Lab 7: Respiratory Air Flow and Volume

primary function of the respiratory system

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

how do out bodies accomplish gas exchange

respiration

four steps of respiration

1. pulmonary ventilation
2. external respiration
3. gas transport
4. internal respiration

movement of air into and out of the lungs so that the gases in the lungs are constantly refreshed with infusions of new air and effusions of old air

pulmonary ventilation

carbon dioxide diffuses to the lungs from the blood, and oxygen diffuses to blood from the lungs

external respiration

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

transportation of respiratory gases

occurs as oxygen diffuses from blood to the cells of the body, and carbon dioxide diffuses from the cells of the body to the blood

internal respiration

during cellular respiration, ____ is produced and ____ is used

carbon dioxide is produced and oxygen is used - this is all for energy production

upper respiratory system structures

nose to the larynx (nose, nasopharynx, oropharynx, larngopharynx, larynx)

lower respiratory system structures

larynx, trachea, bronchi, bronchioles, alveoli

function of the nose

warms and moistens air, provides resonating chamber of vocalizations, cleans and filters air, house the olfactory receptors

why are there different nose shapes

the difference in nasal cartilage, bones are all relatively similar

A small portion of the superior nasal cavity is lined with

olfactory mucosa epithelium containing the receptors of smell

the rest of the nasal cavity is lined with respiratory mucosa composed of

pseudostratified ciliated columnar epithelium with goblet cells and seromucous nasal glands

seromucous nasal glands are composed of

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

respiratory mucosa epithelial cells secrete

antibiotic defensins to assist in killing microbial invaders

the cilia of the nasal cavity sweep the contaminated mucus toward

the throat to be swallowed and digested

what does cold air do to cilia

slows the cilia down and allows some of the mucus to dribble out the nostrils

sneeze reflex is triggered when

irritants (dust, pollen,etc) contact rich supply of sensory nerve endings in the nasal cavity. A sneeze forces these irritants out to protect the body from them

what is the purpose of the superficial location of the thin wall veins and plexuses of capillaries that lie just beneath the nasal epithelium

warm the air as it is inspired - cold air reflexively stimulates these plexuses to engorge with blood allowing for greater heat transfer

what is the problem with the superficial location of the capillaries and veins in the nose

easy damage - nose bleed

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

nasal conchae

how is the heat gradient constantly flipping each time we breathe out and in

inspired air is warmed and the in this process the conchae is cooled so that on expiration the cooled conchae causes moisture to precipitate out and heat to be exchanged into the conchae to warm them

paranasal sinuses are located in the

frontal, sphenoid, maxillary and ethmoid bones

what is the purpose of the paranasal sinuses

lighten the skull bones, act as sound resonators, and provide mucus for the nasal cavity

what happens when the sinuses are inflamed (sinusitis)

additional mucus is produced and can block the openings between the sinus and nasal cavity. This causes the air in the sinus to be absorbed and a partial vacuum is created = pain (sinus headache)

inflammation of the nasal mucosa causes

excessive mucus production leading to congestion and postnasal drip

when swallowing ___ moves superiorly to block off ___ and ____ to keep food out of the nasal cavity and lungs

the muscular hard palate and uvula move superiorly to block off the nasopharynx and the epiglottis flaps over the larynx

in the nasopharynx ___ mucus towards the ____

cilia; stomach

the pharyngeal tonsil (adenoid) of the nasopharynx contains

lymphatic tissue that traps and destroys pathogens

what happens when pharyngeal tonsils are swollen

they block air passage and force the patient to breathe through the mouth which decreases the warming, filtering, and humidifying effect on the air compared to air brought through the nose

pharyngotympanic tubes connect the

middle ear to the nasopharynx so that air in the middle ear can match pressure with atmospheric air

the ___ and ____ receive both food and air and thus have more protective stratified squamous epitheium

oropharynx and laryngopharynx

two zones of the respiratory system

respiratory zone and conducting zone

external respiration

where gas is exchanged

site of external respiration and is made up the microscopic alveoli, alveolar ducts, and respiratory bronchioles

respiratory zone

main site of gas exchange

alveoli

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

the conducting zone

what occurs as the air passes through the conducting zone

air is humidified, warmed, and filtered/cleansed

the larynx houses the

vocal folds (commonly known as vocal cords) for voice production

adams apple

laryngeal prominence of thyroid cartilage

why are adam's apple more prominent in males than females

1. because the thyroid cartilage is stimulated by androgens during puberty to grow larger
2. estrogen stimulates fat deposition in the necks of females that obscure their smaller their laryngeal prominence

anchors the vocal folds

arytenoid cartilages

why are liquids not given orally to a patient who is unconscious

when conscious, a cough reflex is generated when anything other than air is entering the larynx

glottis

the vocal folds and the opening between them

what produces sound in the vocal folds

air passes through the vocal folds

below the vocal folds, into the larynx and trachea, what is the epithelium

changes back into pseudostratified ciliated columnar epithelium that sweeps mucus upward to be swallowed by the pharynx

what opens and closes during intermittent expiration to produce speech

the glottis

what creates pitch and vocalization

the laryngeal muscles move the cartilage of the larynx (arytenoid) to change the length of the vocal folds and size of the glottis to change pitch and produce vocalization

higher pitch is produced by

tense vocal folds - vibrate more

why do males have lower voices after puberty

the thyroid cartilage is getting bigger, the rest of the larynx including the vocal folds become longer and thicker to produce a deeper voice

loudness is determined by

force with which air is expired across vocal folds (more force = louder)

which cavities resonate sounds to enhance and amplify them

pharynx, nasal, oral, and sinus cavities

enunciation to produce recognizable sounds as words is done by

lips, soft palate, tongue, and pharynx that fine tunes the sound waves

laryngitis

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

hoarse tone due to viral infection

laryngitis

Valsalva maneuver

vocal folds cover the glottis stopping air passage. abdominal muscles contract, glottis closed, to increase the intra-abdominal pressure to help empty the rectum

Valsalva maneuver also increases pressure in the thorax which does what

decreases venous return to the heart by squeezing on the major blood vessels and presses on the vagus nerve to increase vagal tone, both slow the heart rate

effects of sinus arrhythmia inhalation on thoracic pressure, venous return, vagal tone, heart rate

thoracic pressure: decrease
venous return: increase
vagal tone: decrease
heart rate: increases

effects of sinus arrhythmia exhalation on thoracic pressure, venous return, vagal tone, heart rate

thoracic pressure: increase
venous return: decrease
vagal tone: increase
heart rate: decrease

pulmonary ventilation

movement of air into and out of the lungs

volume changes pressure to allow flow

of gases down a pressure gradient - allows for pulmonary ventilation

boyles law

at a constant temperature, the pressure of a gas varies inversely with its volume

in order to exhale air what muscles relax

we squeeze on the thorax and decrease the volume by relaxing the diaphragm (domes up) and external intercostals to increase the pressure in the thorax until the intra-thorax cavity pressure is greater than atmospheric

expiration is

passive due to recoil of the pulmonary structures

in order to exhale what muscles contract

abdominal muscles pushes the organs superiorly and the rib cage is pulled inferiorly to increase pressure. Internal intercostal muscles depress the rib cage to further increase pressure

what happens to the heart rate during expiration

decreases

what occurs during inspiration

-diaphragm and external intercostal muscles contract
-the pressure of the intra-thoracic cavity decreases
-pectoralis minor and scalenes help release pressure from great vessels = greater venous return
- greater venous return = heart stretch = increased heart rate = decrease vagal tone

histology of trachea

1. mucosa = pseudostratified ciliated columnar epithelium with goblet cells
2. submucosa = seromucous glands
3. externa = connective tissue sheath

what is an important aspect of the trachea that allows it to partially collapse while still staying open

C-shaped cartilage rings that allow the esophagus behind to expand during swallowing while the trachea is continuously held open for the passage of air

why do respiratory structures not collapse

it would take great amounts of energy to overcome the cohesive and adhesive properties of wet structures

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

trachealis muscle

each lobe of the lung is supplied by

one secondary bronchus (3 on the right and 2 on the left)

when does cartilage stop in the bronchial tree

bronchioles

when does the histology of the bronchial tree

is thins and becomes cuboidal epithelium in the terminal bronchioles with very few cilia and mucus producing cells

as the conducting tube walls of the lungs decrease in diameter what increses

smooth muscle increases to allow for constriction and dilation to control the resistance to air passage to meet physiological demands (dilates during exercise to increase gas exchange)

alveolar sac

cluster of alveoli coming off an alveolar duct

what is the single layer of squamous epithelial cells that makes up the alveoli

type 1 alveolar cells

what creates the respiratory membrane

the capillary and alveolar walls with their fused basement membranes sandwiched between

the thinness of the walls of the alveolar and capillary walls allows for efficient

diffusion and exchange of gases (oxygen into the blood and carbon dioxide into the alveolus) two cell thickness

why is the gradient for diffusion kept as large as possible

continuous flow of blood to ensure blood that is low in oxygen and high in CO2 is always washing onto alveoli and air that is high in O2 and low in CO2 is is being refreshed into the alveoli

ventilation-perfusion coupling

matching of alveolar ventilation with pulmonary blood perfusion

ventilation

amount of gas reaching the alveoli

perfusion

the blood flow of the pulmonary capillaries

histology of alveolar type 2 cells

cuboidal

what is the purpose of the cuboidal type 2 alveolar cells

secrets antimicrobial proteins and pulmonary surfactant that coats alveoli

pulmonary surfactant

decreases surface tension in the alveoli and keep the alveoli open. TO BE CONTINUED

the entire bronchial trees, including alveoli, is surrounded by

elastic fibers

the alveoli are connected to each other through

alveolar pores that provide alternate pathways for air to get to alveoli that would otherwise be blocked in some cases - - allow for equalization of air pressure throughout the entire lung

is the lung sterile

no- - biome is low density and resident biome of microorganisms

since the lung is not sterile what keeps us healthy

macrophages from the alveoli that destroy pathogens and are swept to pharynx by cilia to dispose once too old to function

ventilation-perfusion coupling is locally

auto-regulated in the lung

what makes up the thoracic cavity

lungs and mediastinum

mediastinum is made up of

heart, great vessels, esophagus, bronchi, and other organs

each lung is independently surround by

pleura

what is the pleura composed of

two membranes: parietal (superficial) and visceral (deep and lies directly on the lungs)

what is the space between the parietal and visceral membranes

pleural fluid filled cavity that allows lungs to easily move while we breathe

what force causes the two membranes of the pleura to resist seperation

surface tension

pleurisy

inflammation of the of the pleura - - can result from pneumonia

pneumonia

inflammation of the alveoli in the lungs