Respiratory Anatomy Flashcards
functions of the respiratory system
- supply o2, dispose of co2
- vocalization
- olfaction
respiration equation
C6H12O6 + 6O2 -> ATP + 6CO2 + 6H2O
4 processes of respiration
- pulmonary ventilation
- external respiration
- transportation of respiratory gases
- internal respiration
pulmonary ventilation (respiratory system)
(breathing) inspiration + expiration
- air moving in and out of the lungs
external respiration (respiratory system)
- o2 diffuses from the lungs into the blood
- co2 diffuses from the blood into the lungs
transportation of respiratory gases (cardiovascular system)
completed by the cardiovascular system - blood is the vehicle
internal respiration (cardiovascular system)
- o2 diffuses from blood into the tissue cells
- co2 diffuses from the tissue cells into the blood
major organs of respiratory system
Nose, nasal cavity, and paranasal sinuses
Pharynx
Larynx
Trachea
Bronchi + Branches
Lungs + Alveoli
- not formally included, but essential: diaphragm + intercostal muscles
upper respiratory system organs
Nose -> Larynx
lower respiratory system organs
Larynx -> Alveoli
upper respiratory system
- part of the conducting zone
- fairly rigid conduits down to the microscopic sites of gas exchange
- functions to warm, humidify, and filter air (preparing air to be exchanged)
functions of the nose
Provides an airway
Moistens and warms entering air
Filters/cleans entering air
Serves as a resonating chamber for speech
Houses olfactory receptors
Two Regions of the nose
1- External Nose and 2 -Nasal Cavity
- External nose is nasal, frontal, maxillary bones + hyaline cartilage
- Nasal cavity is within and posterior to the external nose – divided by nasal septum
- Roof formed by the ethmoid and sphenoid bones; floor formed by hard and soft palates
olfactory mucosa
contains olfactory epithelium with smell receptors
respiratory mucosa
lines the remainder of the nasal cavity
- Pseudostratified, ciliated, columnar epithelium
- Mucus and serous secretions contain lysozyme and defensins
- Inspired air is warmed by plexuses of capillaries and veins
- A rich supply of sensory nerve endings will trigger a sneeze upon contact with irritants
cilia
within respiratory mucosa
- move contaminated mucus posteriorly to the throat for swallowing/digestion
- slowed by cold temperatures and harmed by smoking
nasal conchae
- 3 conchae protrude medially from each lateral wall of the cavity - superior, middle, and inferior
- Covered in mucosa
- Increase mucosal surface area and turbulence for enhanced warming/filtering
nasal meatus
the groove inferior to each concha
inhalation
air is filtered, warmed, moistened
exhalation
heat and moisture are reclaimed
paranasal sinuses
form ring around nasal cavity
- located in frontal, sphenoid, ethmoid, and maxillary bones
paranasal sinus functions
- lighten the skull
- give resonance to the voice
- produce mucus/warm and moisten the air
pharynx
muscular tube from the base of the skull
- called the throat
- connects the nasal cavity and mouth to the larynx and esophagus
- composed of skeletal muscle
three regions of the pharynx
- nasopharynx
- oropharynx
- laryngopharynx
nasopharynx
passageway for air posterior to the nasal cavity
- lined by pseudostratified columnar epithelium
- soft palate and uvula close it during swallowing
- posterior wall contains pharyngeal tonsil (adenoids)
pharyngotympanic tubes
within the nasophaynx - drain the middle ear cavities and allow middle ear pressre to equalize with atmospheric pressure
- protected by tubal tonsils
orophayrnx
passageway for food and air
- lined by protective stratified squamous epithelium
- paired palatine tonsils are embedded in lateral walls
- lingual tonsil exists on posterior surface of tongue
- soft palate -> epiglottis
laryngopharynx
- passageway for food and air
- lined by stratified squamous epithelium
- posterior to the upright epiglottis/larynx, extends to the inferior edge of the cricoid cartilage
- continuous with esophagus
larynx
- voice box
- attaches to hyoid bone + extends from c3-c6
- continuous with trachea
- arrangement of 9 cartilages connected by membranes/ligaments
- all cartilage is hyaline (except epiglottis)
larynx 3 functions
- provides a patent airway
- routes air and food into the proper channels
- produces sound/vocalization - houses vocal folds
thyroid cartilage (larynx)
large, shaped like a shield
- laryngeal prominence = adam’s apple
- secondary to secretion of sex hormes during puberty, it’s larger in males
cricoid cartilage (larynx)
ring shaped
- 3 small, paired cartilages form posterior and lateral walls
- arytenoid, cuneiform, corniculate
epiglottis (larynx)
flexible, spoon shaped, elastic cartilage
- covers the laryngeal inlet during swallowing
cough reflex (larynx)
triggered by anything other than air entering the airway
vocal ligaments (larynx)
deep to the laryngeal mucosa, attach arytenoid cartilages to the thyroid cartilage, form the core of the vocal folds
vocal folds (larynx)
true vocal cords
- vibrate to produce sound as air rushes up
- lack blood vessels and appear pearly white
- glottis: the opening between the vocal folds
vestibular folds (larynx)
false vocal cords
- lie superiorly to the vocal cords
- play no part in sound production
- assist in closing the glottis during swallowing
speech
intermittent release of expired air while opening and closing the glottis
vocal pitch
determined by the length and tension of the vocal cords
- as the layrnx grows, the vocal fold become thicker and longer - the voice deepens
volume
determined by force of air - no vibration with a whisper
vocal quality
determined by the resonating chambers og the pharynx and the oral, nasal, and sinus cavities
enunciation
determined by the activity of the muscles of the pharynx, tongue, soft palate, and lips
sphincter function
vocal folds can act as a sphincter to prevent air passage during the valsalva maneuver
trachea
- windpipe
- extends from layrnx down to mediastinum
- 3 layers
- flexible enough to move inferiorly and stretch during inspiration and recoil during exhalation; cartilage rings prevent collapse
- posterior surface of tracheal rings are connected by smooth muscle trachealis - allows esophagus to expand when food is swallowed
3 layers of trachea
mucosa, submucosa, adventitia
mucosa
ciliated, psuedostratified epithelium with goblet cells
submucosa
connective tissue with seromucous glands
adventitia
connective tissue, encases 16-20 c-shaped hyaline cartilage rings
carina
projects posteriorly from the inner surface of the last tracheal cartilage, marks the point where the trachea branches into the 2 main bronchi
heimlich maneuver
- in response to obstructed trachea
- only to be used on conscious adults who can’t speak, breathe, or cough
- exerts pressure on diaphragm to compress lungs and and force air out of the airway
bronchial tree
pattern of air passageways in the lungs that branch ~23 times
bronchi
- trachea divides into right and left main bronchi at about T7
- main bronchi plunge into hilum of each lung
- right main bronchi is wider, shorter, and more vertical than the left
- inside the lung, each main bronchi divides into lobar or secondary bronchi
lobar bronch
divide into segmental or tertiary bronchi
bronchioles
bronchi less the 1 mm in diameter
terminal bronchioles
smallest bronchioles, less than .5mm in diameter
respiratory zone
defined by the presence of thin-walled air sacs called alveoli; begins when the terminal bronchioles feed into respiratory bronchioles
Respiratory Bronchioles -> Alveolar Ducts -> Alveolar Sacs -> Alveoli
alveoli
provide tremendous surface area for gas exchange
- ~300 million alveoli make up most of the volume of each lung
- external surfaces of the alveoli are densely covered with pulmonary capillaries
respiratory membrane
alveolar and capillary walls + their fused basement membranes
- only about .5μm thick - gases are exchanged by simple diffusion
type I alveolar cells
a single layer of squamous epithelial cells that make up alveolar walls
- 15x thinner than tissue paper
type II alveolar cells
scattered, cuboidal cells that secrete surfactant and antimicrobial proteins
surfactant
fluid that contains a detergent-like substance; coats the gas-exposed alveolar surfaces
alveolar macrophages
crawl freely along the internal alveolar surfaces consuming bacteria, dust, and other debris
surroundings of alveoli
fine, elastic fibers and pulmonary capillaries
alveolar pores
openings that connect adjacent alveoli
- equalize air pressure throughout the lung
- allow for re-routing in the event of collapsed/diseased alveoli
– aged and dead macrophages get swept up in the ciliary current and carried to the pharynx (abt 2mil/hour)
lungs position
outside of the mediastinum, the lungs fill the thoracic cavity
- cling tightly to the thoracic wall - they passively expand and recoil in response to changes in the volume of the thoracic cavity
apex
lung’s superior tip, deep to the clavicle
base
lungs inferior surface, rests on the diaphragm
hilum
on the mediastinal surface; site of entry/exit of blood vessels, bronchi, lymphatic vessels, and nerves
left lung
two lobes, smaller than the right
- cardiac notch: the concavity/impression of the heart
- oblique fissure: separates the superior/inferior lobes
right lung
3 lobes, larger than the left
- horizontal fissure: separates superior and middle lobes
- oblique fissure: separates the middle and inferior lobes
pleurae
thin, double layered serosa (parietal/visceral)
parietal pleura
lines the thoracic wall, superior surface of the diaphragm, around the heart, and between the lungs
visceral pleura
lines the external surface of the lungs
pleural cavity
slit-like space between the parietal and visceral pleurae
pleural fluid
produced by the pleurae, fills the cavity
- provides both lubrication and surface tension
pleurisy
inflammation of the pleurae - causes increased friction
- typically results from pneumonia
- symptom: stabbing pain with each breath
- as disease progresses, extra fluid is produced - friction and pain are reduced, but pressure is exerted on the lungs
pleural effusion
fluid accumulation in the pleural cavity, can sometimes be drained
