Lecture Outline #23: Respiratory System Flashcards
respiration basics
it is cellular respiration (glucose + oxygen -> water, carbon dioxide and ATP; oxygen breaks down the glucose)
breathing is the transportation of gases
diffusion of blood gases occurs due to thin walls, moist surfaces, and rich blood supply
what makes up the upper respiratory tract
organs outside of thorax, nasal cavity, paranasal sinuses, larynx, and pharynx
what makes up the lower respiratory tract
organs within thorax, trachea, bronchi, bronchial tree, lungs, pleural cavity
nasal cavity
- Nostril - external nares (bone)
- Alar cartilages support nostril
- flaps on side of nose that make vestibule - Nasal septum
- ant: hyaline cartilage then septal then elastic
- post: vomer & perpendicular plate of ethmoid - Lateral walls
- sup, mid, & inf conchae/meati - Lateral wall openings
- has nasolacrimal duct
- paranasal sinuses (sphenoid, ethmoid, maxillary, frontal) that drain via paranasal ducts
- all ducts/sinuses lined w/ mucous mem (resp epi) & cilia - Internal nares
epithelia of nasal cavity: nasal vestibules and mid/inf conchae
nasal vestibule: lined w/ sebaceous/sweat glands and hairs to filter air
conchae: respiratory epithelium (mucous membrane, pseudostratified ciliated columnar), has cilia catching particulates, snot is always moving from lungs to cavity
pharynx
common passage for resp/dig systems, all have respiratory epithelium
nasopharynx
space above soft palate, posterior to nasal cavity
auditory tubes connect nasopharynx w/mid ear
pharyngeal tonsil on posterior wall
soft palate serves as a flap valve btw caivty/pharynx
oropharynx
space btw soft palate & hyoid
palatine tonsils located in lateral walls
lingual tonsils located at base of tongue
laryngopharynx
space btw hyoid to 1st tracheal ring
contains epiglottal cartilages
larynx
cylinder suspended by hyoid bone
surrounds/protects glottis & trachea
vocal cords located in larynx
has epiglottis
glottis
innervated by CN X
opening for air to pass through, formed by vocal folds
epiglottis (laryngeal/elastic cartilage)
protective valve/cover
folds/pivots over glottis when swallowing to divert food to esophagus
epiglottal cartilage - comprises the epiglottis
laryngeal cartilages
modified tracheal rings
precent you from aspirating during eating
thyroid (laryngeal cartilage)
large, shield-shaped, only anterior portion
protects glottis, ligs, & cords behind it
cricoid (laryngeal cartilage)
medium sized, circumferential shaped
inferior to thryoid
arytenoid (laryngeal cartilage)
x2
anchor for vocal ligs
on top of cricoid
corniculate (laryngeal cartilage)
x2
anchor for vestibular ligs
on top of arytenoid
cuneiform (laryngeal cartilage)
x2
stabilizes epiglottis from below
laryngeal ligs & folds
vestibular ligs + vestibular folds = false vocal cords
vocal ligs + vocal folds = true vocal cords
space btw vocal folds = glottis
tension/spacing of cords = sound pitch, volume
order of laryngeal ligs, vestibule
vestibular fold with ligs coming off = no control, false
vestibule - space
vocal folds with ligs coming off = true cords
trachea structure
tough, flexible tube made of 18-20 C shaped hyaline cartilages that are connected in series by annular ligs, trachialis m. fills the posterior gap of the C rings
lined with respiratory epithelium
divides to form R/L primary bronchi @ carina T5
tracheostomy
surgical opening in trachea to allow air flow
hilus/hilum of an organ
openings for BVs, nerves, lymphatics
r bronchus characteristics
longer & more aligned with trachea = more prone to chocking
1° bronchi
split to form secondary/lobar bronchi
R side - 3 bronchi
L side - 2 bronchi
2° bronchi
split to form tertiary/segmental bronchi
goes to each lobe of lung
located within each bronchopulmonary segment
3° bronchi
split into bronchioles
bronchioles
split into respiratory bronchioles and terminal bronchioles
respiratory bronchioles
alveolar sac - alveoli
alveoli
wrapped in capillaries - site of gas exchange
wall is a thin respiratory membrane - simple squamous epithelium
elastic fibers in alveolus have septal cells that produce surfactant (reduces surface tension)
respiratory bronchus - acinus
end of terminal bronchioles, beginning of respiratory bronchioles & alveolar ducts
morphological changes in bronchial tree
- Tracheal rings switch to plate @ 2° bronchi
- Epithelium: Pseudostratified (respiratory) to simple squamous @ respiratory bronchioles
- Cilia: ciliated epithelium changes to non-ciliated epithelium @ terminal/respiratory bronchioles
- Smooth muscle more common @ 2° bronchi & down
ANS bronchi functions
sym ANS - bronchodilation
psym ANS - bronchoconstriction
SA & miles of tubes in lungs
SA - tennis court, 2100 ft2
miles - 1500 mi
infant respiratory distress syndrome
premature babies don’t produce enough surfactant till around 7 months
alveolar walls stick together - alveolar collapse
lungs
base sits on diaphragm, apex is the top parts
root - bronchus + NAVLs
hilus - pt of entry supported by pulmonary ligs
cardiac impressions - indent of heart & aorta
lobes - 3R & 2L
mediastinum
composed of heart, aorta, vena cavae, trachea, root of lung, esophagus, thymus, CN X & phrenic n.s
visceral pleura
serous membrane on lung surface
lines with simple squamous epi - produce serous fluid
parietal pleura
serious membrane lining pleural cavity
stuck to thoracic wall
pleural cavity
potential space btw vis/par pleura
contains surfactant –> lubricates pleura, decreases tension of heart linings and lung linings
pneumothorax
air in the thorax
1. Air enters into pleural cavity by breath (external or internal) of visc/par pleura
2. Serous fluids can no longer maintain pleural contact
3. Lungs collapse - elastic fibers = no pressure = constant contract
sucking wounds
lungs are deflating- elastic tissue draws lungs into a dense lump of tissue - collapse draws air through open wound
pleural adhesions
often after healing of sucking wound or rib punctures
1. damage to visc/par pleurae
2. tissue healing process confused the pleura
3. pleural adhesions form btw layers
4. painful during deep breaths or movement
emphysema
chronic obstructive pulmonary disease
destruction of alveoli (septum degenerates)
loss of SA for gas exchange - shortness of breath
need tubes in nostrils
pulmonary embolism
blood clots block pulm BVs
leads to infarction/necrosis
often occur in postpartum mothers
diaphragm
muscle separating thoracic and abdominal cavities
shaped like a dome, contracts on centrum
phrenic n. controls contractions, peripheral movements by intercostal n.s, apertures by CN X
caval hiatus - IVC
esophageal hiatus - esophagus
aortic hiatus - aorta
inspiration
active movements
diaphragm contracts, flattens to increase thoracic volume, and compresses abdominal contents
pressure is negative/decreases and becomes like a vacuum
forced inspiration
m.s raise rib cage
- external intercostal, SCM, serratus anterior, pectoralis minor, scalenes.
expiration
passive action due to elasticity of thoracic wall, alveoli, and bronchial tree
diaphragm relaxes up, rebound of abdominal contents
thoracic volume decreases
pressure in lungs increases
forced expiraation
abdominal wall m.s compress gut
- transverse thoracis, rectus abdominus.
internal intercostal ms. compress rib cage
control of breathing
- respiratory centers: left frontal lobe (primary) and pons & medulla oblongata - pace and rhythm
- mechanoreceptors: lung volume & BP
- chemoreceptors: CO2, O2, and blood pH
cough and hiccups
cough - reflex spasm (full contraction of m.s) to protect respiratory tract
hiccup - R/L phrenic n.s normally work in syn, when off rhythm - diaphragm spasms
