Respiratory System

Respiratory Exchange Surfaces

Aveoli

cellular respiration

reactions in cells that break down nutrients to release energy (ATP) • glucose + O2 => CO2 + H2O + Energy

Why do smokers cough more than non-smokers?

• to clear debris, as their cilia have been damaged by smoke large tissue damage=> scar tissue => less surface area for exchange and shallower breath

Respiratory Tubes

Trachea (main airway) =>into Bronchus (plural of bronchi) --> Bronchioles

Respiratory Tract

air enters nose or mouth => goes through pharynx (throat) => goes through larynx (voice box) => thru Trachea (main airway) => into Lungs => into Bronchus (plural of bronchi) --> Bronchioles => Aveoli

How Are Gases Exchanged and Transported?

lungs: oxygen "in" (into blood) and carbon dioxide "out" (out of blood, and released from body through exhalation) tissues: oxygen "out" (of blood and into tissues) and carbon dioxide "in" (into blood)

Respiratory Entrances

noise & mouth => goes through pharynx (throat) => goes through larynx (voice box)

During exhalation

the diaphragm and rib muscles relax, decreasing the volume of the lungs. Air leaves the alveoli and flows up the bronchioles, bronchi, and trachea, and exits through the nose or mouth.

Breathing Machinery

• 2 membranes around the lungs - connected to muscle • ribs connected by muscles • diaphragm

How we Breath

• Inhalation => chest cavity expands -Rib muscles contract to lift ribs up & out Diaphragm contracts (moves downwards) • Exhalation => Rib muscles and diaphragm (diaphragm pulled upwards) relax • Resting State - diaphragm relatively still up, rib muscles relatively relaxed

3 KEY properties of an exchange surface in animals

• Moist - cells need to stay moist • Thin - rely on diffusion, passive process • Sufficient Surface Area

Exhalation

• Rib muscles and diaphragm relax (diaphragm pulled upwards)

Cilia

• moves fluid on top of those cells, cleaning system • Epithelium covered with cilia and mucous acts as a cleaning system ("mucus elevator")

Aveoli

• primary site for gas exchange

Aveoli

• smaller, where exchange takes place • most of the tissue in the lungs • look like bunches of grapes at the the end of a bronchial tube • hollow with mucous lining • large amount of capillary tissues in lungs, surrounds aveoli densely

During inhalation

• the diaphragm and rib muscles contract, increasing the volume of the lungs. Air enters the nose or mouth and flows down the trachea, bronchi, and bronchioles, and into the alveoli.

Purpose for gas exchange

• O2 needed for cellular respiration => breaking down energy to drive all body's processes, CO2 by product

Key to Cellular Respiration

• all animals rely on diffusion to take in O2 and to release CO2 high [ ] to low [ ]

Why is the level of CO2 a direct reflection of the level of oxygen use?

• anytime you make CO2, it means you used O2 (in cellular respiration) • back up systems for both (don't have to know specific names, just know that they exist)

Direction of O2 and CO2 Movement

• based on partial pressure (amount of dissolved gas) • move from high partial pressure to low partial pressure

Inhalation

• chest cavity expands -Rib muscles contract to lift ribs up & out Diaphragm contracts (moves downwards)

Cilia in Smokers

• cilia destroyed => fluid build-up

Respiratory System

• gas exchange

Why molecules moving from outside to inside?

• high [ ] to low [ ] i.e. lungs - O2 in and CO2 out

Cartilage Function in Breathing

• in rings around the Trachea & Bronchi to hold open => So air flow is continuous all the time

Bronchioles

• lined with tissues that look like little hairs (cilia)

Breath Controlled by

• main mechanism: levels of CO2 -control center = medulla oblongata • oxygen sensors in the aorta and carotid arteries detect significant decreases in O2 levels

CO2 Transport

• mainly as a molecule called bicarbonate (HCO3-) • combines with H20 --> forms Carbonic Acid Bicarbonate

O2 Transport

• mainly by hemoglobin • higher altitude => more red blood cells produced => more 02

Partial Pressure

• moves O2 and CO2 in proper direction • similar to high [ ] to low [ ] • higher [ ] in lungs & air into blood • lower (what is ? O2?)in tissues than in blood, • I think (?) that Higher [ ] of O2 or CO2 move to Lower [ ]s of themselves