lab 7: powerlab 4- respiratory air flow and volume

what is the primary function of the respiratory system

release CO2 and acquire oxygen for use by the body

what are the 4 steps of respiration

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

what is pulmonary ventilation

movement of air into (inspiration) and out of (expiration) the lungs

what is external respiration

CO2 diffuses to the lungs from the blood, and oxygen diffuses to the blood from the lungs

how is the transport of respiratory gases accomplished

by using the blood of the cardiovascular system

how does internal respiration occur

as oxygen diffuses from blood to the cells of the body, and CO2 diffuses from the cells of the body to the blood

what is included in the upper respiratory system

structures from the nose to the larynx

what is included in the lower respiratory system

structures inferior to the larynx

what does the nose do

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

a small portion of the superior nasal cavity is lined with ___

olfactory mucosa epithelium (containing receptors for smell)

what is most of the nasal cavity lined with

pseudostratified ciliated columnar epithelium (with goblet cells and seromucous nasal glands)

when is the sneeze reflex triggered

when irritants contact the sensory nerve endings in nasal cavity

what does the nasal chonchae do

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

on which bones are the paranasal sinuses located

frontal, sphenoid, maxillary, and ethmoid bones

which muscles move superiorly to block off the nasopharynx

soft palate and uvula

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

epiglottis

what does the pharyngeal tonsil (adenoid) contain

lymphatic tissue that traps and destroys pathogens

what do the pharyngotympanic tubes connect

the middle ear to the nasopharynx

what are the 2 zones in the respiratory system

respiratory zone and conducting zone

what is the respiratory zone

site of external respiration (where gas is exchanged); contains microscopic alveoli, alveolar ducts, and bronchioles

what is the conducting zone

all the tubes transporting air from nose to bronchioles

what is the laryngeal prominence

adam’s apple

-more prominent in males since thyroid cartilage is stimulated by androgens during male puberty and grow larger

what anchors the vocal folds

arytenoid cartilages

the ___ opens and closes during intermittent expiration to produce speech

glottis

how is loudness determined

by the force with which the air is expired across the vocal folds

define laryngitis

inflammation of the vocal folds causing them to swell and vibrate incorrectly

what is valsalva manuever

when the abdominal muscles contract, and the glottis closes to increase the intra-abdominal pressure to help empty the rectum

what is Boyle’s law

the pressure of a gas varies inversely with its volume

what are the muscles of expiration and what actions do they do

diaphragm relaxes, ribs and sternum depress: chest cavity and lungs contract

what are the muscles of inspiration and what actions do they do

diaphragm contracts, ribs and sternum expand: chest cavity and lungs expand

heart rate ___ when we breathe in and ___ when we breathe out

increases; decreases

what type of tissue is the trachea

Pseudostratified ciliated columnar epithelium with goblet cells

where does the trachealis muscle lie between

the esophagus and trachea

how many lobes does the right and left lungs have

left: 2

right: 3

what are bronchioles

passageways on the lung where the branching produces diameters smaller than 1mm

what is the alveolar sac

cluster of alveoli coming off an alveolar duct

what makes up the walls of the alveoli

single layer of squamous epithelium

what are alveoli densely covered with

pulmonary capillaries

the thinness of the walls allows for…

efficient diffusion and exchange of gases

what is ventilation-perfusion coupling

blood that is low in O2 and high in CO2 is always washing into the alveoli

& vice versa blood that is high in O2 and low in CO2 is being refreshed into the alveoli

what is ventilation

amount of gas reaching the alveoli

what is perfusion

blood flow in the pulmonary capillaries

what are littered among the squamous type I alveolar cells

cuboidal type II alveolar cells

what does pulmonary surfactant do

decreases surface tension in the alveoli

the entire bronchial tree, including alveoli, is surrounded by what?

elastic fibers

the lungs take up the thoracic cavity except for the ___

mediastinum

what do you find in the mediastinum

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

what lies between the 2 pleural membranes in the mediastinum

pleural fluid

what does the pleural fluid do

allows the lungs to easily move as we breathe

what is pleurisy

inflammation of the pleura; a result of pneumonia

what is pneumonia

inflammation of the alveoli of the lungs

what is the cardiac notch

left lung is molded to accommodate the heart

what is the lung compliance

the stretchiness of the lungs

pulmonary circuit is ___ pressure and _ volume

low; high

what does the renin angiotensin aldosterone pathway do

helps regulate BP

what is secreted when blood flow to the kidneys decrease

renin (secreted by juxtaglomerular cells)

what does renin do

converts angiotensinogen (from liver) to angiotensin I

what does angiotensin converting enzyme (ACE) do

catalyzes conversion of angiotensin I to angiotensin II

what does angiotensin II do

stimulates aterioles to constrict and stimulates the secretion of aldosterone from the zona glomerulosa

what changes as we breathe to move gases between lungs and blood and between lungs and atmosphere

intrapulmonary pressure

intrapleural pressure is always slightly ___ than intrapulmonary pressure

less

what will happen if transpulmonary pressure difference is lost

lungs will collapse (atelectasis)

how does the autonomic nervous system regulate resistance of gas flow

changes the diameter of the airway in the medium-sized bronchi

how can airflow be measured directly

with a pnemotachometer

what is tidal volume (TV or VT)

specific volume of air is drawn into and then expired from the lungs

in normal ventilation, the breathing frequency (f) is around ____

15 respiratory cycles per minute

what is the product of f and VT

expired minute volume (MV or VE)

what is residual volume (RV)

volume of air remaining in the lungs after a full expiration

what is functional residual volume

how much is left after TV expiration

how is the vital capacity obtained

by inspiring as deeply and rapidly as possible, then expiring as deeply and rapidly as possible

what is forced expiratory volume

the volume of air expired during the first second of the expiration when performing the forced vital capacity

how much can a healthy individual typically exhale

80% of the forced vital capacity in the first second of the exhalation

what does dalton’s law of partial pressures state

the total pressure exerted by a mixture of gases will equal the sum of the partial pressures exerted independently by each of the gases in the mixure

what element makes up the majority of the gas mixture we breathe

nitrogen

what is Henry’s law

when a gas is in contact with a liquid, the gas will dissolve into the liquid in proportion to its partial pressure

out of the gases in the air we breathe, what is the order from most water soluble to least

CO2 > O2 > Nitrogen

how is oxygen transported in the blood

bound to hemoglobin in erythrocytes

what is hemoglobin made up of

4 iron-containing heme groups, each bound to a polypeptide chain subunit

-the iron atoms bind oxygen

what is affinity in this context

how easily oxygen binds to hemoglobin

even in venous blood, hemoglobin is typically still ___ saturated with oxygen

75%

arterial partial pressure of oxygen can be measured as an…

index of lung function

what is the Bohr effect

increasing partial pressures of CO2 weakening the hemoglobin-oxygen bond

what is Haldane effect

the less hemoglobin is saturated with oxygen the more readily it binds CO2 and can bind to hydrogen ions to buffer CO2 transport as bicarbonate

define hypoxia

inadequate oxygen delivery to the body tissues

define anemic hypoxia

poor oxygen delivery due to erythroyutes that contain too little/abnormal hemoglobin or from too few erythrocytes

define ischemic hypoxia

results from blocked or impaired blood circulation

define histotoxic hypoxia

results when adequate oxygen is delivered but the body cells are unable to use it

-ex. when metabolic poisons (cyanide) are administered

what is hypoxemic hypoxia

when the partial pressure of dissolved oxygen in the arteriole blood is low

what is carbon monoxide poisoning

a type of hypoxemic hypoxia often caused by breathing smoke from fire or inhaling fumes of combustion

what part of the brain controls respiration

pons and medulla oblongota

what sets the rhythm of breathing

ventral respiratory group and the dorsal respiratory group (both medullary respiratory centers of the medulla oblongata)

the ventral respiratory group sends action potentials down the …

phrenic nerve and intercostal nerves

what is eupnea

normal breathing rate

the ____ is an integration center for signals from the peripheral stretch receptors and chemoreceptors

dorsal respiratory group

what does the pontine respiratory center do

modifies and fine-tunes breathing

-smooths alternating transitions between inspiration and expiration

how is the rate of respiration set by

how long the inspiratory center is active or how quickly it is inhibited

what is the breathe signal for our bodies

carbon dioxide levels

define hypercapnia

high carbon dioxide levels in the blood

what measures CO2 levels and will lead to an increase in ventilation if they detect slight increases in CO2

chemoreceptors

define hyperpnea

increase in breathing rate and depth