Lecture Exam #2

The region of the sarcomere that contains both actin & myosin myofilaments is called the

A band

Match the muscle with the most appropriate ORIGIN-INSERTION for each muscle in the trunk/neck/head: Scalenes

1st & 2nd rib - transverse process of cervical vertebrae

An isometric contraction is described as

a muscle produces an tension as the length remains constant

An eccentric contraction is described as

a muscle produces tension, but the length of the muscle is increasing

An antagonist is

a muscle working in opposition to another muscle

What is tropomyosin?

a protein found along the groove of the actin double helix that can block/unblock the actin active site

Synaptic vesicles in the neuromuscular junction contain

acetylcholine

The active sites to which cross-bridges attach are found on the

actin myofilaments

Which of the following correctly describes myoglobin's special function in muscle tissue?

acts as a reservoir for O2

Smooth muscle & cardiac muscle are similar in that they both

are under involuntary control

Which of the following is true concerning isotonic concentric contraction?

the muscle shortens, but tension remains constant

The prime mover is

the muscle that does most of the movement

Whole muscles can respond in a graded fashion to stimuli by varying

the number of motor units recruited

Which of the following muscles moves the scapula?

trapezius

Which of the following muscles extends the forearm & has its insertion on the olecranon process of the ulna?

triceps brachii

Which of the following is a part of the quadriceps femoris muscle group?

vastus lateralis

Channels that open or close in response to changes in the electrical charge or voltage across the plasma membrane are called

voltage gated ion channels

Which of the following muscles would be considered an antagonist to the rectus femoris?

biceps femoris

Which of the following statements regarding the sliding filament model is false?

both actin & myosin myofilaments shorten during contraction

Which type of muscle tissue possesses striations?

both skeletal & cardiac muscle are correct

A condition in which stimuli occur so rapidly that there are no intervening relaxations b/w contractions is called

complete tetanus

The outside of the resting plasma membrane is _____ relative to the inside of the resting plasma membrane

positively charged

Which of the following is true during the resting membrane potential?

potassium is concentrated primarily inside the cell

When the myosin head flexes into a bend, pulling the actin filament along w/ it, this is called the

power stroke

Flexion of the hip is a movement produced by the _____

psoas major & iliacus

Match the muscle w/ the most appropriate INSERTION for each muscle in the arm: Biceps brachii

radial tuberosity

Depolarization of the plasma membrane occurs when there is a rapid influx (inflow) of

sodium ions

The sarcoplasmic reticulum

stores Ca2+

Of the following muscles of the forearm, which one rotates the forearm to turn the palm upwards?

supinator

Rigor mortis occurs after death because

cross-bridges form but can't release

Endomysium is a delicate network of loose CT that

surrounds each muscle fiber

Acetylecholine binds to a membrane bound receptor & causes ligand-gated sodium channels to open & results in

depolarization

The major movement produced during quiet breathing is accomplished by the _____

diaphragm

Which muscle extends the four lateral toes?

surrounds each muscle fiber

When you "pull your tummy in" & compress your abdomen, you use the rectus abdominis, external abdominal oblique, internal abdominal oblique, & transverses abdominis muscles. This is an example of muscles working as _____

synergists

If a person drums their fingers on the table, they would be using which of the following muscles?

flexor digitorum profundus

The adductor longus is named for its _____

function & size

Which of the following is inserted on the calcaneus by the Achilles tendon?

gastrocnemius

The bulge of the calf is caused by the _____ & _____ muscles

gastrocnemius; soleus

Match the muscle w/ the most appropriate INSERTION for each muscle in the leg: Gluteus medius

greater trochanter

Match the muscle w/ the most appropriate INSERTION for each muscle in the arm: Supraspinatus

greater tuberosity (tubercle) of humerus

Betsy took a fall & broke her arm, which required that she wear a cast for a prolonged period of time. When she took the cast off, she was alarmed to see that her muscles

had undergone atrophy

Troponin

has a calcium-binding site

Which of the following muscles contracts during forced expiration?

internal intercostals

Match the muscle w/ the most appropriate INSERTION for each muscle in the arm: Latissimus dorsi

intertubercular (bicipital) groove of humerus

Muscles that change the shape of the tongue are called _____ muscles

intrinsic

Muscle tone

is a constant tension produced by muscles for long periods of time

In the body's lever systems, the

joint represents the fulcrum point

The time b/w application of the stimulus to a motor neuron & the beginning of contraction is called the _____ phase

latent or lag

The sites where a chemical substance is transmitted from the presynaptic terminal of an axon to the postsynaptic membrane of a muscle fiber are called

neuromuscular junction

Match the muscle w/ the most appropriate INSERTION for each muscle in the arm: Flexor carpi radialis

palmar 2nd & 3rd metacarpal base

Which of the following descriptions best represents the appearance of the sarcomere during peak contraction?

the H zone is eliminated, & the I bands are very thin

Match the muscle w/ the most appropriate INSERTION for each muscle in the leg: Gastrocnemius

calcaneus via achilles tendon

Which type of muscle tissue has cells that branch?

cardiac muscle

T tubules

conduct action potentials deep into the muscle fiber

Which of the following is NOT a function of skeletal muscle?

constriction of organs

The H zone

contains only myosin myofilaments

The capacity of a muscle cell to shorten forcefully is known as

contractility

Match the muscle with the most appropriate ORIGIN-INSERTION for each muscle in the trunk/neck/head: Rectus abdominis

diploid process & costal cartilages - symphysis pubis

Contraction of the inferior rectus muscle directs the pupil to look _____

down

Which of the following helps explain the increased tension seen in multiple wave summation?

increased summation of Ca2+ around the myofibrils

Which of the following muscles is part of the rotator cuff?

infraspinatus

When a skeletal muscle contracts to cause a given movement, the more movable end of attachment of the muscle is called its _____

insertion

The infraspinatus _____

laterally rotates the arm

Match the muscle w/ the most appropriate INSERTION for each muscle in the leg: Psoas

lesser trochanter

An action potential

occurs when the local potential reaches threshold level

A sarcomere extends from

one Z disk to an adjacent Z disk

The digastric muscle is involved in _____

opening the mouth

Of the following muscles of the head, which one wraps around the orbits?

orbicularis oculi

Closing or puckering the lips is the action of the _____ muscle

orbicularis oris

The brachioradialis is named for its

origin & insertion

Which muscle retracts (adducts) the scapula?

rhomboideus major

Contracting the right sternocleidomastoid muscle would

rotate the head towards the left

Callie is a world class marathon runner. Which of the descriptions about her dominant type of skeletal muscle is FALSE?

they are well adapted to anaerobic activity

Which of the following is NOT a property of the myosin head?

they bind to troponin

Which of the following statements concerning fast-twitch muscle fibers is true?

they split ATP rapidly

The thenar muscles are involved in controlling the _____; the hypothenar muscles control the _____

thumb; little finger

Match the muscle w/ the most appropriate INSERTION for each muscle in the leg: Rectus femoris

tibial tuberosity via patellar ligament

Aerobic respiration

yields as many as 36 ATP per glucose molecule metabolized

Match the muscle with the most appropriate ORIGIN-INSERTION for each muscle in the trunk/neck/head: Masseter

zygomatic arch - lamus of mandible