Lab Practical 2

Introduction to the Cardiovascular System

  • Blood flow characteristics

    • Superior vena cava: carries deoxygenated blood to the heart.

  • Path of blood flow and heart anatomy

Major Heart Structures

  • Right Atrium

    • Receives deoxygenated blood.

  • Right Auricle (Auricle)

    • Extra flap of tissue on the atria, facilitates additional venous return.

  • Right Ventricle

    • Chamber involved in pumping blood to the lungs.

  • Left Ventricle

    • Chamber responsible for pumping oxygenated blood to the body.

Heart Chamber Identification

  • Apex of the Heart

    • Pointed region of the heart.

  • Base of the Heart

    • Broader area where major vessels emerge.

Layers of the Heart

  • Epicardium

    • Outer layer of heart tissue.

  • Myocardium

    • Middle muscular layer where contraction occurs.

  • Endocardium

    • Innermost layer lining the chambers of the heart.

Specialized Structures within the Heart

  • Trabeculae Carne

    • Ridges and folds of cardiac muscle within the ventricles.

  • Papillary Muscles

    • Muscles attached to the tendinous cords of the AV valves, help anchor them and assist with blood ejection.

  • Interventricular Septum

    • Wall separating the left and right ventricles.

  • Fossa Ovalis

    • Fetal remnant that was once the foramen ovale, an opening between the atria.

  • Ligamentum Arteriosum

    • Fetal remnant of the ductus arteriosus.

Major Blood Vessels

  • Coronary Sinus

    • Drains deoxygenated blood from the heart muscle back to the right atrium.

    • Located in the coronary sulcus.

  • Pulmonary Trunk

    • Carries deoxygenated blood from the right ventricle to the lungs.

  • Ascending Aorta

    • Vessel carrying oxygenated blood from the left ventricle.

  • Aortic Arch

    • Curved portion of the aorta.

  • Descending Aorta

    • Carries blood down through the thorax and abdomen.

Major Arteries and Branches

  • Brachiocephalic Trunk

    • First major branch off the aorta, divides into right common carotid artery and right subclavian artery.

  • Left Common Carotid Artery

  • Left Subclavian Artery

Blood Flow Sequence

  • Blood flow sequence through the heart and major vessels:

    1. Superior Vena Cava → Right Atrium → Tricuspid Valve (Right AV Valve) → Right Ventricle → Pulmonary Valve → Pulmonary Trunk → Pulmonary Arteries → Lungs (oxygenation).

    2. Pulmonary Veins → Left Atrium → Mitral Valve (Bicuspid or Left AV Valve) → Left Ventricle → Aortic Valve → Ascending Aorta → Body.

Blood Understanding: Oxygens and Colors

  • Oxygenated blood: typically represented as red; moves from the left side of the heart.

  • Deoxygenated blood: represented as blue; flows into the right side of the heart.

Blood Vessels

  • Arteries vs. Veins vs. Capillaries

    • Arteries (carry blood away from the heart) vs. Veins (return blood to the heart).

    • Capillaries facilitate the exchange of gases, nutrients, and waste between blood and tissues.

Heart Valves

  • Atrioventricular Valves

    • Right AV Valve (Tricuspid) and Left AV Valve (Mitral/Bicuspid).

  • Semilunar Valves

    • Aortic Valve and Pulmonary Valve.

Cardiac Structures

  • Tendinous Cords (Chordae Tendineae)

    • Connect the papillary muscles to the heart valves, allowing for valve stability during contractions.

  • Cusps

    • Flaps of the heart valves that open and close to regulate blood flow.

Blood Cells Overview

  • Composition of Blood

    • 99% erythrocytes (red blood cells), 1% leukocytes (white blood cells).

  • Varieties of Leukocytes

    • Granulocytes: Neutrophils, Eosinophils, Basophils.

    • Agranulocytes: Lymphocytes, Monocytes.

White Blood Cell Types

  • Eosinophils

    • Bilobed nucleus, involved in combating parasites and allergic reactions.

  • Neutrophils

    • Most abundant WBC (60-75%), multilobed nucleus (often trilobed) and essential in fighting infections.

  • Basophils

    • Least common WBC, large granules obscure nucleus, involved in inflammatory responses.

Agranulocytes Explanation

  • Monocytes

    • Kidney or horseshoe-shaped nucleus, larger cells that can differentiate into macrophages.

  • Lymphocytes

    • Include B cells and T cells; large nucleus with a smaller cytoplasm.

Blood Disorders Overview

  • Leukopenia: Reduced white blood cell count (below 5,000 per microliter).

  • Leukocytosis: Increased white blood cell count (above 10,000 per microliter).

  • Anemia: Decreased red blood cell count, leading to lack of oxygen transport.

  • Polycythemia: Increased red blood cell count.

Relevant Values and Ranges

  • Normal leukocyte levels: 5,000 - 10,000 per microliter.

  • Neutrophils: 60-75%, with variations in ranges accepted as normal.

  • 1% of blood composition being leukocytes emphasizes the dominance of erythrocytes.

Normal Blood Cell Identification

  • Antibodies and Antigens in Blood Types

    • Type A: A antigen, B antibody.

    • Type O: No A or B antigens, A and B antibodies.

  • In blood typing, agglutination indicates the presence of specific antigens.

Conclusion

  • Review key components and processes of the cardiovascular system thoroughly and understand blood composition, types, and disorders for better grasp on function and clinical relevance.