L1 Intro Flashcards
Trachea Anatomy
10cm long
Larynx –> T4/5
C-shaped cartilage ring- keeps airway open as is only entry point for air
Trachealis- a) cough reflex, narrow airway to change pressures b) flexibility for bolus of food in posterior oesophagus
Trachea Histological appearance
Lumen: Respiratory epithelium (pseudo. col. epi. + goblet cells + basal cells)
Glands
Smooth muscle (not that much as not much effect on control of flow in that airway)
Cartilage
Trachea Function
Large open tube
-Conducting zone
Bronchus Anatomy
15 Generations of branching Cartilage plates: keep airway from collapsing Glands Non-continuous Smooth muscle Respiratory EPtihelium
Bronchus Histological appearance
Large Bronchi: Respiratory epi
Smaller Bronchi: Transition to columnar ciliated + goblet
Bronchus Function
- need to keep airways open in segmental + lobar bronchi
1) Conditioning
2) Branching
3) Transition (towards blood air barrier in alveoli)
Bronchiole Anatomy
1mm diameter (narrower + simpler) Last Bronchiole of C.Z.= Terminal Bronchiole
Bronchiole Histological Appearance
cuboidal ciliated epithelium
club cells
Smooth Muscle
-No Glands, cartilage or Goblet cells (not needed, airways so small that can control lumen size via smooth muscle only)
Bronchiole function
Smooth Muscle (contraction/relaxation) Controls flow into alveoli
Journey that air takes
Nasal cavity –> Pharynx –> Larynx –> trachea –> Bronchi –> Bronchioles –> Alveoli
- Protected by thorax/thoracic cage
- Left lung smaller due to heart
- massive surface area/very compact
Bronchial Tree
Trachea
- -> Primary/Main Left and Right Bronchus
- -> Lobar Bronchus
- -> Segmental Bronchus
- -> Terminal Bronchiole
- -> Respiratory Bronchioles
- -> Alveolar duct
- -> Alveolar sacs
- -> Alveoli
Functions of Respiratory System
- Protection against unsterile air
- Sound production (as air goes through larynx)
- Partial role in Blood Volume and pH control
Upper Respiratory Tract
Nasal Vestibule
Nasal Cavity
Pharynx
Lower Respiraotry Tract
Larynx
—>
Alveoli
Upper and Lower Respiratory Tract division
Anatomical divisions
clinical relevance re treatment
1) Upper R.T. Infection: infection isnt too dangerous. cold/pharyngitis. dont need aggressive antibiotics. fast resolving.
2) Lower R. T. I.
-less ability to defend against pathogens
- pneumonia/bronchitis
-dont resolve/fever/wheeze
Ear infection
eustachian tube
- excessive fluid draining into ears
- common in children
Functional divisions
- Conducting zone (Nasal cavity –> terminal bronchioles)
- NO gas exchange
- More complex: preparation for gas exchange - Respiratory Zone (Resp. Bronchiole –> Alveoli)
- Gas exchange
- greater SA
- rich capillary network
- last defense
Pseudostratified columnar ciliated epithelium
Location: Nasal cavity –> Bronchi
Function:
1) Ciliated: Mucociliary escalatory. motile cilia, beating and catching particles in carpet of mucus. move to back of throat to spit out
2) Protective: Tall cell for thick layer
Goblet cells
Location: Nasal cavity –> Bronchi
Function:
1) Mucus production: Acute (for infection/noxious substance/hayfever/smoking)
-stimulate quite response
Basal cells
Location: Base of BM basement Membrane Function: 1) Stem cell population -differentiate into Goblet cells and Pseudostratified Columnar Ciliated Epi. -sit on bottom
Brush cells
Location:
Function:
1) Sensory cells (produce nervous response upon insult)
Small Granule Cells
Location:
Function:
1) Endocrine cells (release e.g histamine. in response to toxin)
Club cells
a.k.a. Clara cells Location: Bronchioles Function: -Cuboidal. Non ciliated 1) secrete watery substance a) hydration b) antimicrobial secretions
Type 1 Pneumocytes
Location: Alveoli
Function:
-squamous (super skinny) - Flat and Thin Blood-Air Barrier/membrane
1) Increase SA in alveoli
Type II Pneumocytes
Location: Alveoli
Function:
1) secrete surfactant - reduce surface tension in alveoli
Macrophages
Location: Alveoli
Function:
a) Defence - wandering (in airspace) (anything that hasnt been filtered in conducting zone)
-impaired mucociliary clearance (chronic infection/smoker/condition)= greater chance of getting pathogens into resp zone = increased macrophage number
Four CT/Parenchyma
- Cartilage
- Elastic Fibres
- Collaged
- Smooth Muscle
Cartilage
Location: Trachea & Bronchi -larger areas, keep open for tubes with great tendency to collapse Function: 1) keep airways open/patent Disease: -not really effected with age -only a lil calcification (arthritis)
Elastic Fibres
Location: All way through Resp, Tract Function: 1) provides elasticity "compliance" -important with age Disease: - Emphysema -COPD/smokers
Collagen
Location: Lamina Propria + Interalveolar septa (walls b/w alveoli)
-all way down in various components
Function:
1) Provide tension (stops over inflation/expansion)
Disease:
-Fibrosis (interstitial lung disease. increased collagen = increased stiffness= harder to breath)
Smooth Muscle
Location: Wall of Airways –> until alveolar ducts
Function:
1) bronchiole function. Controls Tone/Flow in airways
-control diameter via constricting/relaxing
Disease:
Asthma
Mucus
Function: keeps airways hyrdated
Sources:
1. Goblet cells (acute)
2. Seromucous glands (in submucosa/ under epithelial layer). Combination of a) sticky thick mucus (muco polysaccharides) b) watery hydration
Relationship:
-Biphasic to help cilia move
-Lower cilia beat upwards towards pharynx. Upper cilia beat down towards pahrynx. move re pressures.
Layers:
1) Top: Thick mucus capturing particles
2) Under: Watery Sol layer. Cilia able to move
Cystic fibrosis
Thick top mucus layer
- salt balance off
- cilia have difficulty beating as no watery sol layer
Cant clear mucus
- productive cough
- wheeze
- mucociliary escalatory impairment
Cilia beating
Synchronised
Not all beating at same time- Domino effect
-very fast
-Goblet cells are NON-ciliated
Primary Cilia Dyskinesia
3 Tertiary
–> evolves into Cartagenal syndrome
-Tiny hooks in health people, dianine motor proteins, which are important for beating
a) People with Primary Cilia Dyskinesia have congenital defects in dianine proteins production
-immotile/dysfunctional cilia
-beat a little bit/ but in a disorganised fashion/ not full whip-like motion/pattern
-imparied muco ciliary clearance = sinus and lung infections
Note: smoking paralyses cilia = impaired mucociliary clearance= chronic lung infection susceptibility
b) genetic defect so motile cilia in:
i) hearing loss
ii) fertility problems (sperm motile flagella)
iii) brain (swelling and headaches)
Syndrome: multiple pathologies
Heterotaxy/citi-invertus
=in developmental node when body pattern is being decided (asymetrical)
=cilia beating to move morphogen/growth chemical towards left (heart forms)
=Loss of left right symmetry in embryo with this genetic defect.
Perfectly healthy but organs disorganised/different sides.
=require careful monitoring
Nasal brushings
1) Get Cilia samplings
scrape epithelium off
-cant do to children
b) Sacarin tablet inside vestibule layer. Time how long it takes to taste sweet sacrin flavour
-healthy= 3min (mucociliary escalator beating)
-unhealthy= 10 min +
Course diagnosis b4 course diagnosis
Heterotaxy/citi-invertus
Heterotaxy/citi-invertus
=in developmental node when body pattern is being decided (asymetrical)
=cilia beating to move morphogen/growth chemical towards left (heart forms)
=Loss of left right symmetry in embryo with this genetic defect.
Perfectly healthy but organs disorganised/different sides.
=require careful monitoring
Sinisitus
Chronic inflammation of the nasal cavity
-Rhinosinisitis
-constant stream of mucus
-hard to know source when have this chronic infection which cannot be treated
-end up changing composition of epithelium
-hyper proliferation/plasia of airway
-50% goblet cells
=chronic facial pain and whole of sinuses fill up with mucus
-constantly blowing nose –> epithelium becomes squamous/inability to defend/reoccuring cycle of infection
-swallowing mucus to get sore tummy
Cure:
-snip chonci bones, reduce SA producing the mucus
Air Preparation for gas exchange
- Filtration: remove pathogens
- Warmed: 20->37 degrees
- Humidify: saturated with water for efficient gas exchange
Nasal cavity
- Nares/Nostrils have Vibrissae (course hairs)
- beginning of filtration - Lined with Respiratory epithelium (pseudostratified epi + goblet) - layer of mucus
- Conchae = Turbanent bones (Superior, Middle + Inferior (largest)) boney projections) -covered in Resp Epi- Swirling
a) slow air down (swirled) (water hitting rocks)
b) throws big particles onto mucus layer
c) Humidity (watery serous secretions/ + goblet cell mucous layers)
d) increased SA (for all functions)
4) Rich capillary network
- underneath cell layer
- counter current -Heating start warming
5) Pharynx Laminar flow
Nasal Cycle
One side of nose choncae will engorge blood and narrow
- varies every 90 min in mammals
- helps to give one side a break, recover, regenerate, hydrate. patent
- Patent
- CPAP Continuous Positive Air Pressure (dont have good compliance, not good nasal cycle, pushing air at same rate through both sides
