Functions and Components of Blood
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Questions and Answers

What is one of the primary functions of fibrinogens in blood?

  • Facilitating blood clotting (correct)
  • Regulating blood pressure
  • Transporting oxygen
  • Serving as an immune defense
  • Which vitamin is essential for the development of red blood cells?

  • Vitamin A
  • Vitamin D
  • Vitamin C
  • Vitamin B12 (correct)
  • What is the lifespan of platelets in circulation?

  • 30-40 days
  • 8-11 days (correct)
  • 20-30 days
  • 3-5 days
  • What type of white blood cell is primarily responsible for the first response in early inflammation?

    <p>Neutrophil</p> Signup and view all the answers

    Which organ serves as a reserve pool for platelets?

    <p>Spleen</p> Signup and view all the answers

    What is the primary responsibility of erythrocytes?

    <p>Transport oxygen</p> Signup and view all the answers

    Which of the following leukocytes is primarily involved in allergic reactions?

    <p>Eosinophils</p> Signup and view all the answers

    What function does albumin primarily serve in the plasma?

    <p>Maintain oncotic pressure</p> Signup and view all the answers

    What effect can decreased albumin production have on the body?

    <p>Ascites and edema</p> Signup and view all the answers

    Which component of blood is responsible for initiating the immune response?

    <p>Lymphocytes</p> Signup and view all the answers

    What role do platelets play in the circulatory system?

    <p>Aid in blood coagulation</p> Signup and view all the answers

    What is primarily found in the buffy coat of blood?

    <p>Leukocytes and platelets</p> Signup and view all the answers

    What type of globulins are primarily involved in immune defense?

    <p>Immunoglobulins</p> Signup and view all the answers

    What is one of the primary functions of red blood cells in the hematological system?

    <p>Delivery of oxygen</p> Signup and view all the answers

    Which component of blood is responsible for maintaining oncotic pressure?

    <p>Albumin</p> Signup and view all the answers

    Which of the following is NOT a component of plasma?

    <p>Red blood cells</p> Signup and view all the answers

    What is a key role of white blood cells in the hematological system?

    <p>Defense against microorganisms</p> Signup and view all the answers

    Which diagnostic approach is used to identify red blood cell disorders?

    <p>Hemoglobin electrophoresis</p> Signup and view all the answers

    Which factor is NOT considered in the pathophysiology of hematological disorders?

    <p>Psychological stress</p> Signup and view all the answers

    Which component of blood is involved in the clotting process?

    <p>Plasma proteins</p> Signup and view all the answers

    What is the approximate blood volume in adults?

    <p>5.5L</p> Signup and view all the answers

    What is the main site of T cell maturation in the human body?

    <p>Thymus</p> Signup and view all the answers

    What process describes the production of blood cells?

    <p>Hematopoiesis</p> Signup and view all the answers

    Which factor increases the production of leukocytes?

    <p>Presence of pathogens</p> Signup and view all the answers

    Which vitamin is commonly prescribed to pregnant women to prevent anemia?

    <p>Folic acid</p> Signup and view all the answers

    What component is responsible for the oxygen-carrying function of erythrocytes?

    <p>Hemoglobin</p> Signup and view all the answers

    Which organ produces thrombopoietin (TPO), a regulator of platelet levels?

    <p>Liver</p> Signup and view all the answers

    Which of the following is NOT directly associated with the production of erythrocytes?

    <p>Megakaryocytes</p> Signup and view all the answers

    Which part of the body acts as a 'check stop' for immune responses?

    <p>Lymph nodes</p> Signup and view all the answers

    What is the primary function of the clotting factors in hemostasis?

    <p>To form a meshwork of protein strands stabilizing the platelet plug</p> Signup and view all the answers

    Which of the following statements about the aging hematological system is true?

    <p>Platelet adhesiveness may increase with age.</p> Signup and view all the answers

    What triggers the activation of the extrinsic pathway of the clotting cascade?

    <p>Release of tissue factor by damaged endothelial cells</p> Signup and view all the answers

    During hemostasis, what is the first physiological response following vascular injury?

    <p>Vasoconstriction</p> Signup and view all the answers

    What is a primary outcome of fibrinolysis in the clotting process?

    <p>Degradation of fibrin clots</p> Signup and view all the answers

    What role does tissue plasminogen activator (tPA) play in hemostasis?

    <p>Triggers the degradation of fibrin clots</p> Signup and view all the answers

    What percentage of iron is typically lost daily through urine, sweat, and other means?

    <p>Less than 1mg per day</p> Signup and view all the answers

    What is the primary diagnostic use of D-dimer in clinical practice?

    <p>Diagnoses clotting disorders</p> Signup and view all the answers

    What is primarily responsible for the oxygen-carrying function of erythrocytes?

    <p>Hemoglobin</p> Signup and view all the answers

    Which vitamin is essential for erythropoiesis?

    <p>Vitamin B12</p> Signup and view all the answers

    What role do platelets primarily play in hemostasis?

    <p>Blood coagulation</p> Signup and view all the answers

    Which of the following factors is NOT required for the development of red blood cells?

    <p>Calcium</p> Signup and view all the answers

    What type of leukocyte is primarily involved in the immune defense against parasites?

    <p>Eosinophils</p> Signup and view all the answers

    What is the primary site for the maturation of T cells?

    <p>Thymus</p> Signup and view all the answers

    Which hormone stimulates the production and maturation of red blood cells?

    <p>Erythropoietin</p> Signup and view all the answers

    What is the primary role of the spleen in hematological function?

    <p>Phagocytosis of old blood cells</p> Signup and view all the answers

    What is the main component of hemoglobin that binds to oxygen?

    <p>Iron-protoporphyrin complex</p> Signup and view all the answers

    Which factor is likely to increase the production of leukocytes?

    <p>Infection</p> Signup and view all the answers

    What stimulates the release of erythropoietin from the kidneys?

    <p>Tissue hypoxia</p> Signup and view all the answers

    Which of the following is a nutritional requirement for red blood cell and hemoglobin synthesis?

    <p>Folic acid</p> Signup and view all the answers

    Which organ is responsible for the destruction of aging platelets?

    <p>Spleen</p> Signup and view all the answers

    What is the main role of globulins in the blood?

    <p>Act as antibodies and transport proteins.</p> Signup and view all the answers

    How do albumin levels affect overall blood volume?

    <p>Lower levels of albumin decrease blood volume.</p> Signup and view all the answers

    What is the primary function of the buffy coat in blood?

    <p>House platelets and leukocytes.</p> Signup and view all the answers

    Which type of leukocyte is involved in mediating the adaptive immune response?

    <p>Lymphocytes</p> Signup and view all the answers

    What is the consequence of cirrhosis on albumin levels in the body?

    <p>Decreased production of albumin.</p> Signup and view all the answers

    Which type of leukocyte is primarily responsible for combating parasitic infections?

    <p>Eosinophils</p> Signup and view all the answers

    What is the primary physiological role of platelets?

    <p>Facilitate blood coagulation.</p> Signup and view all the answers

    Which of the following is NOT a typical component of the blood?

    <p>Bacteria</p> Signup and view all the answers

    What initiates the intrinsic pathway of the coagulation cascade?

    <p>Contact of factor XII with exposed subendothelial substances</p> Signup and view all the answers

    Which component is primarily responsible for the formation of a blood clot?

    <p>Fibrin</p> Signup and view all the answers

    What is the primary function of the fibrinolytic system after a clot is formed?

    <p>To degrade protein strands in the clot</p> Signup and view all the answers

    What change occurs in the hematological system as one ages?

    <p>Decreased function of lymphocytes</p> Signup and view all the answers

    What is a key characteristic of the hemostatic plug during hemostasis?

    <p>It is formed through platelet-to-platelet interactions.</p> Signup and view all the answers

    What triggers the activation of the coagulation cascade?

    <p>Contact with damaged endothelial cells</p> Signup and view all the answers

    Which group of individuals is characterized by having more atypical lymphocytes due to frequent viral infections?

    <p>Children</p> Signup and view all the answers

    What happens to the size of a clot during the process of fibrinolysis?

    <p>It retracts and decreases.</p> Signup and view all the answers

    What is one of the primary responsibilities of white blood cells in the hematological system?

    <p>Defending against microorganisms and injury</p> Signup and view all the answers

    Which component of blood is primarily responsible for the transport of carbon dioxide?

    <p>Erythrocytes (red blood cells)</p> Signup and view all the answers

    What percentage of blood volume is made up of plasma?

    <p>55%</p> Signup and view all the answers

    Which protein in plasma is primarily responsible for maintaining oncotic pressure?

    <p>Albumin</p> Signup and view all the answers

    What is a common clinical manifestation of anemia?

    <p>Fatigue and weakness</p> Signup and view all the answers

    What role does water play in the composition of blood?

    <p>Serves as a solvent for various blood components</p> Signup and view all the answers

    Which diagnostic test is commonly used to identify disorders related to white blood cells?

    <p>Complete blood count (CBC)</p> Signup and view all the answers

    What is a significant consequence of decreased platelet levels?

    <p>Higher risk of bleeding and bruising</p> Signup and view all the answers

    What is the life cycle duration of erythrocytes in the blood?

    <p>80-120 days</p> Signup and view all the answers

    Which essential component is required for the production of erythrocytes?

    <p>Iron</p> Signup and view all the answers

    Which type of white blood cell is responsible for engulfing and digesting particles?

    <p>Phagocytes</p> Signup and view all the answers

    What primary function do platelets serve in the circulatory system?

    <p>Inducing vasoconstriction</p> Signup and view all the answers

    Which organ serves as a site for the proliferation and differentiation of lymphocytes?

    <p>Spleen</p> Signup and view all the answers

    What is the primary function of albumin in plasma?

    <p>Maintains osmotic pressure</p> Signup and view all the answers

    Which type of leukocyte is primarily responsible for mediating the adaptive immune response?

    <p>Lymphocytes</p> Signup and view all the answers

    What function do white blood cells primarily serve in the hematological system?

    <p>Provide defense against microorganisms and injury</p> Signup and view all the answers

    How do eosinophils participate in immune response?

    <p>Involved in allergic reactions</p> Signup and view all the answers

    Which component of blood primarily helps in maintaining oncotic pressure?

    <p>Albumin</p> Signup and view all the answers

    What is a potential consequence of decreased albumin production in the body?

    <p>Fluid movement into tissues</p> Signup and view all the answers

    Which of the following is a component of plasma involved in clotting?

    <p>Prothrombin</p> Signup and view all the answers

    What percentage of blood volume is typically made up by the buffy coat?

    <p>&lt;2%</p> Signup and view all the answers

    What is the role of basophils in the immune system?

    <p>Release histamine during wound healing</p> Signup and view all the answers

    What is a key factor in the pathophysiology of hematological disorders?

    <p>Reduced oxygen transport capacity</p> Signup and view all the answers

    Which diagnostic test is typically used to identify white blood cell disorders?

    <p>Complete blood count</p> Signup and view all the answers

    Which of the following is a function of globulins in plasma?

    <p>Serve as antibodies and transport proteins</p> Signup and view all the answers

    What complication can arise from disorders affecting platelets?

    <p>Increased risk of bleeding</p> Signup and view all the answers

    What is the impact of excessive loss of albumin due to kidney disease?

    <p>Reduced oncotic pressure and potential edema</p> Signup and view all the answers

    Which type of anemia is characterized by a deficiency of vitamin B12?

    <p>Megaloblastic anemia</p> Signup and view all the answers

    How does the hematological system help maintain acid-base balance?

    <p>Through the action of red blood cells</p> Signup and view all the answers

    What is the primary role of the thymus in the immune system?

    <p>It stores leukocytes and contributes to T cell maturation.</p> Signup and view all the answers

    Which component of the blood is chiefly responsible for the production of thrombopoietin?

    <p>Liver</p> Signup and view all the answers

    What occurs when there is a deficiency of essential vitamins for red blood cell production?

    <p>Slowed production of erythrocytes and potential anemia.</p> Signup and view all the answers

    Which of the following statements about the spleen is false?

    <p>It is primarily responsible for T cell maturation.</p> Signup and view all the answers

    What is erythropoiesis primarily regulated by?

    <p>Erythropoietin produced by the kidneys.</p> Signup and view all the answers

    Which of the following minerals is crucial for hemoglobin synthesis?

    <p>Copper</p> Signup and view all the answers

    What is the role of macrophages in lymph nodes?

    <p>They phagocytize pathogens and dead cells.</p> Signup and view all the answers

    How long do platelets typically circulate before losing their functionality?

    <p>10 days</p> Signup and view all the answers

    What triggers the activation of the intrinsic pathway in the clotting cascade?

    <p>Contact of factor XII with exposed subendothelial substances</p> Signup and view all the answers

    Which component plays a primary role in the formation of the hemostatic plug during hemostasis?

    <p>Platelets</p> Signup and view all the answers

    What is the main function of the fibrinolytic system?

    <p>To break down and dissolve blood clots</p> Signup and view all the answers

    What is a common diagnostic use for D-dimer in clinical practice?

    <p>To assess thrombus formation or breakdown</p> Signup and view all the answers

    Which of the following statements is true regarding the retraction and lysis of blood clots?

    <p>Fibrinolysis reduces clot size and allows for healing to begin</p> Signup and view all the answers

    How does aging affect erythrocyte replacement in the body?

    <p>Erythrocyte replacement occurs at a normal rate despite slower formation</p> Signup and view all the answers

    Which factor contributes to the increase of platelet adhesiveness with age?

    <p>Alterations in vessel wall structure</p> Signup and view all the answers

    What is the significance of petechiae, purpura, and ecchymosis in nursing assessment?

    <p>They result from platelet dysfunction or clotting disorders</p> Signup and view all the answers

    Which of the following clinical manifestations is associated with Benign Prostate Hyperplasia (BPH)?

    <p>Weak stream of urine</p> Signup and view all the answers

    Which treatment option is commonly prescribed for managing Benign Prostate Hyperplasia?

    <p>Tamsulosin</p> Signup and view all the answers

    What is a major risk factor for the development of Benign Prostate Hyperplasia?

    <p>Family history</p> Signup and view all the answers

    Which diagnostic method is primarily used to evaluate prostate health in patients suspected of having BPH?

    <p>Digital rectal examination</p> Signup and view all the answers

    Which of the following is NOT considered a complication of sexually transmitted infections (STIs)?

    <p>Increased aerobic capacity</p> Signup and view all the answers

    What is a primary treatment option available for addressing sexual dysfunction?

    <p>Vasodilators</p> Signup and view all the answers

    Which option accurately describes an inflammation that can occur in conjunction with smegma accumulation?

    <p>Balanitis</p> Signup and view all the answers

    Which type of infection is caused by human papillomavirus (HPV)?

    <p>Viral infection</p> Signup and view all the answers

    What is a key aspect of the management of endometriosis?

    <p>Treatment aimed at preventing progression and alleviating pain</p> Signup and view all the answers

    Which of the following is NOT a common evaluation step in infertility assessment?

    <p>Liver function tests</p> Signup and view all the answers

    What is the primary treatment method for urethral strictures?

    <p>Surgical urethral dilation</p> Signup and view all the answers

    Which cause is most commonly associated with urethritis?

    <p>Sexually transmitted infections</p> Signup and view all the answers

    Which treatment option is least likely to be applied for managing pelvic organ prolapse?

    <p>Immediate surgery</p> Signup and view all the answers

    What is the hallmark symptom of endometriosis?

    <p>Dyschezia (pain on defecation)</p> Signup and view all the answers

    Common risk factors for infertility in women include all of the following EXCEPT:

    <p>Excessive exercise</p> Signup and view all the answers

    In which group is secondary amenorrhea most frequently observed?

    <p>Women with hyperprolactinemia</p> Signup and view all the answers

    What is a characteristic symptom of urethral strictures?

    <p>Diminished urine flow and dribbling</p> Signup and view all the answers

    What is one of the primary symptoms of pelvic inflammatory disease (PID)?

    <p>Sudden severe abdominal pain with fever</p> Signup and view all the answers

    Which of the following reproductive health issues is primarily associated with obesity?

    <p>Polycystic Ovary Syndrome (PCOS)</p> Signup and view all the answers

    Which diagnostic method is most commonly used to evaluate the patency of the fallopian tubes in infertility assessment?

    <p>Hysterosalpingography</p> Signup and view all the answers

    Which symptom would most likely indicate a urethral stricture?

    <p>Weak flow of urine</p> Signup and view all the answers

    Which of the following is a common treatment for urethritis?

    <p>Antibiotic therapy</p> Signup and view all the answers

    Study Notes

    Functions of the Hematological System

    • Blood ensures delivery of substances crucial for cellular metabolism, including oxygen via red blood cells.
    • It removes waste products of metabolism, such as carbon dioxide.
    • Blood also plays a vital role in defense against microorganisms and injuries through white blood cells.
    • It helps maintain acid-base balance and facilitates blood clotting through clotting factors and platelets.

    Components of Blood

    • Blood volume in adults is approximately 5.5 liters.
    • Plasma comprises 55% of blood and contains proteins, water, and solutes.
    • Cellular components, making up 45% of blood, include erythrocytes (red blood cells), platelets, and leukocytes.

    Plasma Proteins

    • Albumin, the major component of plasma osmotic pressure, functions as a carrier molecule and plays a crucial role in maintaining oncotic pressure.
    • Globulins include antibodies and transport proteins, carrying proteins and immunoglobulins.
    • Fibrinogens are essential for blood clotting.
    • Other plasma proteins have various roles, including α-1-antitrypsin, coagulation factors, and more.

    Cellular Components

    Erythrocytes (Red Blood Cells)

    • Erythrocytes are the most abundant blood cells, produced in the bone marrow (erythropoiesis) and have a lifespan of 80-120 days.
    • Responsible for tissue oxygenation, their biconcave shape allows for reversible deformation, facilitating passage through microcirculation.
    • Hemoglobin, responsible for carrying oxygen, is essential for this function.
    • Red blood cell development requires vitamin B12, folic acid, copper, cobalt, and, most importantly, iron.

    Leukocytes (White Blood Cells)

    • Leukocytes are essential for immune defense, categorized into granulocytes and agranulocytes.
    • Granulocytes include neutrophils (first responders in inflammation), eosinophils (ingesting antibodies), and basophils (containing histamine).
    • Agranulocytes include phagocytes (cells engulfing and digesting particles) and immunocytes (immunocytes create immunity, primarily lymphocytes).

    Platelets (Thrombocytes)

    • Platelets are essential for blood coagulation and control of bleeding, inducing vasoconstriction.
    • They change shape to conform to the injured site, forming a platelet plug.
    • Platelets activate the coagulation cascade to stabilize the plug and initiate repair processes including clot retraction and clot dissolution, known as fibrinolysis.
    • The spleen serves as a reserve pool for platelets, and platelets typically live for 8-11 days before being removed by macrophages, primarily in the spleen.
    • Normal platelet concentration ranges from 150 to 400 x 10^9/L.

    Lymphoid Organs

    • Lymphoid organs, connected to the circulatory system, are crucial for residence, proliferation, and differentiation of lymphocytes and phagocytes.

    Primary Lymphoid Organs

    • The thymus is responsible for the maturation of T-cells.
    • Bone marrow is where both T-cells and B-cells are produced.

    Secondary Lymphoid Organs

    • The spleen serves as a blood reserve and is involved in the phagocytosis of old blood cells.
    • Lymph nodes act as "check stops" for immunity, housing macrophages.

    Development of Blood Cells

    • Hematopoiesis, the process of blood cell production, primarily occurs in the bone marrow.
    • Bone marrow is found in the cavities of bones, but not all bones have active marrow.
    • Stem cells differentiate to generate erythrocytes, leukocytes, and platelets.

    Development of Platelets & WBCs

    Platelets

    • Platelets are fragments of megakaryocytes, produced in the bone marrow.
    • Platelet levels are regulated by thrombopoietin (TPO), produced by the liver.
    • Platelets circulate for 10 days before losing functionality.
    • The spleen sequesters and destroys aging platelets through phagocytosis.

    WBCs

    • Leukocytes originate from stem cells within the bone marrow and are stored in the thymus and lymph nodes.
    • Leukocyte production increases during infections, steroid presence, or reduced bone marrow reserves.

    Development of RBCs

    • Erythropoiesis, the production of red blood cells, occurs in the bone marrow.
    • Erythrocytes develop from erythroblasts within the bone marrow, with maturation stimulated by erythropoietin (EPO).
    • Erythropoietin production is regulated by a feedback loop; in cases of tissue hypoxia, the kidney increases erythropoietin production, leading to enhanced red blood cell production and release from the bone marrow.

    Hemoglobin Synthesis

    • Hemoglobin, the oxygen-carrying protein of the erythrocyte, comprises two pairs (alpha and beta) of polypeptide chains (globins) and four iron-protoporphyrin complexes (heme).
    • Each heme molecule carries one molecule of oxygen.

    Nutritional Requirements for RBCs & Hgb

    • Proteins: Amino acids are crucial for hemoglobin synthesis.
    • Vitamins: Vitamins B12, B6, B2, E, and C, folate, pantothenic acid, and niacin are all vital for red blood cell formation. Folate deficiencies are common and can be remedied through supplementation, particularly for pregnant women, as folate demands increase during pregnancy.
    • Minerals: Iron is required for hemoglobin synthesis, and copper plays a supporting role in iron metabolism.

    Iron Cycle

    • Total body iron is bound to heme or muscle cells or stored bound to ferritin.
    • Daily iron loss is minimal, around 1 mg (3%), lost through urine, sweat, bile, and epithelial cells or via the gut.
    • Iron is recycled from aged, abnormal, or damaged red blood cells.

    Mechanisms of Hemostasis

    • Hemostasis refers to the arrest of bleeding.
    • Platelets, clotting factors, and the vasculature are components of hemostasis.

    Sequence of Hemostasis

    1. Vascular injury triggers vasoconstriction, reducing blood flow.
    2. Platelet-to-platelet interactions form a hemostatic plug.
    3. The coagulation cascade, also known as clotting, is activated, forming fibrin clots.
    4. Fibrinolysis is activated to limit clot size and initiate healing.

    Function of Clotting Factors

    • Blood clots are meshwork of protein strands that stabilize the platelet plug and trap other cells, such as erythrocytes and phagocytes, which remove any microorganisms that may have entered.
    • The protein strands are made of fibrin, produced by the clotting (coagulation) system.
    • Initiation triggers the clotting cascade, known as secondary hemostasis.
    • Two pathways exist - the intrinsic pathway, activated by factor XII contact with subendothelial substances exposed by vascular injury, and the extrinsic pathway, activated by tissue factor (TF) release from damaged endothelial cells.

    Retraction and Lysis of Blood Clots

    • After clot formation, clot retraction, or solidification, occurs.
    • Lysis (breakdown) of blood clots is achieved by the fibrinolytic system.
    • Tissue plasminogen activator (tPA) triggers fibrin clot degradation.
    • Fibrin degradation products, such as D-dimer, are used to diagnose conditions like deep vein thrombosis (DVT).

    Age and the Hematological System

    Pediatrics

    • Blood cell counts are higher at birth than in adults due to the trauma of birth and umbilical cord cutting.
    • Children often have more atypical lymphocytes due to frequent viral infections.

    Geriatrics

    • Erythrocyte life span remains normal, but replacement is slower. Iron depletion, decreased total serum iron, iron-binding capacity, and intestinal iron absorption are common.
    • Lymphocyte function diminishes with age.
    • Platelet adhesiveness may potentially increase with age.

    Functions of the Hematological System

    • Ensures delivery of substances needed for cell metabolism, removes waste products, protects against microorganisms and injury, maintains acid-base balance and participates in blood clotting.
    • Oxygen is delivered by red blood cells.
    • Carbon dioxide is removed as a waste product.
    • White blood cells are responsible for immune defense.
    • Clotting factors and platelets are involved in hemostasis.

    Components of Blood

    • Blood volume in adults is about 5.5 liters.
    • Plasma (55%): Composed of proteins, water, and other solutes.
      • Proteins: Albumin (maintains oncotic pressure), globulins (contain antibodies), fibrinogen and prothrombin (involved in clotting).
      • Water: Acts as a solvent for various components.
      • Other Solutes: Electrolytes for osmotic pressure, waste products for excretion.
    • Cellular Components (45%): Includes erythrocytes (RBC), platelets, and leukocytes.
      • Erythrocytes (RBC): Transport oxygen throughout the body.
      • Buffy Coat (<2%): Contains platelets and leukocytes.
        • Platelets: Essential for coagulation and bleeding control.
        • Leukocytes: Fight against microorganisms.
          • Neutrophils: First responders in inflammation.
          • Eosinophils: Respond to allergies and parasitic infections.
          • Basophils: Release histamine during wound healing.
          • Lymphocytes: Mediate adaptive immune response.
          • Monocytes: Involved in phagocytosis.

    Plasma Proteins

    • Albumin: Maintains plasma oncotic pressure, carries molecules, and draws fluid back into the intravascular space. Low levels can lead to edema and ascites.
    • Globulins: Transport proteins and antibodies.
    • Fibrinogens: Involved in blood clotting.
    • Other: Perform various roles, including α-1-antitrypsin and coagulation factors.

    Cellular Components

    Erythrocytes (Red Blood Cells)

    • Most abundant cells in blood.
    • Produced in bone marrow (erythropoiesis).
    • Life cycle is 80-120 days.
    • Responsible for tissue oxygenation.
      • Hemoglobin carries the gases.
    • Biconcave shape allows for reversible deformation (torpedo-like) for microcirculation.

    Leukocytes (White Blood Cells)

    • Immune defense!
    • Granulocytes:
      • Neutrophils: First responders for early inflammation.
      • Eosinophils: Ingest antibodies.
      • Basophils: Contain histamine.
      • Mast Cells: Released during wound healing.
    • Agranulocytes:
      • Phagocytes: Engulf and digest particles in the immune response.
      • Immunocytes: Create immunity (Lymphocytes).

    Platelets (Thrombocytes)

    • Essential for blood coagulation and control of bleeding.
    • Induce vasoconstriction.
    • Change shape to conform to the injured site (platelet plug).
    • Activate the coagulation cascade to stabilize the plug.
    • Initiate repair processes including clot retraction and dissolution (fibrinolysis).
    • The spleen acts as a reserve pool for platelets.
    • Platelets have a lifespan of 8-11 days before being removed by macrophages, usually in the spleen.
    • Normal concentration: 150-400 x 10°/L.

    Lymphoid Organs

    • Lymphoid system is connected with circulatory system via lymphoid organs.
    • Sites for residence, proliferation, and differentiation of lymphocytes and phagocytes.

    Primary Lymphoid Organs

    • Thymus: T cell maturation.
    • Bone Marrow: Production of T and B cells.

    Secondary Lymphoid Organs

    • Spleen: Blood reserve, phagocytosis of old blood cells.
    • Lymph Nodes: Immune checkpoints, harbor macrophages.

    Development of Blood Cells

    • Hematopoiesis: Blood cell production occurring in bone marrow.
    • Bone marrow is found in bone cavities, not all bones have active marrow.
    • Cellular differentiation creates erythrocytes, leukocytes, and platelets from stem cells.

    Development of Platelets and WBCs

    Platelets

    • Fragments of megakaryocytes produced in bone marrow.
    • Platelet levels are regulated by thrombopoietin (TPO) produced in the liver.
    • Platelets circulate for 10 days before becoming functionally inactive.
    • The spleen sequesters and destroys aging platelets through phagocytosis.

    WBCs

    • Arise from stem cells in bone marrow.
    • Stored in thymus and lymph nodes.
    • Production increases in infection, with steroid presence, or reduced bone marrow reserves.

    Development of RBCs

    • Erythropoiesis: Development of RBCs.
    • Erythrocytes originate from erythroblasts in bone marrow and mature stimulated by erythropoietin (EPO).
    • Controlled by a feedback loop.
    • In tissue hypoxia, erythropoietin is stimulated by the kidney.
    • Erythropoietin increases red blood cell production and release from bone marrow.

    Hemoglobin Synthesis

    • Hemoglobin: Oxygen-carrying protein of the erythrocyte.
    • Two pairs of polypeptide chains (Globins): α and β.
    • Four iron-protoporphyrin complexes (Heme): Each heme carries one oxygen molecule.

    Nutritional Requirements for RBCs and Hemoglobin

    • Proteins: Amino acids.
    • Vitamins: B12, B6, B2, E, and C, folic acid, pantothenic acid, and niacin.
      • Folate deficiency is common and develops rapidly. Supplements are prescribed to pregnant women to avoid anemia and neural tube defects in the baby.
    • Minerals: Iron (for hemoglobin) and copper.

    Iron Cycle

    • Total body iron is bound to heme, muscle cells, or stored with ferritin.
    • Less than 1 mg of iron is lost daily through urine, sweat, bile, and epithelial cells or from the gut.
    • Iron is recycled from old, abnormal, or damaged RBCs.

    Mechanisms of Hemostasis

    • Hemostasis: Arrest of bleeding.
    • Components: platelets, clotting factors, and vasculature.

    Sequence of Hemostasis

    1. Vascular injury: Vasoconstriction limits blood flow.
    2. Platelet-to-platelet interactions: Formation of a hemostatic plug (platelet plug).
    3. Coagulation: Activation of the coagulation cascade to form fibrin clots.
    4. Fibrinolysis: Activation to limit clot size and begin healing process (dissolution).

    Function of Clotting Factors

    • Blood Clot: A meshwork of protein strands that stabilizes the platelet plug and traps other cells like erythrocytes and phagocytes.
    • Fibrin: Protein strands produced by the clotting (coagulation) system.
    • Coagulation Cascade: Initiates the clotting process.
      • Intrinsic Pathway: Activated when factor XII (Hageman factor) contacts subendothelial substances exposed by vascular injury.
      • Extrinsic Pathway: Activated when tissue factor (TF) (tissue thromboplastin) is released from damaged endothelial cells.

    Retraction and Lysis of Blood Clots

    • Clot Retraction: Clot solidifies after formation.
    • Fibrinolysis: Breakdown of blood clots by the fibrinolytic system.
      • Tissue Plasminogen Activator (tPA): Triggers fibrin clot degradation.
      • Fibrin Degradation Products: Include D-dimer.
      • D-dimer: Diagnostic marker for blood clots.

    Age and the Hematological System

    Pediatrics

    • Blood cell counts are higher than in adults at birth due to trauma of birth and umbilical cord cutting.
    • Children have more atypical lymphocytes due to frequent viral infections.

    Geriatrics

    • Erythrocyte life span is normal, but replacement is slower.
      • Iron depletion: Decreased total serum iron, iron-binding capacity, and intestinal iron absorption.
    • Lymphocyte function decreases with age.
    • Platelet adhesiveness may increase with age.

    Functions of the Hematological System

    • Blood circulation delivers nutrients and removes waste products.
    • Red blood cells carry oxygen.
    • White blood cells fight against microorganisms and injury.
    • Blood clotting factors and platelets help with hemostasis (stopping bleeding).
    • Acid-base balance is maintained by the hematological system.

    Components of Blood

    • Blood volume: 5.5 liters in adults.
    • Plasma (55%): Contains proteins like albumin, globulins, fibrinogen, and prothrombin, water, and other solutes like ions and waste products.
    • Cellular Components (45%): Contains erythrocytes (RBCs), platelets, and leukocytes.
      • Erythrocytes (RBCs): Transport oxygen throughout the body.
      • Buffy Coat (<2%): Composed of platelets and leukocytes.
        • Platelets: Essential for blood coagulation and control of bleeding.
        • Leukocytes: Fight against microorganisms.
          • Neutrophils: First responders for early inflammation.
          • Eosinophils: Involved in allergic reactions and parasitic infections.
          • Basophils: Contain histamine and are released during wound healing.
          • Lymphocytes: Mediate the adaptive immune response.
          • Monocytes: Involved in phagocytosis.

    Plasma Proteins

    • Albumin: Maintains oncotic pressure, acts as a carrier molecule, and draws fluid back into the intravascular space.
    • Globulins: Include antibodies (immunoglobulins) and transport proteins.
    • Fibrinogens: Functions in blood clotting.
    • Other: Includes α-1-antitrypsin, coagulation factors, etc., and have various roles in the body.
    • Plasma protein functions include clotting, defense, transport, and regulation.

    Cellular Components

    Erythrocytes (Red Blood Cells)

    • Most abundant cells in the blood, produced in bone marrow (erythropoiesis).
    • Life cycle of 80-120 days.
    • Transport oxygen through hemoglobin (Hb).
    • Biconcave shape allows for deformability for passage through microcirculation.
    • Development requires vitamin B12, folic acid, copper, cobalt, and iron.

    Leukocytes (White Blood Cells)

    • Immune defense.
    • Granulocytes:
      • Neutrophils: First responders in early inflammation
      • Eosinophils: Ingest antibodies
      • Basophils: Contain histamine
      • Mast Cells: Released during wound healing.
    • Agranulocytes:
      • Phagocytes: Engulf and digest particles as part of the immune response.
      • Immunocytes: Create immunity (Lymphocytes).

    Platelets (Thrombocytes)

    • Essential for blood coagulation and control of bleeding.
    • Initiate vasoconstriction.
    • Change shape to form a platelet plug at injury sites.
    • Activate the coagulation cascade to stabilize the plug.
    • Initiate repair processes including clot retraction and dissolution (fibrinolysis).
    • Spleen acts as a reserve pool for platelets.
    • Life cycle of 8-11 days, removed by macrophages.
    • Normal concentration of 150-400 x 10^9/L.

    Lymphoid Organs

    • Lymphoid organs are sites for lymphocyte and phagocyte residence, proliferation, and differentiation.

    Primary Lymphoid Organs

    • Thymus: Maturation of T cells.
    • Bone Marrow: Production of T and B cells.

    Secondary Lymphoid Organs

    • Spleen: Blood reserve; phagocytosis of old blood cells.
    • Lymph Nodes: Checkpoints for immunity, residence of macrophages.

    Development of Blood Cells

    • Hematopoiesis: Production of blood cells in the bone marrow.
    • Bone marrow found in cavities of bones.
    • Differentiation of cells from stem cells to create erythrocytes, leukocytes, and platelets.

    Development of Platelets and White Blood Cells

    Platelets

    • Fragments of megakaryocytes, produced in bone marrow.
    • Levels regulated by thrombopoietin (TPO) produced by the liver.
    • Circulate for 10 days before losing functionality.
    • Spleen sequesters and destroys aging platelets.

    White Blood Cells

    • Arise from stem cells in the bone marrow.
    • Stored in the thymus and lymph nodes.
    • Production increases in infection, presence of steroids, and reduced bone marrow reserves.

    Development of Red Blood Cells

    • Erythropoiesis: Development of RBCs.
    • Erythrocytes derived from erythroblasts in bone marrow, stimulated by erythropoietin (EPO).
    • Erythropoietin production is controlled by a feedback loop. Hypoxia stimulates EPO production by the kidney.
    • EPO increases RBC production and release from bone marrow.

    Hemoglobin Synthesis

    • Hemoglobin: Oxygen-carrying protein of the erythrocyte.
    • Contains two pairs (alpha & beta) of polypeptide chains (globins) and four iron-protoporphyrin complexes (heme).
    • Each heme molecule carries one molecule of oxygen.

    Iron Cycle

    • Total body iron is bound to heme, muscle cells, or stored bound to ferritin.
    • Less than 1 mg per day is lost through urine, sweat, bile, epithelial cells, or the gut.
    • Iron is recycled from aged, abnormal, or damaged RBCs.

    Mechanisms of Hemostasis

    • Hemostasis: Arrest of bleeding.
    • Components: Platelets, clotting factors, and vasculature.

    Sequence of Hemostasis

    1. Vascular injury: Vasoconstriction limits blood flow.
    2. Platelet-to-platelet interactions: Form a hemostatic plug.
    3. Coagulation cascade: Activated to form fibrin clots.
    4. Fibrinolysis: Activated to limit clot size (retraction) and begin healing (dissolution).

    Function of Clotting Factors

    • Blood clot: Meshwork of protein strands that stabilizes the platelet plug and traps cells.
    • Fibrin: Protein strands produced by the clotting system (coagulation).
    • Coagulation cascade: Initiated by vascular injury.
    • Intrinsic pathway: Activated when factor XII (Hageman factor) contacts exposed subendothelial substances.
    • Extrinsic pathway: Activated when tissue factor (TF) (tissue thromboplastin) is released by damaged cells.

    Retraction and Lysis of Blood Clots

    • Clot retraction: Solidifies the clot.
    • Fibrinolytic system: Breaks down blood clots through fibrinolysis.
    • Tissue plasminogen activator (tPA): Triggers fibrin clot degradation.
    • Fibrin degradation products include D-dimer.
    • D-dimer can be used to diagnose conditions related to blood clots.

    Age and the Hematological System

    Pediatrics

    • Blood cell counts are higher at birth (due to birth trauma and umbilical cord cutting).
    • Children have more atypical lymphocytes due to frequent viral infections.

    Geriatrics

    • Erythrocyte lifespan is normal but replacement is slower.
      • Iron depletion
      • Decreased total serum iron, iron-binding capacity, and intestinal iron absorption.
    • Lymphocyte function decreases with age.
    • Platelet adhesiveness increases with age.

    Balanitis

    • Inflammation of the glans penis
    • Usually associated with inflammation of the prepuce
    • Related to smegma accumulation

    Benign Prostate Hyperplasia (BPH)

    • Enlarged prostate gland
    • Compresses urethra
    • Risks include family history and obesity
    • FUNWISE clinical manifestations:
      • Frequency
      • Urgency
      • Nocturia
      • Weak stream
      • Intermittency (stop/start)
      • Straining
      • Emptying (do they feel empty after voiding?)
    • Diagnosis involves digital rectal examination, prostate-specific antigen (PSA) measurement, and transurethral ultrasound
    • Treatment includes medications like tamsulosin and education (double voiding, fluid restriction before bed, reducing consumption of mild diuretics like caffeine and alcohol)

    Sexual Dysfunction

    • Impairment of any or all stages of male sexual response (erection, emission, and ejaculation)
    • Causes:
      • Vascular, endocrine, and neurological disorders
      • Chronic diseases including kidney failure and diabetes mellitus
      • Penile diseases and trauma
      • Surgery and pharmacological therapies
    • Treatment includes:
      • Medications (vasodilators like sildenafil)
      • Smoking cessation
      • Penile implants
      • Penile revascularization
      • Correction of anatomical defects

    Sexually Transmitted Infections (STIs)

    • Reportable infections do not include some of the most prevalent STIs
    • Complications:
      • Pelvic inflammatory disease (PID)
      • Infertility
      • Ectopic pregnancy
      • Chronic pelvic pain
      • Neonatal morbidity and mortality
      • Genital cancer
      • Epidemiological synergy with HIV transmission (coinfection, amplifies one another)
    • Most STIs are treatable, but viral STIs are considered incurable

    Bacterial STIs

    • Gonococcal infections
    • Bacterial vaginosis
    • Syphilis
    • Lymphogranuloma venereum
    • Chlamydial infections

    Viral STIs

    • Genital herpes

    Parasitic STIs

    • Trichomoniasis
    • Human papillomavirus (HPV)
    • Condylomata acuminata
    • Scabies
    • Pediculosis pubis

    Dysmenorrhea

    • Primary dysmenorrhea: painful menstruation associated with prostaglandin release in ovulatory cycles
      • Excessive prostaglandin F₂α
        • Increased myometrial contractions
        • Constricted endometrial blood vessels
        • Increased nerve hypersensitivity
    • Secondary dysmenorrhea: related to pelvic pathology and may occur anytime in the menstrual cycle
    • Diagnosis based on medical history and pelvic exam
    • Treatment involves NSAIDs, hormonal contraceptives, exercise, stress reduction, heat application, acupuncture, thiamine, and vitamin E supplements

    Amenorrhea

    • Absence of menstruation
    • Causes: pregnancy, hypothalamic dysfunction, polycystic ovarian syndrome (PCOS), hyperprolactinemia, and ovarian failure
    • Primary amenorrhea: failure of menarche and absence of menstruation by age 13 without development of secondary sex characteristics, or by age 15 regardless of presence of secondary sex characteristics
    • Secondary amenorrhea: absence of menses after previous periods
      • Common in early adolescence, pregnancy, lactation, and during perimenopause
      • Also associated with thyroid disorders, hyperprolactinemia, excessive stress or weight loss, and PCOS
    • Pregnancy must be ruled out before further evaluation

    Polycystic Ovary Syndrome (PCOS)

    • One of the most common endocrine disturbances affecting women
    • Leading cause of infertility in North America
    • Diagnosis requires two of the following:
      • Few or anovulatory menstrual cycles
      • Elevated levels of androgens
      • Polycystic ovaries
    • Associated with genetic predisposition and obesity
      • Insulin resistance, excessive insulin and androgens
    • Symptoms related to anovulation and hyperandrogenism:
      • Amenorrhea
      • Hirsutism
      • Acne
      • Infertility
    • Treatment involves oral contraceptives for irregular cycles and weight loss

    Premenstrual Syndrome (PMS) & Premenstrual Dysphoric Disorder (PMDD)

    • PMDD considered a severe, sometimes disabling extension of PMS
    • Cyclic physical, psychological, or behavioral changes affecting interpersonal relationships or interfering with daily activities
    • Occurs in the luteal phase of the menstrual cycle
    • Theories for causes/symptoms include hormones, genetics, and environmental factors
    • Treatment focuses on symptom management

    Pelvic Inflammatory Disease (PID)

    • Acute inflammatory process caused by infection affecting the upper genital tract, potentially spreading to the entire peritoneal cavity in severe cases
    • Salpingitis (inflammation of the fallopian tubes) is a common component
    • Usually caused by STIs migrating from the vagina to the upper genital tract
    • Risk factors: multiple sexual partners, early sexual activity, previous PID, using douches, and having an intrauterine device (IUD)
    • Clinical manifestations range from no pain to sudden, severe abdominal pain with fever, dysuria, and irregular bleeding
    • Diagnosis involves history, abdominal and cervical motion tenderness, mucopurulent discharge, and STI testing
    • Treatment includes rapid broad-spectrum antibiotic therapy to prevent complications

    Vaginitis

    • Irritation or inflammation of the vagina, usually caused by infection
    • Causes include sexually transmitted pathogens, overgrowth of normal flora, and Candida albicans
    • The acidic nature of the vagina provides some protection, maintained by cervical secretions and normal flora
    • This environment can be altered by douching, soaps, spermicides, feminine hygiene sprays, deodorized pads or tampons, pregnancy, and diabetes
    • Treatment focuses on restoring and maintaining the acidic environment, administering antimicrobials or antifungals, and managing symptoms like pruritus and irritation

    Pelvic Organ Prolapse

    • Uterine prolapse: descent of the cervix or entire uterus into the vaginal canal or completely through the vagina
      • Grade 1: not treated unless discomfort is present
      • Grades 2 and 3: cause feelings of fullness, heaviness, and collapse through the vagina
    • Treatment options:
      • Pessary (removable mechanical device supporting the uterus)
      • Kegel exercises
      • Estrogen therapy
      • Surgery (last resort)

    Endometriosis

    • Presence of functioning endometrial tissue or implants outside the uterus
    • Responds to hormone fluctuations of the menstrual cycle
    • Pathophysiology not fully understood
    • Highly associated with infertility
    • Dyschezia (pain on defecation) is a hallmark symptom
    • Treatment aims to prevent progression, alleviate pain, and restore fertility

    Infertility

    • Inability to conceive after one year of unprotected intercourse
    • Female infertility results from dysfunction in the reproductive process:
      • Menses and ovulation
      • Fallopian tube function
      • Implantation of fertilized egg
    • Initial workup includes semen analysis, ovulation determination, and hysterosalpingography of the fallopian tubes
    • Treatment targets correcting identified problems

    Uretritis

    • Inflammation of the urethra, usually, but not always, caused by a sexually transmitted infection
    • Nonsexual causes include urological procedures, foreign object insertion, anatomical abnormalities, or trauma
    • Clinical manifestations: urethral tingling, itching, or burning sensation, urinary frequency and urgency, purulent discharge
    • Diagnosis involves urine nucleic acid detection amplification tests for gonorrhea and chlamydia
    • Treatment involves antibiotic therapy and preventing future exposure or mechanical irritation

    Urethral Strictures

    • Fibrotic narrowing of the urethra caused by scarring
    • Commonly a result of trauma or untreated or severe urethral infections
    • Can lead to hydronephrosis and kidney failure if severe and prolonged
    • Clinical manifestations: urinary tract infection symptoms, diminished force and caliber, urinary hesitancy, double stream, dribbling after voiding
    • Diagnosis involves reviewing history and physical examination, flow rate measurement, and cystoscopy
    • Treatment is surgical; urethral dilation is performed

    Disorders of the Penis

    • Phimosis: inability to retract foreskin from the glans penis, often due to poor hygiene or chronic infections, may require circumcision
    • Paraphimosis: inability to replace or cover the glans with the foreskin, a surgical emergency to prevent necrosis if severe
    • Peyronie Disease: "bent nail syndrome," fibrous plaque development in erectile tissue causing a painful lateral curvature of the penis during erection
    • Priapism: prolonged penile erection, a urological emergency

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    Description

    This quiz covers the critical functions of the hematological system, including the delivery of oxygen and removal of waste. It also explores the components of blood, such as plasma proteins and cellular elements, and their significance in the body.

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