Lecture 1 resp Flashcards
4 major aspects of resp. system
ventilation, gas xchange, blood xport, regulation of respiration
what % of energy is expended in quiet inspiration
3-5%
4 muscles of forceful inspiration
scalene, sternocleidomastoid, serratus anterior, external intercostals
2 muscles of forceful expiration
rectus abdominis, internal intercostals
all avleoli has elastic recoil force, is this force stronger or weaker in larger alveoli’s
weaker
emphysema has stronger or weaker recoil
weaker (larger barrel chested alveoli)
what provides negative pleural pressure
lymphatic pumping
inspiration decreases pressure from -5 to what?
-7.5 cm water
on inspiration, alveolar pressure momentarily increases or deceases
decreases (slightly below atmospheric)
on expiration, alveolar pressure momentarily increases or decreases
increases (slightly above atmospheric)
alveolar volume increases enough to let how much in liters or air to enter
.5Liter
alveolar pressure increases or decreases in how many cm/h20
+/- 1cm H20
The pressure difference between alveolar and pleural pressure is called?
transpulmonary pressure
when is transpulmonary pressure the biggest/highest difference?
at the end of inspiration
Lung volume per 1cm/H20 in transpulmonary pressure is called
Compliance
1cm change in transpulmonary pressure allows for how much change in lung volume compliance
110ml, would be higher if the lungs were in a backpack w/o resistance
what is the biggest limitation to compliance
the presence of the chest wall
what are the 2 main forces in elastic alveolar recoil?
elastic force (elastin/collagen) and surface tension
elastin and collagen account for what fraction of total elastic recoil of the lungs
1/3rd
what molecular phenomenon keeps h20 together to force surface tension in the lungs
polarity of h20 molecules
what fraction does surface tension contribute to total elastic recoil of the lungs
2/3rd
Surfactant (a mix of phospholipids, proteins, and calcium ions), increases or decreases surface tension in the lungs?
decreases
what is the chemical name for surfactant?
Phosphatidylcholine
small babies have less surfactant, what can happen to their lungs
collapse, with strong recoil
smaller the alveolar radius, the stronger the recoil forces….true or false
true
volume inspired with each breath in quiet respiration
Tidal volume
volume that can be inspired with full force above normal tidal volume
inspiratory reserve volume
volume that can be forcefully expired with full force after end of normal expiratory capacity
expiratory reserve volume
from the bottom of quiet inspiration to the top of total inspiratory volume
inspiratory capacity
from the bottom of forced expiration to the top of the forced inspiration
vital capacity (9 times more than normal tidal volume)
volume of lungs at the end of forceful expiration
residual volume
from the top of forced inspiration to bottom of residual volume
total lung capacity
volume of air in URT that does not participate in respiration (nose to non-terminal bronchioles)
dead space (usually 150ml)
formula for person to normally ventilate about 6L/minute of air
tidal volume of 1 breath x RR
500ml/breath x 12 RR
Term for volume participating in gas exchange in one minute
Alveolar ventilation rate
(tidal volume - dead space) x RR
the nose (“climate control”), has what 3 functions
- Warms
- Humidifies
- Filters
almost no particles larger than how many micrometers reach trachea
6 micrometers
1-5 settle in terminal bronchioles
what airway structure is the most responsible for resistance in quiet respiration
Bronchi
from bronchi to bronchioles, we loose the cartilaginous rings and gain what?
smooth muscle and branching that drop the resistance significantly
introduction of smooth muscle to the airway can introduce what 3 main pathologies
- Edema to mucous membranes
- Muscous plugs
- Constriction/dilation
Anaphylaxis produces inability to do what effectively in respiration
expiration
sympathetic stimulation (sensetive to epi), do what to the airway
airway dilation
parasympathetic stimulation to airway smooth muscle causes constriction by what neurotransmitter?
acetylcholine
every drug anatagonistic to acetylcholine receptors will prevent what function in the bronchioles
dilation
in both cough and sneeze reflex, how many liters are inhaled rapidly
2.5liters
5 times more than tidal volume
Why does the epiglottis close at the end of inspiration
to build up lung pressure, to allow something to be expelled on rapid forced expiration
In a sneeze, what additional physical phenomenon occurs to make the air push out of the nose
Uvula depression
Past what point in the airway will a FB not illicit a cough reflex
Carina
