Anatomy And Physiology Practice Test 1 Flashcards

Which layer of the skin contains melanocytes responsible for producing pigment?

Answer: Stratum basale

Melanocytes are located in the stratum basale (deepest layer of the epidermis), where they produce melanin and transfer it to surrounding keratinocytes to provide skin color and UV protection.

The sinoatrial (SA) node is located in which chamber of the heart?

Answer: Right atrium

The SA node is embedded in the wall of the right atrium near the superior vena cava. It initiates the electrical impulse that triggers each heartbeat, earning it the title of the heart's natural pacemaker.

Which hormone is secreted by the posterior pituitary gland to promote water reabsorption in the kidneys?

Answer: Antidiuretic hormone (ADH)

ADH (also called vasopressin) is released from the posterior pituitary and acts on the collecting ducts of the kidney to increase water reabsorption, concentrating the urine and reducing fluid loss.

The process by which white blood cells move out of capillaries into surrounding tissue is called:

Answer: Diapedesis

Diapedesis (also called extravasation) is the process by which leukocytes squeeze through the walls of capillaries to reach the site of infection or injury in surrounding tissues.

Which part of the brain is primarily responsible for coordinating voluntary muscle movements and maintaining balance?

Answer: Cerebellum

The cerebellum, located at the back and bottom of the brain, coordinates fine motor movements, balance, and posture by integrating sensory input and adjusting motor output for smooth, precise actions.

Which type of joint allows the greatest range of motion in multiple directions?

Answer: Ball-and-socket joint

Ball-and-socket joints, such as the hip and shoulder, allow movement in multiple planes including flexion, extension, abduction, adduction, and rotation, making them the most mobile joint type in the body.