Histo Midterm 2 - Respiratory System Flashcards
What are Vestibules features and location?
Location: just behind the nares, hairs, and glands
Features: non-keratinized stratified squamous epithelium and lamina propria of dense CT
What is the respiratory regions features and location?
Features: PSCC w/G and lamina propria of fibrous CT plus seromucous glands; Extensive venous plexuses
Location: rests on the periosteum of nasal concha
What are the Olfactory region’s features and location?
Location: above and under superior concha
Features: Pseudostratified Columnar epithelium (3 cell types), lamina propria (CT with many glands vessels and nerves)
What 3 cell types are found in the olfactory region?
Supporting cells - free surface has microvilli mucus
Basal cells - small, single layer at the bottom
Olfactory cells - bipolar neurons, nuclei bellow supporting cells, have nonmotile cilia
What are the Paranasal sinuses features and location?
Location: cavities in the frontal maxillary, ethmoid and sphenoid bones of skull
Features: PSCC w/G (has fewer G); drains into nasal cavity
What are the Nasopharynx features and location?
Location: back of the nasal cavity
Features: stratified squamous epithelium
What is the Larynx?
“Voice box”
Connects pharynx to trachea
Holds airway open
Series of irregular hyaline cartilage held together by fibroelastic CT
What does the epiglottis do?
Closes off the airway in the larynx
What is unique about mucosa in the larynx?
true vocal fold has non keratinized stratified squamous epithelium
What is the difference between false vocal cords and true vocal cords?
False vocal cords - upper mucosal folds; lamina propria has many glands and is loose CT
True vocal cords - lower mucosal folds; core of elastic tissue, muscles, and no glands
What are the features of the trachea?
“Wind Pipe”
Has a series of 20 C-shaped cartilage rings
Mucosa - PSCC w/G, lamina propria of loose CT, Thick basement membrane
Submucosa - Dense irregular CT w/ seromucous glands; ends are the perichondrium
Adventitia - C-shaped hyaline cartilage rings, perichondrium, trachealis muscle (smooth muscle connecting open ends of rings)
Mucocillary escalator - cilia provide a coordinated sweeping motion
What are the features of the Main Bronchus?
Trachea bifurcates into main bronchi which enter the lungs at the hilum
What does the Main Bronchus divide into?
Secondary/lobar bronchi
tertiary/segmental bronchi
these bronchi divide into bronchioles
What are the layers of the Main Bronchus?
Mucosa - PSCC w/G in largest, changes to simple columnar w/ cilia as diameter decreases
Submucosa - lots of mucous or seromucous glands and lymph nodules
Adventitia - hyaline cartilage in irregular pieces
What are the features of the bronchiole?
Last part of the conducting passageways
No cartilage, glands, or lymphatic nodules
What happens to the mucosa of the bronchiole?
Epithelium starts out columnar w/ cilia, but changes to cuboidal as diameter decreases; Goblet cells also decrease in number
Lamina propria is thin with elastic fibers
Smooth muscle beneath mucosa
What are the features of Respiratory bronchiole?
Begin the respiratory of the system
Low columnar to cuboidal w/o cilia
Discontinuous
Reduced elastic fibers and smooth muscle
What are Clara cells? Location?
Location: Terminal and respiratory bronchiole epithelium; scattered amongst cuboidal lining epithelial cells
Function: Produce and secrete proteins that protect the lining against pollutants and inflammation
What is the alveolar duct?
Numerous alveoli and sacs budding off
Squamous epithelium
Last segment to have smooth muscle
What are the features of the alveolus?
Simple squamous epithelium and basement membrane
Intralveolar septum - wall between 2 alveoli; 3 types of cells plus capillaries (continuous type)
What are the components of the interalveolar septum?
Lining epithelium/type 1 alveolar cell - simple squamous connected by tight junctions
Septal cells/type 2 alveolar cell - cuboidal w/ microvilli; produce surfactant
Alveolar macrophage/dust cell - derived from monocytes; phagocytoses debris in airway
How doe Type 2/Septal cells appear under EM?
Multilamellar bodies in cytoplasm (make lipoprotein surfactant)
What does surfactant do?
Lines alveolus to lower surface tension and prevent collapse of alveolus
What are the 4 layers of the Pulmonary membrane?
1) Surfactant layer
2) Type 1 lining cell of interstitial space
3) Basement membrane
4) Capillary endothelial cell
