Respiratory System Flashcards
What are the 2 main functional components of the respiratory system?
Conducting portion
Respiratory portion
Function of conducting portion
Where air is conditioned and directed
What structures are included in the conducting zone?
Nasal cavities
Pharynx
Larynx
Trachea
Lungs: bronchi, bronchioles, terminal bronchioles
Function of respiratory portion
Where gas exchange occurs
What structures are included in the respiratory portion?
Respiratory bronchioles, alveolar ducts, alveolar sacs, alveoli
What is the respiratory epithelium of the mucosa that lines the conducting portion?
Respiratory epithelium: pseudostratified ciliated columnar, often with goblet cells
The left and right nasal cavities contain ____
Vestibules
What are vestibules?
Dilated space of the cavity where air enters
Conchae
3 Bony projections of the nasal cavity which create turbulence of inspired air
Vibrissae
Moist hairs which filter air of particulate matter
Olfactory mucosa of nasal cavities has what type of epithelium?
Specialized olfactory epithelium
What does the pharynx connect?
Connects nasal & oral cavities to the larynx & esophagus
Pharynx is divided into ____ and ____
Nasopharynx
Oropharynx (throat)
What is the passageway for air between oropharynx & trachea?
Larynx
Epiglottis
- elastic cartilage
- flattened structure near top of larynx
- prevents swallowed food from entering airway
False vocal cords are covered by ____
Respiratory epithelium (PSCC)
Function of false vocal cords
No movement, but aids in sound resonance
Below each false vocal cord is a ____
Ventricle
(Elongated recess)
2 pairs of vestibular folds in the larynx are called…
False vocal cords
2 vocal folds in larynx are called…
True vocal cords
Function of true vocal cords
Control air flow through larynx and vibrate to produce sound
True vocal cords are covered by ____
Stratified squamous epithelium (non-keratinized)
True vocal cords contain the ____
Vocalis muscle
Vocalis muscle
- Skeletal muscle, attached to a ligament
- tension on ligaments caused by muscle produces different sounds
Functions of trachea
- conduction of air
- conditioning: warming, moistening, removal of particulate matter
Function of C-shaped rings in trachea
Maintains open airway
Trachealis muscle
- Smooth muscle, Connects open ends of hyaline cartilage C rings
- controls luminal diameter of trachea to control air intake
- allows for passage of swallowed bolus of food by esophagus
Name the layers of the wall of the trachea
- mucosa
- submucosa
- cartilaginous
- adventitia
Mucosal layer of trachea
- Epithelium: PSCCwG, thick basement membrane
- Lamina propria: many blood vessels (warming)
Submucosa of trachea
Seromucous glands (moistening)
Cartilaginous layer of trachea
Rings of C-shaped hyaline cartilage
Adventitia of trachea
CT connects trachea to surrounding structures (esophagus)
Bronchial tree
Trachea
2 primary bronchi
secondary bronchi
Tertiary bronchi
Bronchioles
Terminal bronchioles
Respiratory bronchioles
Alveolar ducts
Alveolar sacs
Alveoli
Layers of walls of bronchi
- mucosa
- muscularis
- submucosa
- cartilage layer
- adventitia
Mucosa of bronchi
- epithelium: respiratory epithelium (PSCCwG)
- lamina propria: loose CT
Muscularis layer of bronchi
- spiral bands of smooth muscle, continuous in larger bronchi, thin & discontinuous in smaller bronchi
- important in regulating appropriate diameter of bronchi
Submucosal layer of bronchi
Seromucous glands
Cartilaginous layer of bronchi
- Discontinuous hyaline cartilage plates become smaller as bronchi become smaller
- supports bronchial wall
Adventitia of bronchi
Dense irregular CT continuous with adjacent structures
Epithelium of bronchioles
- Initially PSCCwG in largest bronchioles
- quickly becomes simple columnar ciliated, no goblet cells, eventually cuboidal (ciliated)
Bronchioles do not contain ____ or ____
Cartilage plates or glands
Epithelium of terminal bronchioles
Ciliated simple cuboidal with non-ciliated cuboidal clara cells
Functions of Clara cells
- Secrete surface-active agent
- secrete Clara cell secretory protein (CC16)
Function of surface-active agent
Lipoprotein prevents luminal adhesion
Function of Clara cell secretory protein (CC16)
Protect against lung injury, antimicrobial, detoxifying harmful substances inhaled into lungs
What is the first part of the respiratory portion?
Respiratory bronchioles
mucosal epithelium of respiratory bronchioles
ciliated simple cuboidal with non-ciliated clara cells
what are alveolar ducts?
distal ends of respiratory bronchioles - elongated airways from which alveoli open
lamina propria of alveolar ducts
extremely thin lamina propria of reticular & elastic fibers (no smooth muscle)
alveolar spaces
spaces surrounded by clusters of alveoli, typically at the ends of alveolar ducts
function of alveoli
terminal air spaces of respiratory system: major site of gas exchange between air and blood
alveoli are surrounded by an extremely thin piece of CT containing blood capillaries called the ____
alveolar septal wall (or interalveolar septa)
alveoli are lined by…
type 1 and type 2 alveolar cells (or pneumocytes)
alveolar septum is the site of the ____
blood-air-barrier
alveoli
3 parts of respiratory membrane
- type 1 alveolar cells (pneumocytes)
- fused basal laminae of type 1 alveolar cells & endothelial cells of capillaries
- capillary endothelial cells
type I alveolar cells/pneumocytes
- extremely thin simple squamous
- make up alveolar side of blood-air-barrier, diffusion of O2 & CO2
type II alveolar cells/pneumocytes
- cuboidal cells, bulge into air space, interspersed amongst type I alveolar cells
- secrete surfactant
surfactant
- surface active agent of lipoproteins & phospholipids, spreads over inner alveolar surface
- decreases alveolar surface tension, preventing collapse
alveolar macrophages (dust cells)
- found in alveolar spaces and interalveolar septal wall
- phagocytose particulate matter, infectious organisms, RBCs lost from damaged capillaries
anthracotic pigment
- ingested material macrophages can’t break down (tar, nicotine, pollutants)
- remain in macrophage, accumulates in CT
each lung is covered by…
visceral pleura, continuous with parietal pleura
visceral pleura
thin CT covering with mesothelium
parietal pleura
CT covering that lines pleural cavity
pleural cavity is filled with…
serous fluid, acts as a lubricant
