Chapter 22

air tubes

bronchi

alveolus

tiny thin-walled sac where gas exchange actually occurs

conducting zone

the parts of the respiratory system from the nose to the bronchioles, because air is conducted back and forth through these parts but no gas exchange occurs

respiratory zone

the alveoli, where gas exchange occurs

upper respiratory tract

the region from the nose down to the larynx

lower respiratory tract

region from the trachea down the the alveoli

nose

warms, cleands, humidifies inhaled air, detects odors, is a resonating chamber for the voice

nares

other word for nostrils

posterior nasal apertures

where the air exits the nose

nasal bones

upper ½ of the nose

lateral and alar cartilages

makes up the lower ½ of the nose

nasal ali

flared side of the nose

nasal fossae

nasal cavity divided into right and left sides, these cavities are called

nasal septum

what divides the nasal cavity

horizontal hard palate

separates nasal and oral cavities

gaurd hairs

block debris from entering

superior, middle, inferior nasal conchae

increase air turbulence, assisting debris capture by the mucous membrane. the roof is covered with olfactory epithelium

respiratory epithelium

most of nasal cavity is covered by this, has abundant cilia, these sweep debris posteriorly to the pharynx from which it is swallowed

nasopharynx

the most superior part of the pharynx, located above the soft palate. the eustachian tube from the middle ear enters here. also has cilia, which sweep debris inferiorly for swallowing

oropharynx

makes of the middle part, provides passage for food and drink as well as air

laryngeopharynx

posterior to the larynx, make up the inferior part of the pharynx, just inferior to this is the beginning of the esophagus, provide passage for food and drink as well as air.

larynx

the voice box, composed of 9 different cartilages. initial job was to prevent aspiration (food and water going down the wrong way) but later evolved to help us make sounds

epiglottis

gaurds the top of the larynx, when we swallow, the larynx moves up and this is pushed downward to close of the airway so we do not aspirate

anterior thyroid cartilage

largest of the cartilages, we know its anterior peak as the adam’s apple

lower circoid cartilage

second largest cartilage in the pharynx

hyoid bone

the larynx is suspended from this

vestibular folds

located laterally and just above the vocal chords, also close during swallowing to prevent aspiration

glottis

anatomic term for the vocal cords and the space inbetween them

muscles and cartilage in larynx

control the adduction and abduction of the cord, connected anteriorly and swing medially from the side and back to make contact during speech

trachea

wind pipe that runs from the larynx inferiorly to the carina, where it splits into the right and left mainstem bronchi. supported by about 20- C shaped rings of cartilage

trachealis muscle

the 20 c-shaped cartilags of the trachea are connected posteriorly by this muscle

mucociliary escalator

the columnar epithelium with mucus-secreting goblet cells and ciliated cells trap and move debris superior to the pharynx for swallowing

costal surface

part of the lung that facecs inside of the rib cage

mediastinal surface

the medial surface

hilum

where the bronchi, blood vessels, and lymphatic vessels and nerves enter and exit the lung

cardiac impression

where the heart pushes in on the lung

right lung

superior, middle, inferior lobes. horizontal fissure and oblique fissure

left lung

superior and inferior lobes, oblique fissure

segmental bronchi

what the lobar bronchi separate into, each ventilates a unique bronchopulmonary segment. made of ciliate columnar epithelium, elastic tissue, cartilage, lymphocytic nodules, and smooth muscle

bronchioles

branch off of segmental bronchi, lack cartilage, epithelium is ciliated and cuboidal, smooth muscle becomes more pronounced and well developed

terminal bronchioles

branch from smaller terminal bronchioles, ciliated epithelium is still present to move debris but no more mucus production by mucous glands

respiratory bronchioles

branch off of the terminal bronchioles, some gas exchange begins here

alveoli

this is where gas exchange occurs

pulmonary blood flow

pulmonary arteries follow the air tubes and branch and narrow as they run farther from the herat and deep into the lungs, they narrow into capillary webs when they reach the alveoli.

alveolus

tiny pouch or sack that is lined by squamous epithelieial cells, which cover about 95% of the surface, allow for rapid gas exchange by diffusion. The other 5% is covered by type II alveolar cells, which are round or cuboidal in shape

type 1 alveolar cells

squamous epithelial cells, cover 95% of the surface, these are very thin in order to allow rapid gas exchange by diffusionty

type II alveolar cells

other 5% of the surface of alveolus, round or cuboidal in shape, outnumber the squamous cells. They have two jobs: repair damaged squamous cells and 2. secrete surfactant

parietal pleura

innermost lining of the chest cavity

visceral pleura

outermost lining of the lung

pleural cavity

the space between the parietal pleura and the visceral pleura

inspiration

inhalation, breathing in

expiration

exhalation, breathing out

respiratory cycle

one complete breath

quiet respiration

normal breathing

forced respiration

deep breathing with exercise or blowing up a balloon

diaphragm

accounts for 2/3 of our breathing during quiet respiration, it tenses and flattens during inspiration

intercostals

stiffen during inspiration and enlarge the thoracic cage, this accounts for 1/3 of our breathing during quiet respiration

forced inspiration muscles

scalenes, back muscles, sternocleidomastoid, anterior chest muscles

forced respiration

rectus abdominus, back muscles, other abdominal and pelvic muscles to contract and raise pressure within the abdominal caivity to push the diaphragm higher and more rapidly

valsalva maeuver

when we take a deep breath to fill the lungs with air, close the glottis so air cannot escape, and then tense abdominal muscles to raise abdominal cavity pressure, like bearing down to have a bowel movement, This maneuver is used to help expel abdominal contents

ventral respiratory groups

these paired centers are located in the medulla, they have inspiratory (I) and expiratory (E) neurons. When I neurons fire, the impulse is carried via the phrenic nerves to the diaphragm and by intercostal nerves to the intercostals. The E neurons then fire cuasing musclar relaxation and expiration

dorsal respiratory groups

also located in the medulla, act to modify our relaxed breathing pattern. Gets input from the ponds, the medulla, and chemoreceptors in major arteries, integrate this input and then send signals to the ventral respiratory groups to modify depth and rate of breathing

pontine respiratory groups

located in the pons, they recieve input from higher regions of the brain and send signals to both the ventral and dorsal respiratory groups, these help modify breathing during sleep and conversation

central chemoreceptors

respond to pH changes in the cerebrospinal fluid primarily

peripheral chemoreceptors

in carotid and aortic bodies, send back information regarding blood PH CO2 and O2 levels

stretch receptors

in the bronchi, signal extreme inhalation

irritant receptors

in the epithelium of the airways that cause us to cough out irritants

voluntary control of respiration

occurs when we sing and talk, originates in the motor cortex of the cerebrum, these nerve signals bypass the respiratory centers in the brainstem, but there are limits to our voluntary control

pneumothorax

if a person develops a penetrating chest wound allowing air to enter the pleural space, the seal between the two pleurae is broken and the recoil of the lung pulls it away from the chest wall, allowing part of the lung to collapse

bronchiodilation

dilation of the bronchioles, epinephrine and sympathetic input cause this

bronchoconstriction

parasympathetic input causes constriction

atelelectasis

the medical term for lung collapse

pulmonary compliance

the measure of how easily the lungs expand

surfactant

made by the type 2 alveolar cell, reduces water molecule cohesion on the surface of alveolar epithelium to prevent water from reducing pulmonary compliance, therfore it keeps alveoli expanded even during respiration

dead space

air that fills up the trachea, bronchi, and bronchioles which do not have gas exchange capability

alveolar ventilation rate

the amount of air actually reaching the alveoli each minute

spirometry

measures a person’s ventilatory capacity: the total ability of your lungs to move air in and out

tidal volume

the volume of air inhaled and exhaled in a normal respiratory cycle

vital capacity

the maximum amount of air one can move in one breath

restrictive disorder

when a person cannot move as much air in and out because their lungs are stiff and have lost their stretchiness: TB or black lung

obstructive disorder

when lungs can expand fine, but airflow is blocked or slowedd, and its hard to exhale quickly. Seen in asthma

force expiratory volume

measures the percentage of the vital capacity a person can exhale in one second

eupnea

quiet, relaxed breathing

apnea

cessation of breathing

dyspnea

shortness of breath

hyperventilation

increase in breathing

hypoventilation

reduction in breathing

orthopnea

having to sit to breathe

respiratory arrest

complete lack of breathing

tachypnea

rapid breathing, but getting the same amount of oxygen in

760mmHg

air pressure at sea level

partial pressure

The pressure exerted by one specific gas in a mixture of gases; calculated by multiplying the gas’s percentage by the total atmospheric pressure.

emphysema

destroys lung tissue, including alveoli, reduces the total surface area of the alveoli which reduces the surface area available for gas exchange, lowering blood O2 levels

ventilation-perfusion coupling

the body’s ability to match up alveolar blood flow (perfusion) with alveolar ventilation. If a region of the lung becomes diseased and air is no longer reaching the alveoli, the PO2 will fall and the lung responds by constricting regional arterioles and decreasing perfusion to the lung, vasoconstrction reroutes blood away from the nonventilated area to a normal area of the lung where it will be oxygenated

oxyhemoglobin dissociation chart

graph that shows how saturated hemoglobin is with oxygen at varying levels of Po2 in the blood

oxyhemoglobin

hemoglobin carrying one or more molecules of o@

deoxyhemoglobin

if no oxygen is bound to the hemoglobin

BPG

a metabolite that red blood cells produce that increases O2 release, fever and certain hormones will raise this

carbon monoxide

hemoglobin also binds to this 210 times as avidly as o2, it does not want to dissociate and o2 cannot knock it off of hemoglobin. When hemoglobin is fully saturated with this, it is unable to pick up and transport o2 out of the tissues

arterial blood

comes straight from the arteries (like the radial artery in the wrist) and reflects freshly oxygenated blood from the lungs, testing this reflects how well the lungs are oxygenating the blood