Al Ghoul Histo Of Respiratory Flashcards
Three functions of the respiratory system
- Gas Exchange- O2/CO2, pH regulation, excreion
- Phonation
- Olfacation
What are the two main divisions of the respiratory system and their functions?
- Airway AKA conducting portion- move air in and out of terminal structures
- Respiratory Portion- gas exchange
What the structures in the conducting portion?
The respiratory Portion?
Conducting- nasal cavity, pharynx, larynx, trachea, bronchi, bronchioles
Respiratory portion- respiratory bronchioles, alveolar ducts, alveolar sacs
What makes bronchioles distinct from the other structures in the conducting portion?
It is the only one that lacks cartilage which is the structure that helps keep airways open.
What are the three regions of the nasal cavity, function, and what lines them?
- Vestibule lined with skin
- Respiratory region (AKA Conchae)- lined with respiratory mucous- this warm, filters and moistens the air
- Olfactory region- lined with olfactory mucosa and for a sense of smell
Identify the type of respiratory epithelium?
Pseudostratified ciliated columnar epithelium
function of Ciliated cells? Where are they most present?
Ciliated cells move mucous over the epithelium.
Most abundant in the respiratory and become very sparse in the bronchioles
Function of goblet cells? Where are they very abundant?
Goblet cells produce and secrete mucous. Very abundant in the nasal cavity
Function of Brush cells?
Where are they sparse?
Have blunt mircrovilli with afferent nerve fibers for stimulation of the mucosa,
Sparse in trachea and bronchi.
Function of granule cells?
Which way do they secrete?
Enteroendocrine cells- release things into local environment to affect near by area
Secrete across the basal lamina into the CT space and usually affects local area.
Function of the lamina propria in the respiratory region?
It’s a vascular network to warm and moisten inspired air
Cell types in the respiratory region and trachea and bronchi (5)
- Ciliated
- Goblet
- Brush
- Granule
- Basal- stem cells
Identify epithelium of olfactory region
Specialized psuedostratified ciliated columnar
Cell types in the olfactory region
- olfactory receptor cells
- Sustentacular cells (supporting cells)
- Brush
- Basal- stem cells
Structure and functions of Lamina propria of olfactory?
- Olfactory glands- serous secretions that function as solvent to clear mucous of bad smells
- Olfactory nerves
- Vasculature
What does the pharynx connect? And what are its two components?
Connects the nasal/oral cavity to the larynx and esophagus
- Nasopharynx- connects to middle ear via eustacian tubes, pharyngeal tonsils
- Oropharnyx- palatine tonsils (these are the ones we see that we call tonsils)
What does the larynx connect? Function?
Connects the oropharynx to the trachea
Function- phonation
4 layers of the traches
- Mucosa (comprised of epithelial lining and lamina propria)
- Sub mucous- glands, nerves, blood vessels
- Cartilage layer- HYALINE C-shaped cartilage with trachealis smooth muscle
- Adventitia- CT, blood vessels, nerves
Major difference between trachea and bronchi?
Trachea has C-shaped cartilage while bronchi has discontinuous cartilage
Cells of Bronchioles
- Ciliated (very sparse)
- Goblet
- Clara
- Granule
- Basal- stem cells
Layers of bronchioles
- Mucous- almost cubodial b/c epithelium gets smaller
- Smooth Muscle
- Adventitia- CT, blood vessels, and nerves
Function of clara cells
Secrete surfacant like material to keep the bronchioles open
Discuss what cells become more and which ones become less abudant as you go down respiratory structures
More- Smooth muscle and clara cells
Less- Cilia and cartilage
Possible reasons for an airway to be expanded/something filling it?
- Foreign Object
- Mucous (COPD)
- Fibrosis
- Tumor
Function of mucous (2)
What secretes mucous?
- secreted from goblet***
1. Protect and moisten airways
2. Traps inhaled particles and pathogens
- secreted from goblet***
Has anti-inflammatory and anti-bacterial compounds and mucin proteins
When do goblet cells make mucous?
Constitutively and upon stimulation (sensory input) from CNS
3 ways that mucus production can do wrong due to inflammation
2 genetic ways that lead to mucous in airways
the inflammation cause increase in T-lymphocytes and an increase in interleukin which can
- Hyperplasia of goblet cells
- Hyper-production of mucous
- loss of cilia function
Genetic
- Cystic fibrous
- Primary cilia dyskinesia
What happens in primary cilia dyskinesia?
Congenital disease where both dynein arms are missing
The cilia beat is compromised and the mucous is stasis (inactive)
What happens in cystic firbosis
Cells neighboring the goblet cells have dysfunction in Chloride channel. So the mucous has an increase in viscosity and less clearance and MUCUS STASIS occurs
Causes of Asthma
- Increase in smooth muscle thickness/SM hyperplasia - looks like big bundles rather than lining decreasing the diameter of bronchioles (through mast cells and eosinophils)- this contracts during attack and since their isn’t cartilage airway can’t be opened back up
- Increased mucus secretion through CNS
- Chronic inflammation due to mast cells
How mast and eosinphil affects?
Mast stimulate eosonphils–> stimulate Smooth muscle hypertrophy–> stmulate CNS to increase mucous production
Eosinophils also responsible for major basic proteins that are responsible for epithelial damage
Structures involved in has exchange
- Respiratory bronchioles
- Alveolar Ducts
- Alveolar Sacs
- Capillary
Distinguishing component of respiratory bronchioles
It has elements of both the conducting and exchange system. Must contain at least one alveolus
What are alvolar sacs?
A cluster of alveoli
two components of gas exchange? What lines them? Discuss distuburtion of lining of alveoli
Capillaries (blood) and alveoli/alveolar ducts (air)
Alveolar lined by
1. Type 1 Pnuemocyte make up ~8% of cells but line 95% of SA
2. Type II Pnuemocyte- make up 16% of cells but only line 5% of SA
3. Only contains pulmonary macrophages AKA Dust cells
Capillaries lined by
1. Endothelial cells
2. Very thin CT interstitial layer b/w basal and surface
Distribution and function (2) of Type I pneumocytes?
8% of total cells but line 95% of alveolar ducts SA
- Look for flattened nuclei-squamous cells*
1. Critical for gas exchange
2. Use energy dependent membrance associated pump for transport and normal removal of vascular fluids/exudates (preventing accumulation in alveolar)
Distribution of Pneumocytes Type II?
Identifying factors?
Functions (2)
16% of total cell but only cover 5% of total SA.
Identify by roundness in LM and by lamellar bodies in EM
Functions
- Secrete surfactant(choline derived phospholipids) due to the lamellar bodies which reduces surface tension and prevents alveolar space from collapsing
- Stem Cell to Type 1
Function of alveolar macrophages AKA dust
% of total cells?
Which way to they migrate?
Scavenge particulate matter, virus, bacteria
10% of total cells?
Normally migrate up the brconhiol system or can leave into interstial space and form black deposits in the septae
What causes alveolar walls to collapse thus causing large open spaces?
Cigratte smoke, foreign particle, allergens cause recruitment of macrophages and leukocytes stimulate eosinophils which stimulate proteases, elastase sectrion which break down the CT fibers and expand alveolar walls and they end up with minimal elasticity
What happens in emphysema?
Why is this different from asthma?
Loss of gas exchange
IN asthma there is a blockage of airway
What happens after the alveolar rearrangment?
The walls are opened and there is a tissue repair response so excess CT fibers and there is firbrosis of the the remaining walls
