Respiratory System (Chapter 22) and Cardiac System (Chapters 16 & 18) Review Flashcards

Upper Respiratory Tract: Structures and Functions

• Upper vs lower respiratory tract definitions:
  • Upper respiratory tract: everything outside of the chest, from the nose down to the first half of the trachea.
  • Lower respiratory tract: structures inside the chest, particularly within the lungs.
  • The trachea connects both regions.
• Key upper tract structures and functions:
  • Nose (nares): filters, warms, and humidifies air.
  • Pharynx: passageway for air; part of the shared pathway for air and food.
  • Larynx: voice box; guards airway during swallowing.
  • Trachea: windpipe; reinforced by cartilaginous rings to prevent collapse.
  • Epiglottis: prevents aspiration of food into the airway.
  • Trachea ultimately branches into the bronchi of the lower tract.
• Exam emphasis:
  • Expect questions on structures of the upper respiratory tract and their key characteristics.
• Key lower tract structures and their order:
  • Trachea connects the upper and lower tracts; it branches into the right and left bronchi (main bronchi).
  • Bronchi branch into bronchioles and eventually alveoli.
• Trachea specifics:
  • Composed of C-shaped cartilaginous rings to keep it open and prevent collapse.
• Bronchi, bronchioles, and alveoli:
  • Bronchi: conducting air into each lung; branch from the trachea into the lungs.
  • Bronchioles: small airways with smooth muscle that regulate airflow.
  • Alveoli: grape-like air sacs where gas exchange occurs; single-layer epithelium facilitates diffusion.
• Diffusion and gas exchange:
  • Diffusion: movement of particles from an area of higher concentration to lower concentration; in the alveoli, oxygen moves from air into red blood cells, and CO₂ moves from capillaries into the alveoli.
  • Alveoli are wrapped with their own pulmonary capillary network to enable exchange.
• Alveolar gas exchange Details:
  • Alveoli are lined with water molecules, which contribute to surface tension.
  • Surfactant decreases surface tension to keep alveoli open and prevent collapse.
• Lung anatomy and mechanics:
  • Lungs are located in the thoracic cavity (thoracic cage).
  • Five total lobes: three on the right, two on the left (the heart occupies space on the left).
• Pleura and intrapleural space:
  • Lined by two serous membranes: visceral pleura (covers the lung surface) and parietal pleura (lines the chest wall).
  • Intrapleural space contains a small amount of fluid to reduce friction.
  • A negative intrapleural pressure is essential to keep the lungs expanded; loss of this pressure leads to collapse.
• Forces opposing/promoting lung expansion:
  • Elastic recoil: like a rubber band, the lung tends to snap back to baseline after expansion, aiding expiration.
  • Surface tension: within the alveoli due to water molecules pulling inward, promoting collapse tendency.
  • Surfactant counteracts surface tension to keep alveoli open and stable.
• Lung expansion and pressure relationships:
  • Understand atmospheric pressure, intrapulmonary (intrapulmonary) pressure, and intrapleural pressure.
  • Negative intrapleural pressure is necessary for sustained lung expansion.
• Ventilation and breathing control:
  • Diaphragm: the primary dome-shaped breathing muscle.
  • Intercostal muscles: muscles between the ribs that assist breathing.
  • Medulla oblongata: brainstem region that stimulates involuntary respiration.
• Common respiratory terms:
  • Be familiar with common terms listed on the slides (refer to table 20-22-2 in the textbook) for exam-winning familiarity.

Cardiac Anatomy and Function: Chapters 16

• Heart walls and layers:
  • Endocardium: inner lining of the heart.
  • Myocardium: the muscular middle layer; essential for pumping action.
  • The myocardium thickens in the ventricles, especially the left ventricle, because it does the most work.
• Coronary arteries and myocardial oxygen supply:
  • Coronary arteries supply oxygen-rich blood to the myocardium.
  • The heart’s tissue requires a constant oxygen supply; compromise can impair pumping ability.
• Heart chambers and oxygenation status:
  • Atrium (top chambers) receive blood.
  • Ventricle (bottom chambers) pump blood.
  • Right side of the heart (blue) handles deoxygenated blood to the lungs.
  • Left side of the heart (red) pumps oxygenated blood to the systemic circulation.
• Great vessels:
  • Vena cava: largest veins in the body.
  • Aorta: largest artery.
  • Knowledge of which chambers these vessels connect to and whether blood is oxygenated or deoxygenated.
• Valves and unidirectional flow:
  • Atrioventricular (AV) valves: tricuspid (right) and mitral (left) prevent backflow into the atria.
  • Semilunar valves: pulmonic (pulmonary valve) and aortic valves prevent backflow into the ventricles.
• Blood flow through the heart (order):
  • Right atrium → Right ventricle → Pulmonary artery → Lungs → Pulmonary veins → Left atrium → Left ventricle → Aorta.
• Cardiac sounds and murmurs:
  • Normal sounds: “lub-dub” corresponding to AV valve closure and semilunar valve closure.
  • Murmurs: abnormal heart sounds indicating backflow or valve issues; require identification on exam.
• Blood flow and oxygenation concepts:
  • Oxygenated vs deoxygenated blood must be identified for each structure involved; color coding (blue for deoxygenated, red for oxygenated) is recommended for memory aid.
• Coronary vessels and ischemia/infarction:
  • Coronary vessels supply the myocardium; issues can cause ischemia (reversible) or infarction (toreversible cell death).
• Cardiac conduction system:
  • SA node (sinoatrial node): the pacemaker that generates the impulse.
  • AV node (atrioventricular node): delay in signal transmission to allow atrial filling.
  • Bundle of His and Purkinje fibers: conduct impulse rapidly through ventricles to cause contraction.
• Cardiac conduction and heart rate:
  • Normal adult heart rate: 60-100 ext{ beats per minute}.
  • Bradycardia: HR < 60 bpm; tachycardia: HR > 100 bpm.
  • Importance of conduction pathway for synchronized beating and pumping.
• Concepts of myocardial health:
  • Ischemia vs infarction reviewed here as key terms regarding coronary blood flow and tissue viability.

Blood Vessels: Structure and Function (Chapter 18)

• Vessel layers (tunics):
  • Tunica intima (innermost).
  • Tunica media (middle; smooth muscle).
  • Tunica externa/adventitia (outer layer).
• Vessel types and their roles:
  • Arteries: carry blood away from the heart; high pressure; designed for rapid transport.
  • Arterioles: smaller arteries; known as resistance vessels; contain smooth muscle to regulate diameter and thus flow and pressure.
  • Capillaries: exchange vessels; single-layer walls; most abundant; site of gas, nutrient, and waste exchange.
  • Venules and Veins: return blood toward the heart; low pressure; valves and skeletal muscle pumps assist venous return to prevent pooling.
• Order of the vascular tree:
  • Arteries → Arterioles → Capillaries → Venules → Veins.
• Pulmonary vs systemic considerations:
  • Systemic circulation delivers oxygen to tissues; pulmonary circulation handles gas exchange in the lungs.
• Blood flow assessment and pulse basics:
  • Pulse is an assessment of the heart rate and perfusion; generated by the vibration of blood against vessel walls when the heart beats.
  • Normal adult pulse rate target: 60-100 ext{ beats per minute}.
  • Common pulse sites (examples): wrist (radial), groin (femoral), behind the knee (popliteal), and the foot (dorsalis pedis).
  • Pulse characteristics to assess: rate, rhythm, and strength.
• Practical implications:
  • Understanding pulse sites and vessel anatomy aids assessment of circulation and fluid volume status.
  • Knowledge of vessel structure helps anticipate susceptibility to conditions like varicosities or edema in venous systems.

Practical Connections and Exam Relevance

• Color-coding oxygenation status (blue/deoxygenated vs red/oxygenated) helps memorize organ and vessel roles in circulation.
• The heart’s double pump and the separation into pulmonary and systemic circuits underlie oxygen delivery and waste removal.
• Ischemia vs infarction concepts are clinically critical for recognizing chest pain presentations and urgency of intervention.
• Surfactant, surface tension, and negative intrapleural pressure are key concepts for understanding ventilation efficiency and conditions like atelectasis.
• The diaphragm and intercostal muscles, along with the medulla, provide the muscular and neural basis for breathing control.
• Accurate knowledge of airflow order (trachea → bronchi → bronchioles → alveoli) and gas exchange mechanisms underpins physiology exam questions.
• Understanding heart sounds and potential murmurs helps with auscultation-based assessment skills.
• Knowing the exact blood flow path through the heart helps with questions about oxygenation status and valvular function.
• Correlating vessel structure with function (arteries vs veins, capillary exchange) clarifies pathophysiology and clinical assessment.

Notable Numerical References from the Transcript

• Normal adult heart rate range: 60-100 ext{ beats per minute}.
• Five total lobes of the lungs: three on the right, two on the left, due to cardiac occupancy on the left side.
• The heart’s valve and chamber relationships, while not given as numbers, rely on the standard flow sequence and anatomical order described above.