Muscular System (Questions - EXAM #2) Flashcards
Which muscle type does the muscular system primarily refer to?
The skeletal muscle system.
How do skeletal muscles produce movement?
By contracting.
What are the cells of skeletal muscle called?
Muscle fibers.
What is a fascicle?
A group of muscle fibers.
What is a whole muscle composed of?
A group of fascicles.
What is fascia?
Connective tissue surrounding muscles or other organs.
What does the epimysium surround?
The entire skeletal muscle.
What does the perimysium surround?
Fascicles within the skeletal muscle.
What does the endomysium surround?
Each individual muscle fiber.
How are tendons and aponeuroses related to muscle tissue?
They are extensions of epimysium, perimysium, and endomysium, anchoring muscle to bone or other structures.
What is the difference between a tendon and an aponeurosis?
A tendon is a rope-like bundle, while an aponeurosis is a flat sheet of dense regular connective tissue.
Give an example of a tendon.
The Achilles (calcaneal) tendon.
What is the sarcolemma?
The cell membrane of a muscle fiber.
Give an example of an aponeurosis.
The epicranial aponeurosis of the scalp.
What are T-tubules?
Extensions of the sarcolemma that penetrate deep into the muscle fiber.
What is the sarcoplasm?
The cytoplasm of a muscle fiber.
What are myofibrils?
Intracellular structures within each muscle fiber, composed of sarcomeres.
What proteins form thin myofilaments?
Actin, tropomyosin, and troponin.
What protein forms thick myofilaments?
Myosin.
What structure connects thick myofilaments to Z discs?
Titin.
What are the dark and light bands in a sarcomere called?
The A band (dark) and I band (light).
What is the function of the sarcoplasmic reticulum?
It stores and releases calcium ions, playing a role in muscle
In the biomechanical lever system, what does the bone act as?
The lever
What acts as the fulcrum in the lever system involving muscles?
The joint
What must be greater than resistance for movement to occur in the lever system?
Effort (muscle contraction)
What does the resistance in the lever system represent?
The force that opposes the movement.
What does the origin of a muscle refer to?
The attachment of the tendon to the stationary bone.
What does the insertion of a muscle refer to?
The attachment of the tendon to the movable bone.
What is the function of the agonist in muscle movement?
The agonist is the major muscle responsible for producing the movement.
What role do synergist muscles play?
Synergists help the agonist and prevent undesirable motions.
What is the function of an antagonist muscle?
The antagonist produces the opposite action of the agonist and is inhibited when the agonist contracts.
During flexion of the forearm, which muscle acts as the agonist?
Biceps brachii.
During forearm flexion, which muscle acts as the antagonist?
Triceps brachii.
In forearm flexion, what is the lever, fulcrum, effort, and resistance?
- Lever: radius (insertion of agonist)
- Fulcrum: elbow joint
- Effort: muscle contraction
- Resistance: weight of object plus forearm.
During extension of the forearm, which muscle is the agonist?
Triceps brachii.
During forearm extension, which muscle is the antagonist?
Biceps brachii.
