Lecture 18 Flashcards
Baric means….
Pressure
Oxia means…..
Oxygen
Gas Composition of Ambient Air
- Oxygen: 21%
*Nitrogen: 78% - Argon, carbon dioxide, and other gases: 1%
*at high altitude the column of atmosphere that
compresses the air is shorter:
• Results in a lower barometric pressure
• Which results in fewer molecules of oxygen per volume of air
Hypobaric Hypoxia
- Hypo -> low, baric -> pressure
• Hypo -> low, oxia -> oxygen
• Can refer to either reduced oxygen in
the ambient air or in the blood stream
compared to at sea level
• Begins at around 2500 m (8250 ft) or
higher
Hypobaric hypoxia is when the oxygen levels are lower than normal due to reduced air pressure, usually at high altitudes. This makes it harder to breathe and get enough oxygen into your body.
Chronic Mountain Sickness
Some well-adapted high-altitude residents can
lose their adaptation and become ill
* Symptoms: Headache, breathlessness, bone fatigue, insomnia, confusion
*Risk factors: Male, over 50 years old, overweight
Acute Mountain Sickness
- temporary adverse reaction to hypoxia that typically occurs within a day of arrival
Symptoms: headaches, anorexia, vomiting, fatigue, breathlessness
Hypoxic Ventilatory Response
An immediate increase in depth and rate of breathing
*also increases an increase in energy expenditure
Arterial Saturation (SaO2)
*A percentage of arterial hemoglobin is saturated with (carrying) oxygen
*a physiological measure of hypoxic stress
*measured with pulse ox
*higher heart rate
*increase in hemoglobin by increasing the number of red blood cells
Candidate gene approach
*focuses on associations between genetic variation within pre-specified genes of interest
*genes chosen based on a known biological function or association with a disease
Genome wide association studies
*scan the entire genome for common genetic variation
*used to generate hypotheses
*Involves genotyping loci
Hypoxic Ventilatory Response
Hypoxic ventilatory response is the way your body increases breathing when oxygen levels are low (hypoxia). It helps bring in more oxygen to the body when you’re at high altitudes or in low-oxygen environments.
Vital Capacity
The maximum amount of air that can be expired after a maximal inspiration
Residual Volume
Volume of air that remains in the lungs after a complete expiration
Total Lung Capacity Equation
vital capacity+ residual volume = total lung capacity
O2 transport in Tibetan
*Elevated blood flow to brain and extremities
*high lung capacity due to high RV
*Elevated Hypoxic Ventilatory response
O2 Transport in Andeans
*Elevated blood flow to brain and extremities
*high lung capacity (due to high VC and high RV)
*high hemoglobin concentration
