CSCS CSCS: Structure & Function of Body System 2 — Questions and Answers
Question 1: Which type of muscle fiber has the highest oxidative capacity and fatigue resistance?
- Type IIx
- Type IIa
- Type I (Correct answer)
- Type IIb
Correct answer: Type I
Type I (slow-twitch) fibers have the highest mitochondrial density and oxidative enzyme activity, making them highly fatigue resistant.
Question 2: The sinoatrial (SA) node is located in which chamber of the heart?
- Left ventricle
- Right atrium (Correct answer)
- Left atrium
- Right ventricle
Correct 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.
Question 3: Which connective tissue structure connects bone to bone?
- Tendon
- Fascia
- Ligament (Correct answer)
- Aponeurosis
Correct answer: Ligament
Ligaments are dense fibrous connective tissue bands that connect bone to bone and stabilize joints.
Question 4: During intense exercise, lactic acid dissociates into lactate and which ion that contributes to muscle fatigue?
- Sodium (Na+)
- Potassium (K+)
- Hydrogen (H+) (Correct answer)
- Calcium (Ca2+)
Correct answer: Hydrogen (H+)
Lactic acid dissociates into lactate and hydrogen ions (H+); the accumulation of H+ lowers intramuscular pH and impairs contractile function.
Question 5: The primary function of the nephron in the kidney is to:
- Synthesize erythropoietin
- Filter blood and form urine (Correct answer)
- Regulate blood pressure via the SA node
- Produce aldosterone
Correct 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.
Question 6: Which plane of movement divides the body into anterior and posterior halves?
- Sagittal plane
- Transverse plane
- Frontal (coronal) plane (Correct answer)
- Oblique plane
Correct 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.
Question 7: What is the primary role of the sarcoplasmic reticulum in skeletal muscle?
- Producing ATP via oxidative phosphorylation
- Storing and releasing calcium ions (Correct answer)
- Synthesizing actin and myosin proteins
- Transmitting nerve impulses along the muscle fiber
Correct 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.
CSCS CSCS: Structure & Function of Body System 2
Which type of muscle fiber has the highest oxidative capacity and fatigue resistance?