Chapter 18 – Blood: Review Flashcards

A comprehensive set of question-and-answer flashcards covering key concepts, structures, functions, and disorders related to blood as presented in Chapter 18 of Saladin’s Anatomy & Physiology text.

What are the three main components of the circulatory system?

Heart, blood vessels, and blood

Which study focuses specifically on blood?

Hematology

Name the three primary functions of the circulatory system.

Transport, protection, and regulation

What is the fluid matrix of blood called?

Plasma

List the seven formed elements found in blood.

Erythrocytes, platelets, neutrophils, eosinophils, basophils, lymphocytes, and monocytes

Which formed element is most abundant in blood?

Erythrocytes (RBCs)

What percentage of whole blood is typically erythrocytes (hematocrit) in men?

42%–52%

Define hematocrit.

The percentage of whole blood volume composed of red blood cells

What does the buffy coat contain after centrifugation?

Leukocytes and platelets

Which plasma protein is most abundant and contributes most to blood osmolarity?

Albumin

Name the three major categories of plasma proteins.

Albumins, globulins, and fibrinogen

What is serum?

Plasma without fibrinogen

What effect does high blood osmolarity have on blood pressure?

It raises blood pressure by causing water absorption into the bloodstream

What causes kwashiorkor in children?

Severe protein (plasma protein) deficiency after weaning, leading to edema and swollen abdomen

Where are all formed elements of blood produced after birth?

Red bone marrow

What stem cell gives rise to all formed elements?

Pluripotent stem cell (PPSC)

Which two principal tasks are performed by erythrocytes?

Transport oxygen from lungs to tissues and carry carbon dioxide from tissues to lungs

Why can erythrocytes not undergo mitosis?

They lack a nucleus and DNA

Which enzyme in RBC cytoplasm aids in CO₂ transport and pH balance?

Carbonic anhydrase (CAH)

How many protein chains are present in adult hemoglobin (HbA)?

Four (two alpha and two beta chains)

What part of hemoglobin binds oxygen?

The iron atom at the center of each heme group

Give normal hemoglobin concentration ranges for adult women.

12–16 g/dL

What hormone from the kidneys stimulates RBC production?

Erythropoietin (EPO)

Name the immediate precursor cell that still contains ribosomal network in erythropoiesis.

Reticulocyte

Which vitamin and mineral are essential cofactors in hemoglobin synthesis besides iron?

Vitamin C and copper

Describe negative feedback in erythrocyte homeostasis.

Hypoxemia → kidneys secrete EPO → bone marrow increases erythropoiesis → RBC count rises → O₂ levels normalize

Where are old erythrocytes primarily destroyed?

Spleen and liver

What pigment is bilirubin derived from?

Biliverdin (from heme breakdown)

Define primary polycythemia.

Cancer of erythropoietic cell line causing very high RBC count and hematocrit (~80%)

List one danger associated with polycythemia.

Increased blood viscosity leading to stroke or heart failure

What is pernicious anemia?

Anemia due to autoimmune destruction of stomach tissue resulting in vitamin B12 deficiency

How does sickle-cell hemoglobin (HbS) differ from normal hemoglobin?

One amino-acid substitution in the beta chain

Why are heterozygotes for sickle-cell disease resistant to malaria?

The altered hemoglobin impairs malaria parasite proliferation in RBCs

Which blood type lacks both A and B antigens?

Type O

What are agglutinins?

Plasma antibodies that bind RBC antigens and cause agglutination

What happens in a mismatched transfusion reaction?

Recipient antibodies agglutinate donor RBCs, blocking vessels and releasing hemoglobin that can cause renal failure

Define universal donor blood type and explain why.

Type O; it lacks A and B antigens on RBCs

Which antigen determines Rh positivity?

D antigen

What drug prevents hemolytic disease of the newborn in Rh- mothers?

RhoGAM

State the normal WBC count range.

5,000–10,000 WBCs/µL

Which leukocyte is most abundant in normal blood?

Neutrophils (60–70%)

Name the leukocyte type that increases during parasitic infections and allergies.

Eosinophils

Which leukocyte secretes histamine and heparin?

Basophils

List two primary functions of lymphocytes.

Coordinate immune responses and secrete antibodies (also destroy abnormal cells)

What cell do monocytes become after leaving the bloodstream?

Macrophages

Define leukopoiesis.

Production of white blood cells

What is leukocytosis?

An abnormally high WBC count (>10,000/µL)

Differentiate myeloid and lymphoid leukemia.

Myeloid leukemia involves uncontrolled granulocyte production; lymphoid leukemia involves lymphocytes/monocytes

What is the normal platelet count?

130,000–400,000 platelets/µL

What cell fragments give rise to platelets?

Megakaryocyte cytoplasmic fragments

List three substances platelets release during plug formation.

Serotonin, ADP, and thromboxane A₂

Name the three major steps of hemostasis.

Vascular spasm, platelet plug formation, and coagulation

Which vasodilator and anticoagulant are secreted by basophils?

Histamine (vasodilator) and heparin (anticoagulant)

What converts fibrinogen into fibrin during coagulation?

Thrombin

Which ion is required for both intrinsic and extrinsic clotting pathways?

Calcium (Ca²⁺)

What is clot retraction?

The process where platelets contract to pull on fibrin strands, tightening the clot within about 30 minutes

Name the enzyme that dissolves fibrin during fibrinolysis.

Plasmin

How does antithrombin prevent inappropriate clotting?

It deactivates thrombin before it can convert fibrinogen

Which genetic disorder is due to factor VIII deficiency?

Hemophilia A

Define thrombosis.

Abnormal clot formation in an unbroken vessel

What is a pulmonary embolism?

A clot that breaks free, travels to, and blocks vessels in the lungs

Which vitamin is necessary for clotting factor synthesis in the liver?

Vitamin K

How does warfarin act as an anticoagulant?

It antagonizes vitamin K, reducing synthesis of clotting factors

What bacterial enzyme can dissolve coronary clots but digests many proteins?

Streptokinase

Which lab test includes hematocrit, hemoglobin concentration, and differential WBC count?

Complete Blood Count (CBC)

Why are albumins critical for blood osmotic pressure?

They are the most abundant plasma proteins and draw water into the bloodstream

What condition is indicated by low neutrophil count (neutropenia)?

Often viral infection or bone marrow suppression

What plasma protein transports copper in blood?

Ceruloplasmin (an α2-globulin)

Which globulin class contains antibodies such as IgG and IgM?

Gamma (γ) globulins

What effect does low blood viscosity have on circulation?

It decreases resistance, causing heart to pump faster and blood pressure to drop

Explain intrinsic coagulation pathway initiation.

Platelet degranulation releases factor XII (Hageman factor), starting the cascade

How does aspirin help prevent thrombosis?

It inhibits thromboxane A₂ synthesis, reducing platelet aggregation