Body Fluids and Circulation

• Chapter 18 discusses Body Fluids and Circulation

Multiple Choice Questions

• Basophils do not exhibit phagocytotic activity
• A significant decrease in platelet count is a common symptom of Dengue fever.
• During each cardiac cycle, the volume of blood pumped out by the right (Rt) and left (Lt) ventricles is the same.
• The sympathetic system stimulates heart rate and stroke volume
• Calcium ions and platelet factors are essential for blood coagulation
• The ECG of a normal healthy individual does not represent repolarization of atria.
• Erythrocytes lack a nucleus in humans
• B-Lymphocytes are involved in antibody production
• The correct sequence of cardiac impulse conduction is SA Node, AV Node, AV Bundle, and Purkinje fiber
• Basophils, Neutrophils, and Eosinophils are involved in inflammatory reactions.
• The second heart sound (dubb) is associated with the closure of semilunar valves
• QRS complex on an electrocardiogram indicates ventricular contraction
• It is incorrect to state that blood group is designated based on the presence of antibodies in the blood plasma.
• Cardiac output can be calculated by multiplying heart rate by stroke volume: 72 beats/minute x 50 ml = 3600 mL
• The correct matching of terms under Column A with their functions under Column B are as follows
  • Lymphatic System: To drain back the tissue fluid to the circulatory system
  • Pulmonary Vein: Carries oxygenated blood
  • Thrombocytes: Coagulation of blood
  • Lymphocytes: Immune Response
• Statement 2 which states action potential generated at the sino-atrial node passes from atria to ventricles, is dependent on action mentioned in Statement 1 which states Atria receive blood from all parts of the body which subsequently flows to ventricles

Very Short Answer Type Questions

• The liquid component of the blood which is viscous and straw colored is called plasma. Plasma without factors is called serum.
• Neutrophils and monocytes are phagocytic cells
• Calcium ions play a significant role in clotting
• One can determine heart beat rate by counting the number of QRS complexes in an ECG.

Short Answer Type Questions

• The vascular connection between the digestive tract and liver is the hepatic portal vein.
• Abnormal conditions related to blood circulation include:
  • Angina pectoris refers to acute chest pain due to failure of O₂ supply to heart muscles
  • Hypertension refers to increased systolic pressure
• Atherosclerosis is a coronary artery disease caused by the narrowing of the lumen of arteries
• Definition of terms:
  • Purkinje fibre: specialized conductive fibers located in the ventricles
  • Bundle of His: a collection of heart muscle cells specialized for electrical conduction that transmits from the AV node to the ventricles
• Functions of blood components:
  • Fibrinogen: involved in blood clotting
  • Globulin: involved in immune responses
  • Neutrophils: phagocytic cells
  • Lymphocytes: involved in immune responses
• Erythroblastosis foetalis is caused by Rh incompatibility between the mother and fetus
• If blood does not coagulate, it can lead to excessive bleeding and impaired wound healing
• The time gap in the passage of action potential from the sino-atrial node to the ventricle ensures coordinated contraction of the atria and ventricles
• In an electrocardiogram (ECG), a higher time taken in the QRS complex may indicate a conduction abnormality in the ventricles, such as bundle branch block.
• The walls of ventricles are thicker than atria because the ventricles need to pump blood to the entire body, requiring more force, while the atria only need to pump blood to the ventricles.
• Differences
  • Blood is a fluid connective tissue containing blood cells, plasma, and platelets, while lymph is a fluid derived from tissue fluid containing white blood cells
  • Basophils release histamine and heparin in inflammatory reactions, while eosinophils are involved in allergic reactions and parasitic infections
  • The tricuspid valve is located between the right atrium and right ventricle, while the bicuspid valve is located between the left atrium and left ventricle
• Anaemia is a condition characterized by a deficiency of red blood cells or hemoglobin in the blood, resulting in pallor and fatigue
• Angina Pectoris is a condition characterized by chest pain due to reduced blood flow to the heart muscle

Short Answer Type Questions Cont.

• The advantage of the complete partition of the ventricle among birds and mammals is that it allows for complete separation of oxygenated and deoxygenated blood, leading to more efficient circulation
• The hepatic portal system is important because it transports nutrients and toxins from the digestive system to the liver for processing and detoxification
• The lymphatic system plays a role in fluid balance, immune response, and absorption of fats
• Differences
  • Plasma contains clotting factors, while serum does not
  • An open circulatory system has blood circulating through open spaces, while a closed circulatory system has blood circulating within vessels
  • The sino-atrial node is the heart's natural pacemaker, initiating the heartbeat, while the atrio-ventricular node delays the impulse from the atria to the ventricles
• Thrombocytes are essential for coagulation of blood because they release factors that initiate the clotting cascade.
• Major sites where RBCs are formed is red bone marrow
• The sino-atrial (SA) node is the part of the heart responsible for initiating and maintaining its rhythmic activity
• In crocodiles, the heart has a foramen of Panizza, which allows for mixing of oxygenated and deoxygenated blood during breath-holding

Long Answer Type Questions

• Rh incompatibility in humans occurs when an Rh-negative mother carries an Rh-positive fetus, leading to the mother producing antibodies against the fetal Rh antigens
• The cardiac cycle involves the events related to blood flow in the heart:
  • Atrial systole (contraction)
  • Ventricular systole
  • Diastole (relaxation).
• Double Circulation refers to the pulmonary and systemic circuits of blood flow
• Blood groups and their compatibility depend on the presence of antigens (A, B, Rh) on red blood cells
• Some short notes:
  • Hypertension is high blood pressure
  • Coronary artery disease is the narrowing or blockage of the coronary arteries, leading to reduced blood flow to the heart muscle
• In the diagrammatic representation of the heart, the components are:
  • Sinoatrial Node (SAN)
  • Atrioventricular Node (AVN)
  • Atrioventricular bundles (AV bundles)
  • Bundle of His
  • Purkinje fibers