Resp Anatomy Flashcards
what are the structures of the respiratory system?
upper and lower airways, lungs and pleura, thoracic cage, muscles of respiration
skeletal structure of the thorax
12 thoracic vertebrae, 12 pairs of ribs and costa, sternum (manubrium, body, xyphoid)
what are the functions of the respiratory system?
perform gas exchange, regulate blood pH, provide for olfaction, provide for phonation
features of the ribs
facets and costal grooves
facets
for articulation with the vertebrae (synovial)
costal groove
location of intercostal VAN (neurovascular bundle)
muscles of inhalation
accessory: sternocleidomastoid and scalenes
principal: external intercostals and diaphragm
muscles of exhalation (active)
internal intercostals, internal/external obliques, transverse and rectus abdominis
what do the muscles of inhalation do?
elevate ribs, lower the diaphragm, enlarge the thorax, AP and SI dimensions
what do the muscles of exhalation do?
depress ribs, compress abdomen, elevate diaphragm, compress thorax
what are all skeletal muscles controlled by?
somatic neurons
exhalation
is passive; lets lungs recoil to push air back out (energy efficient), active breathing recruits internal intercostals, obliques and abdominals; when flexed compresses viscera and sends them up against diaphragm to help expel air
intercostal VAN
vein, artery, (thoracic spinal) nerve at each intercostal space
intercostal VAN features
internal and external intercostal muscles only exist b/w the ribs in the intercostal spaces, inner most intercostals are splayed against the entire thing
lung aspiration
lung compression and collapsing can occur w/ fluid, air, pus, etc, accumulation in the pleural cavity, can be aspirated w/ a syringe (need to be careful due to intercostal VAN
best approach: aim for top of a rib (furthest from intercostal VAN)
blood supply of the thoracic cage (arteries)
- subclavian arteries supply thoracic cage
- descending thoracic aorta supplies the back
- blood going through the thoracic cage comes from the front and back; arteries run through intercostal spaces and create anastomoses
- intercostal arteries run in the intercostal groove underneath the ribs
venous drainage of the thoracic cage
- from back -> SVC
- from front -> brachiocephalic and subclavian veins -> SVC
- internal thoracic vein out front + intercostal veins drain into azygos vein out back (right side) and hemi-azygos (left side) -> end up in SVC
what nerve innervates the diaphragm?
phrenic nerve
diaphragm features
composed of skeletal muscle, attaches to the inferior aspects of the ribcage and acts upon a central tendon, separates the pleural from peritoneal cavity; many structures must pass through the diaphragm
openings in diaphragm
aortic hiatus, esophageal hiatus, caval opening
upper respiratory system
consists of channels through the bony parts of the skull; nose, nasal cavity, paranasal sinuses, pharynx
what are the 3 regions of pharynx?
nasopharynx, oropharynx, laryngopharynx
what do the upper airways consist of?
nose, nasal cavity, sinuses (front, ethmoid, maxillary, sphenoid)
what is the transition zone zone between upper and lower airways?
the larynx
what is the purpose of vibrissae?
present in the nose and trap big particulate matter
where does air travel through in the upper respiratory system?
across the moist mucous membrane through conchi/ turbinate bones
nasal cavity
covered by a mucous membrane, filters, warms and humidifies the air, protecting the lower respiratory
the oral cavity contains which type of tissue?
stratified squamous epithelium, b/c it is subjected to many abrasive forces (food)
epiglottis
protects the trachea, expulsive manoeuvres (cough, sneeze, micturition, labour & delivery), structural support
what do the lower airways consist of?
trachia, bronchi, bronchopulmonary segments, bronchioles, lobules, alveolus
trachea
has C shaped cartilage, posterior has smooth muscle, bifurcates into primary bronchi, pseudostratified columnar epithelium (mucociliary apparatus), carina (internal ridge at bronchial junction)
primary bronchi
enter each lung at the hilus and then divide into secondary bronchi
- right primary: shorter, wider, more vertical
- left primary: longer, more angled
secondary (lobar) bronchi
3 in right lung, 2 in left lung; supported by plates of cartilage
what would happen if you aspirated food into the lungs?
it would end up in the path of least resistance (right primary bronchus)
lobes and fissures of the left lung
2 lobes - superior and inferior, oblique fissure; has a cardiac notch (superior; accomodates the heart) and lingula
lobes and fissures of the right lung
3 lobes - superior, middle, inferior, horizontal and oblique fissures
secondary bronchi continue dividing to create:
tertiary (segmental) bronchi, there are 10 in the right lung and 8 in the left; cartilage rings replaced by cartilage plates
bronchopulmonary segment
the area supplied by tertiary bronchi; functionally and anatomically indepent
- have own elastic tiss. covering
- own blood, lymphatic and nerve supply
tertiary bronchi divide into:
bronchioles
tertiary bronchus features
eventually cartilage is replaced by smooth muscle only, smooth muscle bands are regulated by the ANS
tertiary bronchioles branch up to 14x to make
terminal bronchioles
each terminal bronchiole forms a
lobule
what is each lobule composed of?
terminal bronchioles, arteriole, venule, lymphatic vessel - all wrapped in elastic CT
what are respiratory bronchioles connected to?
connect to alveolar sacs by alveolar ducts
what do the bronchial arteries supply?
conducting regions
what do the pulmonary arteries supply?
supply the gas exchange regions (lobules)
what are the functions of the airways?
tructural support, air conditioning, protection, gas exchange (towards alveoli)
alveolus
tiny air sac at the end of a bronchiole in the lungs that provides surface area for gas exchange to occur
what are the types of alveolar cells
type 1 and type 2
type 1 alveolar cells
continuous lining wall; primary site of gas exchange
type 2 alveolar cells
secrete alveolar fluid and surfactant; surfactant reduces the surface tension of alveolar fluid, elastic fibers also help to keep alveoli open
gas exchange membrane consists of:
type I pneumocyte, basement membrane, pulmonary capillary endothelial cell
why is the gas exchange membrane very thin?
to allow for gas exchange
