Question

question 25 1 pts
mechanical devices that permit the flow of blood in one direction only are called
ventricles.
atria.
valves.
vessels.
question 26 1 pts
_____ is used to determine the volume percentage of red blood cells in whole blood.
spectrin
hematocrit
hematopoiesis
hemocytometer
question 27 1 pts
a glycoprotein hormone that is secreted to increase oxygen concentration in the tissues is
erthropoietin.
hemoglobin.
spectrin.
proerythroblast.

Explanation:

• Question 25: Valves in the circulatory system (like heart valves) ensure unidirectional blood flow. Ventricles are chambers of the heart that pump blood, atria are the upper heart chambers that receive blood, and vessels are the tubes (arteries, veins, capillaries) through which blood flows.
• Question 26: Hematocrit is the test that measures the volume percentage of red - blood cells in whole blood. Spectrin is a protein in red - blood cell membranes, hematopoiesis is the process of blood cell formation, and a hemocytometer is a device for counting cells.
• Question 27: Erythropoietin is a glycoprotein hormone (produced mainly by the kidneys) that stimulates red - blood cell production, thereby increasing oxygen delivery to tissues. Hemoglobin is a protein in red - blood cells that carries oxygen, spectrin is a red - blood cell membrane protein, and a proerythroblast is an early red - blood cell precursor.

Answer:

• Question 25: C. valves
• Question 26: B. Hematocrit
• Question 27: A. erythropoietin