Unit 2, L1, Functional Anatomy Flashcards
Primary function of respiratory system
Gas exchange, O2 in and CO2 out
Secondary Functions of respiratory system
Olfaction, communication Barrier function Host-defense - Immune functions Blood filtration (removal of emboli) Metabolic function
For a successful system, we need
System to move air Surface for gas exchange Mechanisms to carry gasses in blood System for moving blood Local and central nervous regulation
External respiration is considered
Exchange of air in the lungs
O2 and CO2 are exhanged in alveoli
Internal respiration is considered
Mitochondria consuming O2 and producing CO2
Upper airways consists of
Nose, pharynx glottis, and vocal cords
Lower airways consists of
Trachea, bronchial tree, and alveoli
The airway system terminates in what (anatomy-wise)
Terminal bronchiole, respiratory bronchiole, and alevolar sacs
Major functions of the upper airways
Filter and condition inspired air, so increase temperature and humidiifu
What are the 3 mechanisms of bypassing upper airways
Intubation (think COVID), trach, and cric
Anatomy of the lobes of the lungs
3 lobes on the right, 2 lobes on the left as you need room for the heart
Pleural space is between what two pleural (names)
Visceral pleura and parietal pleura
Parietal pleura structure and function
Outer wall of the lungs, contains systemic capillaries that releases ultrafiltrate of plasma, aka pleural fluid
Also has stomata and lymphatics that will drain fluid
Visceral pleura is located where on the lungs
Inner wall
Is there air in the pleural space?
Dear god I hope not
Function of pleural fluid
To lubricate, as we need to lubricate as we move back and forth (thats what she said)
Pleural space is what kind of pressure
Negative pressure
What can high protein in the pleural fluid tell us
Signs of inflammatory disease
What can low protein in pleural fluid tell us
Hydrostatic/oncotic imbalance
What is pleural effusion
Excess fluid in the pleural space
Difference between pleural effusion and pulmonary edema
Pleural effusion is excess fluid in the pleural space, while pulmonary edema is excess fluid in the lungs
Structural anatomy of trachea/bronchi consists of
Cartilage, for maintaining structure and protecting the airways, and smooth muscles, which is for constriction and flexibility
Which side of the bronchi tree do inhaled foreign bodies more commonly get lodged in? and why?
Right side, as there is a greater diameter for the right mainstem bronchus so inhaled foreign bodies more commonly end up in the right lung than the left
What is the carina?
First big division of the bronchi, where a lot of damage can occur
Bronchopulmonary segment is a
Functional anatomic unit
Respiratory unit is a
basic physiological unit
What is the flowchart from trachea to the end, for the airways?
Trachea, bronchi, nonrespiratory bronchioles, respiratory bronchioles, and alveolar ducts
What does the conducting airways consist of
Trachea, bronchi, and nonrespiratory bronchioles
What does the respiratory unit consist of?
Respiratory bronchioles and alveolar ducts
Where does gas exchange occur?
In the respiratory unit, so in the respiratory bronchioles and alveolar ducts
Where does no gas exchange occur?
In the conducting airways so in the trachea, bronchi, and nonrespiratory bronchioles
What is anatomical dead space and how much is it (volume)
Air that is not participating in gas exchange, its trapped in the conducting airways. Its about 150 mL
Anatomy of the trachea/bronchus
Mucus and surfactact and the top, then epithelium, then basement membrane, then L. Propria (??), then a smooth muscle layer, and a fibro-cartilaginous layer
Where is the pseudostratified ciliated columnar epithelium layer?
In the trachea/bronchi, its a single layer with all touching basement membrane
Function of goblet cells in the trachea/bronchi?
Mucus secretion
Where are cuboidal cilitated epithelium layer found?
Bronchioles
Function of club cells in the bronchioles?
Protective, they are secretory, secreting surfactant-like solutions, to remove toxins. Have stem cell properties
Where can you find type I and type II pneumocytes and what do they look like/their function?
Alveoli, and type I pneumocytes cover most of the surface. They are squamous epithelium and they are very thin so we can transport O2 and CO2 back and forth. Type II are for surfactant secretion, they are cuboidal and may have some stem cell properties
At what point in the airway system (trachea to alveolar sacs), do we we lose cilia?
There are some in the respiratorry bronchioles but there are none by the time we get to alveolar ducts
At what point in the airway system (trachea to alveolar sacs) do we lose smooth muscle?
Some in the respiratory bronchioles and alveolar ducts but lose it entirely by the time we get to the alveolar sacs
At what point in the airway system (trachea to alveolar sacs) do we lose cartilage?
there are patches of cartilage in the bronchi but is completely gone by the bronchioles
What is the terminal bronchiole?
The last bronchiole without alveoli, without gas exchange, so its the last bronchiole in the conducting zome
Pulmonary arteries will travel (along or not-along) the airways
Along the airways
Veins will travel (along or not-along) the airways
Not along, they go off and do their own thing
Main goal of the respiratory zone and how does volume and surface area play into that
Main goal is to move O2 in and out and need a much bigger volume and surface area to do that
Explain the water tension picture and the sphere
Force that the material is experiencing is an upward force, so that is what is stopping something from going downward into the water. With a sphere, its truly an inward force, with inward meaning towards the inside
Explain alveolar surface tension
H2O molecules attract each other more than H2O-air on the surface, and this creates surface tension. This resists being stretched and tends to reduce surface area, and will create tendency to recoil after stretch. Surface tension is so high that alveoli/lungs would collapse without additional factors
Laplace equation
Magnitude of inward directed pressure (P) in a bubble (alveolus) = 2*surface tension (T)/radius (r) of bubble (alveolus)
Why do alveoli not collapse due to surface tension
Surfactant and interdependnece
Function of surfactant
Normalizes the surface tension so we can maintain different bubbles of different shapes, so neighboring alveoli can distend during an inhale at the same rate
Explain interdependnece in terms of alveoli stability
Two components, mechanically tethered and collateral ventilation. The tendency to collapse is opposed by the traction exerted by the surrounding neighbor alveoli. Collateral ventilation has to do with pores of Kohn, channels of lambert, and channels of martin, which basically connect everything
Blood supply to the lungs is through what two vascular systems
Bronchial circulation (systemic) and pulmonary circulation
Bronchial arteries help supply blood to the lungs how
From aorta to terminal bronchioles, merge with pulmonary arteries and capillaries, take 1-2% of total CO
Bronchial veins in terms of bronchial circulation (rephrase this one eventually)
1/3 of the blood returns to the right heart from the first 2-3 generations of bronchi, and 2/3 brain into pulmonary circulation (de-oxy!), contributes to venous admixture or anatomic shunt
Primary purpose of pulmonary circulation
Deliver blood to the lungs for gas exchange, largest vascular bed in the body
3 mechanisms of what can happen when you breathe materials in
Impaction, sedimentation, and diffusion
What is impaction
Mostly occurs in the upper airways where there is turbulent flow and its when big particles run into the walls of the airways
What is sedimentation
Happens more in bronchioles, when we slow flow down, things in the air will sediment out. Can have major long-term damage of the bronchioles here
What is diffusion of small particles and where does it happen
In alveoli, and macrophages go C H O M P
Three mechanisms for clearance of inhaled particles
Particles are swallowed, mucociliary system will transport them, or alveolar macrophages engulf the particles
Three components of mucociliary clearance system
Mucus layer, periciliary fluid, and cilia
Why do we need humidity in the air?
Humidity impacts both virus containing particles and mucociliary clearance
Low humidity means what for a virus
An increase in stable virus that is more capable of making it deep in the airways
Cilia stall in dry cold air because
Dry air dehydrates mucous layer, increasing viscosity and cold will inhibit ciliary function
Volume and function of respiratory region
2.5-3 L, surface area is 50-100 m^2
Why is the alveolar capillary network very thin
Ideal for gas exchange
What is the metabolic functions of the lung
Conversion of AngI to AngII by ACE
