Anatomy and Physiology Flashcards

The thoracic duct, the largest lymphatic vessel, drains lymph from all areas EXCEPT which region?

Answer: Right side of the head

The right side of the head, right upper extremity, and right thorax drain into the right lymphatic duct, not the thoracic duct.

Which carpal bone is most commonly fractured and has a high risk of avascular necrosis due to its blood supply?

Answer: Scaphoid

The scaphoid is the most frequently fractured carpal bone, and its retrograde blood supply makes it susceptible to avascular necrosis.

What is the primary function of the nephron loop (loop of Henle) in the kidney?

Answer: Creates an osmotic gradient to concentrate urine

The loop of Henle establishes a concentration gradient in the renal medulla by reabsorbing sodium and chloride, enabling the production of concentrated urine.

Which neurotransmitter is released at the neuromuscular junction to initiate skeletal muscle contraction?

Answer: Acetylcholine

Acetylcholine (ACh) is released by motor neurons at the neuromuscular junction and binds to nicotinic receptors on muscle fibers to trigger contraction.

In anatomical position, which term describes a structure closer to the point of attachment of a limb?

Answer: Proximal

Proximal means closer to the point of origin or attachment, such as the shoulder being proximal to the elbow.

The erector spinae muscle group runs parallel to the vertebral column and primarily performs which action?

Answer: Extension and lateral flexion of the spine

The erector spinae group (iliocostalis, longissimus, spinalis) extends the spine and assists with lateral flexion when contracting unilaterally.

Which part of the brain regulates body temperature, hunger, thirst, and circadian rhythms?

Answer: Hypothalamus

The hypothalamus regulates homeostatic functions including body temperature, hunger, thirst, sleep cycles, and hormone release from the pituitary gland.