The Respiratory SystemSBI 3U

January 14th, 2013

The Respiratory SystemExchange of oxygen and carbon dioxide between an

organism and its external environmentRespiratory system: supplies oxygen to cells and

removes carbon dioxideCO 2 and breathing rate

More Respiratory FunctionsDefends body against foreign pathogensControls pH levelsProduces sounds for speakingHelps maintain homeostasis

Components of RespirationVentilation or breathingInhalation and exhalationLungs: specialized structures for respiration (large surface area)

Components of RespirationExternal RespirationExchange of gases across the respiratory

surface between air sacs or alveoli and the blood

Respiratory surface – where oxygen diffuses into organism and CO2 diffuses out

Components of RespirationInternal RespirationExchange of gases between the blood in

capillaries and individual cells in the tissuesOxygen diffuses out of blood and CO2

diffuses in

Components of RespirationOccurs in the mitochondriaGlucose as fuel

Anatomy of Respiratory SystemUpside down tree!Begins with nasal cavity and ends at alveoliConsists of: nose, nasal cavity, pharynx, larynx,

trachea, smaller conducting passageways, and lungs

Nasal and Oral Cavities21% of every air inhalation is oxygenInhalation from mouth vs. noseNasal cavity: lined with mucus-secreting

cells; helps to moisten and filter incoming airOral cavity

The PharynxPharynx: common path for both air and foodTrachea/epiglottisLarynx at top of trachea

The LarynxAdam’s appleProduces soundVocal chords: two highly elastic folds inside

larynx

The TracheaWindpipeAllows air to pass from pharynx into lungsTough, flexible, c-shaped cartilage rings

surrounds the trachea

Respiratory Structures Within the Chest CavityTrachea divides into 2 branches: right and left bronchiLeft bronchus Left lungRight bronchus Right lungLungsBronchi branch into smaller tubes called bronchiolesAlveoli

Respiratory Structures Within the Chest CavityBronchioles enter in a cluster of tiny hollow

air sacs called alveoli150 million alveoli in each lung!Occur in clustersGas exchange