Muscles Anatomy study guide

The arrangement of fascicles in orbiculares oris is

circular

muscles tissue has the ability to shorten when adequately stimulated, a characteristic known as

contracility

The heads of the myosin myofilaments are called ________ when they link the thick and thin filaments together during skeletal muscles contraction

cross bridges

contractions which muscles shorten and produces movement are known as

isotonic contractions

Epiymysium is represented by

label A

The A band witching a myofibril is indicated by

label A

The I band within a skeletal muscle fiber is indicated by

label B

Then endomysim that wraps individual muscle fibers is indicated by

label B

perimysium wraps a fascicle of muscle cells and is represented by

label C

which of the following is a type of isometric exercise in which muscles increase in size and strength

lifting weights

One neuron and all the skeletal muscles it stimulates is known as

motor unit

a motor neuron and all of the skeletal muscle fibers it stimulates are termed a

motor unit

according to the sliding filament theory, how does muscle contraction occur

myosin heads form cross bridges and pull thin filaments, causing them to slide

the points of muscle attachment to an immovable or less movable bone is know as the

origin

the plasma membrane of a skeletal muscle is called the

sarcolemma

What organelle wraps and surrounds the myofibril and stores calcium

sarcoplasmic reticulum

Which type of muscle tissue contracts most quickly apon stimulation

skeletal

which term does not describe smooth muscles

skeletal

Creative phosphate (CP) functions within the muscle cells by

storing energy that will be transferred to adp to resynthesize ATP as needed

Which of the following muscles acts as a generalist to masseter and closes the jaw

temporalis

a sarcomere is

the contractile unit between two Z discs

The condition of skeletal muscle fatigue can be explained best by

the inability of the muscle to contract even if its being stimulated

Why are calcium ions necessary for skeletal muscle contraction?

Calcium ions trigger the binding of myosin heads to actin filaments

What type of muscle is shown

Smooth muscle

The gap between the axon terminal of a motor neuron and the sarcolemma of a skeletal muscles cell is called the

Synaptic cleft

Jason injured his hamstring muscle group during football practice. He will be unable to perform ________.

Thigh extension and knee flex

what is released by axon terminals into the synaptic cleft to stimulate a muscle to contract

acetylcholine

Which of these events most occur first to trigger the keel tail muscle to generate an action potential and contract

acetylcholine (ACh) binds to receptors on the sarcolemma and allows passage of sodium ions into the cell

what enzyme breaks down acetylcholine into acetic acid and choline to prevent continued contraction of the muscle fiber?

acetylcholinesterase

During skeletal muscle contraction , to what do myosin heads bind

actin filaments

what is the unstoppable electrical current that travels down the length of the entire surface of sarcolemma

action potential

which movement is opposite to abduction

adduction

what is covered by the endomysium

an individual muscle cell

Which method of regenerating ATP during muscle contraction can produce lactic acid

anaerobic glycolysis

what creates the alternating light and dark bands that provides the striating pattern on skeletal muscle tissue

A bands and I bands

Striated involuntary muscle tissue found in the heart is ________.

Cardiac muscles

skeletal muscle as a whole can generate different amounts of force and different degrees of shortening in response to stimuli, what is this concept called

Graded response

muscles that perform opposite actions to one another are termed

antagonists

neurotransmitters are released upon stiumulation from a nerve impulse from the

axon terminals of the motor neuron

Striated involuntary muscle tissue is classified as ________ muscle.

cardiac

The prime mover of arm abduction is the Muscle

Deltoid

the myofiliment composed of actin is indicated by

Label C

Muscle fiber (cell) is indicated by

Label D

The H zone, located within the A band, lacks thin filaments and is represented by

Label D

An inherited disease that causes muscles to degenerate and atrophy is known as

Muscular dystrophy

What must rush into a muscle cell to promote its depolarization?

Potassium ions

Which of the following is an example of an isometric contraction

Pushing against an immovable wall

which fascial muscles is considered the smiling muscle since it raises the corners of the mouth

Zygomaticus

What is acetylcholine

a neurotransmitter that stimulates skeletal muscle to contract

The mechanical force of contraction is generated by

a sliding of thin filaments past thick filaments

Which of the following is not a function of the muscular system

blood cell formation

A smooth, sustained contraction, with no evidence of relaxation, is called ________.

fused, or complete, tetanus

anaerobic glycolysis requires ______ to make ATP

glucose only

a skeletal muscle twitch differs from a titanic contraction in that

the muscle twitch is a brief and jerky movement while the tetanic contraction is prolonged and continuous

Which of the following is composed mostly of the protein myosin

thick filaments