Chapter 7 Review
Slower
Are red muscles slower or faster than white muscles?
Neuromuscular junction
The communication link between the nervous system and a skeletal muscle fiber
A band
The dark band that is the area containing thick filaments
Break down
The enzyme acetylcholinesterase causes acetylcholine to
Muscular hypertrophy
The growth and increase of the size of muscle cells
Aerobic endurance
The length of time a muscle can continue to contract while supported by mitochondrial activities
Tibialis anterior
The muscle that dorsiflexes the foot
Actin and myosin arrangement
The striated appearance of skeletal muscle results from what?
Origin
The term for where a muscle begins
Insertion
The term for where a muscle ends
Hypertrophy
The term used to describe muscular growth in response to usage is
Obicularis oculi
This muscle is used in winking
Buccinator
Used to suck in your cheeks
Oxygen
When this type of muscle fiber is resting, it contains oxygen reserves
Elbow flexion
A muscle that inserts on the radial tuberosity is most likely involved in
Masseter
A muscle that originates from the zygomatic arch and functions in elevating the mandible?
Perimysium
A sheath of connective tissue surrounding a bundle of striated muscle fibers
Twitch
A single stimulus-contraction-relaxation sequence in a muscle fiber
Sodium ions
As a skeletal muscle contraction is initiated, acetylcholine binding alters the motor end plate membrane's permeability to what?
Aponeurosis
At the end of the muscle, collagen fibers come together to form a bundle of fibers known as a tendon, or a broad sheet know as what?
Motor end plate
Specialized sarcolemma that contains acetylcholine receptors
Smooth muscle
Spindle-shaped muscle cells
Obicularis oris
The "kissing" muscle
Axon terminal
The ________ contains vesicles filled with acetylcholine.
H zone
The area around the M line where there is only dark fibers present
Sarcomere
The area between Z lines
I band
The area of the sarcomere that is the light region between two successive A-bands
Z line
The boundary between sacromeres
Anaerobic endurance
The length of time muscle contractions can be supported by glycolysis and existing energy reserve of ATP and CP
Teres major
The muscle that adducts and medially rotates the shoulder
Rhomboid
The muscle that adducts and rotates the scapula laterally
Buccinator
The muscle that compresses the cheeks, as when pursing the lips and blowing forcefully
Sarcolemma
The plasma membrane of a muscle fiber
Atrophy
The process by which muscle fibers weaken and become smaller
Muscle tone
The resting tension in a skeletal muscle
Myofibrils
The skeletal muscle structures that actively shorten and are responsible for muscle fiber contraction
Sarcoplasmic reticula
The terminal cisternae are structural features of what?
Cardiac muscle
These muscle cells are striated.
acetylcholine
This is a stimulus for contraction in skeletal muscle
Muscle fatigue
This is caused by the exhaustion of energy reserves of the decline in pH due to production and dissociation of lactic acid
Motor unit
This is made up of a motor neuron and the skeletal muscle fibers innervated by that motor neuron's axonal terminals
erector spinae
This muscle functions to maintain an erect spinal column and head?
Masseter
This muscle is the prime mover of jaw closure
Frontalis
This muscle is used to form the horizontal frown crease on the forehead
Large in diameter, containing densely packed myofibrils, large glycogen reserves, and few mitochondria.
Describe a fast twitch fiber
Half the diameter of fast fibers, specialized for contracting for extended periods. Specialized with oxygen supply (many capillaries), oxygen storage (myoglobin), and oxygen use (many mitochondria)
Describe a slow twitch fiber
Troponin
During active-site exposure, calcium ions bind to what?
Complete tetanus
During which phase is the stimulus frequency so high that the relaxation phase is eliminated?
Acetylcholine
This neurotransmitter is a chemical released by a neuron to communicate with cells. The release of this results in changes in the sarcolemma that trigger the contraction of the muscle fiber
T tubules
This structure plays a major role in coordinating the contraction of all regions of the muscle fiber at the same time
Fast twitch
This type of muscle fiber has high glycogen reserves
Cardiac muscle
This type of muscle has intercalated discs
Smooth muscle
This type of muscle uses primarily aerobic metabolism
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
What are the five functions of skeletal muscle?
Semitendinosus. Semimembranosus Biceps femoris
What are the muscles of the hamstrings?
Subscapularis, infraspinatus, supraspinatus, teres major (SITS)
What are the muscles of the rotator cuff?
Actin (thin), myosin (thick)
What are the two types of myofilaments and what are their widths?
Tension
What does muscle force rely on?
Abduct the arm
What does the deltoid do?
Active sites on actin are exposed
What happens when a calcium ion binds to troponin?
Myofilaments organized into repeating functional units
What is a sarcomere?
To transmit electrical impulses to the cell's interior
What is the function of the transverse tubule?
the vastus intermedius, the vastus medialis, the vastus lateralis, and the rectus femoris
What muscles make up the quadriceps femoris?
Incomplete tetanus
What occurs when tension production rises to a peak and very brief periods of relaxation occur
The A band
When a sarcomere contracts, which band does not change shape?
Synaptic cleft
Where is acetylcholinesterase found?
Triceps brachii
Which muscle extends the elbow during the action of push-ups?
Brachioradialis
Which of the following acts to flex the elbow?
flexor digitorum
Which of the following muscles acts to flex the finger joints and wrist?
Muscle tone
Which of the following occurs as a result of motor units in a particular muscle being always active, even though their contractions do not produce enough movement to cause contraction?
M line
Which of the following sarcomere components is made up of proteins that connect the central portions of each thick filament to its neighbors?
Fascicle
A bundle of muscle fibers
Epimysium
A layer of collagen fibers that surrounds an entire muscle
fiber
A muscle ________ contains a sarcolemma, sarcoplasm, myofilaments, and myofibrils.
Prime mover (agonist)
A muscle responsible for producing a particular movement
Perimysium
Muscle fascicles are separated by what?
Trapezius
Muscles that allow you to shrug your shoulders or extend your head
Antagonist
Muscles whose actions oppose movement produced by another muscle
Myofilaments
Myofibrils are bundles of what?
Actin and myosin
Myofibrils are made primarily of
motor neuron axon terminals.
Neurotransmitters that cause skeletal muscle contraction are normally stored in
Smooth muscle
Nonstriated, involuntary muscle
Pectoralis major
Prime mover for shoulder flexion and aduction
Sarcoplasmic Reticulum
Regarding a skeletal muscle fiber, wherever a T-tubule encircles a myofibril, the tubule is tightly bound to
ATP
Rigor mortis occurs at death due to a lack of
elevates, adducts, depresses, or rotates the scapula
describe the action of the trapezius
Synergist
A muscle that helps a prime mover work efficiently
Latent
Calcium ions are released from the sarcoplasmic reticulum during the ________ phase of contraction
10,000
Each myofibril consists of approximately ________ sarcomeres
Calcium ions
In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases
Isotonic
In this type of muscle contraction, tension rises and the skeletal muscle's length changes
Isometric
In this type of muscle contraction, the muscle as a whole does not change length, and the tension produced never exceeds the load
Myofibrils
Inside each muscle fiber, branches of T tubules encircle cylindrical structures called what?
Mitochondria
Most of the muscle's energy is produced where during activities requiring aerobic endurance,
Fast twitch
Most of the skeleton muscles are made up of this type of muscle fiber
Have many nuclei
Skeletal muscle fibers differ from "typical cells" in that these muscle fibers