Untitled Flashcards Set

Anatomy of the Heart

Heart Valves

• The tricuspid valve lies between the right atrium and right ventricle, preventing backflow of blood during ventricular contraction.

• The bicuspid (mitral) valve is located between the left atrium and left ventricle, ensuring one-way blood flow.

• The aortic semilunar valve is situated between the left ventricle and the aorta, controlling blood flow to the body.

• The pulmonary semilunar valve is found between the right ventricle and the pulmonary artery, directing blood to the lungs for oxygenation.

• Each valve plays a crucial role in maintaining efficient blood circulation and preventing regurgitation.

• Diagram of heart valves can be included to illustrate their locations.

Blood Flow and Circulation

• Arteries typically carry oxygenated blood, with the exception of the pulmonary artery, which carries deoxygenated blood to the lungs.

• The pulmonary veins return oxygenated blood from the lungs to the left atrium of the heart.

• Systemic circulation delivers oxygenated blood to the body, while pulmonary circulation carries deoxygenated blood to the lungs.

• The right atrium receives deoxygenated blood from the body via the vena cava, while the left atrium receives oxygenated blood from the lungs.

• Understanding the flow of blood through the heart is essential for grasping cardiovascular physiology.

• Table comparing systemic and pulmonary circulation can be included.

Blood Components and Functions

Blood Cells

• Erythrocytes (red blood cells) are responsible for transporting oxygen bound to hemoglobin.

• Leukocytes (white blood cells) provide the primary defense against infections and foreign invaders.

• Platelets are crucial for blood clotting and wound healing processes.

• Each type of blood cell has a unique function that contributes to overall health and homeostasis.

• The balance of these cells is vital; for example, an increase in erythrocytes can enhance athletic performance by improving oxygen delivery.

• Diagram of blood components can be included to visualize their proportions.

Blood Plasma

• Plasma is the liquid component of blood, making up about 55% of its volume, and contains water, electrolytes, proteins, and nutrients.

• It serves as a medium for transporting blood cells, hormones, and waste products.

• Plasma proteins, such as antibodies and clotting factors, play critical roles in immune response and hemostasis.

• The composition of plasma can vary based on hydration levels and health status.

• Understanding plasma's role is essential for comprehending blood's overall function.

• Table of plasma components and their functions can be included.

Cardiovascular Physiology

Cardiac Output and Heart Rate

• Cardiac output is defined as the volume of blood pumped by the left ventricle in one minute, calculated as Stroke Volume x Heart Rate.

• Stroke volume refers to the amount of blood ejected with each heartbeat, influenced by factors like preload and afterload.

• Heart rate is the number of beats per minute, which can increase during exercise to meet the body's oxygen demands.

• Understanding these concepts is crucial for assessing cardiovascular health and performance.

• The relationship between heart rate and stroke volume can be illustrated with a graph showing changes during exercise.

• Example: An athlete's cardiac output can significantly increase during intense physical activity.

Electrocardiogram (ECG) Interpretation

• The QRS wave on an ECG represents the depolarization of the ventricles, indicating that the ventricles are contracting while the atria are repolarizing.

• Understanding ECG patterns is essential for diagnosing various cardiac conditions.

• The P wave indicates atrial depolarization, while the T wave represents ventricular repolarization.

• Analyzing ECG readings can provide insights into heart rhythm and electrical activity.

• Example: A normal ECG pattern can be compared to one with arrhythmias to highlight differences.

• Diagram of an ECG waveform can be included for visual reference. 

Overview of Lung Volumes and Capacities

Key Lung Volumes

• Tidal Volume (TV): The amount of air exchanged during normal breathing, approximately 0.5 liters at rest.

• Vital Capacity (VC): The total volume of exchangeable air, calculated as the sum of tidal volume, inspiratory reserve volume, and expiratory reserve volume.

• Inspiratory Reserve Volume (IRV): The additional air that can be inhaled after a normal inhalation.

• Expiratory Reserve Volume (ERV): The additional air that can be forcibly exhaled after a normal exhalation.

• Residual Volume (RV): The volume of air remaining in the lungs after a forced expiration, typically around 1.2 liters.

• Total Lung Capacity (TLC): The maximum amount of air the lungs can hold, calculated as VC + RV.

Lung Volume Calculations

• To calculate Vital Capacity: VC = IRV + TV + ERV.

• Example calculation for an athlete: If IRV = 3.0 liters, TV = 0.5 liters, and ERV = 1.7 liters, then VC = 3.0 + 0.5 + 1.7 = 5.2 liters.

• Total Lung Capacity can be calculated using the recorded values: TLC = VC + RV. For the athlete, if VC = 6.2 liters and RV = 1.2 liters, then TLC = 6.2 + 1.2 = 7.4 liters.

• Understanding these calculations is crucial for assessing respiratory health and fitness levels.

• Pulmonary Ventilation: The total volume of air inhaled and exhaled in one minute, which can be calculated as respiratory rate multiplied by tidal volume.

• Example: If an athlete has a tidal volume of 0.5 liters and a respiratory rate of 61 breaths/min, then pulmonary ventilation = 0.5 * 61 = 30.5 liters/min.

Mechanics of Breathing

Muscular Actions in Breathing

• Inhalation: The diaphragm contracts and moves inferiorly, increasing thoracic volume and drawing air into the lungs.

• Exhalation: The diaphragm relaxes and moves superiorly, while the external intercostal muscles relax, decreasing thoracic volume and expelling air.

• The external intercostal muscles assist in inhalation by elevating the ribs, while the internal intercostal muscles aid in forced exhalation.

• During normal breathing, exhalation is typically passive, relying on elastic recoil of the lungs.

• Forced Exhalation: Involves active contraction of abdominal muscles and internal intercostals to expel air more forcefully.

• Understanding these mechanics is essential for grasping how respiratory diseases can affect breathing.

Pathway of Airflow

• Air enters through the nasal cavity, where it is filtered, warmed, and humidified.

• The pathway of air is: Nasal Cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli.

• During exhalation, the sequence is reversed: Alveoli → Bronchioles → Bronchi → Trachea → Larynx → Pharynx → Nasal Cavity.

• The trachea is also known as the windpipe and is supported by cartilage rings to maintain its structure.

• The epiglottis prevents food from entering the trachea during swallowing, ensuring that air flows correctly into the lungs.

• Understanding this pathway is crucial for recognizing how obstructions can affect breathing.

Gas Exchange and Respiratory Physiology

Gas Exchange Mechanisms

• Diffusion: The primary mechanism for gas exchange in the lungs, where oxygen and carbon dioxide move from areas of higher concentration to lower concentration.

• Oxygen is transported in the blood primarily bound to hemoglobin within red blood cells.

• Carbon dioxide is produced as a by-product of cellular respiration and is transported back to the lungs for exhalation.

• The partial pressure of gases influences their movement; oxygen moves from the alveoli (high concentration) to the blood (low concentration).

• Acid-Base Balance: Increased carbon dioxide levels can lower blood pH, triggering the nervous system to increase the rate and depth of respiration to expel CO2.

• Understanding these processes is vital for assessing respiratory efficiency and fitness.

Circulatory System Interaction

• Pulmonary Circulation: Transports deoxygenated blood from the heart to the lungs for oxygenation.

• Systemic Circulation: Delivers oxygenated blood from the lungs to the rest of the body.

• The heart plays a crucial role in maintaining these circulatory pathways, with the right side pumping blood to the lungs and the left side pumping it to the body.

• The cardiac output and VO2 max are important indicators of cardiovascular and respiratory fitness, with VO2 max representing the maximum amount of oxygen utilized during intense exercise.

• Understanding the relationship between the respiratory and circulatory systems is essential for evaluating overall health.

• Case studies of athletes often show enhanced lung volumes and capacities due to training, illustrating the adaptability of the respiratory system.