Human Body Flashcards
What is the skeleton for
Structural strength
Creates body cavities for organ placement
Characteristics of arteries
Thick walls
Carries oxygenated blood
High pressure blood
No valves
Characteristics of arterials
Extensions off arteries which can store blood
Characteristics of veins
Thin walls
Deoxygenated blood
Valves
Characteristics of capillaries
Walls 1 cell thick
Gaseous exchange
Diffusion
Covering alveoli
What are muscles for
Attached to the skeleton via tendons allowing movement and posture control
Characteristics of red blood cells
Carry oxygen
Contains haemoglobin
No nucleus so more space for haemoglobin
What are white blood cells for
To give immunity
Lymphocytes
What are Platelets for
Clotting (closes wounds)
What is homeostasis
Body used feedback and control mechanisms to maintain a stable environment
What % of the body is made up of water
65%
What does the central nervous system comprise of
Starts at the brain works out to the rest of the body
Involved spinal chord and brain
What is the Peripheral nervous system
Senses travel from sense receptors to brain
Consists of nerves and ganglia (clusters of nerves)
Normal speed in the motor neurone
0.5m/s
Fast speed of the motor neurone
100m/s
What state are the sodium / potassium pumps in when at rest
Open
What 2 branches does the peripheral nervous system slit into
Somatic nervous system (movement)
Autonomic nervous system (automatic body functions)
What does the autonomic nervous system control
Breathing Homeostasis Blinking Reflex Heart rate Blood pressure
What are the 2 branches of the autonomic nervous system
Sympathetic division (fight or flight )
Parasympathetic (return body to normal state)
What must a sense be above the stimulate a response
Sensory threshold
What is an absolute threshold
The minimum level of stimulation To trigger a response
What will frequent exposure to a stimulation cause
Habituation
What is the endocrine system
Chemical messages
Hormones
Slower - multiple cells stimulated at once as a result
What is a proprioceptor
Detect and relay precise info about the length of extensions of each muscle
What is a mechanoreceptor
Gives precise info about the amount of tension in a muscle
Where does the reflex generate its response
The motor nerve in the spinal chord
What is a subcutaneous pressure receptor
Found under the skin to orientate you to your surroundings (ie sitting on a chair)
Why is partial pressure important for breathing
Partial pressure is required to “force” the oxygen through the alveoli and into the bloodstream
At msl what is the total pressure in MMHg
760
At msl what is the oxygen partial pressure in mmgh
160
At what altitude is total pressure and oxygen partial pressure half
18,000
What is the difference in pressure between the inside of the lungs and the outside atmospheric pressure
47mmgh
What law is associated with hypoxia
Dalton’s law
What is hypoxic hypoxia
Not enough pressure to push oxygen through the alveoli
What is anaemic by hypoxia
Not enough haemoglobin in the blood to carry oxygen
What is the supplementary oxygen requirement from 0-10,000 feet
No requirement
What is the supplementary oxygen requirement above 10,000
Supplementary oxygen required
What is the supplementary oxygen requirement from 10,000 - 33,700 feet
Increasing % of oxygen required to be supplied
What is the supplementary oxygen requirement from 33,700 - 40,000 feet
100% oxygen required
What supplementary oxygen is required above 40,000 feet
Pressurised oxygen required
What are the symptoms of hypoxia
Blue lips / fingers Confusion Dizziness Lack of control Feeling happy
At what altitude do you begin to lost night vision
5000 feet
What factors effect hypoxia
Health Smoking Age Obesity Fatigue Rate of decompression
What hypoxia zone is vision affected
Indifferent zone
What hypoxia zone does homeostasis provide some protection
Compensatory zone
What hypoxia zone do common symptoms start to take affect
Disturbance zone
What hypoxia zone can homeostasis no longer cope
Critical zone
What hypoxia threshold is night vision affected
Reaction threshold
What hypoxia threshold is homeostasis trying to fight hypoxia
Disturbance threshold
What hypoxia threshold does incapacitation with loss of consciousness occur
Critical threshold
What is the time of useful consciousness
The time available for a person to still efficiently and effectively mentally and physically preform from point of not having adequate oxygen supply
What is the time of useful consciousness at 20,000 feet
30 mins at rest
5 mins of moderate activity
What is the time of useful consciousness at 30,000 feet
1-2 mins at rest
What is the time of useful consciousness at 35,000 feet
30-90 seconds
What is the time of useful consciousness at 40,000 feet
15-20 seconds
What is the first part of the mouth that air meets
The pharynx
What (in the mouth) does the air meet second
Larynx
What is the tube in the throat called
Trachea
What does the trachea turn into
Branches into 2 bronchi which get thinner until it turns into the alveoli
What is the max king volume
6 litres
What is the lungs residual volume
1.4 litres
What is the tidal volume
5 litres/ minute
How many breathing cycles per min
12-20
10-15
16-20
What can cause problems with breathing
Smoking
Hypoxia
Hyperventilation
What is hyperventilation
Not retaining enough co2
Which contains carbonic acid
Which means the ph of the blood goes up
What is the blood ph during hyperventilation
Alkaline
How to cure hyperventilation
Breath into a paper bag
Encourage “positive” breathing
What can cause hyperventilation
Panic Stress Fear Pressure breathing Pain Altitude / mountain climbing
Symptoms of hyperventilation
Dizziness Tingling in hand and feet Nausea Blurred vision Muscular spasms Unconsciousness
If you breath 100% oxygen @40,000 feet what altitude does it feel like
10,000 feet
Breathing oxygen at 33,700 feet feels like what height
Sea level
What is the law of diffusion
Gasses travel a concentration gradient
What is anaemia
Low number of red blood cells or reduced haemoglobin levels
Where does pulmonary circulation go
The lungs
Where does systemic circulation go
Whole body except the lungs
What does the pulmonary artery do
Transport deoxygenated blood to the lungs
What does the pulmonary vein do
Transport oxygenated blood from the lungs
What are the upper 2 chambers of the heart called
Atria and accumulators
What are the lower 2 chambers of the heart called
Ventricles
What is the ventricle responsible for
Primary pumping system
What is the pulse rate
Number of contractions per minute
What nervous system is the pulse rate controlled by
Autonomic nervous system
What is the pulse rate affected by
Adrenalin Breathing rate Glucose Temperature Digestion
What is the stroke volume
Amount of blood pumped by the heart
What is the average stroke volume
70ml per minute
What is coronary heart disease
Blockage of the coronary arteries and veins
Causes by fatty deposits, cholesterol
What is angina
Pain associated with coronary heart disease
What is a heart attack
Total blockage of coronary artery leading to death of that piece of the heart
Symptoms of a heart attack
Tingling in the left arm Heavy breathing Cold sweat Pale Chest pain
What is a cardiac arrest
Where the heart stops completely
Factors affecting a heart attack
Number 1 is family history
Smoking High blood pressure High blood cholesterol Lack of exercise Diabetes
What multiple of oxygen is carbon monoxide more attracted to haemoglobin
200-250
What is the physiological altitude of smokers
4/5000 feet
How does smoking affect useful consciousness time
Reduces by half
Where are baroreceptors and what do they do
Downstream of the brain and sense blood pressure to maintain homeostasis
Giving blood has the following effects
Possibility of fainting (syncope)
More likely to get hypoxia
How long after giving blood do You need to wait before flying
24 hours
what precautions to take when giving blood
Seek medical advice from a ame before you go
Lying down (supine)
Drink plenty of fluids
Main parts of the visual system
Cortex
Optic nerve
Eye
What is a diopters
Unit of refractive power of the lense (16-30 diopters)
What fluid does the tear duct release
Antibacterial
What muscles control the eye movement
The extraocular muscles (6 in each eye)
What is the rest ‘jerk’ period of a eyes movement called
Saccade which lasts 1/3 of a second
What controls focusing (_accommodation)
The ciliary muscles
How does the lenses in the eye change for distance
Further away the object the flatter / thinner the lense
What effects accommodation (focusing)
Age and fatigue
What are the cones used for
Seeing colour Bright light Central vision Most detail Photopic vision
What area do cones cover and how many cones are there
1° wise and there are 150,000 cones/ mm^2
What do the rods do
Night vision (scoptic)
Peripheral vision
Sensitive to movement not detail
How long does it take to adapt from dark to light
10 seconds
How long does it take for the eyes to adapt from light to dark
Cones around 7 mins
Rods around 30 mins
What affects night vision
Tiredness Altitude of cabin Brightens Oxygen levels Age Smoking Alcohol Vitamin a
How do you optimise night vision
Spend time adapting to new light level
Avoid blinding light
Look to the side of objects
What vision is the ability to interpret alpha numerical data confined to
Central
How much does visual acuity drop by 25° from the fovea
10th
What is the visual field of each eye
120° left and right
150° up and down
When is binocular vision useful
To sense depth of close object less than 1m
What is stereoscopic vision for
Depth perception of object up to 200ft away (60m)
What physical factors helps depth perception
Colour Size Contrast Motion Overlaps
What is empty field myopia
When the eyes naturally rest 1-2 m ahead due to nothing to focus on
How do you prevent empty field myopia
Keep moving eyes
Scan
Look at wing tip
Look at clouds
What causes a visual blind spot
The optic nerve at the back of the eye
What is monocular vision and what effect does it have
Vision with just one eye
Loses depth perception
What is myopia
Short sightedness
Eye is longer than normal
Diverging / concave lense needed
What is hypermetropia
Long sightedness
Eye ball shorter than normal
Converging / convex lense required
What is presbyopia
Lense in eye can’t focus due to age
Usually develops into hypermetropia (long sightedness)
What is astigmatism
Irregular lense or cornea shape
What is cataracts
Lense in eye is cloudy white
What is glaucoma
Too much vitreous humour in the eye if drainage duct is blocked and eye ball keeps filling up
Pressure builds
What happens when your colour deficient
One / 2 / 3 of your red blue or green cones don’t work
What causes flash blindness
Lasers
Lighting
How to counteract flash blindness
If flying in lightning turn flight displays up to full brightness
Sunglasses
What is the caa requirement for all glasses wearers
Carry a spare pair
When wearing contact lenses you must
Carry glasses as well
Problems with contact lenses
Due to low humidity = dry eyes
Tiredness
Can become dislodged
Can starve cornea of oxygen
Requirements for sunglasses
Cut out uv Always wear sunglasses at high altitudes Spare pair should be carried Should be; - impact resistant - have metal frames - be coated with polycarbonate - allow 10-15% of light through - appropriate filtration characteristics
What equalises pressure between the middle and outer ear
The Eustachian tube
What is the human hearing range
20-20,000 hz
What is noise induced hearing loss (NIHL)
Damaging the membrane in the cochlea
Caused by over exposure to noise 90db or more
What happens at 120 decibels
Start to feel discomfort in the ear
What happens at 140 decibels
Ears become painful
What happens at 160 decibels
Ruptured ear drum
What is conductive hearing loss
Failure of the;
- ear drum
- bones
- cochlea
Excessive ear wax
Infection (swelling)
Presbycusis
Hearing loss with age
What is tinnitus
Constant ringing in ears
What do the 3 semi circular canals of the vestibular system measure
Yaw
Roll
Pitch
Angular acceleration
Filled with liquid
Lined with hairs
What do the otoliths of the vestibular system measure
Linear acceleration
What is the cerebellum
Part of the brain responsible for balance
Inputs = vestibular system
Eyes
Pressure receptors
What is somatogravic illusion
Not able to tell the difference between horizontal acceleration and pitching up
What is the somatogyral illusion
Where after turning for a period of time, you are unable to detect a turn anymore as the hairs of the ampulla return to their straight up position
What causes “the leans”
The somatogyral illusion
Or
A roll rate so low that the hairs in the ampulla don’t detect the roll
What is the Coriolis illusion
When moving head during a manoeuvre can cause the sense of violent rolling or pitching
What is vertigo
A disorder of the vestibular system usually brought on by alcohol
Or blocked Eustachian tubes
Or different accelerations
Tumbling or dizzy feeling
On average how much higher is the altitude inside the cabin at the initial drop in pressure during decompression
5000feet
What causes decompression sickness and what gas law is it
Henry’s law
Rapid drop in pressure causes nitrogen to be released from cells
What are symptoms of decompression sickness
The bends (nitrogen bubbles in joints)
The creeps ( rash) (bubbles moving under skin
The staggers (nitrogen bubbles in brain) (loss of coordination)
The chokes (nitrogen bubbles in capillaries around alveoli) (less able to breath)
At what height is decompression sickness unlikely to occur under
14,000
At what height is decompression sickness likely to occur over
18,000
How long must you wait before flying after diving with compressed air at less than 30feet depth
12 hours
How long must you wait before flying if diving with compressed air at a depth greater than 30feet
24 hours
How to prevent decompression sickness
Pre-oxygenate before flight (breath pure oxygen) to flush out nitrogen
3 different types of acceleration
Linear - straight line
Radial (centripetal) around axis
external to you (in spins) (has greatest physiological effect
Transverse - angular acceleration (axis through pilots body)
Factors reducing our g-tolerance
Alcohol Tiredness Body shape / obesity Hypotension (low blood pressure) Smoking Obesity Hypoxia Stress Hyperventilation Hypoglycaemia Heat
How to increase our tolerance to g force
Hold breath
Strain legs / abdominals (can be done by coughing or screaming)
Bend forward
G suit
Repeated exposure
What’s are the symptoms of about 2G
Head and limbs start to feel heavy
Above 2.5 g limbs become hard to move
What are the symptoms of 3-4G
Skin pulled downwards
Blood pools in lower legs
Decrease in blood to eyes results in loss of vision
What are the symptoms of +4 G
Feel fatigued
Without strain body becomes slumped forward
Difficulty breathing
What are the symptoms of +5 G
Black out
G-LOC
What negative g can the body tolerate
Only around -2/-3 G
What is the stroboscopic effect
Flashes of light into the eye >5 flashes/second
Happens when sun shines through sep propellor
Or strobes at wing tips
How can stroboscopic effect be stopped
Looking away
Sunglasses
Turn lights off
What is Otic barotrauma
Differences between the ear drum and outside air pressure caused by a blocked Eustachian tube
What are the damaging effects of otic barotrauma
Potential eardrum rupture
Or hearing loss
What is sinus barotrauma
Where the sinuses are blocked by mucus / infection so can’t equalise pressure between sinuses and outside pressure
What is gastric barotrauma
Trapped grass in the digestion system
What is aerodontalgia
Trapped gasses in teeth cavities
Why is the ozone damaging and where is it found
Solar radiation damages oxygen causing O2 to become O3
Found in the stratosphere between 40-75,000 feet
What are the symptoms of ozone poisoning
Dry eyes Dry nose Dry throat Dry skin Headaches Nausea Coughing Impaired vision Emphysema (damaging lung tissue) Death
What must be done to keep track of galactic and solar radiation exposure
Above 49,000 feet records must be kept
What can galactic radiation cause
Cancer and birth defects
What can solar radiation effect
Sunburn
Skin cancer
Damage CNS and organs
What are ossicles
Middle ear bones that vibrate with sound
“Oscillate”
What does the fovea consist of
Comes only
What does PSN consist of
Motor and sensory nerves only
What is the severity of hypoxia dependant on
Rate of decompression
Physical fitness
Flight level
Individual tolerance
What is a normal blood pressure reading
120/80mmhg
Decompression sickness may occur from what rate of climb and exceeding what height
More than 500 ft/min and exceeding 18,000ft
What does blood pressure depend on
Pulse rate
Peripheral resistance
Elasticity of the arterial walls
Blood volume and viscosity
Hypoxia at altitude is explained by which law
Daltons
Conductive bearing loss can be cause by
Damage to the ossicles in the middle ear caused by infection or trauma
Damage to the auditory nerve
Obstruction in the auditory duct
Visual disturbances can be caused by
Hyperventilation
Hypoxia
Fatigue
What term is given for when the image forms infront of the retina
Shortsightedness
Myopia
What is a high source of vitamin A
Butter
Eggs
Cheese
Fruits
What do vibrations do to eyeballs
Cause blurred vision due to resonance oscillations of the eyeballs
