Lecture 21 Flashcards
Final exam content
What elevation do planes try to mimic pressure when pressurizing the cabins at when flying at 40,000 feet?
They try to mimic pressure at 8,000 ft.
What happens at high altitude in the lungs? What can this have a negative affect on?
hypoxic pulmonary vasoconstriction, this can cause significant strain on the right heart
If the plane suddenly loses pressure at 40,000 feet, what is the PO2 in the cabin? What happens?
PO2 = 29mmHg in the air (this doesn’t account for water vapor)
Gas exchange is reversed, oxygen moves from the pulmonary capillaries to the alveoli and this results in the lose of consciousness. Oxygen also gets pulled from hemoglobin.
Why can’t pilots have beards?
They get special masks with pressure that has to maintain a seal.
Oxygen in the masks that deploy from the ceiling on planes get oxygen how?
Exothermic reactions when they get tugged on. Heat and oxygen are the byproducts.
What is the normal range for pH in the body?
7.35-7.45
If an acid can move into a gas phase what is this called?
A volatile gas
H2CO3 is a______.
HCO3- is a_______.
weak acid
HCO3- is a strong conjugate base (likes to hang onto H+)
HCl is a______.
Is this more likely or less likely to dissociate in aqueous solutions?
Cl- is a _______.
strong acid
more likely to fall apart in solution
Cl- is a weak conjugate base.
CO2 is______.
weak acid
How much more CO2 do we have in comparison to bicarb?
we have about 1,000x more CO2 than HCO3-
What are some examples of non-volatile acids floating around in the body?
- sulfuric acid
- phosphoric acid
- HCl
- lactic acid
What is acetoacetic acid? Where does it come from?
a pathologic acid produced with poorly managed diabetes or with heavy drinking
What is another type of acid produced with poorly managed diabetes?
Butyric acid
NaOH is a_____.
strong base
It is the main component of drain cleaner
Sodium fluoride or potassium fluoride are________.
weak base
The main component of toothpaste
What happens to oxyhemoglobin in an acidic environment?
The Hb is negatively charged and when in an acidic environment there are lots of H+ ions which warps the Hb and knocks of the O2.
The “Bohr Effect”
What happens to the Na+/K+ pump in an acidic environment?
the extra protons change the structure of the pump which slows down the pump. This causes K+ to leak out of the cell leading to hyperkalemia
What happens to the neural control of breathing with acidosis?
At first the higher levels of H+ or CO2 in the CSF are recognized and the respiratory rate picks up. Eventually, in a very acidic environment, the tissues stop working.
What drug is really basic and can be painful if administered to quickly?
Sodium Pentobarbital
What is the most acidic fluid in the body?
Gastric acid, has a pH of 1
What is the most alkaline fluid in the body?
Pancreatic secretions have a pH of 8
If you have increased gut motility and diarrhea, what happens to the pH of the body?
You are losing a lot of the pancreatic secretions (alkaline) and so you tend to be more acidotic.
What happens to the body pH following excessive vomiting?
you are losing a lot of gastric acid and so the body becomes more alkaline
