Chapter 19: Blood

This collection of flashcards covers key concepts, functions, and disorders related to blood, as detailed in Chapter 19.

What are the formed elements of blood?

Erythrocytes (red blood cells), leukocytes (white blood cells), and platelets.

What is the function of erythrocytes?

To carry oxygen (O2) and carbon dioxide (CO2).

Describe the shape of erythrocytes.

They have a discoid shape, resembling biconcave discs.

What do leukocytes do?

Protect against pathogens such as bacteria and viruses.

How are leukocytes classified?

Into granulocytes (neutrophils, eosinophils, basophils) and agranulocytes (lymphocytes, monocytes).

What is the function of neutrophils?

They phagocytize bacteria and secrete antimicrobial chemicals.

Describe the appearance of eosinophils.

They have a nucleus usually with two large lobes and large reddish-pink specific granules.

What is the function of eosinophils?

Phagocytize allergens and secrete enzymes that weaken or destroy parasites.

What do basophils secrete?

Histamine (a vasodilator) and heparin (an anticoagulant).

Describe the function of monocytes once they leave the blood.

They differentiate into macrophages and phagocytize pathogens and debris.

What is the primary role of lymphocytes in the immune response?

To destroy cancer cells, cells infected with viruses, and activate other immune cells.

What do B cells do?

They secrete antibodies that fight infection.

How are platelets formed?

Through thrombopoiesis from megakaryoblasts that become megakaryocytes sprouting proplatelet tendrils.

What is the function of platelets in the blood?

Aid in blood clotting, vasoconstriction, and attraction of white blood cells.

What is anemia?

A disorder characterized by decreased oxygen-carrying capacity in the blood.

What can lead to anemia?

Decreased erythropoiesis, decreased hemoglobin synthesis, increased hemolysis, or hemorrhage.

What is polycythemia?

A condition of excessive red blood cells, often seen with cancer of the bone marrow.

What is leukopenia?

A deficiency of white blood cells.

What can cause leukopenia?

Heavy metal poisoning, radiation exposure, or AIDS.

What is leukemia?

A cancer characterized by high white blood cell counts.

What is thrombocytopenia?

A platelet deficiency that can result from various disorders.

How do neutrophils appear under a microscope?

Their nucleus typically has 3–5 lobes arranged in an S- or C-shape.

What is the role of macrophages in the body?

They are large phagocytic cells that help clear pathogens and debris from tissues.

What distinguishes agranulocytes from granulocytes?

Agranulocytes lack visible granules in their cytoplasm, while granulocytes contain them.

What type of immune cells do lymphocytes include?

B cells and T cells.

What is the purpose of heparin secreted by basophils?

To prevent blood clotting and promote the mobility of other white blood cells.

What can happen if there is an excess of hemolysis in the blood?

It can lead to anemia due to the breakdown of red blood cells.

What is formed when megakaryocytes sprout proplatelet tendrils?

Platelets.

Describe the color of cytoplasm in monocytes.

Abundant light violet cytoplasm with sparse, fine, nonspecific granules.

What are phagocytes?

Cells that can engulf and digest pathogens and debris.

Why might a person experience increased bleeding with a platelet disorder?

Due to a deficiency in platelets which are crucial for blood clotting.

What is the significance of immune memory in lymphocytes?

Allows for a quicker and more effective response to pathogens upon re-exposure.