The Respiratory System Flashcards
Ventilation vs respiration
ventilation- simple movement of air into and out of the lungs
respiration - actual exchange of gases
Other functions of the respiratory system
ph regulation, thermoregulation, protection from disease and particulate matter
effect of hyperventilation vs hypoventilation
hyperventilation raises blood pH while hypoventilation decreases it
conduction zone
part of the respiratory system designed to only allow gases to enter and exit the system
the pathway goes from nose to nasal cavity to pharynx (throat) to larynx to trachea to bronchi to terminal bronchioles to respiratory bronchioles to alveolar ducts to alveoli.
Why does no gas exchange occur in the terminal bronchioles?
The smooth muscle of the walls of the terminal bronchioles is too thick to allow adequate diffusion of gases
respiratory zone
region of system where gas exchange occurs, includes the alveolus which is the actual structure across which gases diffuse
What allows the respiratory bronchioles to perform gas exchange?
They have a few alveoli scattered in its walls.
mucociliary escalator
system of columnar epithelial cells in the upper respiratory tract using cilia on their apical surfaces to constantly sweep the layer of mucus toward the pharynx.
This mucus is coughed out.
What is involved in gas exchange?
The alveoli, alveolar ducts, and the smallest bronchioles.
surfactant function
Soapy substance that coats the alveoli and reduces surface tension
pulmonary ventilation
circulation of air into and out of the lungs to continually replace the gases in the alveoli with those in the atmosphere
inspiration vs expiration
inspiration of air is an active process driven by contraction of the diaphragm, enlarging the chest cavity
Passive expiration doesn’t require active muscle contraction
What two membranes surround the lung?
The parietal pleura, which lines the inside of the chest cavity and the visceral pleura, which lines the surface of the lungs
pleural space function
very narrow space between the two pleura, which has negative pressure.
This negative pressure keeps the outer surface of the lungs drawn up against the inside of the chest wall
What causes inspiration
muscular expansion of the chest wall, drawing the lungs outward and causing air to enter the system, primarily driven by contraction of the diaphragm. The effect of this contraction is the chest cavity being drawn downward.
What causes expiration
It is a passive process driven by elastic recoil of the lungs drawing the chest cavity inward, reducing lung volume and pushing air out of the system and into the atmosphere.
What happens during forcible expiration of exertion
Contraction of abdominal muscles helps the expiration process by pressing upward on the diaphragm and shrinking the lungs.
What happens to pleural pressure during inspiration
It becomes more negative
tidal volume
amount of air that moves in and out of the lungs with normal light breathing
vital capacity
max amount of air that can be forced out of lungs after first taking the deepest possible breath
total lung capacity
vital capacity plus the residual volume
residual volume
amount of air that remains in the lungs after the strongest possible expiration
What carries deoxygenated blood
the pulmonary artery
What is the driving force for the exchange of gases in the lungs?
The difference in partial pressures between alveolar air and the blood
respiratory control center
found in medulla of the brain stem, directs breathing
What are the chemical stimuli that affect ventilation rate?
pCO2, decreased pH, and decreased pO2, monitored by peripheral and central chemoreceptors
What does respiration do to CO2 in the body?
It eliminates it from the body, causing an increase in pH
What mechanical stimuli affect ventilation rate?
physical stretching of the lungs and irritants
bronchoconstriction
stimulated by chemical irritation of inner lining of the lung, which contains smooth muscle. This results in a parasympathetic contractile response involving release of ACh.
bronchodilation
Epinephrine induced, increases ventilation rate causing airway smooth muscles to relax
epidermis
outermost layer of the skin lying upon deeper dermis
hypodermis
protective insulating layer of fat
What is caused by the epidermis being made of epithelial tissue?
The many layers of epithelial cells provide a strong protective structure
sensory receptors
found in the dermis, convey info about touch, pressure, pain, and temperature to the central nervous system.
What is found in the dermis?
sweat glands, oil gland, and hair follicles
What are the strategies to cope with cold weather?
contraction of skeletal muscles, insulation of the skin helps conserve heat, heat loss by conduction is minimized by constriction of blood vessels in the dermis
What allows for dissipation of excess heat?
Sweating and dilation of blood vessels in the dermis
