Muscular

Muscle Actions

100

This muscle is the prime mover in elbow flexion.

Biceps brachii

200

This large back muscle helps with arm adduction and extension.

latissimus dorsi 

300

This group of four muscles extends the knee.

Quadriceps femoris

400

This muscle raises the shoulders and extends the neck.

trapezius

500

This rotator cuff muscle initiates shoulder abduction.

Supraspinatus

Muscle Tissue

100

This muscle type has intercalated discs and contracts involuntarily.

Cardiac

200

The cell membrane of a muscle fiber.

sarcolemma

300

Type of muscle that creates peristalsis.

smooth

400

This protein blocks myosin binding sites on actin at rest.

Tropomyosin

500

These cylindrical structures fill most of the cytoplasm in a muscle cell.

myofibrils

Muscle Contraction

100

The neurotransmitter that starts muscle contraction at the neuromuscular junction.

Acetylcholine (ACh)

200

This ion is released from the sarcoplasmic reticulum to initiate contraction.

Calcium

300

ATP is needed to detach this protein head during cross-bridge cycling.

Myosin Head

400

This is the process where the action potential travels along the sarcolemma and T-tubules.

Excitation-contraction coupling

500

Name this part of the contraction process:

1. ADP and inorganic phosphate (Pi) are released from the myosin head.
2. The myosin head pivots and pulls the actin filament toward the center of the sarcomere.
3.This action shortens the overall length of the muscle fiber.

Power Stroke

Disorders

100

This autoimmune disease disrupts ACh receptors, causing muscle weakness.

Myasthenia Gravis

200

A bacterial toxin causes prolonged contraction in this disease.

Tetanus

300

This condition often causes muscle pain and fatigue and is not fully understood.

Fibromyalgia

400

This disease results from a genetic mutation affecting dystrophin in muscle cells.

Duchenne Muscular Dystrophy

500

This rare syndrome involves muscle breakdown that can lead to kidney failure.

Rhabdomyolysis

Misc

100

This molecule provides immediate energy for muscle contraction.

ATP

200

This high-energy molecule helps regenerate ATP quickly in the first 10 seconds of activity.

phosphocreatine

300

Muscles store this carbohydrate to fuel longer-duration activity.

glycogen

400

This system causes lactic acid buildup when oxygen is low.

anaerobic glycolysis

500

This rare, life-threatening condition is triggered by certain anesthetics and causes uncontrolled calcium release in skeletal muscle, leading to rapid muscle breakdown, high fever, and acidosis. It is linked to a mutation in the RYR1 gene.

malignant hyperthermia