Respiratory Flashcards
Primary Functions of the Resp system
- Exchange of gases between the atmosphere and blood
- Homeostatic regulation of body pH
- Protection from inhaled pathogens and irritating
substances - Vocalization
External resp processes
Exchange
Components of the resp system
- The bones and muscles of the thorax (Chest Cavity) 2. Conducting system or airways
- Alveoli
what composes the chest cavity?
Bones – • Spine(T1-12) • 12Ribs • Sternum Muscles – • Intercostalmuscles • Diaphragm Lining – • 3 membranous sacs
purpose of pleural fluid
- Creates moist slippery surface
2. Holds lungs tight to thoracic wall
lobes of the right lung
superior, middle, and inferior
lobes of the left lung
superior lobe, inferior lobe
upper resp system
pharynx, vocal cords, esophagus, nasal cavity, rongue, larynx, and trachea
low resp system
lungs, bronchi, and diaphragm
role of the upper airway and bronchi?
- Warming air to body temperature
- Adding water vapor
- Filtering out foreign material
air flow
air enters via pharynx (nasal cavity/mouth); then flows through larynx (vocal chords) then trachea (wind pipe)
how does filtering occur in trachea and bronchi?
• Epithelial cells produce saline
Goblet cells produce mucus (forms layer overtop of the saline)
• Mucus contains immunoglobulins
Mucocilliary Escalator = Cilia pushes mucus towards pharynx
what cystic fibrosis?
mutation lol
decreased saline production, decreased mucus clearance–>increased bacteria colonisation of airways; increased occurence of lung infections
alveoli structure
type 1 alveoli cell for gas exchange (95% gas SA); endothelial cell of capillary; type II alveola cell (surfactant cell); limited ISF; alveolar macrophage
how does air enter the lungs?
pass through the nasal cavity, then the nasopharynx, oropharynx, and laryngopharynz OR the oral cavity, then the oropharynx, then laryngopharynx; then into the trachea and lungs
what causes cystic fibrosis?
mutation in the CFTR channel so that chloride cannot enter the saline in the lumen of the lung; water cannot passively diffuse with the Cl to create the saline; mucus then remains thick and cannot be moved up the mucocillary escalator so the filtering method is lost–> increased incidence in lung infection–>scar tissue build up–> tough for gas exchange–> can’t breathe
what is low pressure due to in the lungs?
shorter circuit, increased distensibility, and increase in CSA
why is it important to have low pressure in the capillaries?
if it was high–>fluid would be pushed out–>do not want this; for any filtering methods the lymphatic system takes over
like in the cardio system, there must be a drop in pressure for air to flow in the respiratory system
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mmHg to cm H2O
1 mm Hg = 1.36 cm H2O
mm Hg to kPa
760 mm Hg = 101.325 kPa
Normal sea level Patm is considered to be 760 mmHg but is usually set to 0 cm H2O by respiratory physiologists
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what is dalton’s law
the total pressure exerted by a mixture of gases is the sum of the pressure exerted by each gas
the partial pressure of a gas is dependent on humidity (water vapour) in the air
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eq’n for partial pressure in dry air
Pgas = Patm x % gas in the air
eq’n of Pgas in humid air
(Patm-Ph2o)x % of gas in atmosphere
eq’n for bulk flow of air
F = (Palv-Patm)/R; F = flow, R= resistance
what is Boyle’s law?
P1V1=P2V2
why is boyle’s law important in resipration?
helps explain how a change in lung volume results in a change in lung pressure driving the bulk flow of air; when alveoli relaxes during inhalation and V increases, alveolar pressure decreases –> air wants to enter lung; when it contracts during exhalation, V decreases and P goes up, so air wants to leave alv
what is TV?
tidal volume, 500 mL; amount of air moved during a normal, quiet respiration
what is total pulmonary ventilation?
TV X frequency of breaths = L/min
what is inspiratory reserve volume?
IRV; additional air that could still be inspired after quiet inspiration
what is ERV?
the volume of air that s0ll remains within the lungs that can be expired is known as the
3. Expiratory reserve volume
function of RV?
- Prevents airway collapse, after a collapse it takes an unusually large pressure to re-inflate it (Poiseuille’s law)
- It allows continuous exchange of gases.
what are the four capacities looked at?
Total lung capacity, functional residual capacity, inspiratory capacity, vital capacity
what is FEV1?
forced expiratory volume in 1 s; normally FEV1 in a healthy individual is 80% of vital capacity
what is the major muscle for respiration?
diaphragm
how does the diaphragm work in respiration?
contracts and flattens–>pulls lung (and attached alveoli down); increases volume, decreases pressure–> air moves in
what is Sternocleidomastoids
muscle that lift the sternum outward, contributing the water pump handle effect during forced respiration
what are the muscles of forced inspiration?
- Sternocleidomastoids; 2.Neck and back muscles; 3.Upper respiratory tract muscles
how do neck and back muscles function in forced inspiration?
elevate pectoral girdle increasing thoracic volume and extend back
how do upper resp tract muscles function in forced inspiration?
decreased airway resistance
muscles involved in forced expiration?
1.Abdominal muscles 2.Internal intercostals and triangularis sterni 3.Neck and back muscles
what is total lung capacity, and volume?
the sum of all 4 volumes; approx 5800 mL
what is functional residual capacity, what volumes compose it, volume?
the capacity of air remaining in the lungs aTer quiet expira0on, the sum of ERV and RV, ~2300 mL
what is inspirational capacity, what volumes compose it, and volume?
the sum of IRV and TV represen0ng the maximal amount of air that one can inspire at the end of quiet respiration; ~3500 mL
what is vital capacity, what volumes compose it, and volume?
the sum of IRV, TV, and ERV represen0ng the maximal achievable 0dal volume. Clinician performs FEV1 during VC; ~4600 mL
other than the diaphragm, what plays a role in passive inspiration?
external intercostals, scalenes
how do ext intercost play a role in passive inspiration?
create a bucket handle and water pump handle motion; contraction of the EI muscles cause sternum to move up, along with ribs which move up and out
how do abdominal muscles functions in forced expiration?
push thoracic cavity up more than normal—>exhale more air
how do internal intercostals function in forced expiration?
moves inwards on inner ribs, closer together—>compression
how does the triangular sterni function in forced expiration?
compresses sternum–>decreases volume of lungs
compartments of the pleura, and their functions?
visceral pleura, attached directly to the lungs; intrapleural fluid, inner fluid that lubricates the lungs; parietal pleura, attached to ribcage and diphragm for coordinated movement of ribs/diphragm and lungs
