Unit 11

Unit Overview

  • Unit Topics:

    • Chapter 19: Blood

    • Chapter 20: Heart

    • Chapter 21: Blood Vessels and Circulation

Chapter 19: Blood

Learning Objectives

  • Describe the characteristics and explain functions of blood

  • Describe the composition of plasma

  • Describe the characteristics and explain the functions of RBCs and WBCs found in blood

  • Explain ABO blood groups and apply it to blood typing scenarios

  • Describe the process of hemostasis

Key Terms

  • Whole Blood

  • Agglutinogen

  • Thrombin

  • Plasma

  • Agglutinin

  • Fibrin

  • Formed Elements

  • Hematocrit

  • Hemolysis

  • Embolus

  • Buffy Coat

  • Rh Factor

  • Thrombus

  • Albumin

  • Diapedesis

  • Heparin

  • Globulin

  • Chemotaxis

  • Antithrombin-III

  • Fibrinogen

  • Leukocyte

  • Thrombomodulin

  • Electrolyte

  • Neutrophil

  • Plasminogen

  • Erythrocyte

  • Eosinophil

  • Plasmin

  • Hemoglobin

  • Basophil

  • Oxyhemoglobin

  • Monocyte

  • Deoxyhemoglobin

  • Lymphocyte

  • Carbaminohemoglobin

  • Platelets

  • Erythropoiesis

  • Thrombocytopoiesis

  • Erythropoietin

  • Megakaryocyte

  • Biliverdin

  • Hemostasis

  • Bilirubin

  • Factor X

  • Urobilins

  • Prothrombinase

Characteristics and Functions of Blood

  1. Functions of Blood:

    • Transportation: Transports oxygen, nutrients, hormones, and waste products

    • Regulation: Regulates pH and ion composition, prevents blood loss, stabilizes body temperature

    • Defense: Protects against toxins and pathogens

  2. Components of Blood:

    • Whole blood consists of plasma (55%) and formed elements (cellular components) (45%)

Characteristics of Blood

  • pH: Typically between 7.35 and 7.45

  • Temperature: Approximately 38°C (100.4°F)

  • Viscosity: Blood is more viscous than water due to cellular components

  • Salt Concentration: Key for osmotic balance

  • Total Blood Volume: Approximately 5-6 liters in adult males, 4-5 liters in females

Hematocrit

  • Ratio of volume of packed red blood cells to the total volume of blood

  • Normal Values:

    • Males: 42-54%

    • Females: 38-46%

  • Calculation:

    • Hematocrit = (Volume of packed RBCs / Volume of whole blood) x 100

  • Example Problem: Given plasma volume = 1.5ml and packed RBC volume = 3.5ml, what is the hematocrit?

Composition of Plasma

  1. Water: 92%

  2. Plasma Proteins: 7%

    • Albumins (60%)

    • Globulins (35%)

    • Fibrinogen (4%)

  3. Other Solutes: 1%

    • Electrolytes, Organic Nutrients, Organic Wastes

Formed Elements: Erythrocytes

  • RBC Count:

    • Males: 4.5-6.3 million/mm3

    • Females: 4.2-5.5 million/mm3

  • RBC Structure:

    • Biconcave shape for large surface area

    • Flexible to pass through small capillaries

    • Lifespan: Generally 120 days

  • Conditions:

    • Anemia: Low RBC count

    • Polycythemia: High RBC count

  • Interesting Fact: Sickle cell disease leads to abnormal shape and function.

Hemoglobin

  • Composed of four protein chains (2 alpha, 2 beta) and four heme groups

  • Functions:

    • Binds oxygen (oxyhemoglobin)

    • Releases carbon dioxide (carbaminohemoglobin)

Erythropoiesis

  • Process of RBC formation

  • Occurs in the bone marrow, requiring amino acids, iron, and vitamins

  • Hormone: Erythropoietin stimulates RBC production, especially in response to hypoxia

Blood Groups

  • Types: Type A, B, AB, O

  • Key Points:

    • Antigens determine blood type, antibodies present in plasma determine what blood type can be received

    • Important to match blood types during transfusion to prevent agglutination reactions

Hemostasis

  • Phases:

    1. Vascular Phase: Initial constriction of blood vessels

    2. Platelet Phase: Platelets adhere and aggregate

    3. Coagulation Phase: Formation of a stable blood clot through fibrin

  • Requires calcium and various clotting factors

Chapter 20: The Heart

Learning Objectives

  • Describe the anatomy of the heart

  • Explain the flow of blood through the heart

  • Discuss the origin of heartbeat and electrical activity

  • Understand cardiac cycle and factors affecting cardiac output

Key Terms

  • Pulmonary Circuit

  • Systemic Circuit

  • Coronary Sinus

  • Sinoatrial Node

Anatomy of the Heart

  • Location: Mediastinum, between pleural cavities

  • Heart Structure:

    • Comprised of four chambers: Right Atrium, Right Ventricle, Left Atrium, Left Ventricle

    • Valves prevent backflow (AV and semilunar valves)

Cardiac Cycle Overview

  1. Atrial Systole: Contraction of atria

  2. Ventricular Systole: Contraction of ventricles

  3. Diastole: Relaxation and filling of chambers

Chapter 21: Blood Vessels and Circulation

Learning Objectives

  • Describe types of blood vessels and their structures

  • Explain physiology of circulation

  • Discuss regulation of blood flow and blood pressure

Key Terms

  • Arteries, Veins, Capillaries

  • Blood Pressure, Peripheral Resistance, Cardiac Output

Blood Vessels Overview

  • 5 Classes: Arteries, Arterioles, Capillaries, Venules, Veins

  • Structure: Composed of three layers (Tunica Intima, Tunica Media, Tunica Externa)

  • Function: Varies by vessel type, related to blood flow and pressure management

Blood Pressure Regulation

  • Influenced by heart rate, blood volume, resistance, and blood viscosity

  • Baroreceptors: Monitor and adjust blood pressure

  • Chemoreceptors: Monitor blood chemistry and regulate circulation accordingly

Conclusion

  • Understanding these concepts is crucial for mastering the cardiovascular system's function and structure.