RESPIRATORY SYSTEM

Function Exchange of O 2 and CO 2 to ensure the survival of each cell Why do we need Oxygen? For the combustion of nutrients so that energy can be produced

Cellular Respiration Glucose + O2 O2  Energy + CO 2 + Water Waste

Respiratory Tract Nasal PassagesPharynxLarynxTrachea Bronchi  Bronchioles  Alveoli Inside the Lungs

Respiratory Tract

Set up your notes like this… StructureDescriptionFunction Nasal Passages

Description: – Open to outside through NOSTRILS, end inside at pharynx Function: – Filter Air (with cilia – hairs that coat lining of cavities) – Warm and Moisten Air (with mucus)

Pharynx (throat) Description : – Common Passageway – Respiratory and Digestive Tract Function – Air towards Trachea – Food towards Esophagus (epiglottis seals trachea)

Larynx Description: – Connects pharynx to trachea – Mostly cartilage – Housing for Vocal Chords Function: – Carries Air – Produces sound (As we exhale, vocal chords vibrate and noise is produced. Words produced by movement of tongue.)

Trachea Description: – Tube held open by cartilaginous rings – Located in front of esophagus Function: – Filters air- sweeping motion of hair-like cilia towards pharynx – Warms and moistens air- mucus

Bronchi Description: – Tubes from division of trachea – Cartilaginous rings – Branch into bronchioles once inside lungs Function – Carry air to lungs

Bronchioles Description: – Subdivisions of bronchi – Ends with a cluster of alveoli

Alveoli Description: – Semi-permeable membrane that can allow O 2 and CO 2 to be exchanged Function: – Functional unit of lung – where O 2 and CO 2 are exchanged

Lungs Description: – 2 lungs – 5 lobes (3 right, 2 left) – Bronchi, bronchioles and alveoli found in lungs

Diaphragm Description: – Muscle of respiration Function: – Supports the lungs – Separates the thoracic and abdominal cavities

Respiration (Part 2) How O 2 and CO 2 are Exchanged

Main Concepts Air is a mixture of gases Air is COMPRESSIBLE – its volume can increase or decrease

Main Concepts PRESSURE VOLUME Inverse Relationship

Main Concepts Fluids flow from area of HIGH pressure to area of LOW pressure (see Gizmo)

Main Concepts There is pressure within the lungs and there is air pressure. They must always be balanced (EQUILIBRIUM)

Mechanics of Respiration INHALATIONEXHALATION Intercostal Muscles (between ribs) ContractRelax RibsRiseDescend DiaphragmContracts and descends Relaxes and rises Lung VolumeIncreasesDecreases Air PressureDecreasesIncreases ResultAir flows IN (O 2 rich) Air flows OUT (CO 2 rich)

Gas Exchange within the Lungs Alveoli – ~ 300 million – Surrounded by tiny blood vessels called capillaries

Blood cell

Diffusion Molecules go from HIGH concentration to LOW concentration

The Air we Breathe ComponentInhaled AirExhaled Air Nitrogen78% Oxygen (O 2 )21%16% Carbon Dioxide (CO 2 ) 0.04%5%

Gas Exchange O 2 diffuses from alveoli to blood O 2 : lung  blood  cell

Gas Exchange CO 2 diffuses from blood to the alveoli CO 2 : cell  blood  lung

2 Types of Blood Arterial – O 2 away from heart – Bright red Venous – CO 2 to lungs – Dark red