Bio Unit #
A common site on the lower limb for injections is the
Gluteus Maximus
Identify the statement concerning skeletal muscle that is true.
It is responsible for locomotion.
List the following structures in order from smallest to largest.(1) Muscle fiber(2) Myofilament(3) Myofibril(4) Muscle fascicle
2,3,1,4
The capacity of a muscle cell to shorten forcefully is known as
Contractility
If Na+ cannot enter a muscle fiber in response to a stimulus,
Contraction cannot occur
When you "pull your tummy in" and compress your abdomen, you use the rectus abdominis, external abdominal oblique, internal abdominal oblique, and transversus abdominis muscles. This is an example of muscles working as
synergists
Muscles that elevate the jaw and close the mouth include the
temporalis and digastric
Which of the following muscles is part of the rotator cuff
teres major
A sustained muscle contraction is known as
tetanus
Sarcoplasm is the
cytoplasm of a muscle fiber
The adductor longus is named for its
function and size
The largest buttocks muscle is the
gluteus maximus
The biceps femoris is part of the
hamstring muscles
Troponin
has a calcium-binding site.
Raising the eyebrows is the action of the
occipitofrontalis
A sarcomere extends from
one Z disk to an adjacent Z disk
The digastric muscle is involved in
opening, mouth
The brachioradialis is named for its
origin and insertion
The sternocleidomastoid muscle extends from the mastoid process of the temporal bone to the sternum and medial clavicle. When both sternocleidomastoid muscles contract, the head is flexed. The end of the muscle that connects to the sternum is the
originally
Skeletal muscle fibers
possess striations
When an intramuscular injection is given in the anterior aspect of the thigh, the injection is in the
rectus femoris
After contraction has occurred, the Ca2+ are
released from troponin.
Tubules are invaginations of the
sarcolemma
Fascicle
surrounded by perimysium
Arrange the following list of biochemical events in the correct sequence.(1) An action potential is conducted deep into the muscle fiber by the T tubule.(2) Calcium ions bind to troponin.(3) The membranes of the sarcoplasmic reticulum become more permeable to calcium ions.(4) Calcium ions diffuse into the sarcoplasm around the myofibril.(5) The troponin-tropomyosin complex moves exposing active sites.
1,3,4,2,5
The region of the sarcomere that contains both actin and myosin myofilaments is called the
A Band
In which of the following situations does a resting membrane potential exist?
A relaxed Muscle Fiber
Synaptic vesicles in the neuromuscular junction contain
Acetylcholine
Which of the following is part of a thin myofilament?
Actin
A stimulus either causes an action potential or it doesn't. This is called
All or none response
Which of the following statements regarding the sliding filament model is false
Both actin and myosin myofilaments shorten during contraction.
Which of the following statements regarding the sliding filament model is false?
Both actin and myosin myofilaments shorten during contraction.
Acetylcholine is released from the presynaptic terminal by the process of
Exocytosis
Which of the following changes would have the most dramatic effect on the membrane potential?
Increased permeability of the membrane to Na+
Which of the following causes an unequal ion concentration across the resting plasma membrane?
Negatively charged proteins not readily diffusing across the plasma membrane
he type of muscle that functions as a sphincter is
Orbicular
The type of muscle that can contract with the greatest force is the
Pennate
Which of the following muscles is named for its location?
Quadriceps Femoris
Arrange these structures as they participate in excitation-contraction.
Sarcolemma, T tubules, sarcoplasmic reticulum, Ca2+
Which type of muscle tissue is under voluntary neural control?
Skeletal Muscle
The muscle shape that has the capacity to shorten to the greatest degree is
Straight
Which of the following is NOT a property of the myosin head?
They bind to Troponin
Which of the following muscles is named for its shape?
Trapezius
An antagonist
a muscle working in opposition to another muscle
When an action potential reaches the presynaptic terminal,
acetylcholine moves into the presynaptic terminal.
The active sites to which cross-bridges attach are found on the
actin myofilaments
orbicularis oculi muscle
causes crow's feet wrinkles
Muscle myofibrils
contain myosin and actin myofilaments
A myofibril is the
contractile thread that extends the length of the muscle fiber
Facial muscles are unusual in that they
insert and sometimes originate on skin and connective tissue.
Which of the following muscles is involved in chewing gum?
masseter
Synergist
muscle that aids a prime mover in a movement and helps prevent rotation
ATPase is found in
myosin heads
Which of the following is mismatched?
myosin myofilaments - thin myofilaments
At rest, the inside of the sarcolemma is relative to the outside
negatively charged
When the myosin head flexes into a bend, pulling the actin filament along with it, this is called the
power stroke
The orbicularis oris muscle
puckers the mouth for kissing
Too much acetylcholinesterase causes
rapid degradation of acetycholine.
origin
stationary end of muscle
sarcoplasmic reticulum
stores calcium ions
Sarcomeres are
structural and functional unit of skeletal muscle
In order for muscle relaxation to occur,
the active sites on actin must be blocked.
What is a cross bridge?
the combination of myosin heads with active sites on actin molecules
The type of muscle fatigue known as "psychological fatigue" is the result of
the emotional state of an individual
The insertion is
the end that moves when the muscle contracts
The plasma membrane of an excitable cell is more permeable to K+ because
there are more leak ion channels for K+ than Na+.