Week 20 / The Circulatory System 1 Flashcards
Question: What are the three basic components of the circulatory system?
Answer:
Blood
The Heart
Blood Vessels
Question: What is the transport medium of the circulatory system?
Answer: Blood.
Question: What materials are carried by blood in the circulatory system? [6]
Oxygen,
carbon dioxide,
nutrients,
electrolytes,
hormones,
and metabolic wastes.
Question: What role does the heart play in the circulatory system?
Answer: The heart serves as a pump, generating cardiac output and pressure gradients needed for blood flow to organs and tissues.
Question: What is the function of blood vessels in the circulatory system?
Answer: Blood vessels form a complex network of conduits that carry blood from the heart to all parts of the body and back to the heart.
Question: What are the main functions of the circulatory system?
[1,3]
Answer: The circulatory system’s main functions are transportation, which includes respiratory, nutritive, and excretory roles.
Question: What is the respiratory role of the circulatory system?
Answer: It transports oxygen (O₂) and carbon dioxide (CO₂).
Question: What is the nutritive role of the circulatory system?
Answer: It carries absorbed products of digestion to the liver, as well as to organs and tissues.
Question: What is the excretory role of the circulatory system?
Answer: It transports metabolic wastes to the kidneys for excretion.
Question: What are the regulatory functions of the circulatory system? [3]
Answer: The regulatory functions include hormonal regulation, homeostasis, and temperature control.
Question: What is the hormonal regulatory role of the circulatory system?
Answer: It carries hormones to target tissues to produce their effects.
Question: How does the circulatory system contribute to homeostasis?
Answer: It helps maintain the internal environment, such as pH and electrolyte balance.
Question: How does the circulatory system regulate body temperature?
Answer: It diverts blood flow to cool or warm the body as needed.
Question: What are the protective functions of the circulatory system?
Answer: The protective functions include haemostasis and immunity.
Question: What is the role of haemostasis in the circulatory system?
Answer: Haemostasis mediates blood clotting to prevent bleeding or haemorrhage.
Question: How does the circulatory system provide immunity?
[what does it carry [2] ]
Answer: It carries leukocytes, cytokines, and complement, which protect against invading pathogens.
Question: What type of tissue is blood classified as?
Answer: Blood is a specialized liquid connective tissue.
Question: What is the main function of blood in the circulatory system?
Answer: It acts as a vehicle for short- and long-range mass transport of materials between cells and between cells and the external environment.
Question: What factors influence total blood volume? [3]
Answer:
Body size
Changes in fluid and electrolyte concentration
Amount of adipose tissue
Question: What percentage of body weight does blood constitute?
Answer: Blood constitutes approximately 8% of body weight.
Question: What is the average blood volume in males and females?
Answer:
Males: 5-6 litres
Females: 4-5 litres
Question: What are the two main components of blood?
Answer: Blood consists of plasma (~55%) and formed or cellular elements (~45%).
Question: What is the composition of plasma in blood?
Answer:
Water: ~92%
Dissolved solutes: Electrolytes (ions), nutrients, hormones, and metabolic wastes
Specialized proteins: ~7%
Question: What is the color and primary composition of plasma?
Answer: Plasma is a straw-colored liquid primarily composed of water (~92%).
Question: What are the formed or cellular elements of blood? [3]
Answer:
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets (thrombocytes)
Question: What is the main function of water in plasma?
Answer: It serves as a transport medium and carries heat.
Question: What is the role of electrolytes in plasma? [3]
Answer:
Maintain membrane excitability.
Regulate osmotic distribution of fluid between ECF (extracellular fluid) and ICF (intracellular fluid).
Buffer pH changes.
Question: What is the role of nutrients, wastes, gases, and hormones in plasma?
Answer: They are transported in the blood, with carbon dioxide playing a role in acid-base balance.
Question: What general function do plasma proteins serve? [2]
Answer:
Exert an osmotic effect important for fluid distribution between the vascular and interstitial compartments.
Buffer pH changes.
Question: What is the specific function of albumins in plasma? [1]
Answer:
Transport many substances.
Contribute most to colloid osmotic pressure
Question: What is the function of alpha and beta globulins in plasma?
[1]
Answer: They transport many water-insoluble substances and include clotting factors and inactive precursor molecules.
Question: What is the function of gamma globulins in plasma?
Answer: They act as antibodies, contributing to immunity.
Question: What is the role of fibrinogen in plasma?
Answer: It serves as an inactive precursor for the fibrin meshwork of a blood clot.
Question: What are the three main types of formed or cellular elements in blood?
Answer:
Red blood cells (erythrocytes)
White blood cells (leukocytes)
Platelets (thrombocytes)
Question: What is the function of erythrocytes (red blood cells, RBCs)?
Answer: Erythrocytes contain hemoglobin and transport oxygen (O₂) to cells.
Question: What is the role of leukocytes (white blood cells, WBCs)?
Answer: Leukocytes are mobile units of the immune defense system, transported in the blood to sites of injury or infection by pathogens.
Question: What is the function of platelets (thrombocytes)?
Answer: Platelets are important in haemostasis, the process that arrests bleeding from injured blood vessels.
Question: What is the shape and structure of erythrocytes (RBCs)?
Answer: Erythrocytes are smooth, round, and flexible biconcave discs that lack nuclei, mitochondria, and most organelles.
Question: What do erythrocytes (RBCs) contain, and what is their function?
Answer: Erythrocytes contain large amounts of hemoglobin, which is responsible for transporting oxygen (O₂) and carbon dioxide (CO₂).
Question: Where are erythrocytes formed?
Answer: Erythrocytes are formed in the red bone marrow.
Question: What stimulates the formation of erythrocytes?
Answer: Erythropoiesis is stimulated by erythropoietin, which is produced in the kidneys.
Question: What is the abundance of erythrocytes in different populations?
Answer:
Males: 5.6-6.2 × 10⁶/µL
Females: 4.2-5.4 × 10⁶/µL
Infants: 5.0-6.5 × 10⁶/µL
Question: What is hemoglobin and what is its main function?
Answer: Hemoglobin is an iron-containing molecule that loosely and reversibly binds to oxygen (O₂), enabling the transport of oxygen in the blood.
Question: How is hemoglobin synthesized and where is it packed?
Answer: Hemoglobin is synthesized and packed into red blood cells (RBCs) during their development.
Question: What is the structure of hemoglobin?
Answer: Hemoglobin is a tetrameric polypeptide complex consisting of two alpha (α) and two beta (β) polypeptide chains (globin moiety) and four iron-containing heme prosthetic groups.
Question: How many oxygen molecules can each hemoglobin molecule carry?
Answer: Each hemoglobin molecule can carry four oxygen (O₂) molecules.
Question: What other roles does hemoglobin play in the body? [2]
Answer: In addition to oxygen transport, hemoglobin contributes to carbon dioxide (CO₂) transport and pH buffering of blood.
Question: How are leukocytes (WBCs) classified?
Answer: Leukocytes are classified into granulocytes (70%) and agranulocytes (30%).
Question: What are the types of agranulocytes, and their percentages in WBC count?
Answer:
Lymphocytes: 25%
Monocytes: 5%
Question: What are the types of granulocytes, and their percentages in WBC count?
Answer:
Neutrophils: 65%
Eosinophils: 4%
Basophils: 1%
Question: What is the primary function of leukocytes (WBCs)?
Answer: Leukocytes primarily function as defense agents, protecting the body against tumors, bacterial, viral, and parasitic infections.
Question: What are the key characteristics of neutrophils? [3]
Multi-lobed nucleus (PMN).
Small purple granules in the cytoplasm.
Short life-span in circulation (6-8 hours).
Question: What is the primary role of neutrophils in the immune system?
Answer: Neutrophils are phagocytic specialists that are the first line of defense against invading microbial pathogens. They ingest or trap and destroy bacteria, scavenge cellular debris, and act to slow and localize infections.
Question: When are neutrophils most active?
Answer: Neutrophils are most active during acute bacterial infections.
Question: How do neutrophils contribute to infection control?
Answer: Neutrophils help by ingesting or trapping and destroying invading pathogens, scavenging cellular debris, and acting to slow and localize infections.
Question: What are the key characteristics of eosinophils? [3]
Answer:
Large, bi-lobed nucleus.
Large red granules in the cytoplasm.
Phagocytic.
Question: What is the primary role of eosinophils in the immune system?
Answer: Eosinophils defend against parasitic infestations by attaching to and secreting substances to kill parasitic worms. They also moderate allergic reactions.
Question: When are eosinophils most active?
Answer: Eosinophils are most active during internal parasitic infestations and allergic conditions (e.g., asthma and hay fever).
Question: What are the key characteristics of basophils? [2]
Answer:
Deeply indented nucleus.
Large, dark blue granules.
Question: What do basophils synthesize, store, and release?
Answer: Basophils synthesize, store, and release histamine and heparin.
Question: What are the major roles of basophils?
Answer: Basophils play major roles in hypersensitivity reactions and infections.
Question: What are the key characteristics of lymphocytes? [3]
Answer:
Large, dark spherical nucleus.
Thin rim of light blue cytoplasm.
Major role in the immune system.
Question: When are lymphocytes most active?
Answer: Lymphocytes are most active during chronic infections.
Question: What are the three major types of lymphocytes, and their roles?
Answer:
B cells: Produce antibodies that target and mark invading bacteria and viruses for destruction (adaptive humoral-mediated immunity).
T cells: Produce lymphokines that directly attack and kill virus-infected or tumor cells (cell-mediated immunity).
Natural killer (NK) cells: Attack and kill virus-infected and/or tumor cells.
Question: What are the key characteristics of monocytes?
Answer:
Large, round/oval or kidney-shaped nucleus.
Abundant agranular cytoplasm.
Question: What is the primary role of monocytes in the immune system?
Answer: Monocytes play a key role in the immune system by being phagocytic, engulfing and killing invading bacteria, activating B and T cells, and scavenging dead pathogens and dust particles.
Question: When are monocytes most active?
Answer: Monocytes are most active during acute infections.
Question: What are platelets (thrombocytes) made of?
Answer: Platelets are granule-rich packages of cytoplasm.
Question: What is the key role of platelets in the circulatory system?
Answer: Platelets help maintain the integrity of the endothelial lining and initiate haemostasis, the process of arresting bleeding.
Question: What substances are found in the granules of platelets?
Answer: Platelet granules contain serotonin (5-HT), calcium (Ca²⁺), enzymes, ADP, and platelet-derived growth factor (PDGF).
Question: What is the lifespan of platelets?
Answer: Platelets have a short lifespan of approximately 7-10 days.
Question: What happens when vascular injury exposes collagen and basement membrane proteins?
Answer: Vascular injury exposes collagen and basement membrane proteins, leading to platelet adhesion, activation, and aggregation.
Question: What do activated and aggregated platelets release, and what is their effect?
Answer: Activated platelets release ADP and thromboxane A₂, which are pro-aggregatory mediators that promote further platelet aggregation.
Question: How do activated platelets contribute to clot formation?
Answer: Activated platelets help trigger thrombin generation, initiating the coagulation cascade, leading to mesh-like fibrin deposition that stabilizes the clot.
