6.4 Flashcards
Distinguish between ventilation, gas exchange, and cell respiration
Ventilation: exchange of air between lungs and atmosphere (breathing)
gas exchange: exchange of oxygen and co2 in alveoli and bloodstream by diffusion
Cell respiration: release of ATP from organic molecules (aerobic respiration)
Describe external Respiration:
in lungs.
exchange of gases between alveoli and blood. O2 into blood and CO2 out lungs
Describe Internal Respiration
in tissues
Exchange of gases between cells and blood in capillaries. O2 into cells, and CO2 out cells
What are capillaries
blood vessels that connect arteries and veins
state the process of breathing
- Nasal/oral: warm air, mucus traps small particles, nose hair traps large particles
- Pharynx: path for food and air
Esophagus: to stomach
Trachea: to lungs (epiglottis is a flap that covers the trachea when eating) - Larynx: voice box
- Trachea: a ring of cartilage for support, mucous and cilia
left bronchus - left lung / RIght bronchus - right lung - Bronchi/Bronchioles: Bronchi to bronchioles (further filtering)
- Alveoli: Tiny air sacs for gas exchange, 1 cell thick, surrounded by capilaries
purpose of ventilation
to cycle fresh air into alveoli. O2 levels stay high, CO2 levels stay low,
differentiate between type 1 and type 2 pneumocytes (alveolus cells)
type 1 is involved in process of gas exchange between alveoli and capillaries. They are flattened and thin, connected by occluding junctions, to prevent leakage of tissue fluid into alveolus air space
Type 2 is responsible for the secretion of pulmonary surfactant. They are circular. Can replicate into type 1 cells. Pulmonary surfactant creates moist inside of alveoli allowing for easier diffusion and prevents sides of alveolus from adhering to each other by reducing surface tension.
what happens during inspiration
External intercostal muscles contract. diaphragm muscle contracts, the diaphragm flattens, increase volume in the chest cavity, ribs upwards and outwards.
what happens during the expiration
internal intercostal muscles contract, diaphragm muscles relax, diaphragm curves upwards, decrease in volume of chest cavity ribs inwards and downwards
causes and consequences of lung cancer
caused by smoking, air pollution, 2nd hand smoking, quarry mines. Consequences: trouble breathing, coughing, chest pain, loss of appetite, tumours which create more tumours, loss of lung tissue
what is emphysema
The gradual destruction of alveoli. Inner walls of alveoli rupture to create larger air sacs with thicker walls. The surface area for gas exchange is reduced, lungs become less elastic. Damage is irreversible.
