Respiration PT 1 Flashcards
4 major functions of respiratory physiology?
-Pulmonary ventilation → mechanisms of breathing
-Diffusion of O2 + CO2 between alveoli + blood → respiration
-Transport of O2 + CO2 in body fluids (one of the many factors that determine homeostatic balance)
Tissues have the ability to alter blood flow without direction from the nervous system when there is deficient O2 levels
-Regulation of ventilation → determines pH
What muscles are used during inspiration?
Scalenes
Anterior serrati
Sternocleidomastoid
EXTERNAL intercostals
SAS E
Muscles used during Normal Expiration?
Diaphragm relaxes
Elastic Recoil of Lungs and Chest Wall
What muscles are used for heavy expiration?
Abdominal muscles
internal intercostals
rectus abdominis
AIR
What forms the plural cavity?
visceral (on lungs) and parietal (on thorax) pleura
Continuous suction of excess fluid into the lymph maintains suction between the visceral + parietal surfaces → creating _______ PLEURAL pressure, allowing the lungs to move with the ribs.
Note: The lymph can only drain _____ fluid
What happens when this doesn’t work?
Negative
Excess
Pleural effusions
During inspiration, alveolar pressure _____ from the normal alveoli pressure of ________ (which is _______) → causing a ________ pressure.
As the thorax expands, the ______ in the alveolar pressure allows the air to flow into the lungs.
Falls
0 (which is the atmospheric pressure)
Negative
Decrease
During expiration What happens to the alveolar pressure?
Alveolar pressure increases
During expiration, you want to expel air. If you have increased alveolar pressure, you can push air out, much like squeezing a water bottle full of water.
Trans-Pulmonary Pressure / Recoil Pressure
-The Difference between alveolar and pleural pressures - Recoil Pressure
-A measure of the elastic forces in the lungs that tend to collapse the lungs at each instant of respiration
What gives you an idea of how much the lungs want to pull away from the __________ pleura and collapse (shrink)?
Parietal (thoracic) pleura
Trans-Pulmonary Pressure / Recoil Pressure
forces that makes the lungs want to collapse:
Elastin (+collagen)
Surface tension
The compliance diagram relates:
lung volume changes to changes in transpulmonary pressure.
X axis - pleural pressure (cm H2O)
Y axis - lung volume change (L)
To be able to inspire, muscles have to
overcome:
collagen + elastin forces (inside alveoli walls)
and surface tension
As the hydrogen and oxygen molecules are tensed with air, what happens to hydrogen bonds?
hydrogen bonds are strengthened
A collection of free air in the chest outside the lung causing it to collapse is called a
Pneumothorax
Surfactant ____________ surface tension, making it __________ to breathe. It is produced by
Reduces
Easier
type 2 alveolar epithelial cells
Type I alveolar calls do what?
Type I alveolar cells comprise the major GAS EXCHANGE surface of the alveolus and are integral to the maintenance of the PERMEABILITY BARRIER function of the alveolar membrane.
Type ____ pneumocytes are the progenitors of type ___ cells and are responsible for surfactant production and homeostasis.
Type 2 pneumocytes are the progenitors of type 1 cells and are responsible for surfactant production and homeostasis.
Volume inspired or expired per breath
Tidal Volume (TV)
Maximum inspiration at the end of Tidal Inspiration
Inspiratory Reserve Volume (IRV)
Maximum Expiration at the end of Tidal Expiration
Expiratory Reserve Volume (ERV)
Volume in lungs after maximum inspiration
Total Lung Capacity (TLC)
Volume in lungs after maximum expiration
Residual Lung Volume (RLV) and is 25% of TLC
Maximum volume expired after maximum inspiration
Forced Vital Capacity (FVC)
Maximum volume inspired following tidal expiration
Inspiratory Capacity (IC)
Volume in lungs after tidal expiration
Functional Residual Capacity (FRC)
expiratory volume in 1 minute is called ________.
On average it is _______
Minute ventilation
6L
Dead space ventilation is around ____mL
Does respiration occur here?
around 150mL
No respiration occurs here
If Air goes to ________ without blood flow, it’s called _________
Alveoli
Physiologic dead space
Air goes to ____________________ where gas exchange does not occur, called
Trachea, bronchi, bronchioles
Anatomic dead space
Trachea has _______ to prevent collapse
cartilage rings
Bronchioles are ______ prevented from collapsing their walls
Kept expanded by the _________ pressures expanding the alveoli
Have elastin + connective tissue but no cartilage, meaning they have _____ resistance and ______ with ventilation
Bronchioles are NOT prevented from collapsing their walls
Kept expanded bt the TRANSPULMONARY pressures expanding the alveoli
Have elastin + connective tissue but no cartilage, meaning they have LOW resistance and CHANGE WITH VENTILATION
Bronchi have ______ cartilage than the trachea in order to ________________
Less
Expand and contract
resistance to airflow is _________ in larger bronchioles + bronchi near the trachea.
resistance to airflow is HIGHER in larger bronchioles + bronchi near the trachea.
smaller bronchioles determine air flow resistance more significantly because of their ___________, but also because they can be easily obstructed by ____________
smaller bronchioles determine air flow resistance more significantly because of their small size (power of numbers), but also because they can be easily obstructed by muscle contraction/edema.
Factors affecting bronchial tone
Airway dilation and airway constriction
We have less control over constriction than dilation epinephrine stimulates beta-2-adrenergic neurons to increase dilation
Blood comes from descending aorta to supply the bronchial arteries that branch from the thoracic aorta.
Blood supports tissues themselves.
What pressure/flow?
High pressure- low flow circulation (pulmonary)
Think of high pressure (high stakes) to keep the lung tissues perfused
Blood flows to the lungs through small bronchial arteries which empties their oxygenated blood into the pulmonary veins + enters the left atria (rather than the traditional route through the right atria)
What Pressure/flow?
Do we have 100% SpO2?
High pressure- low flow circulation (pulmonary)
This is why you never have 100% SpO2 because there’s a mix of blood coming from the lungs that has already extracted the oxygen
Supplies venous blood from all parts of the body to the alveolar capillaries where oxygen is added and CO2 is exchanged.
Low pressure- high flow circulation (pulmonary)
Why is this pressure low? in Low pressure- high flow circulation
Because it’s spread thin across the lungs to serve around 6 million alveoli
What happens when Low pressure- high flow circulation pressure is too high?
Pulmonary edema.
LV is weak and cannot pump blood to the aorta, causing blood backing up to the atria, pulmonary veins, and thus pulmonary artery. Can be used to stratify the severity of LV failure
Bronchial arteries, trachea → ______
Alveoli where oxygenation occurs → ______
Lung tissues (such as the visceral pleura) → _______
A. High pressure, low flow; B. Low pressure, high flow
A
B
A
Increased pulmonary artery pressure (PULMONARY ARTERY WEDGE PRESSURE) by a SWAN-GANZ CATHETER (>___mmHg)
Pulmonary Edema
CAN BE USED TO STRATIFY THE SEVERITY OF LEFT VENTRICULAR FAILURE
Remember this clinical correlation
> 20mgHg
Blood perfusion is _____ at the bottom of the lung.
Ventilation (could say air) is _______ at the top of the lung.
This inverse relationship is called a _______
Blood perfusion is HIGHER at the bottom of the lung.
Ventilation (could say air) is HIGER at the top of the lung
This inverse relationship is called a VENTILATION (V)/ PERFUSION (Q) mismatch
This is a constant and normal mismatch!
I like to think of these concepts with gravity.
Blood is heavier than air, so most blood perfusion occurs closer to the ground or bottom.
Air likes to float, so ventilation is highest up top.
V/Q is high at the top of the lung, and low at the bottom of the lung.
V/Q is _____ at the top of the lung, and ______ at the bottom of the lung.
V/Q is HIGH at the top of the lung, and LOW at the bottom of the lung.
Pulmonary capillary walls are _______ by the blood pressure inside them.
At the same time, they are _______ by the alveolar air pressure
If the alveolar air pressure is ______ than the capillary blood pressure, the capillaries close and blood flow is stopped.
distended (enlarged)
Compressed
GREATER
V/Q mismatch, it’s easiest to collapse the alveoli at the ___ of the lung, because the _____ of blood flow
V/Q mismatch, it’s easiest to collapse the alveoli at the TOP of the lung, because the LACK of blood flow (air is constricting blood flow)
There is a ______ V/Q ratio at the top of the lung (as ventilation is greater than perfusion). This is also termed _________.
There is a HIGH V/Q ratio at the top of the lung (as ventilation is greater than perfusion). This is also termed DEAD SPACE.
There is a ______ V/Q ratio at the bottom of the lung, as there is less ventilation and more perfusion. This is called a ___________.
There is a low V/Q ratio at the bottom of the lung, as there is less ventilation and more perfusion. This is called a PHYSIOLOGIC SHUNT.
there can be drastic mismatches in this in lung disorders.
When we exercise, blood flow drastically increases to the lungs, due to arterial dilation to compensate for the blood pressure. (Zone what?)
Number of capillaries _____
Capillaries are ______
Small _______ in pulmonary arterial pressure
When we exercise, blood flow drastically increases to the lungs, due to arterial dilation to compensate for the INCREASED blood pressure. (Zone 3)
Number of capillaries INCREASES
Capillaries are DISTENDED
Small INCREASE in pulmonary arterial pressure
A collection of free air in the chest outside the lung causing it to collapse is called a
Pneumothorax
A collection of free air in the chest outside the lung causing it to collapse called
Pneumothorax
Surfactant _________ surface tension, making it _________ to breathe. It is released by ________
Reduces
Easier
Type 2 alveolar epithelial cells
__________ comprise the major gas exchange surface of the alveolus, and are integral to the maintenance of the __________ function of the alveolar membrane.
_____% of surface area and ______% of cells
Type I alveolar cells
permeability barrier
95%
40%
Type ________ are the progenitors of type ______ cells and are responsible for ____________ and _________
Type II pneumocytes are the progenitors of type I cells and are responsible for surfactant production and homeostasis
The two capacities that make up inspiratory reserve volume and title volume, as well as expiratory reserve volume and residual volume
Inspiratory capacity and functional residual capacity
