Exam 3 workbook 2024 KEY.docx

Heart Anatomy and Function

Pericardium

  • Serous Pericardium

    • A serous membrane producing serous fluid to reduce friction during heart movements.

    • Composed of two layers:

      • Visceral Pericardium (Epicardium): Covers the heart's surface.

      • Parietal Pericardium: Outer layer of the serous pericardium.

    • Pericardial Space: The cavity between the visceral and parietal layers containing serous fluid.

  • Fibrous Pericardium:

    • Dense connective tissue that provides support and protection.

    • The outermost layer of the pericardium.

Pericardial Sac

  • Formed by the fusion of the Parietal Pericardium and Fibrous Pericardium.

Blood Flow Through the Heart

  • Left Atrium → Left Ventricle

  • Right Atrium → Right Ventricle

  • Right Ventricle → Pulmonary Trunk

  • Left Ventricle → Aorta

Heart Structure

Atrioventricular Valves

  • Papillary Muscles and Chordae Tendineae:

    • During ventricular systole, these structures prevent backflow into the atria by maintaining valve closure:

      • Papillary muscles contract to pull on chordae tendineae, keeping valve cusps closed.

Heart Valves Function

Blood Valve Status During Cardiac Cycle

  • Ventricular Systole:

    • Pulmonary Semilunar Valve: Open

    • Bicuspid Valve: Closed

  • Ventricular Diastole:

    • Aortic Semilunar Valve: Closed

    • Tricuspid Valve: Open

Coronary Arteries and Cardiac Veins

  • Posterior Interventricular Artery → Great Cardiac Vein

  • Circumflex Artery → Middle Cardiac Vein

  • Right Coronary Artery → Anterior Cardiac Veins

  • Anterior Interventricular Artery → Coronary Sinus

Impulse Conduction in the Heart

  1. SA Node initiates the impulse.

  2. Impulse spreads through atrial walls, causing contraction.

  3. Converges at the AV Node.

  4. Impulse travels through the AV Bundle into the interventricular septum.

  5. Divides into Left and Right Bundle Branches.

  6. Sends signals via Purkinje Fibers at the apex, causing ventricles to contract.

Fetal Circulation

  • Oxygenated Blood Bypass Mechanisms:

    1. Foramen Ovale: Connects right atrium to left atrium; becomes Fossa Ovalis after birth.

    2. Ductus Arteriosus: Connects pulmonary trunk to aorta; becomes Ligamentum Arteriosum after birth.

Blood Vessel Types

  1. Arteries: Carry blood away from the heart; thick tunica media.

  2. Veins: Carry blood towards the heart; thinner walls, may have valves.

  3. Capillaries: Smallest vessels connecting arteries and veins; allow rapid exchange of substances.

Types of Arteries

  1. Elastic Arteries: Largest, close to the heart; expand and recoil during heartbeat.

  2. Muscular Arteries: Medium-sized, distribute blood to specific organs; thicker tunica media.

  3. Arterioles: Smallest arteries supplying capillaries.

Branches of the Aorta

  1. Brachiocephalic Trunk:

    • Divides into Right Common Carotid and Right Subclavian Arteries.

    • Supplies the right head, neck, and right upper limb.

  2. Left Common Carotid Artery: Supplies the left head and neck.

  3. Left Subclavian Artery: Supplies the left upper limb.

Path of Blood through Vessels

  • Example Pathways:

    • Aorta → Brachiocephalic Trunk → Subclavian Artery → Axillary Artery → Brachial Artery → Radial Artery.

    • Right Atrium → Right Ventricle → Pulmonary Trunk → Pulmonary Arteries → Lungs → Pulmonary Veins → Left Atrium.

    • Deep Muscles of Posterior Leg → Posterior Tibial Vein → Popliteal Vein → Femoral Vein → External Iliac Vein → Common Iliac Vein → Inferior Vena Cava → Right Atrium.

Coronary Blood Supply

  • Match Arteries to Areas:

    • Internal Iliac Artery → Pelvic organs

    • Pulmonary Artery → Right side of the heart

Azygos System Drainage

  • The posterior intercostal veins drain into the Azygos Vein, which feeds into the Superior Vena Cava.

  • Caval system: Deoxygenated blood delivery to the right atrium.

  • Portal system: Nutrient-rich blood from the digestive tract to the liver.

Blood Composition

  • A Hematocrit measures the percentage of formed cells in blood volume.

  • Anemia: Low RBC count/hemoglobin, symptoms may include fatigue and weakness.

Blood Plasma Proteins

  • Albumin: Maintains osmotic pressure and transports substances.

  • Globulin: Transports water-soluble molecules; includes immunoglobulins for infection defense.

  • Fibrinogen: Key enzyme in blood clot formation.

Erythrocytes (RBCs)

  • Originates from Erythropoietin secretion in the kidneys; produced in the bone marrow.

  • Lifespan: 120 days; recycled in the spleen.

  • Hemoglobin binds four oxygen molecules for transportation.

Blood Typing

  • Type A: A antigen, B antibodies.

  • Type B: B antigen, A antibodies.

  • Type O: No antigens, A and B antibodies (universal donor).

  • Type AB: A and B antigens, no antibodies (universal recipient).

Leukocytes and Their Functions

  • Neutrophils: First responders to infection.

  • Basophils: Involved in allergic reactions.

  • Eosinophils: Target parasitic infections.

Lymphatic System Functions

  1. Regulation of blood volume.

  2. Transportation of lipids and fats.

  3. Immunity and response capability.

Lymphatic Vessels

  • Features: Overlapping cells, large diameter, one-way valves.

  • Sequence: Capillaries → Vessels → Trunks → Ducts.

Antigen Presenting Cells (APCs)

  • APC: Cells like macrophages and dendritic cells that destroy antigens and present them to lymphatic cells.

T-Lymphocytes Types

  1. Helper

  2. Cytotoxic

  3. Regulatory

  4. Memory

Immune Response Summary

  • T-helper cells present antigens and release cytokines to activate other immune cells.

  • Memory cells enhance response to previously encountered pathogens.

  • Antibodies from B-cells bind to antigens for neutralization.

Lymphoid Tissue Locations

  • Found in mucosal tissues and lymphatic organs (e.g., tonsils).

  • MALT: Mucosal-Associated Lymphatic Tissue.

Spleen and Lymph Nodes

  • Red Pulp: Macrophages destroy old RBCs.

  • Lymph Nodes filter lymph fluid; contain regions of B- and T-cells.

Respiratory System Anatomy

  • Functionality of structures for:

    • Gas Exchange: Alveoli

    • Defense: Respiratory epithelium

    • Sound Production: Larynx

Sound Production Process

  • Vocal cords produce sound by vibration as air passes through the glottis, controlled by laryngeal muscles.

Trachea and Bronchi

  • C-shaped Cartilage keeps the trachea open.

  • Smooth muscle allows esophageal expansion and regulates airway size.

Airway Pathway

  • Sequence: Primary Bronchi → Secondary Bronchi → Tertiary Bronchi → Bronchioles → Alveoli for gas exchange.

Lung Anatomy

  • Identify structures such as the Hilum, Root, Oblique fissure, etc. in each lung.

Trauma Scenario in Respiratory System

  • Blunt force trauma may cause pleural space puncture, affecting ventilation.

  • Neural control originates in the Medulla Oblongata for ventilation rates.

  • Chemoreceptors relay CO2 and O2 levels to the brain.