Respiratory System Flashcards
What 2 types of macrophages in alveoli?
- Tissue macrophage of septum
2. Pulmonary alveolar macrophage (PAM)
Where are tissue macrophages of the septum located?
Interstitium
Where are pulmonary alveolar macrophages located?
Alveolar lumen or surface
Why is there a large amount of elastic fiber in the alveoli?
Must be very flexible
3 components of blood-air barrier
- Endothelial cell (lines capillary)
- Basement membrane
- Alveolar type I pneumocyte (lines alveolus)
Basement membrane of blood-air barrier
May be fused from the epithelium of both the capillary and alveolus
OR
May be separated by CT
2 types of blood supply to alveoli
- Systemic vessels
2. Pulmonary vessels
Lungs receive nutritional supply from?
Bronchoesophageal a.
Lungs receive functional supply from?
Pulmonary a.
How do pulmonary vessels reach alveoli?
Follow airways → divide into capillary bed surrounding alveoli
How are avian lungs different than mammals?
- Smaller
- Do not change size with inspiration/expiration
- No diaphragm
Avian air passageway system
- Bronchi (primary and secondary)
- Parabronchi (tertiary bronchi)
- Atria (similar to terminal bronchiole)
- Air capillaries (similar to alveolar sac)
Function of avian air sacs
Move air in and out of lungs → have undirectional air flow
How many air sacs are connected to bronchi and parabronchi?
About 8
3 reasons avian respiratory system has more efficient gas exchange
- Thin walls
- Smaller alveoli
- Rich capillary system
What is unique about olfactory cells?
Bipolar neuronal cells
Airway progression
Bronchus → bronchioles → alveolar ducts → alveolar sacs → alveoli
3 types of bronchus
- Primary
- Secondary
- Tertiary
Which type of airway has cartilage?
Bronchus
4 types of bronchioles
- Primary
- Secondary
- Tertiary (terminal)
- Respiratory
4 layers in upper airway
- Mucosa
- Submucosa
- Adventitia
- Serosa
3 layers of mucosa
- Epithelium
- Lamina propria
- Muscularis mucosa (+/-)
What is the CT component of the lining of a mucosal organ?
Lamina propria
What is muscularis mucosa?
Thin layer of smooth m.
What is submucosa?
CT layer deep to mucosa
What is adventitia composed of?
CT
What is serosa?
Membrane lining body cavities and various organs
Serous membranes secrete?
Serous fluid
What is the serosal layer of the lung?
Visceral pleura
What is nasal vestibule?
Mucocutaneous junction (transition from skin of nose to mucosa of nasal cavity)
2 regions of nasal cavity
- Respiratory
2. Olfactory
Respiratory epithelium is what type?
Psuedostratified columnar ciliated with goblet cells
Where is respiratory epithelium found?
Nasal cavity and paranasal sinuses → extends into airway divisions
Lamina propria in respiratory mucosa
Highly vascular - functions in heat exchange
What types of glands found in lamina propria?
Serous and mucus glands
Olfactory mucosa is found where?
Patches in nasal cavity
Epithelium of olfactory mucosa
Thicker pseudostratified columnar, has Bowman’s glands instead of goblet cells
5 types of cells in olfactory mucosa
- Sustenacular cells
- Nuceli with cilia
- Basal cells
- Olfactory cells
- Neurons
Sustenacular cells
Most superficial of olfactory epithelium
Basal cells
Germinal cell layer at base of olfactory epithelium
Olfactory cels
Intraepithelial bipolar
Axons of neurons of nasal cavity become?
Cranial nerve I
Bowman’s glands are?
Serous olfactory glands
Function of Bowman’s gland secretions
Dissolve inhaled substance for detection by olfactory cells
What is vomeronasal organ?
Tubular gland in nasal cavity (located on either side of nasal septum) with both olfactory and respiratory epithelium
Vomeronasal organ functions in olfaction
Related to pheromones (ex: flehmen reaction in cats and horses)
Nasopharynx location
Part of pharynx located dorsal to soft palate
What is nasopharynx?
Large mass of lymphoid tissue associated for defense mechanism
What is larynx?
Complex cartilagenous structure lined by respiratory epithelium (and some stratified squamous epithelium)
Vocal fold is contained by?
Larynx
Stroma of lung
Mainly elastin, some collagen
Lung parenchyma is divided into?
Lobes and lobules
Major parenchyma of lung
Alveoli
Alveoli are contained in?
- Respiratory bronchioles
- Alveolar ducts
- Alveolar sacs
Visceral pleura of long consists of?
- Epithelium (mesothelium)
2. Some CT (collagens)
Layers of tubular airways (trachea and bronchi)
- Mucosa
- Submucosa
- Cartilage
- Adventitia
Trachealis m.
M. in trachea, not continuous around airway
Where is muscularis mucosa in the lung?
Bronchi → alveolar duct
Layers of bronchiole
Mucosa with thickened muscularis mucosae (submucosa is extremely thin)
Trachea bifurcates into?
Primary bronchi (supply each lung)
Rings of trachea are made of?
Hyaline cartilage
Rings of trachea open on what side?
Dorsally
How are ends of rings of trachea connected?
By trachealis m. (smooth m.)
Tracheal mucosa consists of?
Respiratory epithelium + lamina propria
Surface of trachea is covered by?
Mucus layer
Lamina propria of trachea contains?
Elastic fibers parallel to long axis of trachea
Elastic fibers of tracheal lamina propria stain?
Acidophilically
4 cell types in respiratory epithelium
- Ciliated columnar cell
- Basal (germinal) cell
- Goblet cell
- DNES
What regulates tracheal air flow?
DNES
DNES secretes?
- Polypeptides (calcitonin, bombsin, CCK)
2. Biologically active amines (serotonin)
How does DNES regulate tracheal air flow?
Secretes molecules into local blood vessels as local hormones
Type of submucosal glands in trachea
Seromucous (secrete mucin and defense peptides)
How is respiratory epithelium different in the bronchi?
- Cells shorter than in trachea
2. Fewer goblet cells
In bronchi, cartilage rings are replaced by?
Plates or plaques
Progressive changes in successive divisions of bronchi
- Mucosa and submucosa become thinner
- Cartilage plates become smaller
- Muscle layer becomes more prominent
Which is smaller, bronchi or bronchioles?
Bronchioles
Bronchiole diameter
How are bronchioles different from bronchi?
- No cartilage
- Simple epithelium (gets shorter as bronchioles get smaller)
- No goblet cells
- Smooth m. in submucosa
Changes which occur with each division of bronchioles
- Diameter decreases
- Airway wall becomes thinner
- Less glands and cilia
3 cell types in bronchioles
- Ciliated epithelial cells
- Club cells (non-ciliated)
- Neuroendocrine cells
Bronchiolar cells aka?
Non-ciliated Club cells
Mucosa of primary and secondary bronchioles
Ciliated simple columnar
Highly foldered mucosa
Mucosa of tertiary bronchiole
Partially ciliated simple columnar or cuboidal
Thinner lamina propria
1 layer of spiral smooth m.
Terminal bronchiole aka?
Tertiary bronchiole
Clara cells aka?
Club cells
Clara cell functions
- Produce surfactant
- Contain P450 enzymes to detoxify substances
- Act as stem cells
At what level does gaseous exchange begin?
Respiratory bronchiole
Difference in appearance between respiratory and tertiary bronchioles?
Respiratory bronchioles have alveoli openings
What is alveolar duct composed of?
Numerous adjacent alveoli
Alveoli epithelium
Simple squamous
Smooth muscle knobs are found at?
Tips of interalveolar septae (entrances to alveoli)
What is the main site of gaseous exchange?
Alveoli
Alveolar wall is filled with?
Capillaries
2 types of alveolar epithelial cells
- Type I pneumocyte
2. Type II pneumocyte
Type II pneumocyte
- Produces surfactant
- Contains lamellar bodies
- Stem cell
What are lamelar bodies?
Surfactant containing vesicles
Surfactant is?
Phospholipid