The Respiratory System Flashcards
Why do we respire?
1) Take in oxygen
- drives aerobic cellular respiration
2) Remove carbon dioxide
Why do we need to remove carbon dioxide?
- prevents build up of this toxic waste product.
Other roles of Respiratory System?
- Temperature regulation
- Allows speech
- Acid base balance
- Water balance
Even some multicellular organisms are small enough to obtain their O2 by…
…diffusion
Small multicellular organisms which are small enough to obtain their O2 by diffusion tend to be…
…simple animals with flattened or tubular shapes to maximise surface area.
Such as:
- Flatworm
- Planaria
Oxygen diffuses…
…slowly
Because oxygen diffuses slowly, bigger animals including humans cannot…
…obtain oxygen only by diffusion
Larger animals have also evolved …
…transport systems, normally through circulatory systems
Different animals have respiratory systems that differ in:
structure
complexity
What systems have larger animals developed to carry out respiration?
- Tracheal systems
- Gills
- Lungs
Tracheal systems mainly seen in…
…insects
Gills seen in…
- many invertebrates
- fish
- some amphibians
Primitive lungs & book lungs found in…
- some snails
- spiders
Lungs seen in…
- some amphibians
- reptiles and birds
- mammals, including humans
The respiratory systems (RS) of other animals are often not as …
…efficient as ours
eg - the lungs of frogs
- This places limitations on the performance of other animals compared to mammals
avian lungs are more…
…efficient than ours
Getting O2 to cells can be divided into four main stages:
1) Ventilation
2) Gaseous exchange
3) Transport of gases
4) Entry into/exit from cells
What is ventilation?
the movement of air from the external environment to the respiratory surfaces
What is Gaseous exchange?
the diffusion of O2 and CO2 across the respiratory epithelium into the blood circulatory system
What is Transport of gases?
movement of gas from/to the lungs to/from the tissues (via the heart in humans)
What is entry into/exit from cells?
the diffusion of O2 and CO2 across the cell membrane for cellular resp.
Our Ventilation System is divided into…
…2 main regions
The two main regions of the ventilation system:
Upper and lower respiratory tract.
Whats the Upper Respiratory Tract?
airways of the head and neck, which include the nose, nasal cavity, pharynx (throat) and associated structures
Whats the Lower respiratory tract?
airways supplying the lungs and lung tissue, which include the larynx (voice box), trachea (windpipe), bronchi and lungs
Functionally, the respiratory system also consists of …
…two zones
Two zones of the respiratory system?
1) The Conducting Zone
2) The Respiratory Zone
What is The Conducting Zone?
consists of a series of interconnecting cavities and tubes outside and within the lungs
What is The Respiratory Zone?
consists of tubes and tissues within the lungs where gaseous exchange occurs
The conducting zone includes the…
…nose, nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles and terminal bronchioles
THe respiratory zone consists of…
…the respiratory bronchioles, alveolar ducts, alveolar sacs and alveoli
Function of The Conducting Zone?
function is to filter, warm, and moisten air to the lungs
Function of The Respiratory Zone?
- Main sites of gas exchange
- specifically the removal of carbon dioxide from, and the addition of oxygen to, the blood
Upper Respiratory Tract consists of…
Consists of nose, nasal cavity, pharynx & assoc. structures
Whats the nose?
Specialised organ
WHats the visible part of the nose called?
external nose
The nose is a supporting frame of…
- Bone and hyaline cartilage
- Covered with muscle and skin
- Lined by mucous membrane
Hyaline - somewhat…
…flexible (allows flexibility of the nose)
On the undersurface of the external nose are …
…2 openings
On the undersurface of the external nose are two openings called …
…external nares or nostrils.
Nasal vestibules in the nose are lined with …
…coarse hairs
On the undersurface of the external nose are two openings called external nares or nostrils. These openings lead to …
… cavities called nasal cavities.
Nasal vestibules lined with coarse hairs – why?
Filter out large dust particles from inhaled air
In fact, the interior structures of the nose have three functions:
1) warming, moistening and filtering incoming air
2) Detecting olfactory stimuli
3) Modifying speech vibration (hollow resonating chambers)
Whats the internal portion of the nose called?
nasal cavity (internal nose)
The nose is divided into…
right and left sides by:
the nasal septum
What are Nasal Cavity and Sinuses
Ducts from the paranasal sinuses and nasolacrimal ducts
Function of paranasal sinuses and nasolacrimal ducts?
1) also open into nasal cavity
2) paranasal sinuses drain mucous and nasolacrimal ducts drain tears.
Sinuses are …
…air-filled spaces within the bones of the skull
Sinuses connect to…
…the nasal cavity
The sinus reduce…
…skulls relative weight
Sinuses act as
resonating chambers for sound as we speak / sing
Nasal cavity (NC) divided into:
- larger, inferior respiratory region
- smaller, superior olfactory region
the larger, inferior respiratory region is lined with…
…ciliated columnar epithelium with numerous goblet cells
the larger, inferior respiratory region is often called …
…the respiratory epithelium
the smaller, superior olfactory region is responsible for…
…smelling
Nasal Conchae extends out of…
…lateral wall of Nasal cavity
The nasal conchae has…
three shelves formed by projections of the:
- superior nasal conchae
- middle nasal conchae
- inferior nasal conchae
The nasal conchae subdivide…
…each side of the nasal cavity (NC)
- groove-like air passages
- meastuses
Arrangement of nasal conchae and meatuses do what?
Increases surface area and prevents dehydration by trapping H2O
Function of the nasal conchae’s mucous membrane lining?
warms and humidifies inhaled air
Nasal cavity (NC) communicates with the pharynx through two openings :
internal nares or choanae
Pharynx (throat) comprised of the:
1) Nasopharynx
2) Oropharynx
3) Laryngopharynx
Function of the Nasopharynx?
receive air from nasal cavity (NC)
Function of Oropharynx?
receives air from the nose and mouth (+food)
Function of Laryngopharynx?
continuous with larynx and the oesophagus
Pharynx (throat) has a wall made up of…
…skeleteal muscles.
Why does the pharynx (throat) need skeletal muscles?
relaxed = open airways
contract = aids swallowing
tonsils = immune system
Tonsils are involved in the…
…immune system
Lower Respiratory Tract consists of…
…the larynx, trachea, bronchi and lungs
Wheres the larynx (voice box) located?
Located just below the pharynx
the larynx is the…
…voice box
The larynx is made up of…
…several pieces of cartilage surrounded by fibrous tissue
The larynx divides into…
….the trachea and oesophagus
The largest piece of cartilage is found in the …
…larynx
- thyroid cartilage = adams apple
What are the vocal chords?
two ‘V’-shaped bands of muscle
Vocal chords vibrate when…
…air passes between them, producing sound.
The trachea (windpipe) joins…
…larynx and primary bronchi
The trachea (windpipe) is supported by…
…cartilaginous rings which keep the trachea open
The larynx sits on top of…
…the trachea
Whats the eppiglottis?
Leaf shaped piece of elastic cartilage covered with epithelium
The epiglottis prevents…
…food and drink from entering airways and lungs
Function of the Primary bronchi?
Right and left primary bronchi take air into the lungs
cf = ?
shorthand way to say compare
Compare right and left bronchus
- right bronchus more vertical, shorter, and wider
- Aspirated object and so is more likely to lodge in right bronchus
Our pair of lungs lie in …
…the thoracic cavity
The broad base of the lungs rests on…
…the diaphragm
Lungs made up of …
…lobes
THere are 3 lobes in the…
…right lung (shorter)
THere a two lobes in the…
…left lung (which is 10% smaller)
Why does the lung have lobes?
To accommodate heart and liver.
Air enters the…
…bronchial tree and works its way through the lungs passing through:
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
bronchi in the lungs branch into …
…smaller and smaller bronchioles before ending in alveoli
Alveoli are richly supplied with …
…blood capillaries
Alveoli are richly supplied with blood capillaries. Why?
Site of o2 and co2 exchange between lungs and blood
What are the features of alveoli which allow for efficient gas exchange?
- Large surface area
- Short diffusion distance
- Moist surface (not visible)
What is the haem prosthetic group?
flat molecule located in a ‘pocket’ in globin chains
this ‘pocket’ has many non-polar amino acids
as Hb loads/unloads O2, the globin chains …
…move
α/β contacts stabilise …
…Hb
when O2 is unloaded, β-chains …
…pull apart
As Hb loads O2, the globin chains …
…move on eachother
When O2 unloaded β-chains pull apart which permits entry of…
…2,3-DPG
Results in lower affinity for O2
the lungs are surrounded by…
…two membranes
What are the two membranes which surround the lungs?
Parietal pleura and visceral pleura
The parietal pleura is attached to….
…wall of thorax
The visceral pleura is a deep layer which …
…covers the lungs
The pleural cavity is found…
…between the two membranes
The pleural cavity is filled with…
…pleural fluid secreted by the pleurae
Function of pleural fluid?
reduces friction between the membranes during breathing
What’s pleurisy or pleuritis?
Inflammation of the pleural membrane, causing pain due to friction between layers of pleura.
If pleurisy persists…
…Pleural effusion occurs - excess fluid accumulates in the pleural cavity
What is pneumothorax?
Collapsed lung due to air in the pleural cavity.
Most common causes of pneumothorax?
- chest trauma
- excessive pressure on lungs
- underlying lung disease
- Chronic Obstructive Pulmonary Disease (COPD)
- Cystic Fibrosis
- Asthma
Lungs and other vital organs within the thoracic cavity are protected by the …
…ribs
Two sets of muscles, the internal and external intercostal muscles, are located between …
..the ribs
The diaphragm (also a muscle) forms…
…the bottom of the thoracic cavity
Inhalation is an […] process
Inhalation is an active process
During inhalation, the diaphragm contracts and is drawn …
…downwards
During inhalation, the intercostal muscles between the ribs …
…contract and raise the ribcage up and outwards
During inhalation, due to the action of the diaphragm…
…the chest cavity expands and intra-alveolar (lung) pressure is reduced
During inhalation, the diaphragm contracts and is drawn downwards
The intercostal muscles between the ribs contract and raise the ribcage up and outwards
The chest cavity expands and intra-alveolar (lung) pressure is reduced
The lungs are pulled…
… downward and outward, drawing air into them.
Exhalation is a […] process.
Exhalation is a passive process.
During exhalation, the diaphragm relaxes and moves …
…upwards
During exhalation, the intercostal muscles…
…relax and the ribcage moves inward and downward
During exhalation, the volume of the chest cavity is…
…reduced and lung pressure increases
During exhalation, the lungs contract, forcing…
…air out of them.
The amount of work the respiratory muscles must perform during inspiration depends on:
- Stretchability of lungs and thorax
- Resistance within the areas
- Surface tension of water molecules associated with alveolar epithelium
% Energy expended at rest?
1-3% total body’s energy at rest
% Energy expended during exercised?
3-5% during heavy exercise
The lungs have the capacity to stretch and take in more air depending on …
…the O2 needs of the body
Measurements of lung volumes and capacities can provide an indication of…
…lung function
such as:
- COPD; Asthma
- Bronchitis
- Emphysema
Lung volumes and capacities are measured with …
… a spirometer
WHat is Functional Residual Capacity (FRC)?
Amount of air remaining in lungs after normal exhalation
What is Total Lung Capacity?
Total Lung Capacity (TLC) is the maximum volume of air that the lungs can hold after a maximal inhalation.
Total lung capacity (TLC) is also known as…
…Maximum Lung Capacity
What is Tidal Volume (TV) also known as?
Respiratory volume
What is Tidal Volume?
The amount fo air that is inhaled or exhaled during a normal, quiet breath. It represents the volume of air that moves in and out of the lungs with each breath during a respiratory cycle.
What is tidal volume (TV) measured in?
Typically measured in millilitres (mL) and can vary depending on factors such as age, body size, and physical activity level.
What is Inspiratory Reserve Volume (IRV)?
Amount of air over and above the tidal volume that can be inhaled.
Whats Vital Capacity (VC)
Maximum amount of air that can be exhaled after maximal inspiration
Whats Expiratory Reserve Volume (ERV)?
Amount of air that can be forcibly exhaled at end of normal tidal volume.
Whats Residual Volume (RV)?
Amount of air left in lungs after maximal expired effort
In humans, the tidal movement of air into and out of the lungs means…
not all the air in the lungs is exchanged with the atmosphere with every breath.
Air remaining in the airways after inspiration does not take part in gaseous exchange
This is referred to as ‘dead air space’ and amounts to about 150 ml of air
Why are the lungs of humans not as efficient as those of birds?
- air flows through their lungs continually
- gas exchange is therefore more efficient
Humans climbing Mt Everest must carry …
…supplemetary oxygen
However, bar-headed geese can…
… fly over Mt Everest
Respiratory sensors in the carotid artery and aorta monitor …
…changes in pH of the blood
Describe the process of what happens when the respiratory sensors in the carotid artery and aorta detect an increase in CO2 and a decrease in pH
1) Increase in CO2 and decrease in pH detected by respiratory sensors in carotid artery
2) Increase ventilation rate and broncho-dilation
3) Balance restored
Describe the process of what happens when the respiratory sensors in the carotid artery and aorta detect a decrease in CO2 and a increase in pH
1) Decrease in CO2 and increase in pH detected by respiratory sensors in carotid artery.
2) Decrease ventilation rate and broncho-constriction
3) Balance restored
