The Respiratory System/ Gas Exchange

Question 1

What is the purpose of the Respiratory system?

Answer 1

• Supplies gas for cell respiration

- Removes CO2 from cells/body

Question 2

Why does CO2 need to be removed from cells?

Answer 2

• It creates carbonic acid when mixed with water and disturbs the cells

Question 3

What is the chemical reaction of respiration?

Answer 3

Glucose + oxygen –> Carbon dioxide + water + energy

Question 4

What are the requirements of a respiratory system?

Answer 4

• Large surface area
• Moist (to dissolve atmospheric gases)
• A way of bringing gases in and out
• A way to deliver gases efficiently

Question 5

What other features does the human respiratory system have that aren’t required but increase efficiency?

Answer 5

• 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

Question 6

Describe the anatomy of the lung:

Answer 6

• 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

Question 7

How does the Nasal cavity make the respiratory system effective?

Answer 7

• Mucus (salts and proteins) make a filter for air

Question 8

How do the sinuses make the respiratory system effective?

Answer 8

• Opening allows oxygen to resinate in your head

- produces voice

Question 9

How does the Turbinate bones make the respiratory system effective?

Answer 9

• folded to increase surface area and provide more cleaning

Question 10

How does the BCC make the respiratory system effective?

Answer 10

• Part of brain that subconsciously controls breathing

Question 11

How does the uvula make the respiratory system effective?

Answer 11

• closes glottis when you swallow to prevent food from entering the trachea

Question 12

How does the Trachea Cartilage make the respiratory system effective?

Answer 12

• Keep trachea open to prevent it from collapsing

Question 13

How does the trachea make the respiratory system effective?

Answer 13

• flexible to allow breathing in any position

Question 14

Define ventilation:

Answer 14

How we breath; the mechanics of breathing in and out using muscle

Question 15

Define Tidal Ventilation:

Answer 15

A rhythmic sequence that alternates inspiration and expiration

Question 16

How is air drawn into the lungs?

Answer 16

By a concentration gradient

Question 17

Describe internal and external gills

Answer 17

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

Question 18

Describe the Tracheal system

Answer 18

• 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

Question 19

Describe True Lungs

Answer 19

• oxygen diffusing in and carbon dioxide diffusing out in a constant cycle
• Very efficient; does not require alterations
• Unidirectional flow (less efficient)

Question 20

Describe modified true lungs (in birds)

Answer 20

• 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)

Question 21

Describe Book lungs

Answer 21

• accordion like lungs to increase surface are for gas exchange in small animals

Question 22

What is Partial Pressure:

Answer 22

• 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

Question 23

What is partial pressure of oxygen? carbon dioxide?

Answer 23

PO2 and PCO2

Question 24

Why does the PO2 decrease after moving through the trachea?

Answer 24

• It mixes with the “stale” air that remains in the trachea to keep it open which decreases the overall PO2

Question 25

The plasma cannot carry enough oxygen to supply the body’s needs, what solves this problem?

Answer 25

• Haemoglobin in red blood cells binds onto the oxygen removing it from the plasma to allow the plasma to take in more oxygen

Question 26

At rest how much oxygen to the red blood cells give off to tissues?

Answer 26

30%

Question 27

Why don’t red blood cells give off 100% of the oxygen they hold to the tissues?

Answer 27

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

Question 28

Why do red blood cells increase efficiency?

Answer 28

• 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

Question 29

Why does PO2 increase when air is exhaled?

Answer 29

• the air that is being exhaled mixes with the oxygenated air that remains in the trachea

Question 30

How much oxygen is found in haemoglobin? plasma?

Answer 30

• 98.5% in haemoglobin and 1.5% in plasma

Question 31

How is carbon dioxide transported throughout the body?

Answer 31

• 30% in carbinohaemoglobin
• 10% dissolved in plasma
• 60% converted into carbonic acid

Question 32

What percent of carbon dioxide in the body exerts pressure?

Answer 32

• 10% because it only exerts pressure when dissolved in the plasma

Question 33

Define inspiration reserve volume?

Answer 33

Vital capacity - tidal volume