HMX - Partial Pressure

Patm

Atmospheric pressure. The total pressure exerted by surrounding air

760 mmHg at sea level

Partial Pressure

The amount of pressure exerted by a gas if occupied in a container alone

PN₂ and PO₂

Partial pressures for Nitrogen and Oxygen which make up 99% of atmosphere

• PN₂: Partial pressure of Nitrogen (Patm x 0.78)

• PO₂: Partial pressure of oxygen (Patm x 0.21)

Daltons Law

Total pressure of a gas mixture equals the sum of its parts

ex. Patm = PN₂ + PO₂

Partial Pressure of a gas dissolved in liquid

The amount of gas dissolved in liquid is equal to the partial pressure of that gas above the liquid.

equilibrium is always trying to be maintained

(Bubbles caused by this)

Alveolus

Tiny air sacs in lungs with thin walls surrounded by capillaries making them the site of gas exchange.

O2 diffuses into blood from alveolus and CO2 moves out

Capillary

Smallest blood vessels in body with one cell thick walls making them perfect for gas, nutrient, and waste exchange between blood and cells. Pulmonary capillaries wrap around the alveoli for O2 exchange.

hemoglobin

Protein in red blood cells that carries O2 throughout the blood.

Total oxygen in the blood

The amount of O2 bound to hemoglobin and the amount of O2 dissolved in liquid

O₂ total = hemoglobin O₂ + dissolved O₂

Explanation for stroke caused by rapid ascension out of water

When deep under water, nitrogen levels build up in blood and tissues as they are not metabolized and used for aerobic activity like oxygen. When ascending the water pressure begins to decrease so nitrogen begins to diffuse from high levels in the blood and tissues to low levels in the lungs where it can be exhaled. If done rapidly then nitrogen will not leave fast enough and in order to maintain equilibrium between water pressure and partial pressure in vessels, bubbles form. Bubbles can then reach the heart and get pumped to brain which disrupt blood flow and may cause a stroke.

Patent foramen ovale (PFO)

hole between the left and right atria.

Often is closed after being born but when not it is called PFO

Hyperbaric oxygen therapy

special pressure chamber used to increase amount of oxygen in blood. If pressure of surroundings is high than partial pressure of oxygen and nitrogen follows.

Could be used to treat air or gas embolism like the one the father had in video

Boyles law and breathing

Pressure and volume are inversely proportional (P x V = k_constant)

Inhale: volume of lungs increases, pressure drops, air flows in

Exhale: volume of lungs decreases, pressure increases, air flows out

Endotracheal tube (ET)

Flexible plastic catheter inserted into trachea (windpipe) in order to open the airway and deliver oxygen through a ventilator

ventilator

Life support device that mechanically pumps oxygen into patient, sometimes through Endotracheal tube

Cyanosis

lack of oxygen in blood causing nails and/or lips to appear blue