PSL301: Respiratory 1 Flashcards
What lung structures are affected during an asthma attack?
Muscles around bronchi constrict; very difficult to get air in and out
If a lung function test was observed during an asthma attack, what would be seen?
FEV/FVC ratio is decreased; can only get a very small % of the air in their lungs out in 1 second
Functions of the respiratory system
- Transfer gas between air and blood
- Regulate pH
- Defense from inhaled pathogens
- Volcalization
3 exchanges occur in the respiratory system. what are they?
- between atomosphere and lungs
- between lungs and blood
- between blood and cells
The respiratory system is divided into the…
upper respiratory tract
lower respiratory tract
What divides the upper and lower respiratory tract?
trachea (part of lower)
Order air goes through to get to the lungs
- Nasal cavity / mouth
- pharynx
- vocal cords / larynx / esophagus
- trachea
- primary bonchi
- secondary bronchi
- bronchiole
- alveoli
What structure is shared between the digestive and respiratory systems?
pharynx
Difference between internal & external intercostals
Orientation
internal: vertical to ribs
external: horizontal to ribs
List the muscles of inspiration
- sternocleidomastoids
- scalenes
- external intercostals
- diaphragm
List the muscles of expiration
- internal intercostals
2. abdominal muscles
___ enclose the lungs
pleural sacs
What are the pleural sacs?
double membrane that covers each lung separately
space between the membranes = pleural cavity
The pleural cavities are filled with…
fluid
The primary bronchi divides more than ___ times to reach alveoli
22
Purpose of the airway
- warm air to 37 C
- humidify to 100%
- filter out particles
What filters out the particles in the air?
nose hair & respiratory cilia
What secretes mucus?
goblet cells
Where are goblet cells located?
between ciliated endothelial cells
What allows the cilia to push mucus towards the pharynx?
watery saline layer
Which antibody disables pathogens in the respiratory system?
IgA
How many bifurcations are there in the conducting airways?
16
how many bifurcations are there in the primary lobule?
7
How many total bifurcations are there?
23
Cutpoints of the bifurcations in the conducting airways
1: primary bronchi
2-4: lobular bronchi
5-11: segmental bronchi
12-16: bronchiolar muscles
bifurcations 1-4 is supported by…
cartilage and smooth muscle
bifurcations 5-16 is supported by…
bronchiolar muscles
define: conducting airway
no gas exchange happens here
The conducting airways constitute an ___ because air in this area does not undergo gas exchange
anatomical dead space
define: anatomical dead space
volume of air which is inhaled that does not take part in the gas exchange
Cutpoints of the primary lobule
17-19: respiratory bronchioles
20: alveolar ducts
21-23: alveolar sac
Velocity in primary lobule. Why?
Almost 0
Many branches; big x-sectional area
Distinguish between type I and type II alveolar cells
type I: make up structure of alveolar walls
type II: secrete surfactant to lower surface tension of water -> alveoli does not collapse
What is found in the areas between alveolar cells?
- elastic fibres
- capillaries
- alveolar macrophages
Alveolar gas exchange occurs by…
passive diffusion
Pulmonary circulation
right ventricle -> pulmonary trunk -> pulmonary arteries -> capillaries -> pulmonary venules -> pulmonary veins -> left atrium
__% of blood volume goes to the lungs
10
The BP at the lungs is…
very low
25/8
Difference between pulmonary and systemic capillaries
Pulmonary: multiple capillary beds for 1 location
If embolus blocks 1 bed, gas exchange can still happen
Systemic: 1 bed of capillaries for 1 region
If this bed is blocked by embolus, the tissue infarcts
What defends the respiratory system from pathogens?
- nose filters
- mucous & cilia
- antibodies on respiratory surfaces
- macrophages in respiratory tract
How is lung function measured?
spirometry
spirometry measures the…
volume of the lungs
Normal lung volume
0.5L
total lung capacity for men
6L
total lung capacity for women
5L
VT =
tidal volume
how much air you breath in and out normally
IRV =
inspiratory reserve volume
Everything above VT
ERV =
expiratory reserve volume
Everything below VT
RV =
residual volume
~1.5L
Air that does not leave the lungs no matter how hard you breathe
VC =
vital capacity; the most you can breathe in and out
ERV + VT + IRV
IC =
inspiratory capacity
IRV + VT
FRC =
functional residual capcity
ERV + RV
Is IRV bigger or ERV?
IRV (2.5L vs. 1.5L)
TLC
total lung capacity
RV + ERV + VT + IRV
Capacities are ____, while volumes are ___
sums of different volumes
unique
The elderly have more/less ___ (what volume) than young people
more RV
Types of obstructive lung disease
- early emphysema
- severe emphysema
- asthma
Emphysema
some of the air sacs in your lungs are damaged;
barrel chest
Emphysema have more/less ___ (what volume) than young people
more TLC caused by more RV
what are obstructive lung diseases
hard to get air out of lungs quickly, but you can still get enough oxygen
what are restrictive lung diseases?
Hard to move air in and out of lungs; might not be getting enough oxygen
types of restrictive lung diseases:
- pulmonary fibrosis
- neuromuscular disease
- severe obesity
restrictive lung diseases have more/less ___ (what volume) than young people
Less TLC
Pulmonary fibrosis
damage causes your lungs to stiffen and makes breathing more and more difficult
Every volume is proportionally smaller
Neuromuscular disease lung function test
Very high RV
Low ERV
Low IRV
Severe obesity lung function test
Very low ERV
FEV =
forced expiratory volume
Inhale big, then how much air you can get out in 1 second if you try.
FVC
forced vital capacity
maximum amount of air a person can expel from the lungs after a maximum inhalation
What does the ratio of FEV / FVC tell you?
in 1 second, how much of the air in your lungs you can get out
In restrictive lung disease, what does the FEV/FVC look like?
About the same as normal, because both FEV and FVC is decreased
In obstructive lung disease, what does FEV/FVC look like?
Ratio is much lower
What is the normal FEV/FVC ratio?
80%
