CSCS: Structure & Function of Body System Flashcards

Which type of muscle fiber has the highest oxidative capacity and fatigue resistance?

Answer: Type I

Type I (slow-twitch) fibers have the highest mitochondrial density and oxidative enzyme activity, making them highly fatigue resistant.

The sinoatrial (SA) node is located in which chamber of the heart?

Answer: Right atrium

The SA node, the heart's primary pacemaker, is located in the posterior wall of the right atrium near the opening of the superior vena cava.

Which connective tissue structure connects bone to bone?

Answer: Ligament

Ligaments are dense fibrous connective tissue bands that connect bone to bone and stabilize joints.

During intense exercise, lactic acid dissociates into lactate and which ion that contributes to muscle fatigue?

Answer: Hydrogen (H+)

Lactic acid dissociates into lactate and hydrogen ions (H+); the accumulation of H+ lowers intramuscular pH and impairs contractile function.

The primary function of the nephron in the kidney is to:

Answer: Filter blood and form urine

The nephron is the functional unit of the kidney responsible for filtering blood, reabsorbing needed substances, and producing urine.

Which plane of movement divides the body into anterior and posterior halves?

Answer: Frontal (coronal) plane

The frontal (coronal) plane divides the body into anterior (front) and posterior (back) sections and is the plane of abduction and adduction movements.

What is the primary role of the sarcoplasmic reticulum in skeletal muscle?

Answer: Storing and releasing calcium ions

The sarcoplasmic reticulum is a specialized form of endoplasmic reticulum that stores calcium and releases it upon neural stimulation to trigger muscle contraction.