The Respiratory System Flashcards
Which of the lungs is wider and shorter, has 3 lobes (superior, middle, inferior) and 2 fissures (oblique, horizontal)?
Right lung
What are the 3 functions of the respiratory system?
To supply the body with oxygen
Excrete things (carbon dioxide, heat, ketone bodies, alcohol…)
Maintain pH of body fluids
Which of the lungs is narrower and longer, has 2 lobes (superior and inferior) and 1 fissure (oblique)?
The left lung, as it needs to accommodate the heart
What is the name of the point where the left and right bronchi and blood vessels enter lung tissue?
Hilium
What is the name of the lining of the chest wall?
Parietal pleura
What reduces friction during breathing, creates a pressure gradient to assist ventilation and isolates each lung?
the pleura - visceral on each lung and parietal on the chest wall
What covers each lung?
Visceral pleura
What are the divisions of the respiratory system according to position?
Upper Respiratory Tract (nose, nasal cavity, paranasal sinuses, pharynx, larynx)
Lower Respiratory Tract (trachea, bronchi, bronchioles, alveoli)
How can the respiratory system be classified according to function?
Conducting zone (nose, pharynx, larynx, trachea, bronchi, bronchioles, terminal bronchioles) this warms and moistens air and then transmits to and from lungs
Respiratory zone (respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli) - site of gas exchange
The airways in the respiratory system get smaller after the trachea, what do they also do at each stage?
Divide into 2
What are the 3 functions of the nasal cavity, and the 3 areas?
Warms, cleanses and humidifies inhaled air
Detects odours
Resonating chamber to modify voice
Conchae, meati and paranasal air sinuses
What part of the nasal cavity has a large air pocket for lots of mucous production?
Sinus
What extends from the nose to the larynx, is a passageway for air and food and mucus, warms and humidifies air, provides a resonating chamber for speech sounds and provided protection?
Pharynx
What connects the laryngopharynx with the trachea, is well composed of 9 pieces of cartilage, maintains an open airway, has a switching mechanism when swallowing and acts as a voice box?
The larynx
What is made up of 16-20 C shaped cartilage rings, smooth muscle, respiratory mucosa (pseudostratified ciliated columnar epithelium), mucous glands and is in front of the oesophagus?
Trachea
What is a muci-ciliary escalator?
It is in the Upper Respiratory Tract and has cilia that moves mucus down toward the pharynx
It is also in the Lower Respiratory Tract where the cilia moves mucus up to the pharynx
What do goblet cells do in the respiratory system?
Secrete mucus to trap debris
What is the structure of the bronchial tree?
Trachea - primary bronchi - secondary bronchi - tertiary bronchi - bronchioles - terminal bronchioles
What is carina?
Mucous membrane vs sensitive cough reflex
What is the difference between bronchi/bronchus and bronchioles?
There is cartilage in the wall of a bronchus but not a bronchiole (or alveoli) as microscopic
Primary bronchi, secondary bronchi, tertiary bronchi, bronchioles and terminal bronchioles have different types of what kind of cell?
Columnar - you have no hope of learning which is which type but start of tall pseudostratified, then just pseudo and non pseuod then just columnar
What cells are respiratory bronchioles?
cuboidal
What cells are alveoli?
Squamous
Where does gas exchange take place in the respiratory system?
Alveoli network - they have really thin walls so can diffuse easily - squamous
oxygen diffuses through squamous epithelial cells to basement membranes then capillary endothelial cells. but what are type 2 alveloar cells?
Septal and make sure airways stay open and don’t collapse
What carries blood to the lungs for it to be oxygenated? (they lie anterior to primary bronchus, branch with bronchi and terminate in capillary networks surrounding alveoli)
Pulmonary arteries
What take oxygenated blood to the heart?
Pulmonary veins
What supply lung tissue with blood?
arise from aorta, enter hilium and branch with bronchi - DON’T supply alveoli like the pulmonary arteries
Bronchial arteries
Regions of the respiratory tract can be classified according to what 2 things?
position and function
What do you call the exchange of air between the atmosphere and the alveoli of the lungs?
pulmonary ventilation
getting air in and out of lungs
Quiet inspiration involves what 2 important muscles?
diaphragm (80%) external intercostals (20%)
What is the diaphragm like when we are at rest?
relaxed and dome like
What do the external intercostals connect?
The top of one rib with the bottom of the next one
During quiet inspiration, what do the diaphragm and external intercostals do?
The diaphragm contracts and flattens, moving down and pushing down contents of abdomen, and the external intercostals move the ribcage upwards and outwards
(provides space for air to get into lungs)
What muscles are used during quiet expiration?
None - it is a passive process based on the elasticity of the lungs
everything relaxes and falls back into place, decreasing space in the thoracic cavity and forcing air out
What 4 additional muscles are involved during forced inspiration?
scalenes
sternocleidomastoid
pectoralis major
pectoralis minor
these all assist the diaphragm to create more space and depth for air
What additional muscles are involved in forced expiration?
internal intercostals
oblique and rectus abdominis muscles
quadratus lumborum
How to remember that external intercostals are used for quiet inspiration?
External - to get outside air in
internal for forced expiration is to get inside air out
Where do most of the accessory muscles lie for forced inspiration?
Neck or shoulder
How does movement of the chest wall help air to enter and leave the lungs?
Pressure differences between the atmosphere and the alveoli
What 2 things create pressure differences between the atmosphere and alveoli?
Pressure differences already present in the thoracic cavity
contraction and relaxation of respiratory muscles
What are respiratory pressures always related to?
Atmospheric pressure
What is interapleural pressure?
Opposing forces - recoil vs elasticity of the chest wall
it is impossible to separate the pleural membranes to it creates a vacuum to stop the lungs collapsing
What is the name of the law where the pressure of a gas varies inversely with volume?
Boyles Law - so pressure up when volume down
Outline the chain of intrapulmonary pressure during inspiration
Diaphragm rises and external intercostals contract
Rib cage rises
thoracic cavity volume increases
intrapulmonary volume increases
intrapulmonary pressure increases until same as outside lungs
air enters lungs down pressure gradient until INTRAPULMONARY PRESSURE = ATMOSPHERIC PRESSURE
Outline chain of intrapulmonary pressure in expiration?
Diaphragm and external intercostals relax
rib cage falls
thoracic cavity volume decreases
intrapulmonary volume decreases
INTRAPULMONARY PRESSURE IS GREATER THAN ATMOSPHERIC PRESSURE TO AIR LEAVE LUNGS DOWN PRESSURE GRADIENT UNTIL PRESSURE IS ZERO
What is pulmonary compliance?
Ease with which the lungs can be expanded
Healthy lungs are stretchy
What does scar tissue in the lungs, difficulty in expanding lungs, blockages in smaller respiratory passages and low levels of surfactant reduce?
pulmonary compliance
What does fluid and blood cells in alveoli and thickened alveolar walls in pneumonia affect?
Harder to expand alveoli in inspiration
What happens in emphysema?
Confluent alveoli - breaks down walls so low surface area for gas exchange and large air spaces filled with air throughout exhalation - build up of CO2
During inhalation the bronchioles enlarge, which decreases resistance to air flow. What happens in exhalation?
The resistance decreases as bronchioles decrease
What is airway diameter regulated by?
Contraction/relaxation of smooth muscle in air ways
Do asthmatics find it harder to breathe out or in?
Out, as airways stay narrow
What 2 ways can lung function be assessed?
Chest sounds (for musus or absence of breath)
Pulmonary functions (speed can breathe out, volume out)
What is Forced Vital Capacity?
Deep breath followed by rapid maximal exhalation
What is Forced Expiratory Volume?
how much can breathe out in first and second breath
In quiet breathing, what is active and what is passive?
inhalation = active expiration = passive
in forced both use additional muscles
What is atmospheric air?
a mixture of gases
What is Dalton’s law of partial pressure?
the total pressure exerted by a mixture of gases is the sum of the pressures exerted independently by each gas in the mixture
so the pressure exerted by each gas is directly proportional to its %
In the respiratory membrane, how do gases diffuse?
down the pressure gradients
what is henrys law?
the amount of gas that dissolves in water is determined by its solubility in water and partial pressure in air
What factors affect the affinity of Hb for oxygen?
Carbon dioxide
Temperature
How acidic blood is
Structure of Hb
How is carbon dioxide transported in the blood?
In plasma, bound to Hb and as bicarbonate
What changes in CO2 transport to ensure breathing is smooth?
pH
Changing body demands, altitude, disease and changing levels of co2, H and o2 in arterial blood can affect what?
rate and depth of breathing
What are the key regulators of breathing?
CO2 (increases and decreases accordingly)
Hydrogen
Should you give COPD patients lots of oxygen?
No as chemoreceptors will have adapted to take into account having lots of CO2 all the time.
If you did this would take away hypoxic drive and slow breathing further
