RESPIRATORY SYSTEM UNIT REVIEW Flashcards
4 functions of respiratory system:
- Exchanges oxygen for cells and removes carbon dioxide from cells/tissues
- Production of vocal sounds
- Provides sense of smell through olfactory sacs
- Regulation of blood pH
Respiration
Process of gas exchange
Inhalation
Movement of air into lungs
Exhalation
Removal of air out of lungs
External respiration
Exchange of O2 and CO2 gas between pulmonary capillaries and alveoli
Internal respiration
Exchange of O2 and CO2 gas between blood and muscle cells
Cellular respiration
O2 and glucose yields CO2 and H2O and ATP
Where does cellular respiration occur
Mitochondria
Organs of the upper respiratory tract
Nose, sinuses, pharynx
Organs of the lower respiratory tract
Larynx, trachea, bronchial tubes, lungs
What helps structure of the nose
Bones and cartilages and it contains two openings (nostrils)
Nasal cavity
Hollow space behind the nose
Nasal septum
Divides the done (bone)
4 purposes of nasal cavity:
- Alternate air passage
- Warms air using blood vessels
- Filters air using hairs, cilia, and mucus
- Humidifies air using mucus
Deviated septum
When nasal septum is significantly displaced to one side, making one nasal air passage smaller than the other
Nasal concha
Bones that divide nasal cavity, support mucus membrane, and increase surface area
Paranasal sinuses
Space within bones that reduce weight of skull
Where is the pharynx located
Behind oral cavity
3 sections of the pharynx:
- Nasal pharynx
- Oral pharynx
- Laryngo pharynx
Two sections of the pharynx that meets
Nasopharynx and laryngo pharynx
Where is the larynx located
Top of trachea (vocal cords)
3 muscles and cartilages that support structure of larynx:
- Cricoid
- Corniculate
- Arytenoid
How is pitch of voice determined
Length, thickness, elasticity and tension of vocal cords
Function of testosterone in larynx
Steroid hormones like testosterone in males can result in an Adam’s apple and deeper voice
Laryngitis
Inflammation of larynx that makes the voice sound raspy, or person loses voice to speak
Glottis
Part of larynx that consists of vocal cords
Epiglottis
Allows air to enter larynx
How does epiglottis work so you don’t choke when eating
It will close during ingestion so that you do not choke when you eat
Epiglottis malfunction
Inability to close properly
Why does trachea not collapse
Contains cylindrical cartilage (C rings) so it holds trachea open and does not collapse
Trachea wall
Contains mucus which traps debris and humidifies air. As well as cilia which sweep debris upwards for it to be coughed out or swallowed
What cells creates mucus
Goblet cells
Bronchi
Two main divisions of trachea
Bronchioles
Many smaller branching tubes inside lungs made of smooth muscle with alveoli attached
Alveoli
Air sacs attached to bronchioles which are connected to circulatory system through pulmonary capillaries
How thick are alveoli
1 cell layer thick
How many alveoli in each lung
700 million
Pros of alveoli being surrounded by pulmonary capillaries
Results in high surface area for oxygen and carbon dioxide gas exchange
Lipoprotein/surfactant in alveoli
Prevents alveoli from sticking together and decreases surface tension
Stretch receptors in alveoli
Detects when lungs are saturated with air
Lungs
Spongy tissue that sits within thoracic cavity
How many lobes does left lung have
2 and contains space for heart called cardiac notch
How many lobes does right lung have
3
Serous fluid
Lubricates lung during breathing
Where do lungs sit
Thoracic (chest) cavity
2 membranes of lung
Outer pleural and inner pleural membrane
Outer pleural membrane
AKA parietal pleura which adheres to chest and diaphragm
Inner pleural membrane
AKA visceral pleura that is fused to lungs
Function of lung membranes
Maintain lung pressure to be slightly lower than atmospheric pressure which is 760mm of Hg
What are the ribs hinged to and why
Vertebrae and sternum so it can move up and outwards
Diaphragm shape
Dome shaped
Diaphragm shape
Dome shaped
Diaphragm function
Separates thoracic and abdominal cavities
Chemoreceptors in medulla, carotid and aortic bodies function
Responds to low O2, high CO2, and high H ion concentrations in blood
What part of the brain controls respiration
Medulla oblongata
Primary stimuli to cause breathing to occur
High concentrations of CO2 and hydrogen ions
Inhalation
Process of breathing in. It is an active process using ATP. Pressure in lungs lower than atmospheric pressure causing air to enter
What is sensed when air is exhaled out lungs
Aortic and carotid bodies and medulla senses high CO2 and high H concentration in blood
Results of phrenic nerve stimulation INHALATION (3):
- Ribs contract to move up and outwards which increase volume of chest cavity
- Diaphragm contracts and flattens
- Pressure in lungs drop lower
Exhalation
Process of breathing out. It is a passive process so NO ATP
When air enters lungs, what happens to alveoli
Becomes saturated/filled with air and expands
Stretch receptors of alveolar walls during exhalation
Sends nerve impulses to breathing centre of medulla oblangata. The nerve impulse is sent through vagus nerve
Nerve impulses in exhalation after reaching breathing centre
It will stop sending impulse to ribs and diaphragm
Results of nerve impulse stimulation EXHALATION (3):
- Diaphragm relaxes and goes back to dome shape
- Ribs move down and inwards
- Stretch alveolar walls recoil and cause pressure in lungs to increase forcing air out of lungs
What do premature babies usually lack
Sometimes lack the development of lipoprotein or surfactant due to early arrival
Surfactant’s function
Prevents alveoli from sticking together. Therefore, if preemies lack this then they are unable to breathe when born
Respirators
Mask or device worn over mouth and nose to protect respiratory system by filtering out dangerous substances
Blue baby
Where baby has not had its first breath of air to inflate lungs causing baby to look blue
What happens when a baby cries
It will inflate the lungs and the oval opening or the foramen oval closes
What happens when oval opening or foramen oval closes
Seals right and left side of heart causing ride side to carry DEOXYGENATED blood and left side to carry OXYGENATED blood
Pneumothorax
Collapsed lung caused by hole in pleural membrane cavity
Dead air
Air that does not reach alveoli
Dead space
Air that remains in lung
Residual volume
Air which does not empty from lungs
Tidal volume
Normal amount of air in one normal breath
Vital capacity
The maximum amount of air that can be moved in and out during one single breath
Summary for saturation of O2 (2):
- Hb becomes saturated with oxygen and holds (HbO2) and holds on to O2 tightly (high O2 tension) in lungs
- HbO2 becomes less saturated rapidly give up O2 and releases O2 easily at muscle tissue
Summary for pH
Hb holds onto O2 (HbO2) more tightly when blood pH is neutral in lungs
Lung pH
7.4
Muscle tissue pH
7.38
Summary for temperature (2):
- Hb holds onto O2 more tightly when blood is cooler in lungs
- Hb release O2 readily when blood is warmer in muscle tissue
Lung temperature
37C
Muscle tissue temperature
38C
Non-respiratory movements
Do not involve gas exchange
Examples of non-respiratory movements
Coughing, sneezing, hiccup, yawn
Illness related to respiratory system
Hyperventilation which is rapid or dep breathing usually caused by anxiety or panic
Hypoxia
Overall lack of oxygen in tissues and organs
Asphyxia
Unable to breathe normally which causes hypoxia
Other respiratory illnesses
Asthma, lung cancer, bronchitis. cystic fibrosis
Equation that shows how oxygen is used in body
O2 + C6H12O6 CO2 + H2O
+ ATP
Factors that affect how much oxygen is needed by body (3):
- How much energy is required
- Eating/digestion
- Sleep/rest
4 processes of respiration
- Breathing (entrance/exit of air in and out of lungs)
- External respiration (exchange of O2 and CO2 of air and pulmonary capillaries and alveoli)
- Internal respiration (exchange of O2 and CO2 of blood and tissue fluid at tissue capillary)
- Cellular respiration (production of ATP in cells using mitochondria)
Normal resting breathing rate
14-20 times/min
Major difference between inspired and expired air
Inspired is O2 and expired is CO2
Tubes and passages air goes through to get to lung sacs (8):
- Oral cavity
- Nasal cavities
- Nasal pharynx
- Pharynx
- Glottis
- Trachea
- Bronchi
- Bronchioles
- Alveoli
Oral cavity passage
Air through mouth to pharynx
Nasal cavity function
Filters, warms and moistens air
Nasal pharynx passage
Air from nose to throat
Pharynx passage
Air through throat
Glottis function
Opening of trachea
Trachea passage
Air from pharynx to thoracic cavity
Bronchi passage
air to each lung
Bronchioles passage
Air to each alveoli
Alveoli function
Air sacs for O2 and CO2 exchange
Why must air entering lungs be almost completely saturated with water vapour
So that it does not withdraw H2O from cells lining the alveolar cells. It prevents drying of cells
Why can we see breath on cold day
Air contains H2O so that it condenses when it hits air so we can see the particles
How do we smell
Through ciliated cells in upper nasal cavity. The nerves from cells to brain interpret different smells
Why does our nose run when we cry
Tear ducts drain into nasal cavity
Where do the Eustachian tubes lead
Into nasal pharynx from middle ear
Which 2 channels cross in pharynx
Trachea (contains air) in the front and the esophagus (contains food) behind trachea
How is windpipe/trachea kept free of debris
Ciliated mucus membrane
How does smoking affect trachea
Destroys/clogs cilia
Tracheotomy
Tube inserted through trachea for breathing
How is bronchioles different from bronchi
Smaller tubes, no cartilage, no cilia but contains smooth muscle
How do each bronchiole end
With an alveoli
Why does alveoli not collapse
Layers of lipoprotein which lowers surface tension
Arterioles passage
To lung to increase CO2 and decrease O2
Venules passage
Away from lungs to increase O2 and decrease CO2
What type of blood is carried in pulmonary arteries
Deoxygenated
What type of blood is carried in pulmonary veins
Oxygenated
What are lungs enclosed by
Pleural membranes
What separates the membranes
Intra pleural fluid
Significance of intra pleural fluid
Reduces friction and resistance
What happens when membrane is punctured and air enters space
Lung will collapse
What forms wall of chest cavity
Ribs/sternum on sides (Front and back) and the diaphragm on bottom
Movement of diaphragm when diaphragm muscle contracts
Downwards
Movement of ribcage when muscle of ribs contract
Up and outwards
What happens to size of chest and lungs when diaphragm and intercoastal muscles contract
Size of chest and lungs expand and increases
What is meant by breathing by negative pressure
Creation of partial vacuum that sucks in air into lungs
What chemicals stimulate inspiration
CO2 and H+
Which part of your brain detects chemicals that stimulate inspiration
Medulla oblongata
Phrenic nerve
Stimulates medulla to cause diaphragm and intercostal muscles to contract
How is decrease in oxygen detected
Through chemoreceptors in carotid and aortic bodies
Vagus nerve
Signals medulla to stop sending signals to inhibit respiration centre. Lack of stimulation causes rib muscles and diaphragm to relax AKA expiration
Why is it impossible to commit suicide by holding your breath
CO2 builds up in blood and forces us to breathe
Dead space
Space containing air not used in gas exchange
Which parts of respiratory system represent dead space
Trachea, pharynx, bronchi, bronchioles
Residual air
Air that never leaves lungs
Volume of air we inhale
500cc
How much volume of air reaches alveoli
350cc
Why can’t we breathe through very long tube
An increase in dead space will cause air to never reach alveoli
Why O2 diffuses in blood and CO2 diffuses out
O2 into blood = lower O2 partial pressure
CO2 into air = lower CO2 partial pressure
How is carbon dioxide carried in blood
HCO3 (bicarbonate)
How is carbon dioxide reformed
Carbonic anhydrase works on H+ + HCO3- and creates H2O + CO2
Enzyme that speeds up chemical reaction
CArbonic anhydrase
Oxygen concentration in lungs
50mmHg
Why does hemoglobin lose oxygen in tissues (3)
- pH is more acidic
- Temp is higher
- Partial pressure of O2 is lower
Why is temperature warmer in tissues
Because of metabolism reducing heat
What happens to oxyhemoglobin at tissue capillary
Oxyhemoglobin loses oxygen and becomes hemoglobin. Partial pressure of oxygen is lower because cells use oxygen for cellular respiration
Oxygen function in tissues
Cellular metabolism and respiration
What happens to carbon dioxide at tissue capillary
Carbon dioxide increases due to product from cellular respiration
How is blood pH kept constant
Hemoglobin acts as buffer