AK Anatomy & Physiology Fundamentals 3 — Questions and Answers
Question 1: In AK, the psoas muscle weakness is most commonly associated with dysfunction in which organ system?
- Liver and gallbladder
- Kidneys and adrenal glands (Correct answer)
- Heart and small intestine
- Lungs and large intestine
Correct answer: Kidneys and adrenal glands
In the AK organ-muscle relationship framework, the psoas major is associated with the kidneys and adrenal glands.
Question 2: The anterior longitudinal ligament of the spine primarily resists which motion?
- Flexion
- Extension (Correct answer)
- Lateral flexion
- Rotation
Correct answer: Extension
The anterior longitudinal ligament runs along the anterior vertebral bodies and limits hyperextension of the spine.
Question 3: Which type of muscle fiber contracts slowly, is highly resistant to fatigue, and is predominant in postural muscles?
- Type IIb (fast glycolytic)
- Type IIa (fast oxidative)
- Type I (slow oxidative) (Correct answer)
- Type IIx
Correct answer: Type I (slow oxidative)
Type I (slow-twitch) fibers have high oxidative capacity and mitochondrial density, making them ideal for sustained postural activity.
Question 4: A patient presents with weakness of hip abduction. Which muscle is most likely primarily inhibited?
- Tensor fasciae latae
- Gluteus medius (Correct answer)
- Piriformis
- Iliopsoas
Correct answer: Gluteus medius
The gluteus medius is the primary hip abductor and its inhibition is a common clinical finding in AK assessment of pelvic dysfunction.
Question 5: The thoracolumbar fascia plays a critical role in force transfer during lifting because it connects:
- The quadratus lumborum directly to the femur
- The erector spinae to the gluteus maximus via the posterior layer (Correct answer)
- The latissimus dorsi to the diaphragm only
- The iliacus to the psoas at the inguinal ligament
Correct answer: The erector spinae to the gluteus maximus via the posterior layer
The posterior layer of the thoracolumbar fascia allows force transfer between the erector spinae, gluteus maximus, and latissimus dorsi during functional movements.
Question 6: Reciprocal inhibition occurs when contraction of an agonist muscle causes:
- Facilitation of the synergist muscle only
- Inhibition of the direct antagonist via Ia afferent interneurons (Correct answer)
- Co-contraction of agonist and antagonist simultaneously
- Activation of the Golgi tendon organ in the agonist
Correct answer: Inhibition of the direct antagonist via Ia afferent interneurons
Ia afferents from the agonist's muscle spindle synapse on inhibitory interneurons that suppress the antagonist, allowing smooth movement.
Question 7: Which vertebral level corresponds to the origin of the phrenic nerve, which innervates the diaphragm?
- T1–T4
- C3–C5 (Correct answer)
- C6–C8
- T6–T8
Correct answer: C3–C5
The phrenic nerve arises from cervical spinal levels C3, C4, and C5, remembered by the mnemonic 'C3, 4, 5 keep the diaphragm alive.'
AK Anatomy & Physiology Fundamentals 3
In AK, the psoas muscle weakness is most commonly associated with dysfunction in which organ system?