Larry M. Frolich, Human Anatomy, Respiratory Function Thoracic Cavity and Respiration Alveoli Respiratory Tree Lungs Diaphragm Intercostal Muscles

Larry M. Frolich, Human Anatomy, Respiratory Function Alveoli Key to lung function Where O2 enters blood, CO2 leaves blood Every alveoli is capillary covered sac Lining of sac is squamous epithelium Also cuboidal epithelial cells that secret surfactant (keeps surfaces from sticking) and cilia (to move mucous and particles up respiratory tree

Larry M. Frolich, Human Anatomy, Respiratory Function Respiratory Tree (how does air get to alveoli?) Branching pattern –Trachea –Primary bronchi (left, right) –Secondary bronchi (each lobe) –Tertiary bronchi, bronchioles –Alveoli Vessels accompany respiratory tree to alveoli

Larry M. Frolich, Human Anatomy, Respiratory Function

LUNGS Located in Pleural Cavities Lateral to Mediastinum Location –Apex posterior to clavicle –Base lays on Diaphragm –Costal Surface = Ant, Lat, Post surfaces contact wall of chest cavity Root - all vessels, nerves enter each lung –2 Pulmonary Veins = carries O 2 blood from each lung to heart –1 Pulmonary Artery = carries De-O 2 blood to each lung –Primary Bronchi –Nerves ––Lymph Vessels Pg 618

Larry M. Frolich, Human Anatomy, Respiratory Function LOBES OF LUNGS Left Lung = 2 lobes –Upper –Lower –Oblique Fissure –Cardiac Notch Right Lung = 3 lobes –Upper –Middle –Lower –Oblique fissure –Horizontal fissure Pg 622

Larry M. Frolich, Human Anatomy, Respiratory Function Specific Location of Lungs Right Lung –1” above Rib 1 –Crosses Costal Cartilage 6 –Midclavicular at Rib 6 –Midaxillary at Rib 8 –Vertebral Border at Rib 10 –Inferior border 2 rib widths above diaphragm Left Lung –1” above Rib 1 –Deep to Manubroclavicular joint –Midsternally to Rib 4 –Jogs to left, continues to Rib 6 –Midaxillary Rib 8 –Vertebral Border at Rib 10

Larry M. Frolich, Human Anatomy, Respiratory Function Action of the Diaphragm Primary muscle of respiration (involuntary) –Contraction during inspiration Increases volume of thoracic cavity Decreases pressure of thoracic cavity Air moves into lungs (high  low pressure) Forced contraction (voluntary) –Used for defecation, urination, labor Increases pressure in abdominal cavity Pushes on abdominal organs to move contents out

Larry M. Frolich, Human Anatomy, Respiratory Function Anatomy of the Diaphragm Skeletal Muscle Dome-shaped (relaxed) Divides thoracic & abdominal cavities Attachments –Origin: Inferior Internal rib cage –Insertion: Central tendon Innervated by right + left PHRENIC Nerves Pg 288 Superior View

Larry M. Frolich, Human Anatomy, Respiratory Function INTERCOSTAL MUSCLES Lift ribs to expand chest cavity for inspiration Three layers