1. Control of Breathing Breathing control centers in the brain
Breathing control centers in the brain
Keep breathing in tune with body needs,
sensing and responding to the CO2 level in the blood
Brain
Cerebrospinal
fluid
Pons
Medulla
Nerve signals
trigger
contraction
of muscles
Breathing
control
centers
stimulated by:
CO2 increase /
pH decrease
in blood
indicating CO2
and O2 levels
CO2 and O2
sensors in
aorta
Diaphragm
Rib muscles

2. Neural Regulation of ventilation rate
Activity of respiratory muscles is transmitted to the brain by the nerves
Neural centers that control rate and depth are located in the medulla
Normal respiratory rate is 12–15 respirations per minute
increased respiratory rate often due to extra oxygen needs

3. Factors Influencing Respiratory Rate and Depth
Chemical factors
Carbon dioxide levels
Level of carbon dioxide in the blood is the main regulatory chemical for respiration
Oxygen levels is Less effective than changes in blood CO2 level
Changes in Co2 and O2 concentration in the blood are detected by chemoreceptors in the aorta and carotid artery
Information is sent to the medulla oblongata

4. Homeostasis of blood CO2 level helps regulate breathing rate – negative feedback

5. Factors Influencing Respiratory Rate and Depth
Physical factors
Increased body temperature
Exercise
Talking
Coughing
Conscious control
Emotional factors

6. Chronic Bronchitis

7. Emphysema airways and air sacs have been damaged.
need to forcefully blow the air out in order to empty the lungs --- puts pressure on the airways and causes them to collapse.
walls of the air sacs are destroyed-- less surface area for gas exchange..
Emphysema is characterized by shortness of breath (SOB).

8. Destruction of tissue leaves little surface area, few capillaries, and large air spaces
Much normal tissue creates large surface area
with many capillaries, which are filled with RBCs (red cells)

9. Emphysema Alveoli enlarge as adjacent chambers break through
Loss of elastic recoil of lung tissue
Over-inflation of the lungs leads to a permanently expanded barrel chest
Cyanosis appears late in the disease
Cyanosis--A bluish discolouration of the skin and mucous membranes; a sign that oxygen in the blood is dangerously diminished --as in carbon monoxide poisoning

10. Asthma -- reference only
Chronic inflamed hypersensitive bronchiole passages
Response to irritants with dyspnea*, coughing, and wheezing
Dyspnea--Difficult or laboured respiration

11. Volume of air moved in / out of the Lungs
Between which points is air moving into the lungs?
Between which points is air moving out of the lungs?
At which point is the lungs most inflated / lung volume largest?

12. Between which points is air moving into the lungs? A1-A3
Between which points is air moving out of the lungs? A3-A5
At which point is the lungs most inflated / lung volume largest? A3 / C2