Biology - Respiratory System Flashcards
Function
- Providing oxygen required by the body
2. Removes carbon dioxide made during cellular respiration as a waste product
How many times does a person breathe in + out a minute?
On average, a person breathes in and out 15 times a minute. This increases as physical activity increases.
Nose
- warms and humidifies the air
- contain cilia that filters out foreign particles
Mouth
- is a secondary structure for breathing
- used when nose is not enough
Pharynx
- is a common pathway for nose + mouth
- commonly known as a throat
- leads to trachea and esophagus
Trachea
- known as windpipe
- collects air from pharynx and filters it with cilia
- leads to 2 bronchus (pl. bronchi)
Bronchi
- 2 tubes that lead air from trachea, one to each lung
- leads air to smaller branches called bronchioles
Bronchioles
tiny branches that lead air to alveoli
Alveoli
- site of gas exchange (O2 + CO2)
- tiny sacs surrounded by capillaries
Cilia
- lining of trachea
- hair-like projections that function to move mucus + filter out any foreign material
Gas Exchange?
- Oxygen enters the blood + Carbon Dioxide leaves by diffusion
- Concentration of oxygen in blood is always less than the air in the alveoli
- Oxygenated blood moves to heart while carbon dioxide moves from cells into blood into alveoli and is released outside when you breathe out
How have organs adapted to make gas exchange more efficient?
- Bronchi Branching: Each bronchi branches many times to increase surface area
- Alveoli Design: Only 1 cell layer thick; surrounded by capillaries for easy diffusion of O2 and CO2
- Surrounding of capillaries for quicker gas exchange
- Thin Walls: O2 and CO2 only have to cross 2 cell layers
- lots of blood to make efficient
Breathing
There needs to be a movement of air into and out of the lungs to facilitate gas exchange.
Exhalation
diaphragm is dome-shaped and lungs contract
Inhalation
diaphragm flattens down, lungs expand
