Respiratory Histology Flashcards
Hilum of lung
Medium indentation in the trachea in which the arteries veins and lymphatics, and bronchi go through
Root of the lung
Those first two bronchis from the trachea
Two anatomical Division of the lung
The upper Respiratory Airways and theLower respiratory Airways
Three parts of the respiratory system
lungs and respiratory portion
the ventalation mechanism (ie the rib and muscle)
and the air passages
Two functional regions of the lungs
Conducting portion and the respiratory portion
Conducting Portion of Lung
Function - conduct air and condition the air (filter heat and humidify)
Structure - varying size, much thicker than lower
Outside the lung - is the nasal cavity nasal pharynx and trachea
in the lung - is the bronchi bronchioles and the last part is the terminal bronchioles
Terminal Bronchioles
The last bronchiloles in the conducting zone
Respiratory Portion of Lung
Function - Gas exchange
Structure - thin walls only location of alveoli
First part is the respiratory bronchioles
Respiratory Bronchioles
the first part of the respiratory zone in the lung
Blood Supply in the Lung (Two Systems)
Bronchiole Circulation - nutrient vessels bring nutrients to lung, to the tunica adventitia and muscle layer
Pulmonary circulation - function as respiratory vessels, like the pumonary artery brings deoxy blood
Location of the pumonary artery and vein near the lung
They do not travel together, the pulmonary artery - is adjacent to the airway
the pulmonary vein - is in the connective tissue
4 veins return blood to left atrium
Cartilage in the lung (and regional qualities)
It is hyaline cartalige
C Shaped in the trachea - lays open to the esophagus for food
Bronchi have plates of cartilage less supportive and more prone to colapse
bronchioles have no cartilage
Smooth Muscle In lungs
Regulate airway Diameter
Type of Fibers in the Lung
Collagen and Elastic for recoil
Emphysema
Breakdown of fibers causing decrease Surface area, is a COPD and enlarged airspace distal. It causes problems
The Pleura is What in the lungs
the serous membrane around the lungs that is mesothelium and connective tissue
it hangs in the pulmonary cavity
Pleura is continuous with hilum
The two pleuras seen around the lung and whats between
We see the visceral peura adhering to the lung surface
we see the pleural cavity crucial next for vaccum
then we see pariatel pleura which is on the edge of the pulmonary cavity
Nasal Cavity (Structure and Function)
Turbinates or Conchae are the bone shelf
Structure - bone shelf projections lined with pseudostratified epithelium. Well vascularized
also olfactory epithelium located at the roof
Function - increase surface area so resp epithelium can humidify and filter
Trachea layers that Exist (3)
Mucosa, Submucosa, and Adventitia Cartilage
Trachea Mucosa
Elastic rich, with lamina propria (loose connective tissue)
We see pseudostratified cells on the epithelium
There is no muscularis mucosa
Basement membrane looks glassy looking can see in fibrosis
Tracheal Submucosa
location of glands along with basement membrane, mucous production
Tracheal perichondrium
inner cell layer outer fibrous surrounds the cartilage
this is the adventitia layer that is also cartilage
5 Cell Types of epithelium in the trachea
Ciliated, Mucous, Brush Cells, Small granule Cell, Basal Cells
Ciliated Cells of the Trachea
Secretes pericilliary Fluid (water layer) that is critical. surround the cilia so mucous does not thicken around the cilia too much
cilia can also form mucociliary escalator - that moves mucous up and out of the body
each cell has so man cilia that sweep
Cystic Fibrosis
Increase mucus and a decrease in the pericilliary fluid
so the cilia can not move as well
Mucous Cells of trachea
Secretes mucous in to the cytoplasm. The mucous floats on the serous fluid
Cilia moves this up and out
Mucociliary escalator
The movement of mucous coat out up the trachea
Brush Cells of trachea
Columnar Cells with blunt microvilli
sensory receptor cells with synaptic contact on the basal side
It is a receptor cell
Small Granule Cells of trachea
AKA enteroendocrine cells
Contain secreotory ranules
may function in reflexes
Basal Cell of trachea
Stem cell and will regenerate trachea epithelial
Metaplasia
The changing of epithelia from type to type in response to an irritant or toxin
ex// ciliated pseudostrat to strat squamous
will happen causing a caugh because of lack of cilia and smokers cough
Layers of the Bronchi
Mucosa - Same cells as the trachea, has the lamina propria and such more elastic fibers seen
Muscularis mucosa - regulates diameter of airway
Submucosa - location of glands
Adventiatia/ cartilage - has the cartilage plates and decrease diameter
Epithelial Change in Bronchioles
Psuedostratified to simple columnar to Simple Cuboidal (not abrupt)
Layers in the Bronchioles
No Cartilage layer, no submucosal, thick smooth muscle layer, simple columnar to simple cuboidal
Cell Type Changes in the Bronchioles
The ciliated cells gradual decrease while club cells increase
Club Cells (Aka Clara Cells)
Take over epithelum from above. BEcome stem cell
Secrete lipoportein to prevent adhesion to walls
Detoxifies harmful compounds
Non ciliated simple columnar
Alveoli Progression of Names
Alveoli - to alverolar ducts - to Alveolar Sacks
Alveoli Lining
Pneumocytes line the alveoli. this is the side of gas exchange
Alveolar Ducts
Only elastin and collagen fibers support with no smooth muscle
Alveolar Sacks
Just space surrounded by alveoli
Type I Pneumocytes
Gas Exchange happens
V thin cell
Squamous shaped with organelles wrapped aorund nucleus (so the cytoplasm is free for gas exchange)
95% of SA in alveolus
Type II pneumocytes
Septal Cells -
Structure - rounded cells contains lamellar bodies
Brown nucleus poke in to air space seen in corners occupy 5% of area
Function - undergo mitosis to regenerate self and Type I
also produce Surfactant to prevent collapse of alveoli
Interalveolar Septum Two Portions
Thick - pulmonary interstitium - we have collagen elastin, fibroblast, immune cells in these walls between sacks
Thin - is the blood air barrier
thin region one capillary wide only I pneumocytes
blood air barrier Cell layers
Endothelium of capillary. Basement membrane fuses t the Type I pneumocyte basement membrane with capillary.
Four Components - Surfactant, alveolar epithelium, fused basement, endothelial
What connects the Type I and II pneumocytes
Desmosomes and occluding tight junctions
Alveolar Pores
Pores of Kohn **
Function - equalize pressure in alveoli
enable colateral ventilation - if you block one oyu can shunt to another
Allows for Dust Cell Migration
Defenses within the Lung System (3)
Nose and Trachea (done by Cilia)
Mucociliary Ecalator - transport toward phayrnx
Macrophages - called dust cells engulf and then migrate away or stay (depending on if system is overloaded)
What are the stem cells of each section
Trachea and Bronchi - the basal cell
Bronchiole - club cell
Alveolar - Type II pneumocyte
