Biology Human Anatomy & Physiology Flashcards

Which type of muscle tissue is characterized by involuntary control and intercalated discs?

Answer: Cardiac muscle

Cardiac muscle is involuntary, striated, and connected by intercalated discs that allow coordinated contractions.

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

Answer: Right atrium

The SA node, the heart's primary pacemaker, is located in the wall of the right atrium.

Which hormone is primarily responsible for regulating blood calcium levels by stimulating osteoclast activity?

Answer: Parathyroid hormone (PTH)

PTH stimulates osteoclasts to resorb bone, releasing calcium into the bloodstream to raise blood calcium levels.

Which part of the nephron is primarily responsible for the reabsorption of glucose and amino acids?

Answer: Proximal convoluted tubule

The proximal convoluted tubule reabsorbs virtually all filtered glucose and amino acids via active transport.

What is the name of the protective membrane that directly covers the surface of the lungs?

Answer: Visceral pleura

The visceral pleura is the inner layer of the pleural membrane that directly covers the lung surface.

During which phase of the cardiac cycle do the ventricles fill with blood?

Answer: Diastole

During diastole, the ventricles relax and fill with blood from the atria through the open AV valves.

Which WBC type releases histamine and heparin during allergic and inflammatory responses?

Answer: Basophil

Basophils release histamine (promoting vasodilation) and heparin (preventing clotting) during immune responses.