Anatomy and Physiology Flashcards

The sinoatrial (SA) node is known as the heart's pacemaker because it:

Answer: Initiates the electrical impulse that triggers each heartbeat

The SA node, located in the right atrium, spontaneously generates electrical impulses at 60–100 times per minute, setting the normal heart rate.

The nephron is the functional unit of which organ?

Answer: Kidney

Each kidney contains approximately one million nephrons, which filter blood, reabsorb nutrients, and produce urine.

Which vitamin is synthesized by the skin upon exposure to ultraviolet B (UVB) radiation?

Answer: Vitamin D

Ultraviolet B radiation converts 7-dehydrocholesterol in the skin to previtamin D3, which is then converted to active vitamin D (calcitriol) in the liver and kidneys.

The function of the cerebellum is primarily to:

Answer: Regulate voluntary movement, coordination, and balance

The cerebellum coordinates voluntary movements, maintains balance and posture, and refines motor skills through feedback from muscles, joints, and the vestibular system.

Which hormone is released by the posterior pituitary and promotes water reabsorption by the kidneys?

Answer: Antidiuretic hormone (ADH/vasopressin)

ADH (antidiuretic hormone, also called vasopressin) is released from the posterior pituitary in response to high blood osmolality, stimulating renal water reabsorption to concentrate urine.

The largest artery in the human body is the:

Answer: Aorta

The aorta is the largest artery, arising from the left ventricle and distributing oxygenated blood to the entire systemic circulation.