9.3 Regulation of Breathing Movements

Question 1

What is the regulation of breathing?

Answer 1

The regulation of breathing involves the brain, and is controlled by the medulla oblongata. It involves detecting the CO2 and O2 levels in the blood. Chemoreceptors detect changes in CO2 and O2. There are two types:
- CO2 receptors are the most sensitive receptors, and are located in the medulla oblongata. They work by high levels of carbonic acid stimulating CO2 receptors in the medulla oblongata. The medulla oblongata sends a signal to the intercostal muscles, the diaphragm, and it increases the breathing rate.
- O2 receptors are located in the carotid and aortic arteries and are only used as backup. They are only stimulated when O2 levels drop. Eg: carbon monoxide present or high altitudes.

Question 2

What are the factors that affect breathing rate?

Answer 2

The factors that affect breathing rate include:
- High CO2 levels: Fires, they cause an increased breathing rate.
- Low O2 levels: High altitudes and less O2 in the air cause increased breathing rate. Carbon monoxide (binds faster to hemoglobin than O2 and deprives the cells, increased breathing rate.)
- Exercise: More O2 is needed for ETC, breathing rate increases.
- Stretching lung tissue: Stretch receptors in pleura, bronchioles, and alveoli are stimulated. The nerve impulse are sent to the medulla oblongata. The breathing rate decreases.
- Emotional State: Fear and pain causes breathing rate to increase, and happiness causes breathing rate to decrease.
- Stomach Injury: A large quantity of air is expelled and breathing rate increase.

Question 3

What are some respiratory disorders?

Answer 3

Respiratory disorders include:
- Bronchitis: Is the narrowing of the bronchi or bronchioles and is caused by inflammation. Excess mucous is produced and the body responds by coughing. Tissues swell up as well.
- Emphysema: IS when the air sacs lose their elasticity, stretch and rupture. There is less surface area, and the air becomes trapped in the lungs. CO2 builds up and the breathing rate increases. The main cause is smoking.
- Chronic Obstructive Pulmonary Disease: This is a disease where both emphysema and bronchitis is present.
- Asthma: Is the extreme immune reaction caused by the particulates in the air or allergens. The bronchioles are inflamed and constrict. The CO2 pressure builds in the lungs.

Question 4

What does smoking do to your respiratory system?

Answer 4

Smoking kills the cells that contain cilia. The tar in tobacco coats the cilia disabling them, the carbon monoxide in smoke starves cells of oxygen, the cyanide stops the electron transport chain.

Question 5

What are respiratory air volumes?

Answer 5

The respiratory air volumes include:
1. Total Lung Capacity (TLC): The total that can be held in the lungs.
2. Tidal Volume (TV): The aire entering and leaving during a normal exhale.
3. Inspiratory Reserve Volume (IRV): The additional air that can be taken into the lungs.
4. Expiratory Reserve Volumes (ERV): The extra air that can be expelled from lungs.
5. Residual Volume (RV): Air that is always left in your lungs.
6. Vital Capacity (VC): TV+IRV+ERV (total lung capacity minus residual).