intermedius vastus medialis vastus lateralis rectus femoris

muscles that form the quadriceps femoris muscle group

rhomboid major trapezius levator scapula serratus anterior

muscles that move the pectoral girdle

levator ani coccygeus

pelvic floor diaphragm spans the pelvic outlet

what two muscles move the thigh and are located anteriorly?

psoas major Iliacus

tibialis anterior fibularis (peroneus) tertius extensor digitorum longus

pulls foot upward

subscapularis infraspinatus teres minor

rotators turn (twist) the humerus within the glenoid cavity

muscle fiber features called ? are repeating units within muscle fibers that act as the functional units of muscle contraction

sarcomeres

since the shortening of ? results in shortening of entire skeletal muscles, these structures are called the "functional units" of skeletal muscle

sarcomeres

the membranous organelle within muscle fibers, called the ? reticulum, corresponds to the endoplasmic reticulum of other cells

sarcoplasmic

which muscle type has multinucleated cells that are cylindrical in shape?

skeletal

the cells of ? muscle are tapered, lack striations, and have a sarcoplasmic reticulum that is not very extensive

smooth

the ? muscle is located just deep to the gastrocnemius

soleus

the organization of the thin and thick filaments within a muscle cell results in the formation of what muscle feature?

striations

when a muscle fiber is stimulated at a high enough frequency that it doesn't have time to relax, the forces of the individual twitches combine. what is this process called?

summation

what are thin filaments composed of?

two inteertwined strands of actin

actin (thin) filaments are attached to a Z line, which is located in the middle of what region of the striations?

I band

the region of a sarcomere composed primarily of actin is called the ? band

I band

actin (thin) filaments only

I band (light band)

acetylcholinesterase functions to break down ? in the synaptic cleft

acetylcholine

name the enzyme that breaks down acetycholine in the synaptic cleft

acetylcholinesterase

adductor longus adductor magnus gracilis

act to adduct the thigh medial group

gluteus maximus gluteus medius tensor fasciae latae

act to extend hip and/or abduct thigh posterior group

psoas major iliacus

act to flex thigh at hip anterior group

binding sites for the myosin heads (cross-bridges) are found on the which of the proteins found within the thin filaments?

actin

troponin and tropomyosin are associated with what other protein within the muscle fibers?

actin

name the action of the adductor magnus

adducts thigh

what is oxygen debt?

amount of oxygen needed to restore resting state

plantar flexion

back of leg

cells that are branching, uninucleated, involuntary, and striated

cardiac muscle cells

lateral pterygoid temporalis medial pterygoid massester

considered muscles of mastication

a muscle fiber shortens and generates force during the ? period of a muscle twitch

contraction

what is the first source of energy used to convert ADP and phosphate to ATP at the start of a contraction

creatine phosphate

ATP can be regenerated by transferring a phosphate from ? to ADP in a reaction catalyzed by the enzyme ? phosphokinase

creatine phosphate; creatine

one possible cause of muscle fatigue is the ? in pH as lactic acid accumulates and dissociates

decrease

differentiate between the deep fascia and the subcutaneous fascia

deep fascia surrounds individual muscles; subcutaneous fascia underlies the skin

the fascia enclosing muscle is called ? fascia, while that lying just beneath the skin is the ?

deep; subcutaneous

nerve impulses arrives at distal end of axon acetycholine is released ACh diffuses across synaptic cleft ACh binds to its receptors on muscle fiber sarcolemma permeability of sarcolemma to sodium ions is increased

events leading to excitation of a muscle fiber

vastus lateralis vastus medialis quadriceps femoris group

extend the knee

name the action of the quadriceps femoris muscle group

extends knee

teres major latissimus dorsi

extensors move arm back and upward at the shoulder

a drop in pH and the depletion of glycogen are factors that lead to muscle ?

fatigue

muscles that move the foot will originate on the ?, tibia, and/or ? (name the bones)

femur; fibula

in order for muscles to move the thigh, they need to have attachments (origins and insertions) at what two areas?

femur; pelvic girdle

due to their shape, muscle cells are also called muscle ?

fibers

biceps femoris semitendinosus semimembranosus

flex the knee

coracobrachialis pectoralis major

flexors move the arm forward and upward at the shoulder

what is the outcome of the movements of the cocked myosin heads?

increase in overlap between thin and thick filaments

which of the following leads to shortening of sarcomeres?

increasing overlap between thin and thick filaments

when a muscle contracts, its attachment point, called its ?, is pulled towards its origin

insertion

what root word means between?

inter-

what structures contain gap junctions that allow action potentials to pass rapidly between cardiac cells, causing the entire cardiac muscle to contract in unison

intercalated discs

internal oblique

intermediate layer

the concentration of calcium in the sarcoplasm ? during muscle contraction; and ? when relaxation occurs

is increased; decreases

muscles do not change length muscles to undergo changing force no movement occurs

isometric contractions

muscles change length concentric contractions eccentric contractions

isotonic contractions

the product of glycolysis, pyruvic acid, is converted to ? when oxygen is not available

lactic acid

muscles that insert on the tibia and/or fibula will act to move what body part

leg

external oblique

most superficial layer

long bundles of contractile proteins found in the sarcoplasm are called ?

myofibrils

the thick filaments are composed of ? proteins

myosin

during a muscle contraction, what happens when ATP binds to the myosin heads

myosin cross-bridge releases from actin

a cross-bridge is best described as a ?

myosin head bound to actin

what are the two major protein types found in myofibrils?

myosin; actin

muscles that move the foot have their ? on the femur, the tibia, or the fibula

origins

describe the location of the protein troponin

part of thin filament; holds tropomyosin in place

name the insertion for the muscles of the quadriceps femoris muscle group

patella and tibial tuberosity

within a sarcomere, what is the H zone?

region within the A band that lacks thin filaments

what term is used for the plasma membrane of a muscle fiber

sarcolemma

within myofibrils, the area between two successive Z lines is called a(n) ?

sarcomere

what is the effect of the shortening of sarcomeres?

shortening of the muscle

multiple nuclei per cell striated well-developed sarcoplasmic reticulum

skeletal muscle cell

cells that are cylindrical, multinucleated, voluntary, and striated

skeletal muscle cells

name the types of muscle: ? muscle, ? muscle, and ? muscle

skeletal, smooth, cardiac

single nucleus lacks striations lacks transverse tubules

smooth muscle cell

cells that are tapered, uninucleated, involuntary, and nonstriated

smooth muscle cells

nerve signal ceases acetylcholine release into the synaptic cleft stops; ACh already in synaptic cleft is broken down calcium is actively transported into the sarcoplasmic reticulum; Ca+2 diffuses away from troponin troponin returns to its relaxed configuration, causing tropomyosin to cover the myosin binding sites on actin

steps leading to the relaxation of muscle

epimysium perimysium endomysium

superficial to deep; the connective tissue layers associated with a skeletal muscle

what is the action of the biceps brachii?

supination; flexes shoulder and elbow

which of the following best describes the M line found within sarcomeres

the M line is in the middle of the H zone, providing an attachment point for the thick filaments

what forms the striations seen in skeletal muscle?

the arrangement of thin and thick filaments

actin tropomyosin troponin

three components of thin filaments

the protein called ? anchors myosin filaments to the Z lines

titin

what describing the roles of muscles in an action, what is the role of the antagonist?

to oppose the action

what is the role of the neurotransmitters released by motor neurons?

to stimulate skeletal muscle cells

name the invaginations of the sarcolemma that extend through the muscle fiber

transverse (T) tubules

numerous openings in the sarcolemma of a muscle fiber lead down into structures called the ?

transverse tubules

what structures are positioned between adjacent cisternae of the sarcoplasmic reticulum

transverse tubules

what structures are positioned between adjacent cisternae of the sarcoplasmic reticulum?

transverse tubules

name the long rod-like protein that sets in the longitudinal grooves along the thin filaments

tropomyosin

three proteins form the thin filaments of muscle myofibrils?

tropomyosin actin troponin

name the proteins involved in blocking the binding sites on actin molecules, resulting in the inability of myosin to bind to the thin filaments

tropomyosin and troponin

the protein ? holds tropomyosin in place along the thin filament

troponin

true or false the transverse tubules are located between structures called citernae

true

iliacus psoas major

two muscles that move the thigh and are located anteriorly

external urethral sphincter deep transverse perinel

urogenital diaphragm located within the pubic arch

the two types of smooth muscle are ? smooth muscle and ? smooth muscle

visceral; multiunit