PSIO 202 Exam 2

Multiple Choice

Which of the following correctly describes the sequence of red blood cell (RBC) formation?

• Myeloid stem cell → Reticulocyte → Erythroblast → Proerythroblast → Erythrocyte

• Hematopoietic stem cell → Proerythroblast → Erythroblast → Reticulocyte → Erythrocyte

• Reticulocyte → Erythroblast → Proerythroblast → Erythrocyte

• Hematopoietic stem cell → Myeloid stem cell → Erythrocyte → Reticulocyte

Multiple Choice

What is the primary function of thrombopoietin (TPO)?

• To stimulate white blood cell production

• To stimulate RBC production

• Stimulate platelet formation

• Enhance hemoglobin synthesis

Multiple Choice

During RBC destruction, the heme portion of hemoglobin is broken down into:

• Amino Acids and transferrin

• Iron and biliverdin

• Globulin and amino acids

• Ferritin and bilirubin

Multiple Choice

Which of the following correctly describes the role of cytokines in hematopoiesis?

• They stimulate platelet formation by acting on megakaryocytes.

• They promote RBC precursor proliferation in the bone marrow.

• They regulate WBC production by stimulating interleukins.

• They bind to iron molecules for transport in the bloodstream.

Multiple Choice

Which of the following best describes the fate of bilirubin after RBC destruction?

• It is recycled into new hemoglobin molecules.

• It is stored in the spleen for future RBC synthesis.

• It is excreted as part of bile and contributes to fecal coloration.

• It is reabsorbed into the kidneys and converted into transferrin.

Multiple Choice

Which of the following best describes the common pathway in the coagulation process?

• Activation of vitamin K to synthesize clotting factors

• The conversion of fibrinogen to fibrin and the stabilization of the fibrin network by factor XIII

• The formation of a platelet plug to stop bleeding

• The release of serotonin and ADP to activate platelets

Multiple Choice

What would most likely result from a deficiency in factor VIII?

• Increased risk of excessive clotting

• The inability to form the platelet plug

• Hemophilia, leading to impaired blood clotting

• Excessive fibrinolysis causing premature clot breakdown

Multiple Choice

In which step of hemostasis does the intrinsic pathway primarily become involved?

• Vascular spasm

• Platelet plug formation

• Coagulation, particularly after activation of factor XII

• Fibrinolysis

Multiple Choice

What is the primary function of vitamin K in blood clotting?

• To convert prothrombin into thrombin

• To synthesize clotting factors II, VII, IX, and X in the liver

• To stabilize fibrin threads after clot formation

• To release thromboxane A2 during platelet plug formation

Multiple Choice

What is the primary function of the "end-expiratory lung volume" (EELV)?

• To define the volume of air that mixes with fresh air to regulate oxygen and carbon dioxide levels

• To determine the volume of air in the alveoli during expiration

• To define the amount of air the lungs can hold during forced exhalation

• To measure the total lung capacity

Multiple Choice

Which of the following statements is true about platelet plug formation during hemostasis?

• Platelets are initially attracted to collagen fibers by thrombin.

• Platelets do not stick to the endothelial lining of blood vessels under normal conditions.

• Platelet aggregation prevents the formation of a clot.

• Thrombopoietin is released during platelet plug formation to activate platelets.

Multiple Choice

Which of the following structures is responsible for preventing the collapse of alveoli during exhalation?

• Type I alveolar cells

• Type II alveolar cells

• Pulmonary capillaries

• Alveolar macrophages

Multiple Choice

In which part of the lung does the process of gas exchange (diffusion of O₂ and CO₂) primarily occur?

• Bronchial tree

• Respiratory Bronchioles

• Alveoli

• Terminal Bronchioles

Multiple Choice

What is the primary function of the mucociliary escalator in the bronchial tree?

• To facilitate the exchange of gases between the alveoli and capillaries

• To propel mucus and trapped particles out of the respiratory system

• To provide oxygenated blood to lung tissue

• To regulate the movement of vocal cords during speech

Multiple Choice

Which of the following describes the pressure relationship during inspiration?

• Pleural pressure increases while alveolar pressure remains constant.

• Alveolar pressure decreases while pleural pressure becomes less negative.

• Pleural pressure becomes more positive, pushing air out of the lungs.

• Alveolar pressure is lower than atmospheric pressure, allowing air to flow into the lungs.

Multiple Choice

What effect does emphysema have on lung compliance?

• It decreases lung compliance.

• It increases lung compliance and raises FRC.

• It causes no change in lung compliance.

• It increases lung stiffness, reducing FRC.

Multiple Choice

How is pulmonary ventilation calculated?

• Tidal volume X breathing frequency

• Alveolar ventilation X tidal volume

• Residual volume X breathing frequency

• Tidal volume x lung compliance

Multiple Choice

Which of the following describes the function of the negative pleural pressure during normal breathing?

• It facilitates expiration by raising the intrapulmonary pressure.

• It increases alveolar pressure, pushing air into the lungs.

• It equalizes pressure between the lungs and the atmosphere.

• It prevents the lungs from deflating by "pulling" on the lung tissue.

Multiple Choice

What is the primary cause of carbon monoxide (CO) poisoning?

• CO binds to the hemoglobin heme group 200-250 times more successfully than O2.

• CO displaces oxygen from hemoglobin without binding.

• CO prevents carbon dioxide from being transported in the blood

• CO disrupts the chloride shift, preventing oxygen loading in the lungs.

Multiple Choice

How is most of the carbon dioxide (CO2) transported in the blood?

• As dissolved CO2 in plasma

• Bound to hemoglobin as carbaminohemoglobin

• As bicarbonate ions in plasma

• In the alveoli as CO2 gas for exhalation

Multiple Choice

What is the role of carbonic anhydrase in carbon dioxide transport?

• It increases the rate of CO2 and H2O conversion to carbonic acid.

• It prevents the formation of bicarbonate ions in red blood cells.

• It helps in the conversion of bicarbonate ions back to CO2 in the lungs.

• It accelerates the reverse chloride shift in pulmonary capillaries.

Multiple Choice

What happens during the chloride shift in red blood cells?

• Chloride ions are exchanged with potassium ions to prevent acidity.

• Oxygen binds to hemoglobin and replaces chloride ions.

• Chloride ions leave red blood cells to aid in CO2 loading from tissues.

• Chloride ions enter red blood cells to balance the loss of bicarbonate ions.

Multiple Choice

What is the "transit time" in the pulmonary capillaries, and why is it important?

• It is the time it takes for CO2 to diffuse from the lungs into the bloodstream.

• It refers to the rate at which blood flows through the capillaries, allowing oxygen to diffuse into the blood.

• It is the time it takes for oxygen to reach the tissues from the lungs.

• It is the time required for the reverse chloride shift to occur.