Lung Mechanics Lec 22

The process of moving air in and out of the lungs

Ventilation

The process of diffusion and perfusion

Gas exchange

The process of regulating blood pH

Acid-bas balance

What are the four functions of the respiratory system

ventilation, gas exchange, acid-base balance (blood pH), protection

What structures are a part of the upper respiratory tract

nasal cavity, nasopharynx, oropharynx, larynx, trachea

What structures are a part of the lower respiratory tract

Bronchus, lung, bronchiole/ respiratory bronchiole, alveolar duct, alveolia sacs/ducts, diaphragm

As the trachea continues on it splits in a series of

continuous bifurcation

What cells in the lungs hold mucus

Goblet

The trachea, bronchi, and bronchioles are all part of the conducting zone of the respiratory system. What is its function

movement of air in and out

The repiratory bronchioles, alveolar ducts, and alveolar sacs are all part of the respiratory zone. What is its function

Gas exchange

The primary functional/ gas exchange unit

Alveoli

Type 1 alveolar cells are responsible for _____

Type 2 alveolar cells are responsible for ______

alveolar structure; surfactant production

Produced by type II alveolar cells to prevent lung collapse

Surfactant

What part of the alveoli aid in maintaining airflow to equalize pressure

Pores of Kohn

Cells with a thin layer that cover 95% of the alveolar surface and aid in gas exchange

Type I pneumocytes

Cuboidal cells that only cover 2% of the alveolar surface and produce surfactant

Type II pneumocytes

What are the main functions of pulmonary circulation

facilitate gas exchange, deliver nutrients to lungs, act as a blood reservoir for LV< and serve as a filtering system

When compared to systemic circulation the pressure of pulmonary circulation is

lower

In pulmonary circulation what fraction of vessel are filled with blood at a given time

1/3rd

Membrane formed by shared alveolar and capillary walls where gas exchange occurs

Alveolocapillary

A mixture of phospholipids that line alveoli and reduce surface tension, Consists primarily of DPPC or lecithin

pulmonary surfactant

Explain the relationship of lung surfactant and alveolar surface tension and lung compliance

dec tension, inc compliance

What affect does decreasing alveolar surface tension have on alveolus

decreased the collapsing pressure keeping alveolus open

What impact does increasing lung compliance have on the lungs and respiration

decrease the work of lungs during inspiration

What impact does surfactant have on water

breaks up surface tension

What is a condition that is a concern in premature babies that is caused by a deficiency or abscence in surfactant that leads to alveolar collapse, decrease perfusion, inc work of lungs, and hypoxemia

Neonatal respiratory distress syndrome

What are the major muscles of inspiration

Diaphragm, external intercostal

What are the accessory muscles of inspiration

SCM, scalene

There are no major muscles of expiration due to it being what type of process

passive

What are the accessory muscles of expiration

abdominal, internal intercostal

Inspiration is able to occur due to what characteristic of pressure in the lungs

negative

serous membrane that adhere to the lungs, folds over itself and firmly attaches to the chest wall

Pleura

Membrane that covers the lungs

Visceral pleura

Membrane/lining of the thoracic cavity

Parietal pleura

The movement of the diaphragm ____ and the chest wall ____ aids in decreasing the pressure in the intrapleural space during inspiration

down; out

________ generates a pressure tha tends to collapse alveolus

surface tension

pressure tensing to collapse alveolus and surface tension are ________ proportional

directly

pressure tensing to collapse alveolus and alveolar radius are ________ proportional

indirectly

A big radius mean that the alveolus collapse at what type of pressure

low pressure (less likely to collapse)

A small radius mean that the alveolus collapse at what type of pressure

high pressure (more likely to collapse)

how does expiration impact the alveolar radius

decreased

As you inspire, the pressure in the lungs becomes more

negative

A buildup of fluid, pus, blood, air, or gases in the pleural space

pleaural effusion

A buildup of air or gas in the pleural space

pneumothorax

a buildup of blood in the pleural space

Hemothorax

Inflammation of the pleura that can cause sharp pain when breathing

pleurisy

What is the ability of the lungs and thoracic cage to explant when subjected to a change in pressure (stretch)

compliance

____ compliance = Stiff lung

____ compliance = High stretch

low, high

what is the ability of the lung to return back to it’s shape after lung expansion. essential for exhalation

elasticity

explain the relationship between lung compliance and elasticity

inverse

The alveolar surface tension and elastic properties of the lung and chest wall are what

opposing elastic forces

utilizes surfactant to keep alveoli open and free of fluid and pathogens

alveolar surface tension

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