Systems Physiology Exam Review: Respiratory and Renal Systems

Flashcards covering respiratory physiology, acid-base balance, and pulmonary gas exchange based on the provided lecture notes and sample exam questions.

pK value of $NH_4^+$

The pK value for ammonium is $9.0$, used to calculate the ratio of base to acid in urine samples.

Acute 6% $CO_2$ Exposure

Relative to control animals, experimental animals 10 minutes after being placed in a chamber containing $6\%$ $CO_2$ at normal barometric pressure exhibit respiratory acidosis.

Chronic 6% $CO_2$ Exposure

The physiological state of experimental animals 24 hours after being placed in a chamber containing $6\%$ $CO_2$ at normal barometric pressure, allowing for compensatory mechanisms.

Minimum Urine pH

The ability of the collecting duct to decrease urine $pH$ values to as low as $4.5$.

Hyperoxic Arterial $PO_2$

In a normal person breathing room air, $PaO_2$ is $100\,torr$; when breathing $100\%$ oxygen, arterial $PO_2$ increases to $663\,torr$.

SCUBA Total Pressure at 10 Meters

At a depth of $10\,meters$, the total pressure on a diver is twice atmospheric pressure ($2\,atm$).

Emphysema

An obstructive lung disease where a patient is most likely to exhibit specific changes in air flow and lung volumes.

Inspired $PIO_2$ at Sea Level

The partial pressure of inspired oxygen when the fraction of inspired oxygen ($FIO_2$) is $60\%$.

$V/Q$ Mismatch Compensation

Increasing ventilation in a patient with a ventilation to perfusion mismatch restores $PaCO_2$ to normal by removing more $CO_2$ from the blood flowing through normal lung units.

Alveolar Ventilation and $PaCO_2$ Relationship

In a normal individual with a constant metabolic rate, increasing alveolar ventilation to twice the normal level results in an arterial partial pressure of carbon dioxide ($PaCO_2$) being halved.

Forced Expiratory Volume in 1 second ($FEV_1$)

A measurement used to reflect airway conductance and the degree of airway obstruction.

Lung Recoil

The elastic force of the lung which is greatest at the highest lung volume (Total Lung Capacity).

Isocapnic Hyperpnea

A state where alveolar ventilation increases during exercise (e.g., to match an increase in $CO_2$ production from $200\,mls\,CO_2/min$ to $450\,mls\,CO_2/min$) to maintain a constant $PaCO_2$ of $40\,torr$.

Functional Residual Capacity (FRC)

The volume of air remaining in the lungs at the end of a normal expiration.

Mild Anemia Chemoreceptor Response

A condition that does not result in the stimulation of central or peripheral chemoreceptors.

Intrapulmonary Shunt Fraction

The fraction of cardiac output that passes through vessels without participating in gas exchange; at a $50\%$ shunt, increasing ventilation has little effect on $PaO_2$.

SimBioSis

A lab program where a patient is paralyzed and ventilated to observe the effects of ventilator settings and intrapulmonary shunts.

Mild Anemia

A condition in which the oxygen-carrying capacity of the blood is reduced, but arterial $PO_2$ remains normal.