Muscular System mock questions

These flashcards cover key concepts and facts from the muscular system, including functions, anatomy, physiology, and clinical applications.

What is not a major function of the muscular system?

Storing calcium.

What is the connective tissue surrounding a fascicle called?

Perimysium.

What defines the region between two Z-lines?

Sarcomere.

What ability allows a muscle to return to its original length after stretching?

Elasticity.

What is the deltoid muscle a prime mover for?

Arm abduction.

What do we call a muscle whose contraction assists the prime mover?

Synergist.

What is the insertion of a muscle?

Movable attachment.

What type of muscle is the biceps brachii classified as?

Flexor.

List the arrangement of muscle components from largest to smallest.

Muscle → Fascicle → Fiber → Myofibril → Myofilament.

Which muscle type is involuntary and striated?

Cardiac.

What does the sarcoplasmic reticulum store?

Calcium ions.

What does the dark band seen under a microscope correspond to?

A-band.

What happens when calcium binds to troponin?

Tropomyosin shifts, exposing binding sites.

Why is ATP required in muscle contraction?

To detach myosin from actin.

What does the disappearance of the H-zone during contraction mean?

Sarcomeres are fully shortened.

What causes rigor mortis after death?

A lack of ATP.

What is the function of AChE (acetylcholinesterase)?

Break down acetylcholine.

What happens if calcium cannot be pumped back into the SR?

The muscle will stay contracted.

What term describes a muscle’s ability to respond to stimulation?

Excitability.

What function do T-tubules serve?

Conduct impulses deep into the muscle fiber.

What type of muscle contraction does not change length?

Isometric.

During the relaxation phase of a twitch, what happens to calcium?

Calcium is reabsorbed into the SR.

What explains stronger contractions after repeated stimulation?

Treppe.

What does increasing motor unit recruitment do?

Increase contraction strength.

What ensures maximum overlap of actin and myosin in a sarcomere?

Optimal length-tension relationship.

Fast-twitch fibers are best adapted for what type of activity?

Quick, powerful bursts.

What causes smooth, sustained contractions?

Wave summation and recruitment.

What is the condition called when muscle tone is abnormally low?

Hypotonia.

The all-or-none law applies to which structure?

Muscle fibers.

What occurs during eccentric contraction?

Muscle lengthens under tension.

What is the immediate source of energy for muscle contraction?

ATP.

How does creatine phosphate regenerate ATP?

By donating a phosphate to ADP.

What does anaerobic glycolysis lead to?

Lactic acid buildup.

Which system provides energy for the first few seconds of contraction?

Creatine phosphate.

What are runners repaying when breathing heavily after a sprint?

Oxygen debt.

What contributes most to muscle fatigue?

Decreased ATP and pH.

What does hypertrophy result from in muscle tissue?

Larger muscle fibers.

What does endurance training primarily increase?

Mitochondrial density and capillaries.

What happens when a muscle is disused?

Atrophy.

How does testosterone promote muscle growth?

By increasing protein synthesis.

What does calcium bind to in smooth muscle to initiate contraction?

Calmodulin.

What is the primary difference between single-unit and multi-unit smooth muscle?

Interconnectedness via gap junctions.

Which lever type is used when standing on tiptoes?

Second-class.

What lever system is used in the biceps curl?

Third-class.

What is the advantage of third-class levers?

Speed and range of motion.

What does Duchenne muscular dystrophy primarily affect?

Dystrophin.

What does inflammation of the plantar fascia cause?

Heel and arch pain.

What does compression of the median nerve cause?

Carpal tunnel syndrome.

What is likely the cause of pain in the front of a runner's lower leg?

Shin splints.

What type of muscle injury involves internal bleeding without tearing fibers?

Contusion.