Respiratory System BSC 2086 A&P 2 Professor Tcherina Duncombe Palm Beach State College Respiration • Ventilation of lungs • Gas exchange between air/bld and bld/tissue • Use of oxygen in cellular respiration Respiratory System: Function • O2/CO2 exchange • Speech/vocalizations • Smell • Controls pH of body fluids • Regulates blood pressure • Promote flow of lymph and venous blood • Breath-holding helps to expel abdominal contents (Valsalva maneuver) Lower Respiratory System Organs of Respiratory System • Nose • Pharynx • Larynx • Trachea • bronchi • Lungs Conducting Division: Nostrils → bronchioles Respiratory Division: Alveoli/gas exchange regions Upper: head/neck Lower: thorax 22-5 Anatomy of Nasal Region • warms • Cleanses • humidifies • Detects odors • resonating chamber: amplifies voice • external nares to internal nares 22-6 Anatomy of Nasal Region • Shaped by bone and hyaline cartilage 22-7 Upper Respiratory Tract • Nasal cavity: begins at vestibule 22-8 Upper Respiratory Tract 22-9 Mucosa: extends into lungs • Ciliated pseudostratified • Sensory/Nonsensory • Goblet cells; ciliated cells • Lysozyme destroys bacteria • Lamina propria: lymphocytes, plasma cells Mucosa • Olfactory mucosa: sensory • Respiratory mucosa: nonsensory • Erectile tissue: large blood vessels: warm air • Air flow alternates between right and left nostrils every 30 to 60 • Nosebleeds: from lower minutes septum Regions of Pharynx 22-12 Larynx: voicebox • 9 cartilages 22-13 Action of Vocal Cords Lower Respiratory Tract Endoscopic View • Lower end of trachea • Forks into primary bronchii • Bronchoscope • C-shaped rings: hyaline cartilage: posterior open part: trachealis • Pseudostratified columnar epithelium: goblet cells, ciliated cells, short, basal stem cells • Mucociliary escalator Lungs - Surface Anatomy Lung Tissue: spongy texture 22-18 Alveolar Blood Supply Alveolus •Squamous alveolar cell: gas exchange •Great alveolar cell: 1)repair 2) pulmonary surfactant: enhances inflation of alveoli/prevents collapse when exhale • alveolar macrophages: much lymph drainage •Respiratory membrane: low bld pressure in capillaries prevent rupture Pleurae • Visceral pleura • Parietal pleura • Pleural cavity • Pleural fluid • Reduce friction • Create pressure gradient • Forms compartments: prevent spread of infection Thorax - Cross Section 22-22 Respiratory Muscles Respiratory Control Centers Neural Control of Breathing • Dependent on brain: Skeletal muscles need nervous stimulation to contract pneumotaxic → Breathing requires many muscles; need coordination mechanism Cerebral: conscious Unconscious: •Dorsal respiratory group •Ventral respiratory group •Pneumotaxic center Peripheral Chemoreceptor Paths • central: brainstem •Peripheral: carotid/aortic bodies • Stretch: smooth muscle: lungs • irritant: epithelial cells in airway Respiratory Cycle Pressure Resistance to Airflow • diameter of bronchioles • pulmonary compliance: ease of lung expansion • surface tension of alveoli/distal bronchioles: infant respiratory distress syndrome • anatomical dead space 150 mL : in conducting tubes: pathological dead space • physiological dead space: anatomical + pathological •Relaxation = minimized: parasympathetic • Arousal = increased: parasympathetic Hydrogen Bonds: form network Cohesion: surface tension: “skin” Spirometry • Spirometer • Capacities • Respiratory Volumes • Vital = ERV + TV = IRV • Inspiratory= TV + IRV tidal volume • Func residual = RV + ERV inspiratory reserve • Total lung = RV + VC = volume max ability to ventilate expiratory reserve lungs in one breath volume • Restrictive disorders residual volume • Obstructive disorders • FEV/peak flow/MRV/MVV(max breathing capacity) Air Flow • Atmospheric pressure • Intrapulmonary pressure • Intrapleural pressure • Transpulmonary pressure • Temperature Pneumothorax → Atelectasis: puncture; obstruction → tumor; aneurysm; swollen lymph node; inhaled object Gas Laws • Boyles Law: pressure/volume • Charles Law: volume/temperature • Dalton’s Law: partial pressure • Henry’s Law: air-water interface Boyles Law: Pressure and Volume: inversely proportional Atmospheric pressure drives respiration Alveolar Gas Exchange Concentration Gradients of Gases 22-35 Ambient Pressure and Concentration Gradients 22-36 Lung Disease Affects Gas Exchange 22-37 Perfusion Adjustments Ventilation Adjustments Oxyhemoglobin Dissociation Curve 22-40 Systemic Gas Exchange Alveolar Gas Exchange Oxygen Dissociation and Temperature 22-43 Oxygen Dissociation and pH Bohr effect: release of O2 in response to low pH Obstructive Pulmonary Diseases • COPD • Bronchitis • Emphysema • Corpulmonale • Carcinoma Healthy Lung/Smokers Lung- Carcinoma.