Dr. Jitendra Patel (MBBS, MD, ACME, Ph.D…)

Medical Educator, Researcher & Academic Administrator

Associate Professor, Department of Physiology

Email: dr.jrpatel84@gmail.com Web: www.esphys.weebly.com

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Competency

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No. PY X.0 (Integrated Physiology)

Competency Describe and discuss space Physiology

D/L/Core K/KH/Y

AM Written/Viva voce

Integration No

Imp. Concept Gravitional forces

Phy. Trivia Effect of microgravity on human body

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OUTLINE

General consideration

Positive g

Negative g

Effect of zero gravity

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1. Which of the following would not differ between a human on Earth and a human traveling in space?

(A) Atmospheric conditions

(B) Ambient temperature

(C) Exposure to high energy radiation

(D) Body temperature

(E) Gravity

2. Which of the following systems is/are affected by microgravity?

(A) Kidneys

(B) Musculoskeletal

(C) Cardiovascular

(D) Neurovestibular

(E) All of the above

Earth vs. “Space”

– Atmosphere

– Radiation

– Gravity

Space-normalphysiology

Earth-normal physiology

Acclimation Response

Response Acclimation

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The force of gravity on a human body is referred to

as “G”

1 G is the force exerted upon a body at rest

During flight, an aircraft moves and maneuvers

through the atmosphere with force (thrust) and

centrifugal forces are applied along various axes

Gravitational Forces

Gravitational Forces

Direction of Force Standard Terminology

Pull head toward feet +Gz

Pull foot toward head -Gz

Pull from chest to back +Gz

Pull from back to chest -Gz

Pull from right to left +Gz

Pull from left to right -Gz

The force due to acceleration acting in

the long axis of the body from head to

foot is called positive g.

When the body moves upwards..

Acceleration

Blackout (fluid shifted towards the foot)

Px - Antigravity suit or the g-suit is used by

the astronauts to effectively cushion the

effects of gravitational force.

Positive g

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The force due to deceleration acting in

the long axis of the body from foot to

head is called negative g.

When the body moves downwards..

Deceleration

Red out (fluid shifted towards the head)

Headache and mental confusion

Negative g

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Weightlessness,

Movements of the body become effortless,

Absence of hydrostatic pressure on the blood

column.

A data of 14 months stay in the zero gravity zone

are available, which shows following documental

effects. (next slide)

Zero gravity (space)

Some atrophy of myocardium

Flaccidity and atrophy of skeletal muscles

Space motion sickness

Space anemia

Bone mineral is lost steadily with increased Ca2+

excretion.

Psychological problems due to the isolation and

monotony

A data of 14 months stay in the zero gravity zone are available, which shows following documental effects.

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