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Circulatory and Respiratory Systems - General Biology

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  • Function of the circulatory system

    The circulatory system transports blood, nutrients, gases, and wastes throughout the body to maintain homeostasis.

  • Define homeostasis and circulatory system's role

    Homeostasis is the maintenance of a stable internal environment. The circulatory system helps by regulating temperature, pH, and distributing hormones and nutrients.

  • Difference between pulmonary and systemic circuits

    The pulmonary circuit carries blood between the heart and lungs for gas exchange; the systemic circuit carries oxygenated blood from the heart to the body and returns deoxygenated blood back.

  • Four chambers of the heart

    The heart has two atria (right and left) and two ventricles (right and left) that pump blood through the circuits.

  • Five major blood vessels of the heart

    Major vessels include: vena cava (vein), pulmonary arteries, pulmonary veins, aorta, and coronary arteries.

  • Pathway of blood starting at right atrium

    Right atrium → right ventricle → pulmonary artery → lungs → pulmonary veins → left atrium → left ventricle → aorta → body → vena cava → right atrium.

  • Heart valves and their function

    Valves (tricuspid, pulmonary, mitral, aortic) prevent backflow of blood and produce heart sounds when they close.

  • How is heartbeat controlled?

    The sinoatrial (SA) node initiates the heartbeat, sending impulses to the atrioventricular (AV) node, then to the bundle of His and Purkinje fibers, coordinating contraction.

  • What is a heart attack and its cause?

    A heart attack occurs when blood flow to heart muscle is blocked, often by a clot, causing tissue damage.

  • Compare arteries, veins, and capillaries

    Arteries carry blood away from the heart, thick walls; veins carry blood to the heart, have valves; capillaries are thin-walled for exchange.

  • Components of blood and their functions

    Blood contains red blood cells (carry oxygen), white blood cells (immune defense), platelets (clotting), and plasma (transports nutrients and wastes).

  • What is hypertension and why is it called the silent killer?

    Hypertension is high blood pressure that often has no symptoms but increases risk of heart disease and stroke.

  • Function of the respiratory system

    The respiratory system facilitates gas exchange, supplying oxygen to blood and removing carbon dioxide.

  • Relation of respiratory system to cellular respiration

    Oxygen from the respiratory system is used in cellular respiration to produce energy; carbon dioxide is a waste product expelled by breathing.

  • Gas exchange in earthworms and fish

    Earthworms exchange gases through moist skin; fish use gills with a countercurrent mechanism to maximize oxygen uptake.

  • Function of alveoli, diaphragm, larynx, and trachea

    Alveoli are sites of gas exchange; diaphragm controls breathing; larynx produces sound; trachea conducts air to lungs.

  • Human mechanisms to prevent lung irritants

    Humans use mucus, cilia, and coughing to trap and remove dust, bacteria, and other irritants from airways.

  • How cold, dry air affects breathing

    Cold, dry air can reduce moisture in airways, causing irritation and increased mucus production.

  • Volume and pressure changes during inhalation

    Diaphragm contracts and rib muscles expand thoracic cavity, increasing volume and decreasing pressure to draw air in.

  • Volume and pressure changes during exhalation

    Diaphragm relaxes and rib muscles contract, decreasing thoracic volume and increasing pressure to push air out.

  • What is surfactant and its importance?

    Surfactant reduces surface tension in alveoli, preventing collapse and aiding efficient gas exchange.

  • Relation of homeostasis to SpO2 and breathing rate

    Homeostasis maintains blood oxygen saturation (SpO2) by adjusting breathing rate to meet oxygen demand.