Chapter 19: Cardiovascular System — Blood Flashcards

Comprehensive practice flashcards in question-and-answer format covering Chapter 19: Cardiovascular System — Blood from Seeley's Anatomy & Physiology 12th Edition.

What are the seven main functions of blood in maintaining homeostasis?

1. Transport of gases, nutrients, and waste products; 2. Transport of processed molecules; 3. Transport of regulatory molecules; 4. Regulation of pH and osmosis; 5. Maintenance of body temperature; 6. Protection against foreign substances; 7. Clot formation.

What is the normal pH range of blood maintained by buffers?

$$7.35\text{--}7.45$$

What percentage of blood volume is composed of plasma versus formed elements?

Plasma accounts for $55\%$ and formed elements account for $45\%$ of total blood volume.

What are the average total blood volumes in adult females and males?

Females: approximately $4\text{--}5\,L$; Males: approximately $5\text{--}6\,L$.

Blood makes up approximately what percentage of total body weight?

Approximately $8\%$ of total body weight.

What are the percentages of water and other solutes in blood plasma?

Plasma is composed of $91\%$ water and $9\%$ other solutes (proteins, ions, nutrients, gases, wastes, regulatory substances).

What are the three major plasma proteins, their abundance, and their primary functions?

1. Albumin ($58\%$): regulates water movement (colloid osmotic pressure), transports fatty acids, bilirubin, thyroid hormones; 2. Globulins ($38\%$): transport substances, antibodies (γ-globulins) protect against microorganisms; 3. Fibrinogen ($4\%$): blood clot formation.

How is blood serum defined relative to blood plasma?

Serum is defined as plasma without clotting factors.

What are the specific transport and functional roles of α-globulins, β-globulins, and γ-globulins?

α-globulins transport thyroid hormones, cortisol, sex hormones, lipids, and iron; β-globulins transport iron (transferrin), lipids, complement, and coagulation factors; γ-globulins are mostly antibodies.

What are the normal cell abundance ranges per microliter for red blood cells, white blood cells, and platelets?

Red blood cells: $4.2\text{--}6.1 \times 10^6/\mu L$; White blood cells: $4,500\text{--}11,000/\mu L$; Platelets: $150,000\text{--}400,000/\mu L$.

Where does hematopoiesis occur before and after birth?

After birth, it occurs in red bone marrow. Before birth, it occurs in the yolk sac, liver, thymus, spleen, and lymph nodes.

All formed elements derive from which stem cell, and what two lineages does it divide into?

Hemocytoblasts; they divide into myeloid stem cells (forming RBCs, platelets, neutrophils, eosinophils, basophils, monocytes) and lymphoid stem cells (forming lymphocytes).

What hormone stimulates red blood cell production, and where is it produced?

Erythropoietin (EPO), which is released primarily from the kidneys.

What are the structural dimensions and cellular features of red blood cells (erythrocytes)?

They are biconcave discs with a diameter of $7.5\,\mu m$, and they lack a nucleus.

What are the normal red blood cell counts per microliter for adult males and females?

Males: $4.7\text{--}6.1 \times 10^6/\mu L$; Females: $4.2\text{--}5.4 \times 10^6/\mu L$.

What are the three ways carbon dioxide is transported in blood and their relative percentages?

Dissolved in plasma ($7\%$), bound to hemoglobin ($23\%$), and converted to bicarbonate ions (HCO₃⁻) ($70\%$).

What is the structural makeup of an adult hemoglobin molecule?

It consists of $4$ subunits, where each subunit contains $1$ globin protein chain ($2$ alpha and $2$ beta globins) and $1$ heme group containing $1$ iron (Fe) atom.

How many oxygen molecules can be carried by a single hemoglobin molecule and a single RBC?

Each hemoglobin molecule carries up to $4\,\text{O}_2$ molecules. Each RBC has approximately $280 \times 10^6$ hemoglobin molecules, carrying about $1 \times 10^9\,\text{O}_2$ molecules.

How do embryonic, fetal, and adult hemoglobin differ in globin composition and oxygen affinity?

Embryonic Hb has the earliest globins and highest $\text{O}_2$ affinity; Fetal Hb has $2$ alpha + $2$ gamma globins with a higher affinity than adult Hb; Adult Hb has $2$ alpha + $2$ beta globins (fetal Hb drops to $<2\%$ by $2\text{--}4$ years old).

What are the four functional states of hemoglobin?

Oxyhemoglobin (bound to $\text{O}_2$, bright red), Deoxyhemoglobin (without $\text{O}_2$, dark red), Carbaminohemoglobin (bound to $\text{CO}_2$ at globin), and Carboxyhemoglobin (bound strongly to $\text{CO}$).

How much total iron is in the human body, and how is its intestinal absorption enhanced?

The body contains about $4\,g$ of total iron ($2/3$ associated with Hb). Intestinal absorption is aided by stomach acid and vitamin C, which convert $\text{Fe}^{3+}$ to $\text{Fe}^{2+}$.

What is the genetic mutation and cellular consequence of sickle-cell disease?

An autosomal recessive mutation in the beta globin gene causes RBCs to become sickle-shaped when oxygen levels drop, blocking capillaries and causing tissue damage.

What is the average lifespan of red blood cells in adult males and females?

$120\,\text{days}$ in males and $110\,\text{days}$ in females.

What is the correct sequential developmental pathway of erythropoiesis?

Proerythroblast $\rightarrow$ Early erythroblast $\rightarrow$ Intermediate erythroblast $\rightarrow$ Late erythroblast $\rightarrow$ Reticulocyte $\rightarrow$ Mature RBC.

What are the two major structural categories of white blood cells and their constituent cell types?

Granulocytes (Neutrophils, Eosinophils, Basophils) and Agranulocytes (Lymphocytes, Monocytes).

What are the definitions of ameboid movement, diapedesis, and chemotaxis in WBCs?

Ameboid movement: independent movement using cytoplasmic projections; Diapedesis: squeezing between endothelial cells of vessel walls into tissues; Chemotaxis: movement directed toward infection or foreign material sites.

What are platelets, what cell do they originate from, and what is their lifespan?

Platelets (thrombocytes) are membrane-bound cell fragments containing actin and myosin; they derive from megakaryocytes and have a lifespan of $5\text{--}9\,\text{days}$.

What are the three processes involved in hemostasis?

1. Vascular spasm; 2. Platelet plug formation; 3. Coagulation.

What triggers vascular spasm during hemostasis?

Nervous system reflexes, endothelin released from endothelial cells, and thromboxanes released from platelets.

How do aspirin and Plavix (clopidogrel) interfere with platelet plug formation?

Aspirin inhibits cyclooxygenase (COX), blocking thromboxane synthesis; Plavix blocks ADP receptors on platelets.

How do the extrinsic and intrinsic clotting pathways differ in their activation triggers?

The extrinsic pathway is triggered by damaged tissue outside blood releasing thromboplastin (Factor III); the intrinsic pathway is triggered by chemicals inside blood when Factor XII contacts exposed collagen.

What sequence of reactions occurs in the common pathway of blood coagulation?

Activated Factor X + Factor V + phospholipids + $\text{Ca}^{2+}$ form prothrombinase $\rightarrow$ converts prothrombin to thrombin $\rightarrow$ converts fibrinogen to fibrin $\rightarrow$ thrombin activates Factor XIII to stabilize the clot.

What are the actions of the anticoagulants antithrombin, heparin, prostacyclin, and EDTA?

Antithrombin slowly inactivates thrombin; Heparin works with antithrombin to rapidly inactivate thrombin; Prostacyclin causes vasodilation and inhibits clotting factor release; EDTA binds $\text{Ca}^{2+}$ to prevent clotting in vitro.

How is a blood clot dissolved during fibrinolysis?

Plasmin (formed from inactive plasminogen by thrombin, Factor XII, t-PA, or urokinase) dissolves the fibrin network of the clot.

What is the difference between a thrombus and an embolus?

A thrombus is a clot attached to a blood vessel or heart wall; an embolus is a thrombus that breaks loose and floats freely in the circulation.

What antigens and antibodies are associated with each ABO blood type?

Type A: A antigen, Anti-B antibody; Type B: B antigen, Anti-A antibody; Type AB: A and B antigens, neither antibody; Type O: neither antigen, Anti-A and Anti-B antibodies.

Why is Type O considered the universal donor and Type AB the universal recipient?

Type O RBCs lack A and B antigens so recipient antibodies generally will not react; Type AB plasma lacks Anti-A and Anti-B antibodies so it will not attack donor RBC antigens.

What causes Hemolytic Disease of the Newborn (HDN) and how is it clinically prevented?

HDN occurs when an Rh⁻ mother is sensitized by Rh⁺ fetal blood during a previous pregnancy and her anti-Rh antibodies cross the placenta to hemolyze RBCs of a subsequent Rh⁺ fetus; it is prevented by giving RhoGAM (Rh₀(D) immune globulin) to the mother.

What are the normal reference ranges for Hemoglobin and Hematocrit in adults?

Hemoglobin: Males $14\text{--}17\,g/100\,mL$, Females $12\text{--}15\,g/100\,mL$; Hematocrit: Males $40\text{--}54\%$, Females $38\text{--}47\%$.

What are the normal differential WBC percentages in human blood?

Neutrophils: $55\text{--}70\%$, Lymphocytes: $20\text{--}40\%$, Monocytes: $2\text{--}8\%$, Eosinophils: $1\text{--}4\%$, Basophils: $0.5\text{--}1\%$.

What clinical conditions are indicated by elevated levels of glucose, BUN, bilirubin, and cholesterol?

Elevated glucose indicates insufficient insulin production; elevated BUN indicates reduced kidney function; elevated bilirubin indicates liver dysfunction or hemolysis; elevated cholesterol indicates cardiovascular disease risk.