Histology (respi) Flashcards
Factors affecting lung capacity
Person’s size
Age
Gender
Respiratory health
Fn of respi epithelium in lungs
Provides extensive area for gas exchange
Protects respi surfaces from environmental variations and pathogenic invasion
Involved in phonation
Components of the conducting zone
Nose, pharynx, larynx, trachea, brinchi, bronchioles and terminal bronchioles
Composed of 1st-16th division of respi tract
Fn of conducting zone
Filter, warm and moisten air and conduct it into the lungs
Where is the respi zone located?
Site of O2 and CO2 exchange of blood
Parts responsible for gas exchange
Majority is alveoli
Minority is respi bronchioles and alveolar ducts
Which division of the respi tract does the respi zone represent?
16th to 23rd
How is inspired air conditioned?
Cleansed
Moistened by mucus
Warmed by rich vascular network in mucosa
Components of URT
Nasal cavity
Pharynx
Larynx
Components of LRT
Trachea
Pri bronchi
Lungs
Type of epithelium lining upper RT
Pseudostratified epithelium
Main fn of upper RT
Conduct air to bottom part of respi tract
Type of epithelium lining lower RT
Simple squamous epithelium
Main fn of lower RT
Conduction of air and gas exchange
Where does air enter the nose?
Enter via external nostrils
Parts of nasal cavity
External vestibule
Internal nasal fossa
What conditions the air in the nasal cavity?
Air conditioned in the shelf-like projections
Name for respi epithelium
Pseudostratified, ciliated columnar epithelium
Cell types of the respi epithelium and their fn if applicable
Ciliated columnar cells -> protect nasal tract
Mucous goblet cells
Brush cells -> for sensation
Basal cells -> stem cells
- repairs protective fn
Small granule cells
Features of basal cells
Large nucleus
Few organelles
Scattered microvilli
Which cells are the first to be affected by cigarette smoke?
Basal cells
What is lamina propria (LP)?
Layer of connective tissue
- contains vessels and mucous glands
What forms the mucosa?
Epithelium and LP
What is rhinitis?
Inflammatory disease of nasal cavities
Histological and pathological changes during rhinitis
Goblet cells are hypertrophic and loaded w/ mucus secretion
LP is edematous and infiltrated w/ few inflammatory cells
Narrowing of nasal cavities due to fluid leakage from blood vessels
What does smoking do to the cells?
Inhibits ciliary movement
What does coughing do?
Removes dust-laden mucus from airways
How does smoking lead to squamous cell carcinoma?
Chronic smoking induces the transformation of the respi epithelium into stratified squamous epithelium -> initial step in eventual differentiation into tumor
What does paranasal air sinus add to your voice?
Resonance
Which structure is your paranasal sinus adjacent to?
Nasal cavity
What are the paranasal sinuses?
Frontal sinus (FS)
Maxillary sinus (MS)
Ethmoidal sinus (ES)
Sphenoidal sinus (SS)
What type of epithelium lines paranasal sinus?
Typical respiratory epithelium
What is sinusitis?
Inflammatory process involving 1/more of the paranasal sinus
- cause swelling -> obstruction of drainage orifices
How would mucus drain into nose against gravity?
Cilia push mucus up
Where does pharynx extend into?
Internal nares and larynx
Layers of pharynx (superior to inferior)
Nasopharynx
Oropharynx
Laryngopharynx
What is the soft palate?
Extension of hard palate
Location of soft palate
Anteriorly (aka near back of throat)
Superior to back of tongue
Fn of soft palate
Close off such that food doesn’t get into nasopharynx
What kind of epithelium lines oral surface?
Stratified squamous epithelium
What kind of epithelium lines nasal surface?
Respiratory epithelium
Features of the larynx
Connects pharynx to the trachea
Contains 9 cartilages
Location of vocal cords
Below the epiglottis
How many vocal cords are there?
2 pairs
Upper vs lower pair of vocal cords
Upper -> false vocal cords
Lower -> true vocal cords
Position of vocal cords during inspiration
Opened
Position of vocal cords during phonation
Closed
Type of epithelium lining the larynx
Entire lingual and apical larnygeal surface covered w/ stratified squamous epithelium
Type of epithelium lining base of epiglottis
Undergoes transition -> ciliated pseudostratified columnar epithelium
Type of epithelium lining false vocal cords
Typical respiratory epithelium
Type of epithelium lining true vocal cords
Stratified squamous epithelium
What is the shape of the cartilage in the trachea?
Ring-shaped
Location of trachea
Extends from below the larynx
Right vs left main bronchus
Right
- wide
- more vertical
- short
Left
- narrow
- longer
What is the carina of the trachea?
Hook-shaped process projecting backward from the lower margin of the lowest tracheal ring
Feature of carina
Sensitive area
Location of the carina
At area where the trachea bifurcate into left and right primary bronchus
How do the arteries run in the bronchopulmonary segment?
Run through the centre of the segment
How do the veins and lymphatic run in the bronchopulmonary segment?
Drain along the edges of the segment
Does infection stay restricted within the bronchopulmonary segment?
Usually yes
- but can spread from one segment to another
What connects the 2 ends of the C-shaped cartilage in the trachea?
Fibroelastic ligament and smooth muscle bundle
What kind of epithelium lines the trachea?
Respiratory epithelium
What lines the visceral pleura adherent to the lung?
Mesothelium
How do the pulmonary lymphatic vessels run?
Follow bronchi and pulmonary vessels
Where are the pulmonary lymphatic vessels found?
In the interlobular septum
Where do pulmonary lymphatic vessels drain into?
Into the lymph nodes at the hilum of the lung
What does the pri bronchi divide into right and left lung?
3 bronchi in the right lung
2 in the left lung
Is there cartilage in the bronchi?
Yes
Is there cartilage in alveoli?
No
What does terminal bronchiole divide into?
Respiratory bronchiole
What does respiratory bronchiole open into?
Alveolar ducts/alveoli
Features of bronchiole in lung
No cartilage and mucus glands
Presence of smooth muscle
What kind of receptors are present in the respiratory tract?
Beta-2 adrenergic receptors
How does the epithelium transition as you enter the respiratory bronchiole?
Ciliated columnar epithelium gradually becomes ciliated cuboidal and later to non-ciliated squamous epithelium
Type 1 vs type 2 cell
Type 1
- flat nucleus
Type 2
- thick nucleus
Main cell types in interalveolar septum (5)
Capillary endothelial cells
Type 1 epithelial cells
Type 2 epithelial cells
Interstitial cells (fibroblast)
Alveolar macrophage
Where does fluid collect in event of pulmonary edema?
Mainly in btw alveoli and interstitial space
- if fluid go inside alveoli -> pink frothy sputum
Fn of type 2 cell
Produce surfactant to prevent collapse of alveolus and inner walls sticking tgt
Replenish type 1 in event of loss
Fn of type 1 cell
Allow gas exchange btw alveolus and capillaries
How does surfactant enable the lung to inflate?
Reduce surface tension -> increase pulmonary compliance -> lung inflate much more easily
Pulmonary innervation for parasympathetic and what it causes
M3 -> bronchoconstriction
Pulmonary innervation for sympathetic and what it causes
Beta 2 -> bronchodilation
Looking at a slide of lung tissue, how to know if the lumen is due to a bronchus or blood vessel?
Bronchus -> cartilage present
Blood vessel -> irregular shape
