Module 10: Special Senses Flashcards Preview

Physiology Module > Module 10: Special Senses > Flashcards

Flashcards in Module 10: Special Senses Deck (313)
Loading flashcards...
91

Use of a Parachute

• Opening shock load of 1200 lbs maybe felt
• Reduces speed of skydiver to 1/9th the terminal velocity
- Equivalent to speed of jumping from a height of 6 feet
- Fall to the ground with kneed bent, muscles taut to prevent fractures

92

SPACE

• Earlier Space Missions: 100% pure oxygen at 260mmHg
- Prone to fires
- Astronauts prone to small patches of lung atelectasis when mucus plugs are present

• Currently: 20% Oxygen at 760mmHg

• For space travel lasting months to years, oxygen recycling system must be used
- Electrolysis of water
- Bringing algae

93

Weightlessness/Microgravity in Space

• Gravity is still present!
- Acts on astronauts and the space shuttle in the same direction, same time, same acceleration

• If acute, little effect
- Motion sickness
- Translocation of fluids
- Diminished physical activity

94

Weightlessness/Microgravity in Space (If chronic, “deconditioning” may occur)

• Decreased blood volume
• Decreased RBC
• Decreased muscle strength
• Decreased maximum cardiac output
• Loss of calcium and phosphate from bones

95

Deep Sea Diving

• To keep the lungs from collapsing due to high water pressure, air used by divers are given in high pressures
- May lead to toxicities from high nitrogen, oxygen and carbon dioxide pressures

96

• nitrogen dissolves in fatty substances in neuronal membranes causing altered ionic conductance through membranes

HIGH NITROGEN PRESSURE

97

Effects of High Nitrogen Pressure:

• At 120 Feet: Joviality, loss of cares

• At 200-250 Feet: drowsiness

• Beyond 250 Feet: “raptures of the depths”

98

• Alveolar PO2 -> excess O2 will be buffered in the blood -> maintain PO2 pressure in tissues at 40mmhg -> does not affect tissues
• But if more excess -> cannot be buffered oxygen toxicities
• Breathing oxygen at 4atm (PO2=3040mmHg) will cause sudden brain seizures followed by coma [Due to Oxygen Free Radicals (O2- and H2O2)]

HIGH OXYGEN PRESSURE

99

• Happens only if diving apparatus has a malfunction
• Severe respiratory acidosis, lethargy, narcosis

HIGH CARBON DIOXIDE PRESSURE

100

• Sudden ascent can lead to formation of nitrogen bubbles -> blocks blood vessels -> signs and symptoms

Decompression sickness

101

Decompression sickness: Manifestations

• “Bends” (Pain in the joints and muscles)
• “Chokes” (Dyspnea)
• Caisson’s Disease (Chronic Decompression Sickness

102

Decompression sickness: Treatment

• US Navy Decompression Tables
• Tank Decompression
• Use helium in very deep dives (>250 feet)
*Advantages of helium over nitrogen:
- 1/5 narcotic effect of nitrogen
- Less dissolved in body tissues and does not diffuse rapidly upon decompression
- Lower density

103

Decompression schedule for a diver who has been on the sea bottom for 60minutes at a depth of 190 feet:

• 10 minutes at 50 feet depth
• 17 minutes at 40 feet depth
• 19 minutes at 30 feet depth
• 50 minutes at 20 feet depth
• 84 minutes at 10 feet depth

104

SCUBA (Self-Contained Underwater Breathing Apparatus): Components

1. Compressed air tanks
2. Reducing valve
3. Inhalation demand valve and exhalation valve
4. Mask and tube system

105

Most important problem in use of SCUBA?

Limited amount of time one can remain beneath sea surface

106

• Escape from submarine at 300 feet possible,
• if with scuba, 600 feet
• prone to pulmonary gas embolism
• Hazards in internal environment:
- Radiation in atomic submarines
- Poisonous gases

SUBMARINE

107

• due to oxidizing properties used to treat gas gangrene, decompression sickness, arterial gas embolism, CO poisoning, osteomyelitis and MI

Hyperbaric oxygen therapy

108

OVERALL STRENGTH: MORE
STRENGTH PER SQUARE CENTIMETER OF X-SEC AREA : 3-4 KG/CM2
WORLD RECORDS : MARATHON
EFFECT OF HORMONES: TESTOSTERONE -> MORE MUSCLE

MEN

109

OVERALL STRENGTH: LESS
STRENGTH PER SQUARE CENTIMETER OF X-SEC AREA: 3-4 KG/CM2
WORLD RECORDS: LONG-DISTANCE SWIMMING
EFFECT OF HORMONES: ESTROGEN -> MORE FAT

WOMEN

110

What is the basis for muscle endurance?

Glycogen levels in the body

111

What is the best diet for muscle glycogen recovery?

High Carbohydrate Diet

112

How long does it take to recover muscle glycogen?

2 Days (High Carbohydrate Diet)

113

An increase in muscle strength is always due to what?

Increase in muscle size

114

Notes: Cell ATP, cell phosphocreatine
Onset and Duration: First 8-10 seconds
Example: 100m dash, jumping, diving

Phosphagen energy system

115

Notes: Anaerobic; reconstitute atp & phosphocreatine
Onset and Duration: For 1.3 to 1.6 minutes after phosphagen system used up
Example: Tennis, soccer

Glycogen-lactic acid system

116

Notes: Aerobic; reconstitute atp, phosphocreatine, glycogen-lactic acid cycle

Onset and Duration: For unlimited time as long as with energy supply (glycogen, fat, ketones, amino acids. Fats supply 50% energy requirements after 3-4 hours) after glycogen-lactic acid system used up

Example: Long-distance jogging

Aerobic system

117

EFFECT OF ATHLETIC TRAINING ON MUSCLES AND MUSCLE PERFORMANCE: Muscle Hypertrophy*

1. increased numbers of myofibrils, proportionate to the degree of hypertrophy;
2. 120 percent increase in mitochondrial enzymes;
3. 60 to 80 percent increase in the components of the phosphagen metabolic system
4. 50 percent increase in stored glycogen
5. 75 to 100 percent increase in stored triglyceride

118

Respiratory System in Exercise

• Maximal breathing capacity: 150-170L/min
• Pulmonary ventilation during maximal exercise: 100-110L/min
• Difference (50L/min) is used to compensate for:
- Exercise at high altitude
- Exercise under hot conditions
- Abnormalities of the respiratory sytem

119

Cardiovascular Effects of Exercise

• Muscle blood flow increases up to 20x during the most strenous exercise

• Cardiac Output also increases during exercise
- Athletes: 30L/min (Resting CO: 5L/min)
- Non-athletes: 20L/min (Resting CO: 5L/min)

• At Maximal Exercise
- CO is at 90% of its maximum
- Pulmonary ventilation is at 65% of its maximum
- Cardiovascular system: most limiting factor in delivery of oxygen to muscles during maximal muscle aerobic metabolism

120

Body Heat in Exercise

• Only 25% of nutrient energy is converted to muscle work
- Rest is released as Heat

• Heatstroke
- When T > 42 deg Celcius during exercise
- May damage neurons including temperature-regulating centers
- Doubles the rate of all intracellular reactions further compounding the problem
- Tx: remove clothing, sponge/spray with water, fan, give fluids