Anatomy and Physiology Flashcards

Which of the following is a function of the spleen in the adult human body?

Answer: Filtration of blood and destruction of old red blood cells

The spleen filters blood, removes old or damaged red blood cells, stores platelets, and plays a role in immune surveillance.

The brachial plexus originates from which spinal cord levels?

Answer: C5–T1

The brachial plexus arises from anterior rami of spinal nerves C5 through T1 and innervates the entire upper extremity.

Which muscle is the primary flexor of the elbow and is innervated by the musculocutaneous nerve?

Answer: Biceps brachii

The biceps brachii is the primary elbow flexor, also supinating the forearm; it is innervated by the musculocutaneous nerve (C5–C6).

In the digestive system, where does the majority of chemical digestion and nutrient absorption occur?

Answer: Small intestine

The small intestine, with its villi and microvilli, is the primary site of chemical digestion by enzymes and absorption of nutrients into the bloodstream.

What is the name of the tough fibrous membrane that covers the outer surface of bone, excluding joint surfaces?

Answer: Periosteum

The periosteum is the dense fibrous connective tissue sheath covering the outer surface of bone and contains osteogenic cells essential for bone repair and growth.

Which structure connects the hypothalamus to the posterior pituitary gland and allows direct neural control of hormone release?

Answer: Infundibulum

The infundibulum (pituitary stalk) is the neural connection between the hypothalamus and posterior pituitary, through which axons carry ADH and oxytocin for release.

Which type of receptor detects changes in the length of a muscle and helps regulate muscle tone through the stretch reflex?

Answer: Muscle spindle

Muscle spindles (intrafusal fibers) detect changes in muscle length and send signals to the spinal cord to initiate a stretch reflex, maintaining muscle tone.