Sunday, December 4, 2016

ch. 13 | the respiratory system

functions: gas exchange 
  • delivering oxygen from air to cells & tissues
  • removing carbon dioxide from cells & tissues
  • expelling carbon dioxide into the air
UPPER RESPIRATORY TRACT: nose, pharynx (throat)
  • nasal septum: divides nasal cavity into right & left sides
  • bronchioles: smaller tubes that branch from tertiary bronchi
  • oropharynx & laryngopharynx can transport food & air 
  • the nasal pharynx is continuous w the nasal cavity & only transport air 
  • the right lung has 3 lobes; the left has 2 lobes
  • serous fluid is located in the pleural cavity
  • terminal bronchioles sends air directly into the respiratory bronchioles
LOWER RESPIRATORY TRACT: larynx, trachea, bronchi, bronchioles, lungs
  • the thyroid cartilage of the larynx is the largest
  • the epiglottis forms a lid over the larynx when we swallow 
  • during swallowing, muscles of the pharynx & larynx move the larynx superiorly
BRANCHING OF BRONCHIAL TREE: trachea-->primary bronchi--> secondary bronchi--> tertiary bronchi--> bronchioles--> terminal bronchioles--> respiratory bronchioles--> alveolar ducts--> alveolar sacs--> alveoli

alveolus: air sac in the lungs 
  • pulmonary ventilation: (breathing) flow of air into & out of the lungs
  • external respiration: gas exchange btwn alveoli & blood in pulmonary capillaries (blood picks up oxygen from air & releases carbon dioxide into the air)
  • internal respiration: gas exchange btwn tissue cells & blood in the systemic capillaries (blood releases oxygen into the tissues & picks up carbon dioxide from them)
  • inhale: pressure inside lungs < atmospheric air pressure
  • exhale: pressure inside lungs > atmospheric air pressure
  • with each inhalation and exhalation moves about 500 mL of air into & out of the lungs
  • diffusion moves gases across the capillary membranes (high-->low)
  • oxygen is transported through the blood attached to hemoglobin
  • 1 hemoglobin molecule can bind to 4 oxygen (oxyhemoglobin)
  • carbon dioxide travels through the blood:
7% in the plasma
23% bound to hemoglobin (carbaminohemoglobin)
70% as bicarbonate ions
  • transport of oxygen:
1.5% dissolved in plasma
98.5% as oxyhemoglobin
  • smoking can damage lung tissue; major contributing factor of pulmonary disease 
  • internal respiration does not occur in the lungs

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