Lab Final Study Guide: Blood, Cardiovascular, and Lymphatic Systems

Blood (Ch. 17): Composition & Cells

Blood Composition

Blood is a specialized connective tissue essential for transport, regulation, and protection. It consists of plasma and formed elements, each with distinct functions.

• Whole blood = Plasma (~55%) + Formed elements (~45%)

• Plasma (92% water): Contains proteins (albumin, globulins, fibrinogen), nutrients, electrolytes, and waste products.

• Plasma proteins:

  • Albumin: Maintains osmotic pressure.

  • Globulins: Includes antibodies for immune defense.

  • Fibrinogen: Key for blood clotting.

• Formed elements: Cellular components of blood.

Formed Elements Table

Cell type	Function	Lab identification
Erythrocytes (RBC)	O2/CO2 transport (hemoglobin)	Biconcave, no nucleus, red (H&E)
Neutrophil (most common WBC)	Phagocytize bacteria	Multi-lobed nucleus, pale granules
Lymphocyte	Immune response (B & T cells)	Large round nucleus, scant cytoplasm
Monocyte	Becomes macrophage	Kidney-shaped nucleus
Eosinophil	Fights parasites; allergy	Bilobed nucleus, red granules
Basophil (rarest)	Releases histamine	Dark purple granules, S-shaped nucleus
Platelets	Clotting (thrombocytes)	Small fragments, no nucleus

• Hematocrit: Percentage of RBCs in whole blood (normal ~45% men, ~42% women).

Clinical Connections – Blood

• Anemia: Low RBC count or hemoglobin → fatigue, pallor.

• Polycythemia: Excess RBCs → increased viscosity.

• Leukocytosis: High WBC count (infection).

• Leukopenia: Low WBC count (bone marrow suppression).

• Thrombocytopenia: Low platelets → bleeding risk.

• Hemophilia: Genetic clotting factor deficiency.

Heart Anatomy (Ch. 18/19): External, Internal, and Sheep Dissection

External Heart Anatomy

The heart is a muscular organ with distinct external landmarks and vessels.

• Apex: Pointed inferior end (left ventricle).

• Base: Superior part (atria).

• Auricles: Wrinkled "ear" flaps on atria.

• Coronary sulcus: Fat-filled groove between atria and ventricles.

• Anterior/Posterior interventricular sulcus: Grooves between ventricles (contain coronary arteries).

• Great vessels: SVC, IVC, pulmonary trunk, pulmonary veins, aorta.

Internal Heart Anatomy

• Right side (deoxygenated blood):

  • Right atrium: Receives from SVC, IVC, coronary sinus; fossa ovalis.

  • Tricuspid valve (3 cusps): Between RA and RV.

  • Chordae tendineae & papillary muscles: Prevent valve prolapse.

  • Right ventricle: Trabeculae carneae, moderator band (Purkinje fibers).

  • Pulmonary semilunar valve: To pulmonary trunk.

• Left side (oxygenated blood):

  • Left atrium: Receives 4 pulmonary veins.

  • Bicuspid (mitral) valve (2 cusps): Between LA and LV.

  • Left ventricle: Thickest wall, trabeculae carneae.

  • Aortic semilunar valve: To aorta; coronary arteries open behind cusps.

• Wall thickness: Left ventricle is much thicker due to systemic circulation (high resistance); right ventricle pumps to lungs (low resistance).

Sheep Heart vs. Human Heart

• Similar structure, slightly different shape.

• More visible fat in sheep heart.

• Same chambers, valves, vessels.

• Left ventricle is thicker and more muscular.

• Pulmonary veins may be cut short; identify by opening into left atrium.

Heart Valves & Clinical Correlations

• Murmurs: Abnormal heart sounds due to turbulent flow across valves.

  • Mitral regurgitation: Blood leaks backward during systole (holosystolic murmur).

  • Aortic stenosis: Narrowed aortic valve (systolic ejection murmur).

• Prolapse: Valve cusps bulge into atrium (e.g., mitral valve prolapse).

Blood Vessel Anatomy (Ch. 19/20): Arteries & Veins

Major Arteries – Tracing Blood from Heart

• Aorta: Ascending → arch → descending.

• Branches of aortic arch:

  1. Brachiocephalic trunk → right subclavian & right common carotid.

  2. Left common carotid artery.

  3. Left subclavian artery.

• Common carotid: Internal (brain) & external (face/neck).

• Subclavian: Axillary → brachial → radial/ulnar → palmar arches.

• Descending aorta: Thoracic aorta → intercostal arteries; abdominal aorta → celiac trunk, superior/inferior mesenteric, renal, common iliac.

• Lower limb: External iliac → femoral → popliteal → anterior/posterior tibial → dorsalis pedis.

Major Veins – Returning to Heart

• Superior vena cava (SVC): Internal jugular + subclavian → brachiocephalic veins → SVC.

• Inferior vena cava (IVC): Common iliac → external/internal iliac → femoral → popliteal → posterior tibial; renal veins, hepatic veins.

• Hepatic portal system: Veins from digestive organs → hepatic portal vein → liver → hepatic veins → IVC.

• Coronary sinus: Collects blood from heart muscle → drains into right atrium.

Histology: Artery vs. Vein (Lab Slide ID)

Feature	Artery	Vein
Lumen	Small, round, star-shaped	Large, irregular, collapsed
Wall thickness	Thick (especially media)	Thin
Elastic fibers	Prominent (internal & external elastic lamina)	Fewer
Endothelium	Wavy (contracted smooth muscle)	Smooth
Valves	Absent	Present (in some)

Pulse Rate & Blood Pressure Physiology

Pulse – Definition & Sites

The pulse is the rhythmic expansion of arteries caused by the ejection of blood from the left ventricle during systole.

• Common pulse points: Radial (wrist), carotid (neck), brachial (inner arm), femoral (groin), popliteal (behind knee), dorsalis pedis (top of foot), posterior tibial (ankle).

• Normal resting heart rate: 60–100 bpm.

• Tachycardia: >100 bpm.

• Bradycardia: <60 bpm (normal in athletes).

Blood Pressure Measurement (Sphygmomanometer)

• Systolic: Pressure during ventricular contraction (top number).

• Diastolic: Pressure during relaxation (bottom number).

• Normal: 120/80 mmHg.

• Korotkoff sounds: Sounds heard during BP measurement.

  • First sound: Cuff pressure falls below systolic – marks systolic BP.

  • Disappearance: Cuff pressure falls below diastolic – marks diastolic BP.

• Factors affecting BP: Cardiac output, peripheral resistance, blood volume, vessel elasticity.

• Mean Arterial Pressure (MAP):

$MAP = \text{Diastolic} + \frac{\text{Pulse Pressure}}{3}$

Normal MAP ~93 mmHg.

Clinical: Hypertension & Hypotension

• Hypertension: Sustained BP ≥130/80 mmHg – risk for heart disease, stroke, kidney failure.

• Orthostatic hypotension: BP drops upon standing → dizziness.

• Shock: Inadequate tissue perfusion (low BP).

Lymphatic System (Ch. 20): Functions, Organs, Flow

Lymphatic System Functions

The lymphatic system maintains fluid balance, absorbs dietary fats, and provides immune defense.

• Fluid balance: Returns excess interstitial fluid (~3.6 L/day) to blood.

• Fat absorption: Lacteals in small intestine absorb dietary lipids.

• Immunity: Filters pathogens; produces lymphocytes.

Lymphatic Organs & Structures

• Lymphatic capillaries: Blind-ended, more permeable than blood capillaries.

• Lymphatic vessels: Have valves, converge into larger trunks.

• Lymph nodes: Bean-shaped; filter lymph; contain lymphocytes and macrophages; located in cervical, axillary, inguinal, thoracic, abdominal regions.

• Thoracic duct: Largest lymphatic vessel; drains lower body, left arm, left side of head/neck; empties into left subclavian vein.

• Right lymphatic duct: Drains right upper quadrant; empties into right subclavian vein.

• Spleen: Filters blood (not lymph); stores platelets; removes old RBCs.

• Thymus: T-lymphocyte maturation; atrophies with age.

• Tonsils: Pharyngeal, palatine, lingual – trap pathogens at entrances.

• Peyer's patches: Lymphoid tissue in small intestine.

Lymph Flow Pathway

Interstitial fluid → lymphatic capillaries → lymphatic vessels → lymph nodes → lymphatic trunks → thoracic duct/right lymphatic duct → subclavian veins → blood circulation.

Clinical Connections – Lymphatic

• Lymphedema: Swelling due to lymphatic blockage (e.g., after mastectomy).

• Lymphadenopathy: Swollen lymph nodes (infection, cancer).

• Splenomegaly: Enlarged spleen (mononucleosis, trauma).

• Hodgkin's lymphoma: Cancer of lymphocytes (Reed-Sternberg cells).

Lab Practical Tips & Common Identifications

Microscope Slides – What You Will See

• Blood smear: RBCs (pink, biconcave), WBCs (purple nuclei), platelets (small fragments).

• Artery vs. vein cross-section: Artery has thick media, smaller lumen.

• Lymph node: Outer capsule, cortex (follicles with germinal centers), medulla, hilus.

• Spleen: White pulp (lymphocytes around arteries), red pulp (RBCs).

• Thymus: Lobules with cortex (dense lymphocytes) and medulla.

Sheep Heart Dissection – Labeling Checklist

• Right atrium & right ventricle

• Left atrium & left ventricle

• Tricuspid valve (3 flaps)

• Bicuspid (mitral) valve (2 flaps)

• Pulmonary semilunar valve

• Aortic semilunar valve

• Chordae tendineae & papillary muscles

• Moderator band (right ventricle)

• Trabeculae carneae

• Aorta (ascending, arch)

• Pulmonary trunk

• Superior & inferior vena cava

• Coronary vessels (if visible)

• Apex

Self-Test – Lab Final Practice Questions

Short Answer (Written Final)

1. List the 5 types of leukocytes and one function of each.

2. What is the function of the moderator band in the right ventricle?

3. Trace a drop of blood from the superior vena cava to the aorta.

4. Why is the left ventricular wall thicker than the right?

5. What is the difference between systolic and diastolic pressure?

6. Name 3 structures that are part of the lymphatic system.

7. What happens to excess interstitial fluid if the lymphatic system is blocked?

8. What vessel carries deoxygenated blood from the digestive tract to the liver?

9. Which valve is located between the left ventricle and the aorta?

10. What are Korotkoff sounds? When do they appear/disappear?

Identification (Practical)

1. Left ventricle (sheep heart)

2. Aortic semilunar valve

3. Artery vs. vein (microscope slide)

4. Lymph node

5. Neutrophil (blood smear)

Answer Key

• Leukocytes: Neutrophil (bacteria), Lymphocyte (immune), Monocyte (macrophage), Eosinophil (parasites/allergy), Basophil (histamine).

• Moderator band: Conducts Purkinje fibers to papillary muscle, speeds RV contraction.

• Blood path: SVC → RA → tricuspid → RV → pulmonary valve → pulmonary trunk → pulmonary arteries → lungs → pulmonary veins → LA → mitral valve → LV → aortic valve → aorta.

• Left ventricle pumps against high systemic resistance; RV to low-resistance lungs.

• Systolic = pressure during contraction; diastolic = pressure during relaxation.

• Lymph nodes, spleen, thymus, tonsils, lymphatic vessels (any 3).

• Edema (swelling).

• Hepatic portal vein.

• Aortic semilunar valve.

• Korotkoff sounds: Sounds of turbulent blood flow during BP measurement; first sound = systolic; disappearance = diastolic.

• Identification: Left ventricle (thickest wall, apex); aortic semilunar valve (between LV and aorta, 3 cusps); artery vs. vein (artery: thick media, smaller lumen, wavy intima; vein: thin wall, collapsed lumen); lymph node (bean-shaped, capsule, cortex, medulla, hilus); neutrophil (multi-lobed nucleus, pale granules).

Final Checklist

• Blood: Hematocrit, plasma components, formed elements, RBC morphology, WBC types, ABO blood typing.

• Heart: External anatomy, internal chambers, valves, papillary muscles, chordae tendineae, sheep heart dissection landmarks, path of blood through the heart.

• Blood Vessels: Major arteries & veins, histology slide ID, hepatic portal system.

• Pulse & BP: Pulse sites, BP measurement steps, Korotkoff sounds, normal values.

• Lymphatic System: Functions, major organs, lymph flow pathway, histology.

Example: Tracing blood from the SVC to the aorta involves passing through the right atrium, tricuspid valve, right ventricle, pulmonary valve, pulmonary trunk, lungs, pulmonary veins, left atrium, mitral valve, left ventricle, aortic valve, and finally the aorta.

Additional info: ABO blood typing is a common lab practical topic, though not detailed in these notes. Review antigens and antibodies for blood compatibility.