Anatomy & Physiology Fundamentals Flashcards

Which hepatic cells line the sinusoids and function as resident macrophages of the liver?

Answer: Kupffer cells

Kupffer cells are specialized macrophages located in hepatic sinusoids that phagocytose pathogens, debris, and senescent red blood cells.

What is the normal pH range of arterial blood?

Answer: 7.35–7.45

Normal arterial blood pH is 7.35–7.45; values below 7.35 indicate acidosis and above 7.45 indicate alkalosis.

The collecting duct's permeability to water is primarily regulated by which hormone?

Answer: Antidiuretic hormone (ADH)

ADH (vasopressin) inserts aquaporin-2 channels into collecting duct cells, increasing water reabsorption and concentrating urine.

Which clotting factor is known as the 'stable factor' and is synthesized by the liver, activated in both intrinsic and extrinsic pathways?

Answer: Factor X

Factor X (Stuart-Prower factor) is the convergence point of both coagulation pathways, initiating the common pathway to thrombin generation.

Which segment of the small intestine is the primary site for iron absorption?

Answer: Duodenum

The duodenum is the primary site for dietary iron absorption, where the acidic environment from gastric acid keeps iron in the soluble Fe2+ form.

The zona pellucida surrounding the oocyte is primarily composed of which glycoprotein relevant to sperm binding?

Answer: ZP3

ZP3 serves as the primary sperm receptor on the zona pellucida, initiating the acrosome reaction during fertilization.

In the complement system, which component forms the membrane attack complex (MAC) that lyses target cells?

Answer: C5–C9

The MAC is assembled from complement components C5b, C6, C7, C8, and multiple C9 molecules, forming a pore that lyses cells.