two parts of the brain stem
medulla and pons
2 parts of medulla
ventral and dorsal respiratory groups
2 parts of pons
pneumotaxic center and apneustic center
dorsal respiratory group function
drives inspiratory response; communicates w pre-motor neurons
what innervates the diaphragm?
what nerve sends info back to brain for respiratory system?
bronchodilation is caused by
bronchoconstriction is caused by
negative pressure allows
gases to fill pleural space
quiet inspiration =
muscle action - diaphram moves 1 cm and ribs are lifted by muscles intrathoracic pressure falls and air is inhaled
passive process with no muscle action; uses elastic recoil and alveolar surface tension to pull inward and push air out
in forced breathing, which muscles inspire and which expire?
inspiration - sternocleidomastoid, scalenes, pectoralis minor exp -abdominal mm, internal intecostals
has: bopolar neurons, supporting cells, stem cells, thin basement membrance, bowmans glands doesnt have: no goblet cells,
what muscle underlies true vocal cords?
false vs true vocal cords
false - before true ones, surface is PCC, core of serous glands true - right before trachea (after false ones), surface is stratified squamous epithelium, core = vocalis muscle
path after mouth -->
pharynx, larynx, then trachea
tracheal cartilage C rings are
in the front, back is attached by trachealis muscle - which allows esophagus to expand as food passes by
respiratory epithelium is =
pseudostratified ciliated columnar (PCC) epithelium
how to tell difference between bronchi and bronchioles?
bronchioles do NOT have cartilage
when bronchus turns into bronchiole...
cartilage disappears and then there is just smooth muscle no opening into alveoli yet fewer ciliated cells, no goblet cells new cell = CLARA cells
bronchiolar expocrine cells with microvilli secrete surfactant , CC16 (modulates inflammation), and detox using p450 enzymes
requirements for efficient gas exchange
large area for diffusion minimal distance match ventilation and blood flow
termoinal bronchus leads to -->
lobular bronchiole --> terminal bronchiole --> respiratory bronchiole --> alveolar duct -> alveolar sac
pulmonary resistance is ____ compared to systemic resistance
as PO2 drops in an alveolus,
resistance in arterioles increase (perfusion to non ventilated sections!) and when alveoli is higher in Pressure than the capillaries, the air pressure can collapse the capillaries
west zones of lung pressure top, middle, bottom?
top - alveolar >arterial > venous middle: arterial > alveolar > venous bottom: arterial > venous > alveolar
type 1 vs type 2 pneumocytes
1 - squamous cells, flatter 2- larger and produce surfactant, rounder
what are alveolar cells called?
type 1 and 2 pneumocytes
type 2 alveolar cell/pneumocyte
"septal cell" secretes surfactant develops late in pregnancy premature baby ---> deficient surfactant --> respiratory distress syndrome or hyaline membrane disease