EnviroPhys: Navigating Human Limits

Episode 37 - Microgravity - Part 3

We wrap up the microgravity series by focusing on the countermeasures used to fight physiological decline in space. These include treadmill harnesses, cycling, resistive training, and pharmacological strategies like calcium, vitamin D, and bisphosphonates. We also discuss the challenges of returning to gravity, including orthostatic hypotension, weakness, and vestibular disorientation, as well as the long-term risks of extended missions. Finally, we explore future solutions, such as artificial gravity and gene-based therapies.

Episode 36 - Microgravity - Part 2

In this episode, we explore the long-term physiological effects of microgravity, focusing on the musculoskeletal, cardiovascular, and vestibular systems, as well as cognitive and psychological challenges. We discuss bone loss, muscle atrophy, reduced VO₂ max, and how the vestibular system malfunctions in space. The episode also touches on the impact of disrupted circadian rhythms, sensory overload, and emotional strain during long-duration missions.

Episode 35 - Microgravity - Part 1

This episode kicks off our discussion of space physiology, focusing on the body’s initial responses to microgravity. We examine the headward fluid shift, changes in cardiovascular dynamics, and the impact on the vestibular system, which contributes to motion sickness and sensory disorientation. We also touch on how plasma volume reduction and cardiac remodeling affect astronaut performance and challenges upon re-entry to gravity.

Episode 34 - SCUBA - Part 3

In the final diving episode, we explore thermal challenges in the underwater environment. Water conducts heat 25 times faster than air, increasing the risk of hypothermia. We cover mechanisms of heat loss, physiological responses to cold water, and protective gear like wetsuits and drysuits. We also discuss how cold affects dexterity, decision-making, and safety, and highlight strategies for heat retention and safe diving practices in cold environments.

Episode 33 - SCUBA - Part 2

This episode dives into the effects of gas exchange under pressure. We explain Dalton’s Law, the causes and symptoms of nitrogen narcosis, and the risks of oxygen toxicity at depth. We also introduce Henry’s Law, explaining how nitrogen dissolves into tissues and leads to decompression sickness (DCS) if ascent is too rapid. We discuss prevention strategies such as slow ascent, safety stops, and treatment with hyperbaric oxygen therapy.