LC Excretion (breathing and skin)

The taking of oxygen and releasing of carbon dioxide via the lungs.

The maintenance of a constant internal environment in a living organism

Using the oxygen that has been inhaled in breathing to release energy from food during aerobic respiration

in the thoracic cavity

• Are air tight
• protected by rib cage and sternum (breastbone)
• pleural membrane

• allows for friction-free movement
• lubricant

lined with cilia

to trap dust particles

• a flap of tissue at top of trachea to seal over trachea during eating
• (to prevent food going down the wrong way)

• part of the airway passage
• allows air to enter the lungs

lined with rings of cartilage to prevent the collapse of the trachea

The trachea divides into two bronchi, one leading into each lung

the point of gaseous exchange where gases (o2 and co2) are exchanged between the lungs and blood

controlling the volume of lungs

protection

voice box

Presence of many alveoli increase large surface area (more co2 and o2 can be exchanged)

• Walls are one cell thick (allow for faster movement of molecules)
• (o2 and co2 diffused between alveoli and blood)

Moist surface (gases can only travel dissolved in water)(liquid)

Surrounded by a good blood supply.

endoderm germ layer

• Nose
• trachea
• bronchus
• Bronchiole
• alveoli
• blood

• Blood
• Alveoli
• Bronchiole
• Bronchus
• Trachea
• Mouth

• High levels of co2 in blood detected by the medulla oblongata
• in the brain

sends an electrical impulse (through nerves) from the brain to lungs

Diaphragm contracts and flattens

Intercostal muscles contract between ribs

ribcage moves up and out

the volume of lungs increase

the pressure inside the lungs is lower than external surroundings

Air is taken in from the surrounding environment

The diaphragm relaxes and becomes a dome (arch shape)

Intercostal muscles relax

Ribcage moves down and in

The volume of lungs decreases

The pressure inside the lungs is higher than the external surroundings

Air is released to the surrounding environment

symptoms: coughing and difficulty breathing

cause: presence of dust, pollen and other allergies

treatment: inhaler/bronchodialtor

Prevention: Inhaler and avoid allergens

Increased breathing (faster and deeper) during exercise is due to an increase in the presence of co2.

co2 is a poisonous gas and the body work at a faster rate to try and eliminate it from the body and dilute its presence with an increased presence of co2