The Respiratory System/ Gas Exchange Flashcards
What is the purpose of the Respiratory system?
- Supplies gas for cell respiration
- Removes CO2 from cells/body
Why does CO2 need to be removed from cells?
- It creates carbonic acid when mixed with water and disturbs the cells
What is the chemical reaction of respiration?
Glucose + oxygen –> Carbon dioxide + water + energy
What are the requirements of a respiratory system?
- Large surface area
- Moist (to dissolve atmospheric gases)
- A way of bringing gases in and out
- A way to deliver gases efficiently
What other features does the human respiratory system have that aren’t required but increase efficiency?
- A way to regulate the rate/speed of ventilation and delivery
- Ways to maintain and protect itself since the exchange surface is fragile and vulnerable to harsh environments
Describe the anatomy of the lung:
- Has many pours, gaps, and air pockets to hold gases
- Epithelial cells -> one cell thick (helps with diffusion of gases)
- Capillaries run between single cells to deliver blood
How does the Nasal cavity make the respiratory system effective?
- Mucus (salts and proteins) make a filter for air
How do the sinuses make the respiratory system effective?
- Opening allows oxygen to resinate in your head
- produces voice
How does the Turbinate bones make the respiratory system effective?
- folded to increase surface area and provide more cleaning
How does the BCC make the respiratory system effective?
- Part of brain that subconsciously controls breathing
How does the uvula make the respiratory system effective?
- closes glottis when you swallow to prevent food from entering the trachea
How does the Trachea Cartilage make the respiratory system effective?
- Keep trachea open to prevent it from collapsing
How does the trachea make the respiratory system effective?
- flexible to allow breathing in any position
Define ventilation:
How we breath; the mechanics of breathing in and out using muscle
Define Tidal Ventilation:
A rhythmic sequence that alternates inspiration and expiration
How is air drawn into the lungs?
By a concentration gradient
Describe internal and external gills
Internal: - Act similar to lung - connected to blood vessels - have many gills to increase SA External: - Rely on diffusion - connected to blood vessels - have many gills to increase SA
Describe the Tracheal system
- For small organisms as it will not function well for species more than 5cm long
- Series of inside tubes that are the length of the body and connect to the outside
Describe True Lungs
- oxygen diffusing in and carbon dioxide diffusing out in a constant cycle
- Very efficient; does not require alterations
- Unidirectional flow (less efficient)
Describe modified true lungs (in birds)
- Parabronchi branch off to fill lungs with air quickly
- Parabronchi and air sacks fill with air to keep bird in air
- Air space in bones to decrease density
- CO2 and O2 can enter/exit at the same time (efficient)
Describe Book lungs
- accordion like lungs to increase surface are for gas exchange in small animals
What is Partial Pressure:
- Measures the amount of force a given molecule exerts on a given surface
- Measured in mmHg
- Comparable measurement since units do no change when molecule changes state
What is partial pressure of oxygen? carbon dioxide?
PO2 and PCO2
Why does the PO2 decrease after moving through the trachea?
- It mixes with the “stale” air that remains in the trachea to keep it open which decreases the overall PO2
The plasma cannot carry enough oxygen to supply the body’s needs, what solves this problem?
- Haemoglobin in red blood cells binds onto the oxygen removing it from the plasma to allow the plasma to take in more oxygen
At rest how much oxygen to the red blood cells give off to tissues?
30%
Why don’t red blood cells give off 100% of the oxygen they hold to the tissues?
Because the lungs would no longer be able to keep up with the high demand for oxygen and you would constantly be out of breath
Why do red blood cells increase efficiency?
- Can carry more oxygen in the blood
- When oxygen in the plasma diffuses into tissues, oxygen from the red blood cells transfers to the plasma so that the blood can supply oxygen to many cells instead of having to go back to the lungs to recharge right away
Why does PO2 increase when air is exhaled?
- the air that is being exhaled mixes with the oxygenated air that remains in the trachea
How much oxygen is found in haemoglobin? plasma?
- 98.5% in haemoglobin and 1.5% in plasma
How is carbon dioxide transported throughout the body?
- 30% in carbinohaemoglobin
- 10% dissolved in plasma
- 60% converted into carbonic acid
What percent of carbon dioxide in the body exerts pressure?
- 10% because it only exerts pressure when dissolved in the plasma
Define inspiration reserve volume?
Vital capacity - tidal volume