BSC 109 Lecture 15 Outline of Last Lecture I Transmissibility, mode of transmission and virulence determine health riskII The lymphatic system defends the bodyIII Lymphatic vessels transport lymphIV Lymph nodes cleanse the lymphV Spleen cleanses the bloodVI Thymus gland hormones cause T Lymphocytes to matureVII Keeping pathogens out: the first line of defenseVIII Keeping pathogens out: the first line of defenseIX Nonspecific defenses: Second line of defenseX Specific defense mechanism: the third line of defenseXI The immune system targets antigensXII Medical assistance in the war against pathogensXIII Inappropriate immune system activity causes problemsOutline of Current Lecture I. Respiratory system consists of upper and lower respiratory tractII. Upper respiratory tract filters, warms, and humidifies airIII. Lower respiratory tract exchanges gases (oxygen and carbon dioxide)IV. The lungs are organs of gas exchangeV. Gas exchange occurs in alveoliVI. Pulmonary capillaries bring blood and air into close contactVII. Defenses of the respiratory tractVIII. Lung volumes and vital capacity measure lung functionIX. Gas exchange and transport occur passivelyX. Hemoglobin transports most oxygen moleculesXI. The nervous system regulates breathingXII. Disorders of the respiratory systemCurrent LectureChapter 10XIII. Respiratory system consists of upper and lower respiratory tractA. Upper respiratory tract1. Nose, nasal passages, sinuses2. PharynxThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.B. Lower respiratory tract1. Larynx2. Trachea3. Bronchi and bronchioles4. Lungs5. AlveoliXIV. Upper respiratory tract filters, warms, and humidifies airA. Functions of nose and pharynx1. Acts as passageway for respiration2. Has receptors for smell3. Has resonating chambers for voiceXV. Lower respiratory tract exchanges gases (oxygen and carbon dioxide)A. Larynx1. Epiglottis: flexible flap of cartilage that routes air and food appropriately2. Vocal cords: assist in sound production3. Maintains open airwayB. Trachea1. Aka “windpipe”2. Kept open by C-shaped rings of cartilage3. Lined with mucus-secreting ciliated epithelium4. Cough reflexC. Bronchi1. Trachea branches into two airways- right and left bronchi2. Contain ciliated epithelia, smooth muscle, cartilageD. Bronchioles: smaller branches, lack cartilageE. Functions of bronchi and bronchioles: clean, warm, and humidify incoming airXVI. The lungs are organs of gas exchangeA. Supportive tissue enclosing the bronchi, bronchioles, blood vessels, and alveoli (air pockets where gas exchange occurs)B. DiffusionC. Simple squamousD. Area between pleural membranes (pleural cavity) contains fluid which reduces friction as lungs moveE. Three lobes in right lung, two in left (due to presence of the heart)F. Lungs function relatively independently of each otherXVII. Gas exchange occurs in alveoliA. Alveoli: tiny air-filled sacs clustered at end of terminal bronchiolesB. One squamous epithelial cell layerC. Combined surface area of alveoli: 800 ft2D. Lipoprotein surfactant secreted by alveolar cells reduces surface tension enablinginflation of alveoliXVIII. Pulmonary capillaries bring blood and air into close contactA. Lungs receive deoxygenated blood from right ventricle of heart through pulmonary arteriesB. Pulmonary capillaries allow blood to come into close proximity with air in alveoliC. Venules and veins collect the oxygenated blood from alveolar capillaries and return it to the left side of the hear for distribution throughout the bodyXIX. Defenses of the respiratory tractA. Mucus: entraps microorganismsB. Cilia: push microorganisms and mucus up and out of respiratory tractC. Cough reflex: if buildupXX. Lung volumes and vital capacity measure lung functionA. Tidal volume: volume of air inhaled and exhaled in a single breathB. Dead space volume: volume of air that remains in the airways and does not participate in gas exchangeC. Vital capacity: maximal volume that can be exhaled after maximal inhalationD. Measured by spirometerXXI. Gas exchange and transport occur passivelyA. Partial pressure: the pressure exerted by one particular gas in a mixture of gasesB. A gas always diffuses down its partial pressure gradient, from higher to lower partial pressureXXII. Hemoglobin transports most oxygen moleculesA. Hemoglobin + oxygen -> HbO2B. A shortage of iron1. Causes a decrease in the rate of hemoglobin synthesis2. Can lead to anemiaC. Most CO2 (70%) is transported in plasma as bicarbonateXXIII. The nervous system regulates breathingA. Neurons in medulla generate impulses every 4-5 secondsB. Stimulates intercostal muscles and diaphragmC. The rate and depth of normal breathing is determined by the need to get rid of CO2 rather than the need to obtain O2D. Conscious control resides in the cerebral cortexXXIV. Disorders of the respiratory systemA. Asthma: spasmodic contraction of bronchi (caused by episodic allergic responses); controlled by bronchodilators and corticosteroidsB. Emphysema: alveoli permanently impaired; breathlessness due to decreased surface area for gas exchangeC. Bronchitis: inflammation of bronchiD. Cystic fibrosis: inherited condition; abnormally thick mucus in lungs impedes air flowE. Upper respiratory infections1. Colds and flua) Caused by virusesb) Antibiotics NOT effective2. Pneumonia: infection of the lungsa) May be caused by bacteria or virusesb) Treatment depends on causeF. Respiratory infections and intoxications (microorganisms)1. Tuberculosis: bacterial infection that scars the lungsa) Diagnosis: skin test/chest X-rayb) Treatment: antibiotics2. Botulism: poisoning by bacterial toxina) Improperly preserved foodsb) Causes paralysis of skeletal muscles including intercostals and diaphragmG. Lung cancer is caused by proliferation of abnormal cells1. Cancer: uncontrolled growth of abnormal cells; Impairs air flow, gas exchange, blood flow2. Mesothelioma: deadly cancer of lining of lungs heart, and abdomenH. Pneumothorax and atelectasis: a failure of gas exchange1. Pneumothorax: collapse of one or more lobes of the lungs; most often due to penetrating wound; treatment: remove air from pleural cavity2. Atelectasis: lack of gas exchange due to alveolar collapse or fluid build-up;can be a complication of surgery; may result from deficient surfactantI. Congestive heart failure impairs lung function1. Heart becomes a less efficient