Anatomy of Lungs, Airways and Blood Supply Flashcards
What are the main anatomical features of the respiratory system?
Pharynx
Trachea
Lung
Nose
Epiglottis
Larynx
Bronchus
What structures make up the upper respiratory tract?
Pharynx
Vocal cords
Nasal cavity
Tongue
Esophagus
Larynx
What structures make up the lower respiratory tract?
Right lung
Right main bronchus
Left lung
Left main bronchus
Diaphragm
What are the types of alveolar cells?
Type One
Type Two
Describe type one alveolar cells
Very thin and have walls thin enough for gas exchange to take place across
What are type one cells studded by?
Type two cells
What is the role of type two alveolar cells?
Secreting surfactant.
Not involved in gas exchange.
They make it easier for us to inspire.
What type of alveolar cells do capillaries lie near and why?
Directly abutted to a type one cell but never type two cells
Because they are the parts of the cardiovascular system that are thin enough to allow gas exchange to take place
What are the functions of the respiratory system?
Gas exchange: oxygen added to the blood from the air, carbon dioxide removed from the blood into the air.
Acid - base balance: regulation of body pH
Protection from infection
Communication via speech
What is the role of the pulmonary circulation?
Moves blood between the heart and the lungs.
It transports deoxygenated blood to the lungs to absorb oxygen and release carbon dioxide.
The oxygenated blood then flows back to the heart.
What is the role of the systemic circulation?
Moves blood between the heart and the rest of the body.
It sends the oxygenated blood out to cells and returns deoxygenated blood to the heart.
What do the pulmonary artery and vein do?
The pulmonary artery carries deoxygenated blood from the body to the lungs whereas the pulmonary vein carries oxygenated blood from the lungs to the left atria of the heart.
What do the systemic vessels do?
The arteries are carrying oxygenated blood and the veins are carrying deoxygenated blood.
What does an artery do?
Carry blood away from the heart
What does a vein do?
Carry blood to heart
What are the three points of gas exchange between the respiratory and cardiovascular systems?
Exchange I: between atmosphere and lung
Exchange II: between lung and blood
Exchange III: between blood and cells
What is cellular/internal respiration?
Biochemical process that releases energy from glucose via glycolysis or oxidative phosphorylation.
Latter requires oxygen and depends on external respiration.
What is external respiration?
Movement of gases between the air and the body’s cells, via both respiratory and cardiovascular systems
What does the trachea branch into?
Two bronchi, one to each lung
What do the bronchi branch into?
Each bronchus branches 22 more times, finally terminating in a cluster of alveoli.
What do bronchi and trachea contain?
Cartilaginous rings
Help maintain patency (the condition of being open or unobstructed) of airways.
What happens below the level of the bronchi?
Lose the cartilaginous rings and the patency of airways instead is maintained by physical forces that act on the lungs.
What are bronchi known as once we lose the cartilaginous rings?
Bronchiole
Carry on dividing and eventually terminate in the alveoli.
What are the terminal branches of the respiratory tree?
Alveoli
What are alveoli and what takes place in the alveoli?
Tiny, blind ended sacs, filled with air and is where gas exchange takes place.
Why does gas exchange take place in the alveoli?
The walls of the alveoli share a membrane with the capillaries. They are also very thin.
That’s how close they are.
This lets oxygen and carbon dioxide diffuse, or move freely, between the respiratory system and the bloodstream
Why does gas exchange not take place anywhere other than the alveoli?
Airways have walls that are too thick for gas exchange to occur.
What is the difference between the right and left bronchus?
The right bronchus is shorter and wider while the left bronchus is longer and narrower
The right bronchus is more vertical compared to the left bronchus
How many generations of branching occur between the trachea and alveoli?
24 generations
What zones can the respiratory system be divided into?
Conducting zone
Respiratory zone
What does the conducting zone contain?
The organs and structures are not directly involved in gas exchange.
Trachea, brochi, bronchioles.
What is air in the conducting zone referred to as?
Anatomical dead space
What is the role of the conducting zone?
Provide a route for incoming and outgoing air, remove debris and pathogens from the incoming air, and warm and humidify the incoming air.
What is anatomical dead space?
Volume of air located responsible for conducting air to the alveoli and respiratory bronchioles but do not take part in the process of gas exchange itself
What is the impact of dead space?
Impact breathing, the surface area available for gas diffusion is reduced.
Oxygen in the blood decreases, whereas the carbon dioxide level increases.
What is physiological dead space?
The volume of air in the respiratory zone that does not take part in gas exchange
What is the respiratory zone?
Consists of alveoli.
Alveolar ventilation and gas exchange occur as oxygen moves down its concentration gradient and into the red blood cells.
What does airway resistance determine?
How much air flows into the lungs at any given pressure difference between the atmosphere and alveoli.
What is the major determining factor of airway resistance?
Radii of airways.
