Lab 7: PowerLab 4 - Respiratory Air Flow and Volume - A&P2

primary function of the respiratory system

release carbon dioxide from the body and to acquire oxygen for use by the body

steps of respiration

pulmonary ventilation, external respiration, transport of respiratory gases, internal respiration

pulmonary ventilation

the movement of air into (inspiration) and out of (expiration) the lungs so that the gases in the lung are constantly refreshed with infusions of new air and effusions of old air (the respiratory system does this)

external respiration

carbon dioxide diffuses to the lungs from blood, and oxygen diffuses to the blood from the lungs (occurs in respiratory system)

transport of respiratory gases

using the blood of the cardiovascular system, carbon dioxide is transported from the cells of body tissues to the lungs, and oxygen is transported from the lungs to the cells of the body tissues

internal respiration

oxygen diffuses from blood to cells of the body, and carbon dioxide diffuses from the cells of the body to the blood (more so a function of cardiovascular system)

nose

warms and moistens entering air, provides a resonating chamber for vocalizations, cleans and filters entering air, and houses the olfactory receptors

olfactory mucosa epithelium

lines a small portion of the superior nasal cavity that contains the receptors for smell

pseudostratified ciliated columnar epithelium

majority of nasal cavity is lined with respiratory mucosa with goblet cells, and seromucous nasal glands; larynx, trachea

seromucous glands

composed of cells that secrete mucus (traps bacteria, dust, and debris) and cells that secrete a watery (to humidify incoming air), enzyme rich (contains lysozyme which is antibacterial) fluid

sneeze reflex

triggered when irritants contact the rich supply of sensory nerve endings in the nasal cavity —> forces irritants out to protect the body from them

nasal conchae

increases surface area and helps create turbulence which deflects non-gaseous particles onto the mucus coatings

paranasal sinuses

located in the frontal, sphenoid, maxillary, and ethmoid bones and lighten the skull but are prone to inflammation, especially due to infection or allergies

sinusitis

inflammation of sinuses —> additional mucus and inflammatory products are produced and can block the openings between the sinuses and nasal cavity —> partial vacuum is created —> pain

soft palate and uvula

moves superiorly to block off the nasopharynx to keep food out of the nasal cavity and lungs

epiglottis

flaps over the larynx to keep food out of the nasal cavity and lungs

pharyngeal tonsil (adenoid)

contains lymphatic tissue that traps and destroys pathogens; located in the nasopharynx

pharyngotympanic tubes

connect the middle ear to the nasopharynx so that air in the middle ear can match pressure with atmospheric air which is important for sound conduction and proper hearing

oropharynx and laryngopharynx

receive both food and air —> have a more protective stratified squamous epithelium

respiratory zone

site of external respiration (where gas is exchanged) and is made up of microscopic alveoli, alveolar ducts, and respiratory bronchioles

conducting zone

consists of all the tubes transporting air from the nose to the respiratory bronchioles

larynx

houses the vocal folds/cords for voice production

laryngeal prominence

thyroid cartilage seen external to the body (Adam’s apple); more prominent in males because of androgens during male puberty cause the cartilage to grow larger; estrogen stimulates fat deposition in the necks of females that obscure their smaller ones

arytenoid cartilages

anchor the vocal folds

glottis

the vocal folds and the opening between them (air passes through and produces sound when the vocal folds are positioned strategically); opens and closes during intermittent expiration to produce speech

enunciation to produce recognizable sounds as words

completed by muscles in the lips, soft palate, tongue, and pharynx that fine tune the sound as the waves escape us

laryngitis

inflammation of the vocal folds causing them to swell and vibrate incorrectly; results in hoarse tone; most commonly caused by viral infection

Valsalva maneuver

abdominal muscles contract, and the glottis closes, to increase the intra-abdominal pressure to help empty the rectum; also increases the pressure of the thoracic cavity

Boyle’s Law

P1V1=P2V2

trachea

composed of a mucosa (with pseudostratified columnar ciliated epithelium containing goblet cells which produces and moves mucus up out of lungs), a submucosa (with seromucous glands), and adventitia (outermost connective tissue sheath)

trachealis muscle

lies between the esophagus and trachea and contraction of this aids in the rapid movement of air and mucus out of the lungs and trachea during coughing

alveolar sac

cluster or alveoli

alveoli

densely covered with pulmonary capillaries

ventilation

the amount of gas reaching the alveoli

perfusion

the blood flow in the pulmonary capillaries

ventilation-perfusion coupling

there must be a close match between these two parameters so that gas exchange is done most efficiently

pulmonary surfactant

decreases surface tension in the alveoli

elastic fibers

entire bronchial tree, including the alveoli, is surrounded by these

medastinum

heart, great vessels, esophagus, bronchi, other organs

pleura

surrounded by the serous parietal and visceral membranes

pleural fluid

allows lungs to easily move as we breathe