ACSM-EP Anatomy & Physiology 2 — Questions and Answers
Question 1: Which muscle fiber type has the highest oxidative capacity and is most resistant to fatigue?
- 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 brachialis muscle inserts on which bone?
- Radial tuberosity
- Coronoid process of ulna (Correct answer)
- Olecranon
- Styloid process of radius
Correct answer: Coronoid process of ulna
The brachialis inserts on the coronoid process and tuberosity of the ulna, making it the primary elbow flexor.
Question 3: During maximal exercise, cardiac output increases primarily due to which factor?
- Increased stroke volume alone
- Increased heart rate alone
- Combined increases in heart rate and stroke volume (Correct answer)
- Decreased peripheral resistance only
Correct answer: Combined increases in heart rate and stroke volume
Cardiac output rises during maximal exercise through simultaneous increases in both heart rate and stroke volume.
Question 4: Which structure in the heart initiates the electrical impulse for each heartbeat?
- Atrioventricular node
- Bundle of His
- Sinoatrial node (Correct answer)
- Purkinje fibers
Correct answer: Sinoatrial node
The sinoatrial (SA) node is the heart's natural pacemaker, spontaneously generating electrical impulses at the highest intrinsic rate.
Question 5: Which joint action occurs at the hip during the concentric phase of a squat ascent?
- Flexion
- Adduction
- Extension (Correct answer)
- Internal rotation
Correct answer: Extension
During squat ascent, the hip moves from a flexed to a more extended position, which is hip extension.
Question 6: The VO2max of an individual is most accurately determined by which measurement?
- Resting heart rate
- Maximal oxygen consumption during graded exercise (Correct answer)
- Blood lactate at rest
- Forced vital capacity
Correct answer: Maximal oxygen consumption during graded exercise
VO2max is defined as the highest rate of oxygen consumption achievable during maximal or exhaustive exercise.
Question 7: Which nerve innervates the diaphragm?
- Vagus nerve (CN X)
- Intercostal nerves
- Phrenic nerve (Correct answer)
- Thoracic spinal nerves T1-T6
Correct answer: Phrenic nerve
The phrenic nerve, originating from cervical spinal levels C3-C5, is the primary motor nerve to the diaphragm.
ACSM-EP Anatomy & Physiology 2
Which muscle fiber type has the highest oxidative capacity and is most resistant to fatigue?