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.