Lecture 16: Mediastinum, Lungs, Pleura Flashcards
what structures are found w/in the mediastinum
heart, great vessels, esophagus, trachea, autonomic and phrenic nerves, thymus, thoracic duct
what organs do the great vessels supply blood to?
head, neck, thoracic limbs
what spinal cord levels is the phrenic nerve located
C5-C7
sheets of mesothelium (single cell layer) that secrete small amounts of fluid and compost the pleura
serous membrane layer
what is the function of pleura
allows the external surfaces of lung lobes to smoothly glide during expansion and deflation
the out pouching of the foregut forms the ??
respiratory diverticulum AKA tracheobronchial diverticulum
what does the tracheobronchial tube form
larynx, trachea, lungs
what is the visceral pleura adherent to? what is the parietal (costal) pleura adherent to?
Visceral pleura - lung surface
Parietal (costal) pleura - body wall
what is central circulation and its inlet/outlet
blood supply to the heart
inlet: coronary arteries
outlet: cornonary sinus
what is systemic circulation and its inlet/outlet
oxygenated blood flow to the body
inlet: aorta
outlet: vena cavae
what is pulmonary circulation and its inlet/outlet
poorly oxygenated blood flow to the lungs for gas exchange
inlet: pulmonary arteries
outlet: pulmonary veins
where are the great vessels located
cranial mediastinum
what is the name of the embryonic layer that lines the developing gut tube
endoderm
what are the airways, lungs and visceral pleura derived from
visceral mesoderm and endoderm
what are muscle, CT and cartilage derived from
visceral mesoderm
what is internal epithelial lining and glands derived from
endoderm
what is the pleural cavity derived from
coelom
where is the horizontal fissure of the lungs
b/w the cranial lobe and middle lobe
where is the oblique fissure of the lungs
b/w middle lobe and caudal lobe
what is the cardia notch
a gap where the cranial and middle lung lobes don’t cover the heart
what type of epithelium is found at the mucosa layer and what 3 cell types
respiratory epithelium
- ciliated cells
- goblet cells
- basal cells
what is the Lamina Propria and where is it found
it is a layer of highly vascular loose CT
- has mucous and seromucous glands
**primary site of immune response (lymphocytes+neutrophils)
what happens to the epithelium as the tracheobronchial tree branches out
it gets shorter and thinner closer to alveoli
lose goblet cells then ciliated cells
what do basal cells become
basal cells –> club cells –> type II alveolar cells
characteristics of the smooth layer of epithelium
- smooth muscle
- bronchoconstriction
- parasympathetic innervation
the mucosa layer is comprised of what two things
epithelium lining
lamina propria
layer of tissues that is characterized by dense, irregular fibroelastic CT and mucus and seromucous glands
submucosa
cartilage layer
hyaline cartilage support
adventitia
characteristics of club cells
- dome shaped
- no cilia
- secretory granules provide protection from pollutants + prevent luminal adhesion (collapse)
what is the anatomical unit of gas exchange
alveolus
site of blood-air barrier
alveolar septum
what cells are found in the alveoli and what are their functions
type I alveolar (pneumocyte): gas exchange
- makes up 95% of alveolar surface
type II alveolar: secrete surfactant and regenerate the epithelium
alveolar macrophages
