Anatomy & Physiology Study Guide: Blood, Heart, Circulation, and Respiratory System

Blood and Blood Cells

Formed Elements of Blood

The formed elements of blood are the cellular components suspended in plasma. They include:

• Erythrocytes (Red Blood Cells, RBCs): Responsible for oxygen transport.

• Leukocytes (White Blood Cells, WBCs): Involved in immune defense. Types include neutrophils, lymphocytes, monocytes, eosinophils, and basophils.

• Platelets (Thrombocytes): Cell fragments important for blood clotting.

Key Point: Each type of blood cell has distinct structural features and functions, which can be identified under a microscope or in diagrams.

Blood Typing and Blood Groups

Blood type is determined by the presence or absence of specific antigens on the surface of red blood cells. The main blood group systems are:

• ABO System: Based on the presence of A and/or B antigens.

• Rh System: Based on the presence (+) or absence (−) of the Rh antigen (D antigen).

Universal Donor: Type O negative blood (O−) can be given to most recipients. Universal Recipient: Type AB positive blood (AB+) can receive from all blood types.

Blood Typing Procedure: Involves mixing a blood sample with anti-A, anti-B, and anti-Rh antibodies and observing for agglutination (clumping).

Heart Anatomy and Physiology

Heart Structure

The heart is a muscular organ divided into four chambers: two atria (upper) and two ventricles (lower). Key anatomical structures include:

• Coronary Vessels: Supply blood to the heart muscle itself.

• Valves: Ensure unidirectional blood flow (tricuspid, bicuspid/mitral, pulmonary, and aortic valves).

• Major Blood Vessels: Superior/inferior vena cava, pulmonary arteries/veins, aorta.

Sheep Heart Dissection: Used in labs to identify anatomical structures and understand heart function.

Blood Flow Through the Heart

1. Deoxygenated blood enters the right atrium via the vena cava.

2. Passes to the right ventricle, then to the lungs via the pulmonary artery.

3. Oxygenated blood returns to the left atrium via pulmonary veins.

4. Moves to the left ventricle, then pumped to the body via the aorta.

Key Point: The heart acts as a double pump, separating pulmonary (lungs) and systemic (body) circulation.

Cardiac Cycle and EKG Interpretation

Cardiac Cycle

The cardiac cycle refers to the sequence of events in one heartbeat, including contraction (systole) and relaxation (diastole) of the atria and ventricles.

• Systolic Pressure: Pressure during ventricular contraction.

• Diastolic Pressure: Pressure during ventricular relaxation.

• Pulse Pressure: Difference between systolic and diastolic pressures. $\text{Pulse Pressure} = \text{Systolic Pressure} - \text{Diastolic Pressure}$

Electrocardiogram (EKG/ECG)

An EKG records the electrical activity of the heart. Key components include:

• P wave: Atrial depolarization

• QRS complex: Ventricular depolarization

• T wave: Ventricular repolarization

• Intervals: PR, QT, and ST intervals represent specific periods in the cardiac cycle.

Heart Rate Calculation: Count the number of QRS complexes in a set time or use the formula: $\text{Heart Rate (bpm)} = \frac{60}{\text{R-R interval (seconds)}}$

Cardiac Output: The volume of blood pumped by the heart per minute. $\text{Cardiac Output (CO)} = \text{Stroke Volume (SV)} \times \text{Heart Rate (HR)}$

Blood Pressure Measurement

Measuring Blood Pressure

Blood pressure is measured using a sphygmomanometer and stethoscope. The two main values are:

• Systolic Pressure: First sound heard as the cuff deflates.

• Diastolic Pressure: Disappearance of sound.

Pulse Pressure: Calculated as the difference between systolic and diastolic pressures.

Respiratory System

Pathway of Air

Air travels through the upper and lower respiratory tracts:

1. Nasal cavity or mouth

2. Pharynx

3. Larynx

4. Trachea

5. Bronchi

6. Bronchioles

7. Alveoli (site of gas exchange)

Respiratory Volumes and Capacities

Respiratory volumes and capacities are measured using a spirometer. Key terms include:

Volume/Capacity	Definition
Tidal Volume (TV)	Amount of air inhaled or exhaled in a normal breath
Inspiratory Reserve Volume (IRV)	Additional air inhaled after a normal inhalation
Expiratory Reserve Volume (ERV)	Additional air exhaled after a normal exhalation
Residual Volume (RV)	Air remaining in lungs after maximal exhalation
Vital Capacity (VC)	Maximum air exhaled after maximal inhalation $VC = TV + IRV + ERV$
Total Lung Capacity (TLC)	Total volume in lungs after maximal inhalation $TLC = VC + RV$
Inspiratory Capacity (IC)	Maximum air inhaled after normal exhalation $IC = TV + IRV$
Functional Residual Capacity (FRC)	Air remaining after normal exhalation $FRC = ERV + RV$
Minute Ventilation (VE)	Total air entering lungs per minute $VE = TV \times \text{Respiratory Rate}$
Alveolar Ventilation (VA)	Air reaching alveoli per minute

Application: Calculating these values is essential for assessing lung function in health and disease.

Example Problem

If a person has a tidal volume of 500 mL, a respiratory rate of 12 breaths/min, and an expiratory reserve volume of 1200 mL, calculate the minute ventilation and vital capacity.

• Minute Ventilation: $VE = 500 \times 12 = 6000$ mL/min

• Vital Capacity: $VC = TV + IRV + ERV$ (IRV needed for full calculation)

Additional info: These study notes are based on a list of exam review questions covering blood, heart anatomy, cardiac cycle, EKG interpretation, blood pressure, and respiratory physiology. The content has been expanded to provide definitions, explanations, and example calculations for key concepts in Anatomy & Physiology.