Respiratory System Flashcards
What is internal respiration
Exchange of gas in the lungs and body tissues.
diffusion of oxygen from lung into the blood
and CO2 from blood to lungs
diffusion of oxygen from blood into into the cells
and CO2 from cells to blood
what is External respiration
process of inhaling air and transporting oxygen from nose or mouth to the lungs till oxygen is defused in the blood stream. And vice versa, where we expel CO2
this function is controlled by the prephiral system - the autonomic nervous system - because it’s done unconsciously
however we constant control the depth and rate of our breathing
Explain inhilation process
1.Air enters mouth or nose
2.Air passes through pharynx (tube between nose and larynx) and then to larynx (voice box)
3.Air passes to Trachea (semi-regid tube built with cartilage rings).
4.Trachea branches into 2 bronchi servicing each lung
5.Particles in the air get caught here the mucus lined walls of bronchi and trachea then slowly back up the mouth
6.Bronchi split into 2 again and again
7.As air passes through, it gets moist and warm
8.Bronchi eventually end at the Avleoli. Its walls are coated with fine layer of moisture
9.Alveoli are small spherical bags grouped in Alveoli sacs.
10.Membrane of the alveoli are thin and surrounded by capillaries
11.The pressure of oxygen in the air helps with the oxygen diffusion into the blood
12.The oxygen molecules entering each alveolus dissolve into liquid and through its members and into the capillaries, into the blood plasma
13.O2 molecules bind to the haemoglobin in the red blood cells
14.oxygenated blood passes to the left side of the heart, which then pumps it out into the body via arteries.
Explain Expiration
1.Simultaneously, deoxygenated blood travels to the right side of the heart
2.Pumps it back into the alveoli
3.In the Alveoli sac, CO2 molecules in the blood diffuse across the membrane into the alveoli from where they are expelled from the body via breathing out. Some of this process also happens at the final stages of bronchi
How much oxygen does the brain take
(even though our brain makes up 2% of our body weight) our brain consumes 20% of the oxygen we take in
how many alveolis are in normal human
300,000 alveolis exist in the body - this makes up 80m2 of gas exchange area
during hard excercise, how fast does blood pass from alveoli to capillaries
To keep the body oxyginated during excercise, it take 0.3 seconds for blood to pass from alveoli to capillaries
how many inhilations/exhilations are made per min and what does this equate in heart beats per min
15 inhilations & exhilations per min
= 70 heart beats/min
Relationship between Oxygen and Carbon Dioxide
- Body stores more CO2 than O2 hence why the body needs sufficient levels of O2
- CO2 helps body regulate O2
- CO2 helps maintain chemical balance in the body
- Breathing rate is affected by CO2 but also stress, anxiety, illness or injury
- O2 saturation levels in the blood is usually held at 98%. It drops below 90% when the Partial Pressure drops to 60mmHG
- Might seem when take in a lot of oxygen when we exercise but oxygen levels in the blood are held at tight limits
External mechanism to assist the lungs in external respiration
Brochi don’t have the ability to support themselves, therefore the lungs cannot inflat themselves. Infact, lungs can collapse if pressure in lungs is lower than that of the chest cavity
therefore, external mechanism is required that relies on:
Pleural cavity
Thorax
Diaphragm
InterCostal muscle
What is pleural cavity
The lungs are protected by the pleural membrane
The space between the lungs and the pleural memberane is the pleural cavity
What is thorax
Lungs and heart are located in the Thorax (chest cavity)
The thorax also has airtight membrane
the thorax is seprated from lower abdominal cavity by the diaphragm
What is the diaphragm
a muscle that separates thorax from abdominal cavity.
it flattens when breathing in, and relaxes into cone shape when breathing out.
Explain what happens when breathing in
Breathing in causes the diaphragm to flatten because the volume of ai in the lungs expands.
Here the pressure in the pleural cavity is lower
compared to the pressure in the lungs
What happens when breathing out
Breathing out causes the diaphragm to relax and go back to its cone shape.
the volume of air in the lungs reduces.
Here the pressure in the pleural cavity is higher
compared to the pressure in the lungs
the compressed lungs expel CO2
What is the muscle that helps the Diaphragm
During intense excercise, the body needs a lot of oxygen and to the support the speed of inhalation and exhilation, the diaphragm needs the
InterCostal Muscle - sits in the ribs and helps expand the ribs to allow the lungs to expand ( more volume) and vice versa
What is volutary respiration
When you can consciously control your breathing (holding breath, signing, etc)
Involunatry repiration
Occurs in the inenr body (with the brain) and to some degree is automatic
How does Carotid arteries assis in involutary respiration
in the coratid artery, there are sensors that monitor the acidity of the blood and the levels of CO2 and O2.
If CO2 are high, these sensors send signals to the brain and the brain sends signals to the Thorax to expand and ‘inhale’ more air
Hyperventiation definition
when body is needing to **breath fast and deeply **more oxygen more than the usual
feeling breathlesness even though you are breathing more oxygen
What is happening physiologically during hyperventilation
Overbreathing causes excessive flushing out of CO2 from the body.
The carotid artery recognizes that the carbonic acid is reduced and thus sends signals to the nervous system, and this signal constricts the blood vessels …..hence reduced blood flow to the brain
What causes hyperventilation
Anxiety & stress
Movements such as: turbulence, vibration, g force, motion sickness
Stroke & brain injury
Voluntary hyperventilation
What are symptoms of hyperventilation
dizziness, headache, light headed
Tingly lips, hands and feet
hot and cold flushes
impaired performance
imparied vision
unconsciousness / fainting
how to resolve hyperventilation
control breathing voluntarily or
breath into a paper bag to re-breath CO2
The more CO2 brought back to the body, the more the oxygen levels are balanced, and blood flow is unrestricted to the brain.
what is a panic attack
usually caused by stress and anxiety and when the sympathetic nervous system releases adrenaline, hyperventilation can be triggered.
Hypoxia definition
In high Cabin altitude:
As you fly up in altitude, air pressure and density decrease,:
- the mass of oxygen taken into the lungs decreases
- partial pressure of oxygen decreases
- less oxygen diffuse acrosse the alveoli
- less energy generated for cells and brain
the amount of oxygen available isn’t sufficient to meet the body’s needs (primiarly to meet the brain’s needs)
4 types of hypoxia
Hypoxic Hypoxia
Aenemic Hypoxia
Stagnant Hypoxia
Histotoxic Hypoxia
Hypoxic Hypoxia
When body is not getting sufficient oxygen to the lungs themselves (oxygen diffusions at blood level assumed to be working fine)
Due to lung infection, blocked airways, drug overdose
Due to drop in oxygen partial pressure at altitudes esp 10,000 ft AMSL and above where the body struggles to taken in enough oxygen
Aenimic Hypoxia
When body is not getting sufficient oxygen at blood level
This asssumes there is sufficient oxygen from the environment is coming through to the lungs, but not sufficient oxygen is transported to the blood.
aenimic, heamoglobin difficiencies, Asthma, carbon dioxide poisoning
Histotoxic hypoxia
caused by poisning in blood stream
- such in the case of carbon monoxide poisoning
Stagnant hypoxia
Caused by reduced blood flow to the brain due to clogged arteries & vessels
- caused by heart conditions
explain how carbon monoxide poisoning can happen
carbon monoxide is a product of combusion of material using carbon (aviation fuel)
it’s an ordorless and colorless gas
when cold air passes into an exhaust system to be warmed, this process produces carbon monoxide. If the pipes have holes in them, the gas can leak into the vents
when this gas is breathed into the body, it tends to bind 200x more to the haemoglobin than oxygen, therefore the blood carries more CO2 than O2 to the brain.
Symptoms of hypoxia
Subtle
sneaks up on you
starts with change in personality - feeling euphoric throughout
imparied judgement - feeling like you are right but actually not
impaired decision making, confusion
impaired coordination
dizzy, drowsy, headache
impaired vision - color vision, night, bluriness
cyanosis - blue lips, hands and feet
Tingly hands and feet
slurred speech
loss of memory
irritability
stomach gas
ear discomfort
hyperventilation
unconsciousness/fainting/death
some of these symptoms are more noticeable at 10,000ft +)
Other factors that affect the threshold of hypoxia (ie. can reduce time of usefull consciousness)
The effects of oxygen depreviation is different from one person to another - deterioration happens at different cabin altitudue for each person..but 10K ft is critical
pressurized cabins if they are depressurized
alcohol, drugs, smoking
stress and anxiety
fatigue or workload
illness/cold
Time in altitude
Excercise
What is time of usefull consciousness
time left that pilot is consciously aware during hypoxia (ie without supplementary oxygen) - this time reduces as altitude increases:
20,000 ft = 30 min
22,000 ft = 5 - 10 min
25,000 ft = 1 min - 180 sec
30,000 ft - 45 - 90 sec
35,000 ft - 30 - 45 sec
40,000 ft - 12 - 15 sec
Solutions to apply during hypoxia
reduce altitude to below 10,000 ft
check on each other
oxygen supplementation
oximeter to test level of oxygen in the blood
CO2 detector (visual/audible)
how to distinguish hypoxia from hypeventilation
Hypoxia symptoms tends to show at 10,000 ft
Hypoxia causes cyanosis (blue lips, hands and feet)
hyperventilation can be a symptoms of hypoxia, not the other way around.
Other issues that can be gas related
1) eating gassy food as gas can expand and cause abdominal pain - barotrauma
2) air trapped in dental fillings - barotrauma
3) air trapped in sinus - respiratory tract infection/barotrauma
4) decompression sickness due to diving. Should not dive 24 hrs prior to flying or 12 hrs if only dived 10m (30 ft). You many notice symptoms of DCS at 6000 ft altitude
Carbon monoxide
caused by cigarrette smoke OR product of internal incomplete combustion engines.
gas is vented thrug the exhaust pipe of of a piston engine
Piston exhaust gas
contains 9% CO
usually engine and exhaust pip are close to the cabin
can be used as a heat source to warm the cabin but if it’s damaged, exhaust gas can enter the cabin
eHypoxia causs cyanosis but not in the case of CO poisoning…
No cyanosis
Here the skin is flush and rosy
Carbon monoxide is cumulative
0.5% is removed per 4 hours
meaning if you fly in low CO over time, you can still contaminate your blood
if CO is detected in cabin
turn off all cabin heating
open all air vents
use 100% oxygen (not mixed air) or used oxygen supplement
land
Prevent: fresh air, regular maintenance
why does the body need oxygen frequently
because the body can’t store oxygen
what is external respiration called
ventilation
what is a respiratory system
respiration brings energy-given O2 to the body so it can absorb it and removed CO2 that it expels
The use of oxygen in each cell and creating energy by using oxidation (oxidizing fuel)
function of resporatory system
gas exchange between outside environment and circulatory system
immune defence to help fight infection entering from the lung
talking
release of chemicals, proteins, enzymes to control other body systems
cellular respiration
occurs inside cells where oxygen is used in a biochemical pathways to produce energy
Breathing rate
Ventilation rate
the autonomic nervous system senses
- the need for more blood in the body
- amount of CO2 in the blood
a higher than normal amount of CO2 means a lot of oxygen has been burned and need for more
as a result of high carbon dioxide in the blood, the breathing rate is automatially increased to bring more oxygen into thelungs for the blood stream to absorb
capacity of lung
can take up to 5 litres of air
at rest, one breath is 1/2 a litre
content of the lung
there is always some air in the lungs that contains higher concentration of CO2 than the atmoshphere and lower concentration of O2.
also saturated with water vapor
Symptoms of CO2 poisoning
headache, dizzy,nausea
imparied vision
imparied motor skills, decision making or judgement
imparied memory, change of personality
slow breathing
convulsion
coma, death
upper respiratory tract infection
when the upper tract like nose, mouth, sinuses are affected due to an infection or a cold, and disable you from equalizing your ear pressure
partial pressure
when altitude is gained, air thins out with fewer molecules in the same volume but % of compositions doesn’t change
Boyl’s , charles, Henry, dalton laws
Boyles
if Temp is constant, Pressure decreases then volume increases
Charles,
If pressures is constant, temperature increases, voume increases
Dalton, the total pressure is the sume of its partial pressure
Henry, Decomposition sickness
