17 - Gas exchange Flashcards
What are some of the protective festures of the Respratory system?
- cilia
- mucus
- cartilage
- caughting & sneezing
What are the white blood cells in the lungs?
aveolar macrophages
Why can you hold your breath longer when you take a big breath of air first?
less CO2 and higher pH
What kind of cells are in the aveoli?
simple squalmous
________________ are how the lungs are attached to the thoracic cavity
plura mambrane
In order to inhale what three things have to happen?
- decreas in aveoloar pressure = draws pressure in
- diaphram contracts
- intercostals contract
what happens when we exhale?
- diaphram relaxes
- intercostals relax
- and elastic recoil of the lungs
what is going on with a patient with emphysema?
- decreased surface area of aveoli
- elastic tissue of the lungs have hardened
Therefore
- lower CO2 exchange
- decreased mobility
- laboured breathing
What areas of the brain regulates breathing?
- pons: sensors from aorta
- medulla: intercostals & diaphram
How would the following affect respiration rate?
[CO2] if high would ____ rate. If Low would ___ rate
increase
decrease
[H+] if high would ___ rate. If low would ___ rate.
increase
decrease
how does the concentration of O2 affect respiration?
not as sensitive - only responds to decreased [] of O2
Why does O2 move from the lungs into the blood?
concentration gradient
Why does O2 move fromt eh blood into the tissues?
conentration gradient
Why is the concentration of O2 lower in the aveoli than in the atmosphere?
b/c we never fully exhale all of the gasses, so the mingling of the CO2 that never made it all of the way out lowers the concentration of O2
What is the enzyme in the blood that helps speed up the creation of H+ ions and maintains a CO2 gradient?
carbonic anhydrase
What are the three ways that CO2 are removed from the tissue?
- disolved in plasma ~ 7%
- as carbaminohemoglobin (CO2 x Hgb) ~ 23% O2 saturation
- bicarbonate ion ~ 70%
What are the factors that affect the affinity of Hgb for O2?
- low pH
- high Temp
- high CO2
- low O2
how many oxygen molecules can hemoglobin carry?
4
What is the blood ph level held at?
7.35-7.45
How does the body help to regulate acid production?
- buffers: proteins, phosphate, bone, carbonic acid (H2CO3)
- kidneys: secretion of H+ amd saves HCO3- or secretes HCO3- and save H+
- respriatory system can only remove carbonic acids not metabolic acids
CO2 + H2O <-> H2CO3 <-> HCO3- + H+
Which side of the equation does the blood tend to lie on when we are underbreathing?
Overbreathing?
Underbreathing to the right = decreased pH
Overbreathing to the left = increased pH
How does the stomach flu affect pH and respiration?
decreases pH in gut
increases blood pH
decreases respiration
Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a
Select one:
A. Higher PO2
B. Higher PCO2
C. Greater bicarbonate concentration
D. Lower pH
E. Lower osmotic pressure
Higher PO2
One feature that bird lungs and human lungs have in common is that
Select one:
A. They both have unidirectional air flow
B. They both use countercurrent mechanisms to maximize oxygen uptake
C. They are both internalized to reduce water loss
D. The both have low blood pressure in the systemic circuit
They are both internalized to reduce water loss
The driving force for diffusion of oxygen across the cells of a respiratory organ is
Select one or more:
A. The difference in partial pressure of oxygen between the respiratory surface and the blood
B. The humidity
C. The partial pressure of carbon dioxide in the blood
D. The air temperature
E. All answers apply
F. A function of altitude
The difference in partial pressure of oxygen between the respiratory surface and the blood
Carbonic anhydrase is helpful in that it
Select one:
A. Helps carbon dioxide come into equilibrium between the tissues and the blood
B. Promotes the release of oxygen from hemoglobin by stimulating H+ production
C. Increases the PO2 of the arterial blood
D. Increases the pH of the blood
Promotes the release of oxygen from hemoglobin by stimulating H+ production
Hypoventilation (low breathing rate) would cause a/an
Select one:
A. Increase in pH
B. Decrease in pH
C. Excess O2 levels in the Hgb
D. Loss of bicarbonate ions
E. Decrease in H+ ions
Decrease in pH
When you hold your breath, which of the following blood gas changes first leads to the urge to breathe?
Select one:
A. Rising O2
B. Falling O2
C. Rising CO2
D. Falling CO2
E. Rising CO2 and falling O2
Rising CO2
