The Muscular System

When muscles are actively contracting, the process requires large amounts of energy in the form of

ATP.

___________ exercise requires oxygen and is of ___________ duration than ___________ exercise.

Aerobic; longer; anaerobic

___________ can make skeletal muscles less elastic as well as restrict movement and circulation.

Aging

Thin filaments at either end of the sarcomere are attached to interconnecting filaments that make up the

Z lines.

An example of an activity that requires anaerobic endurance is

a 50-yard dash.

The neurotransmitter released from the synaptic vesicles that initiates an action potential in the sarcolemma is

acetylcholine.

The thin filaments of a sarcomere consist of

actin.

The length of time a muscle can continue to contract while supported by mitochondrial activities is referred to as

aerobic endurance.

A resting muscle generates most of its ATP by

aerobic respiration.

Slow fibers are the type of muscle fibers that contain

an extensive network of capillaries, the red pigment myoglobin, a relatively large number of mitochondria.

Terms that indicate position, direction, or muscle fiber orientation

anterior, posterior, lateralis, rectus

Tendons are bundles of collagen fibers at the end of a skeletal muscle that

attach muscle to bone.

Mitochondrial activities are relatively efficient, but their rate of ATP generation is limited by the

availability of of oxygen.

List the muscles that are included in the hamstrings

biceps femoris, semitendinosus, gastrocnemius

Terms indicating specific regions of the body

brachialis, cutaneous, lumborum, popliteus

aponeurosis

broad sheet of collagen fibers

Includes only muscles of facial expression

buccinator, orbicularis oris, zygomaticus, frontalis

Active sites on the actin filaments become available for binding when

calcium binds to troponin.

The presence of intercalated discs is a characteristic unique to

cardiac muscle cells.

The three layers of connective tissues comprising each muscle are

cardiac, smooth, and skeletal.

The system that accelerates oxygen delivery and carbon dioxide removal in muscles is the

cardiovascular system.

A muscle that inserts on the body of the mandible is probably involved in

chewing.

There is clear evidence that the benefits of regular exercise throughout life include

control of body weight, increase in bone strength, improving the quality of life.

The primary energy reserve in muscle tissue is

creatine phosphate (CP).

In the aging process, skeletal muscle fibers decrease in diameter, causing

decreased muscular strength and endurance, and rapid fatigue.

Terms indicating structural characteristics (shape) of the muscle

deltoid, orbicularis, piriformis, teres

Includes the muscles that move the upper arm

deltoid, trees major, latissimus dorsi, pectoralis major

The system that releases hormones that adjust muscle metabolism and growth is the

endocrine system.

The origin of the rentals muscle is the

epicranial aponeurosis.

What are the three layers of connective tissue that are part of each muscle?

epimysium, permysium, endomysium

cisternae

expanded chambers of SR

Muscles that insert on the olecranon process of the ulna act to

extend the forearm.

When the gluteus maximus contacts, it

extends the thigh backward.

In humans, slow fibers are not found in the muscle of the

eyes and hands.

When energy reserves in a muscle are exhausted or lactic acid levels increase,

fatigue occurs.

Terms indicating actions

flexor, supinator, abductor, levator

The typical result of repairing aging skeletal muscle tissue is

formation of scar tissue.

Athletes training to develop anaerobic endurance perform

frequent, brief, intensive workouts.

The muscle that inserts on the iliotibial tract and gluteal tuberosity of the femur is the

gluteus maximus.

What are the four groups of muscles that comprise the axial musculature?

head and neck vertebral column oblique and rectus muscles pelvic floor

Subdivisions of the spinal extensors include

iliocostalis, longissimus, and spinalis.

A muscle producing almost peak tension during rapid cycles of contraction and relaxation is said to be in

incomplete tetanus.

The process of recruitment is the smooth but steady increase in muscle tension produced by

increasing the number of active motor units.

Two of the muscles comprising the rotator cuff are the

infraspinatus and teres minor.

What are the differences between an isometric contraction and an isotonic contraction?

isometric - the muscle stays the same length even if the force of contraction increases isotonic - the muscle is at a constant pulling with the same force but shortens

During anaerobic glycolysis,

lactic acid is produced.

During a specific action, the insertion is the

more movable end of a muscle.

Resting tension in a skeletal muscle is called

muscle tone.

The axial musculature consists of

muscles of the head and neck, muscles of the spine and pelvic floor, and muscles of the trunk.

The thick filaments of a sarcomere consist of

myosin.

The system that controls skeletal muscle contractions is the

nervous system.

What is the primary functional difference between an origin and an insertion?

origin - attachment point does not move insertion - attachment point does move

The amount of oxygen used in the recovery period to restore normal pre-exertion conditions is referred to as the

oxygen debt.

What two major groups of muscles comprise the appendicular musculature?

pelvic girdle and upper limbs lower limbs

Bundles of muscle fibers called fascicles are surrounded by connective tissue fibers of the

perimysium.

The layer of connective tissue that contains blood vessels and nerves is the

perimysium.

Fast fibers are the type of muscle fibers that

produce powerful contractions but fatigue rapidly.

The muscles that arise on the humerus and the forearm and rotate the radius without producing flexion or extension of the elbow are the

pronator teres and supinator.

tropomyosin

protein cover of active sites

The iliac crest is the origin of the

quadratus lumborum.

The quadriceps femurs are a group of anterior thigh muscles that include the ___________ muscles.

rectus femoris, vastus medialis, vastus lateralis, and vastus intermedius

The muscle that originates along the entire length of the linea aspera of the femur is the

vastus medialis.

What are the five functions performed by skeletal muscles?

1. produce movement of the skeleton 2. maintain posture and body position 3. support soft tissues 4. guard entrances and exits 5. maintain body temperature

Why do fast fibers fatigue more rapidly than slow fibers?

Fast fibers use anaerobic metabolism; better at generating short bursts of strength.

What is the relationship among fatigue, anaerobic glycolysis, and oxygen debt?

Fatigue and lack of oxygen cause anaerobic glycolysis.

A motor neuron initiates skeletal muscle contraction by first

releasing acetylcholine into the neuromuscular junction.

The command to contract is distributed throughout a muscle fiber by the

sarcomere.

The smallest functional unit of the muscle fiber is the

sarcomere.

In response to action potentials arriving from the transverse tubules, calcium ions are released from the

sarcoplasmic reticulum.

The hamstrings are a group of posterior thigh muscles that include the ___________ muscles.

semimembranosus, rectus femoris, and semitendinosus

A twitch is a

single stimulus-contraction-relaxation sequence.

The system that provides for muscle attachment in the body is the

skeletal system.

sarcomere contraction

sliding filament theory

The type of muscle cells that contract either automatically or in response to environmental or hormonal stimulation are

smooth muscle cells.

The type of muscle tissue that lacks myofibrils, sarcomeres, and striations is

smooth muscle tissue.

The muscles of the perineum

support organs of the pelvic cavity, flex the coccyx, control movement of materials through the urethra and anus.

The endomysium is the layer of connective tissue that

surrounds each skeletal muscle fiber and ties adjacent muscle fibers together.

The dense layer of collagen fibers that surrounds an entire skeletal muscle is the

tendon.

In an isometric contraction, the

tension produced never exceeds the resistance and the length of the muscle remains constant.

In an isotonic contraction, the

tension rises and the skeletal muscle's length changes.

List the four muscles that are included in the quadriceps

tensor fascia latae, rectus femoris, vastus lateralis, vastus medialis

The final result of muscle relaxation is that

the muscle returns passively to its resting length.

Includes muscles that move the shoulder girdle

trapezius, levator scapulae, pectoralis minor, subclavius

The muscle that inserts on the acromion and scapular spine is the

trapezius.