Across
- 1. Also known as red blood cells (RBCs), these are biconcave, non-nucleated cells containing hemoglobin, designed for oxygen transport from the lungs to tissues.
- 4. Tiny, thin-walled vessels that connect arterioles to venules, acting as the primary site for the exchange of water, oxygen, nutrients, and waste between blood and tissues.
- 7. The cellular components of blood—red blood cells (erythrocytes), white blood cells (leukocytes), and cell fragments called platelets—which make up about 45% of total blood volume.
- 8. Substances (usually proteins or carbohydrates) that, when introduced into the body, trigger an immune response and the production of antibodies.
- 10. White blood cells (WBCs), which are nucleated cells involved in defending the body against pathogens and immune responses.
- 13. The phase of the cardiac cycle when the heart muscle (ventricles) contracts, pushing blood into the arteries.
- 15. The complete sequence of events—including contraction (systole) and relaxation (diastole)—that occur in the heart during one heartbeat.
- 16. The resistance of a fluid to flow, often described as its "thickness" or "stickiness". Blood is about 4.5–5.5 times more viscous than water, largely due to the presence of blood cells and plasma proteins.
- 17. The straw-colored, liquid portion of the blood that suspends the formed elements, making up about 55% of total blood volume. It is composed of ~92% water, along with electrolytes, nutrients, and proteins like albumin.
- 19. Blood vessels that carry blood away from the heart, typically carrying oxygenated blood (except in the pulmonary circuit).
- 21. The process by which the formed elements of blood are produced, occurring primarily in the red bone marrow.
- 22. The attraction of cells (such as white blood cells) to chemical stimuli, guiding them toward the site of an infection or tissue damage.
Down
- 2. Proteins circulating in the blood plasma—mainly synthesized by the liver—that are activated to initiate the blood clotting process.
- 3. The phase of the cardiac cycle when the heart muscle relaxes, allowing the chambers to fill with blood.
- 5. Also known as thrombocytes, these are cell fragments that play a critical role in blood clotting (hemostasis) to prevent blood loss.
- 6. Blood vessels that carry blood back toward the heart, generally carrying deoxygenated blood (except in the pulmonary circuit).
- 9. The part of the cardiovascular system that carries deoxygenated blood from the right side of the heart to the lungs for oxygenation and back to the left side of the heart.
- 11. The part of the cardiovascular system that carries oxygenated blood from the left side of the heart to all body tissues and returns deoxygenated blood to the right side of the heart.
- 12. The passage of leukocytes (white blood cells) through the pores of blood vessels to enter tissue spaces, commonly occurring during inflammation.
- 14. The physiological process by which the body stops bleeding or blood loss, involving vascular spasm, platelet plug formation, and blood clotting.
- 18. Small branches of arteries that lead to capillaries; they are the primary site of vascular resistance and control blood pressure.
- 20. Very small blood vessels that collect blood from capillaries and join together to form veins