LIFESCI 2 Lecture Notes - Lecture 20: Internal Intercostal Muscles, Intercostal Muscle, External Intercostal Muscles

• School: UCLA
• Department: Life Sciences
• Course: LIFESCI 2
• Professor: Arnold, A.P., Esdin, J.

Document Summary

Respiratory system: ventilation: breathing; o2 into lungs, diffusion: o2 from lung to blood, circulation: bulk transport of o2 in blood, diffusion: o2 from capillaries to cells, air composed mostly of n2. Partial pressure of o2: 0. 2 * 760mmhg at sea level: alveolus. Type i alveolar cell: cells making up alveolar wall. Type ii alveolar cell: release surfactant -> prevent lungs from collapsing. Synchronize chest, lungs, ribcage: boyle"s law: change in container volume changes pressure. Important for respiration: inhale -> lung volume increase -> pressure decrease -> air goes in. Pressure gradient: respiration initiated by nervous system; neurons initiate skeletal muscles, diaphragm: dome shaped muscle lungs sit on. Ab contract -> diaphragm pushed up internal intercostal muscle contract: o2 bond to protein haemoglobin in red blood cells/erythrocyte. 99% o2 bond to haemoglobin, rest dissolved. Co2+h2o -> h+ + hco3- (enzyme carbonic anhydrase) control of breathing. Medulla oblongata: respiratory center (other in pons)