lecture 13/14 Flashcards
respiratory
how does the embryotic growth process comapre for exocrine and endocrine glands?
both come from epithelium that starts dividing making the downward growth into the CT:
* exocrine: duct stays there and an acinus develops
* endocrine: duct cells disappeares and forms the future endocrine gland
glandular epithelia classification, according to their ducts
with examples
- simple tubular: gastric gland
- simple coild tubular: sweat gland
- simple branched tubular: pyloric glands
- simple branched acinar: trachea
- compound tubulo-acinar: submandibular gland
- compound acinar: parotid/sublingual gland
general function of the respiratory system
provide O2 and remove CO2 from the blood
parts of the respiratory system
- conducting portion: nasal cavity, nasopharynx, oropharynx, larynx, trachea, bronchi, bronchioles
- respirtaory portion: repiratory bronchioles, alveoalr ducts, alveoalr sacs, and lung alveoli
function of the conducting portion
warming, humidifying, cleaning, and delivery of air
function of the respiratory portion
where gas exchange takes place
features of the conducting portion
- has structures that ensure uninterrupted supply or air (cartilage, SM, CT, which privide rigidity, flexibility, and extensibility)
- has glands and cililated cells to remove foreign particles
general plan of conducting portion (trachea)
- mucosa: pseudostratified columnar epithelium with gobelet cells and lamina propria (loose CT, elastic fibers, capillaries)
- submucosa: dense CT and glands (serous and mucous acini)
- cartilage muscle: hyaline cartilage with trachealis muscle (SM)
- adventitia: dense irregular CT
how do serous and mucous acinus campare in the trachea?
- serous: Smaller, pyramidal cells, small lumen, round nuclei at the base, myoepithelial cells
- mucous: Columnar cells, bigger, stain light, secretory vesicles with mucous, no myoepithelial cells,
what cells are found in respiartoy epithelium?
- goblet cells: secrete mucous
- small granule cell: produces epinephrine and serotonin which affects permeability of capilalries, has argentaffin so stains well with silver salt
- short cells: stem cells
what is the cilia made of?
a basal body, which is a centrole, with a long axoneme, which is made of microtubules with other “arms”
describe the makeup of an axoneme
- central pair of full microtubules (which is made from 13 protofilaments of a-tubulin and b-tubulin monomers)
- this is surrounded by a small inner sheath
- all around there are 9 other pairs of microtubules, but here there is 1 full one and one partial one
- there are radial spokes that go from the outer pairs to the middle, along with each having dynein arms
- nexins connect the pais on the outside
- and finally, it is all surrounded by a plasma membrane
what is primary cililary diskinesia? what are the effects of this disease?
lack of dynein arms, which:
* renders cilia and sperm immotile or dysmobile
* imapired mucous clearnace
* chronic sinusitis
* situs inversus
* male infertility
what happens with radial spoke protein mutations?
results in immotile cilia and sperm
what is the name of the structure seperating alveolar sacs?
septum
alveolar ducts are delimited by knobs of ___________ covered by _________________
smooth muscle fibers; clara cells
what do the lamellar bodies in pneumocyte type II cells contain and what is its role?
- surfactant proteins A, B, C, D and phospholipids (mostly lecithin)
- this helps reduce the surface tension of the pneumocyte type I
what are the 3 ways that carbon dioxide is transported in the bloodstream from peripheral tissue and back to the lung?
- dissolved gas
- bicarbonate
- carbaminohemoglobin (bound to Hb + other proteins)
what is respiratory distress syndrome of the newborn and its outcomes?
- lung disorder caused by surfactant deficiency
- associated with prematuraity and is the leading cause of mortality among premature infants
what is emphysema and its outcomes?
- chronic disease characterized by destruction of septi, leading to respiratory insufficiency
- major caue of smoking, prob. due to the impairment of elastic fiber synthesis
- can also be a result from increase of elastase production from macrophages
