Respiratory System

what is the respiratory system and what does it provide/assist with?

the respiratory system provides the body with adequate oxygen and eliminates waste products such as carbon dioxide (CO₂). the respiratory system helps regulate pH levels to assist in maintaining homeostasis

what is included in the respiratory system?

upper airway and lower airway

what are the mechanisms found in the respiratory system?

lung expansion, muscles of breathing, carbon dioxide drive, hypoxic drive, lung volumes, and normal breathing/abnormal breathing

components of the upper airway include:

• nose and mouth

• nasopharynx (upper part of the throat behind the nose)

• oropharynx (area of the throat behind the mouth)

• hypopharynx (aka laryngopharynx)

• epiglottis (valve that protects the opening of the trachea)

why are most manual airway techniques and mechanical airway adjuncts used by EMTs designed to do what?

they are designed to clear and protect the upper airway

what is a concern for EMTs regarding upper/lower airway?

foreign-body airway obstruction is a concern for EMTs

a common cause of upper-airway obstructions is what?

the tongue by far is the most common cause

components of the lower airway include:

• trachea

• carina (where the trachea branches into left and right mainstem bronchi)

• left and right mainstem bronchi (primary branches of the trachea leading to left and right lungs)

• alveoli

what is the function of the alveoli?

• all airway structures above the alveoli serve to get air to this point in the respiratory system

• this is the only place in the respiratory system where oxygen and carbon dioxide are exchanged

• alveoli are in contact with pulmonary capillaries

• the pulmonary capillaries diffuse carbon dioxide from the body to the alveoli

• alveoli diffuse oxygen from the respiratory system to the body

• surfactant is a substance that helps keep the alveolu from collapsing

what is pleura?

two thin, smooth layers of tissue with thin film of fluid in between to allow frictionless movement across one another

visceral pleura lines what?

visceral pleura lines the outer surface of the lungs

parietal pleura lines what?

parietal pleura lines the inside surface of the chest cavity

in lung expansion, what occurs?

during inhalation, as the chest expands, the parietal pleura pull the visceral pleura, which pulls the lungs

what is included in the mechanisms of breathing?

diaphragm, intercostal muscles, respiration and ventilation

what is the diaphragm and its functions?

• the diaphragm is the primary muscle of respiration

• it separates the thoracic cavity from the abdominal cavity

• it is usually under involuntary control but can be controlled voluntarily

what passes through the diaphragm?

the esophagus and the great vessels

how is the diaphragm shaped during inhalation?

it is dome shaped until it contracts during inhalation. during inhalation, it moves down and expands the size of the thoracic cavity

what are intercostal muscles and what are their function/location?

located between the ribs, the intercostal muscles contract during inhalation and expand the thoracic cage

regarding the terms, “respiration,” “ventilation,” and “breathing,” what do these refer to?

they refer to the movement of air in and out of the lungs. although they are often used synonymously, there are some distinctions to be made. ventilation is also called pulmonary ventilation.

what occurs in inhalation through negative pressure breathing?

• The diaphragm and intercostal muscles contract, the thoracic cage expands, pressure in the chest cavity decreases, and air rushes in.

• Inhalation is an active process and requires energy.

• Atmospheric air contains 21% oxygen

what occurs in exhalation?

• The diaphragm and intercostal muscles relax, the thoracic cage contracts, pressure in the chest cavity rises, and air is expelled.

• Exhalation is normally passive and does not require energy.

• Exhaled air contains 16% oxygen.

what is external respiration? and what is it exchanging?

the exchange of oxygen and carbon dioxide between the alveoli and pulmonary capillaries

what is internal respiration and what is happening between our cells and the systemic capillaries?

internal respiration refers to the gas exchange between the body’s cells and the systemic capillaries

what is cellular respiration and what does it use to break down glucose to create energy?

cellular respiration (also known as aerobic metabolism) uses oxygen to break down glucose to create energy

what is the carbon dioxide drive, and how does the brain stem use it as the primary mechanism to control breathing and respond to high CO2 levels?

• This is the primary mechanism of breathing control for most people.

• The brain stem monitors carbon dioxide (CO,) levels in the blood and cerebrospinal fluid.

• High CO, levels will stimulate an increase in respiratory rate and tidal volume.

what is the hypoxic drive?

the hypoxic drive is a backup system to the CO₂ drive

where are the specialized sensors that monitor oxygen levels located? / what do the sensors in the brain, aorta, and carotid arteries do?

Specialized sensors in the brain, aorta, and carotid arteries monitor oxygen levels

what stimulates breathing when oxygen levels drop?

low oxygen levels will stimulate breathing

how does the effectiveness of the hypoxic drive compare to the CO₂ drive?

the hypoxic drive is less effective than the CO₂ drive

what is tidal volume?

the amount of air inhaled or exhaled in one breath

how do you define residual volume?

the amount of air in the lungs after completely exhaling

why is residual volume important?

residual volume keeps the lungs open

what is inspiratory and expiratory reserve volume?

the amount of air you can still inhale or exhale after a normal breath

dead space refers to what?

the amount of air in the respiratory system not including the alveoli

what is the formula for minute volume?

respiratory rate x tidal volume

normal breathing is described as what

non-labored, regular rhythm, clear and equal breath sounds bilaterally

abnormal breathing can be described as what

• abnormal rate or tidal volume

• labored breathing

• muscle retractions

• abnormal skin color

• tripod position

• agonal breaths

what types of muscle retractions may be observed during respiratory distress?

• intercostal retractions: between the ribs

• supraclavicular retractions: above the clavicles

• use of abdominal muscles

What are examples of abnormal skin color that may indicate a problem?

• pale

• cyanosis

• jaundice

• flushed

what is the tripod position and what does it help with

a seated, leaning forward position using the arms to help breath

what are agonal breaths

dying gasps that are slow and shallow and do not effectively move air into the alveoli