Muscular System 1.0
Muscular system 2.0
Muscle Physiology 1.0
Muscle Physiology 2.0
Bonus
100

What is the function of skeletal muscles?

Skeletal muscles function in movement, posture maintenance, joint stabilization, and heat production.

100

Define the term 'antagonist' in the context of muscle function.

The antagonist is the muscle that opposes the action of the agonist during muscle contraction.

100

What is the difference between skeletal, cardiac, and smooth muscle tissue?

Skeletal muscle is striated and voluntary, cardiac muscle is striated and involuntary, and smooth muscle is non-striated and involuntary.

100

What is the role of myosin and actin in muscle contraction?

Myosin (thick filaments) and actin (thin filaments) interact to produce muscle contraction. Myosin heads bind to actin and pull it, shortening the sarcomere.

100

What is the role of troponin and tropomyosin in muscle contraction?

Troponin and tropomyosin are regulatory proteins that block or allow the interaction between actin and myosin by controlling the availability of the binding sites on actin.

200

Name and describe the major muscles of the head and neck.

Major muscles include the temporalis (chewing), masseter (closes the jaw), and sternocleidomastoid (neck rotation).

200

How does the name "rectus abdominis" describe the muscle’s appearance?

"Rectus" refers to the straight alignment of the muscle fibers, and "abdominis" refers to its location in the abdomen.

200

Describe the structure of a muscle fiber.

A muscle fiber is a multinucleated cell that contains myofibrils, which are made up of repeating units called sarcomeres.

200

What is the function of the sarcoplasmic reticulum in muscle contraction?

The sarcoplasmic reticulum stores and releases calcium ions, which are necessary for muscle contraction.

200

Describe the function of a motor unit in muscle contraction.

A motor unit consists of a motor neuron and all the muscle fibers it controls, and it is responsible for transmitting nerve signals to initiate muscle contraction.

300

What is the action of the sternocleidomastoid muscle?

The sternocleidomastoid muscle is responsible for rotating the head to the opposite side and flexing the neck.

300

What is the difference between the origin and insertion of a muscle?

The origin is the fixed attachment point of the muscle, while the insertion is the point that moves during muscle contraction.

300

Describe the sequence of events involved in a skeletal muscle fiber action potential.

An action potential is generated when a motor neuron releases acetylcholine at the neuromuscular junction, which causes depolarization of the muscle fiber and triggers the release of calcium ions from the sarcoplasmic reticulum.

300

Explain the sliding-filament mechanism of muscle contraction.

The sliding-filament mechanism involves the myosin heads attaching to actin filaments, pulling them inward, which shortens the sarcomere and causes muscle contraction.

300

What is excitation-contraction coupling and how does it occur in skeletal muscle fibers?

Excitation-contraction coupling is the process where an action potential in a muscle fiber triggers the release of calcium from the sarcoplasmic reticulum, leading to muscle contraction.

400

Identify the muscles responsible for flexion and extension of the elbow.

The biceps brachii is responsible for flexion, and the triceps brachii is responsible for extension of the elbow.

400

What is the primary action of the muscles of the pelvic floor?

The muscles of the pelvic floor support the pelvic organs and help in urinary and bowel control.

400

What ions are involved in the resting membrane potential, and how are they distributed?

Sodium (Na⁺) is more concentrated outside the cell, and potassium (K⁺) is more concentrated inside the cell, which creates the resting membrane potential.

400

What is the difference between glycolytic and oxidative mechanisms for ATP production in muscle fibers?

Glycolysis is an anaerobic process that produces ATP quickly but inefficiently, while oxidative phosphorylation is aerobic, producing more ATP but at a slower rate.

400

How does the structure of cardiac muscle differ from skeletal muscle?

Extra Bonus: give one location of these muscles.

Cardiac muscle is striated, involuntary, and has branched fibers with intercalated discs, whereas skeletal muscle is voluntary and has long, cylindrical fibers without branches.

Extra bonus: Heart and bone.

500

Describe the basic action of the gluteus maximus.

The gluteus maximus primarily extends and laterally rotates the hip.

500

What muscles are involved in moving the pectoral girdle and upper limb?

The trapezius, pectoralis major, deltoid, and latissimus dorsi are key muscles that move the pectoral girdle and upper limbs.

500

Describe the stages of a twitch contraction and how they are affected by the frequency of stimulation.

A twitch consists of a latent period, contraction phase, and relaxation phase. Increased frequency of stimulation leads to summation and stronger contractions.

500

What is the relationship between sarcomere length and tension production?

Maximum tension occurs when the sarcomere is at an optimal length, neither too stretched nor too compressed.

500

Compare and contrast isometric, concentric, and eccentric contractions.

  • Isometric: Muscle contracts but does not change length.
  • Concentric: Muscle shortens while contracting.
  • Eccentric: Muscle lengthens while contracting.