Anatomy of breathing 1 Flashcards
Upper respiratory tract?
Nasal cavities
Oral cavity
Pharynx
Larynx
Lower respiratory tract aka ?
The respiratory tree
What does LRT consist of?
Trachea R & L main bronchus Lobar bronchi Segmental bronchi Bronchioles Alveoli
What happens at level C6 of vertebra?
Larynx becomes trachea
Pharynx becomes oesophagus
Bifurcation of trachea?
Division into 2 main bronchi
Lobar bronchi?
One lobar bronchi for each of 5 lung lobes
Segmental bronchi?
One for each of the 10 bronchopulmonary segments
Bronchopulmonary segments?
Area of lung lobe that each of segmental bronchi supply with air
10 per lung
Order of bronchi?
Main bronchi –> Lobar bronchi –> Segmental bronchi
What do each lung lobe and bronchopulmonary segment have?
Own air supply (bronchus)
Blood supply
Lymphatic drainage
Nerve supply
Lining of inside of bronchial tree?
Respiratory epithelium -
Pseudostratified columnar ciliated epithelium
Pseudostratified?
Tissues formed by a single layer of cells that give the appearance of being made from multiple layers
Where does this respiratory lining not line in the bronchial tree?
Distal bronchioles & alveoli
Mucociliary escalator?
Mucuous glands secrete mucous onto epithelial surface
Cilia beat to sweep mucous (+ foreign bodies stuck in mucous) superiorly towards pharynx –> swallowed
Hyaline cartilage function?
Supports walls of trachea and all of the bronchi which maintains patency of airways (holds them open)
What happens to the amount of cartilage as you move distally in the respiratory tree?
Gradually reduces
Is there cartilage in the most distal bronchioles and alveoli walls?
NO as this would impact on diffusion
What happens to the amount of smooth muscle as you move distally in the airways?
Smooth muscle in walls of airways becomes more prominent
Most prominent feature of bronchiole walls?
Smooth muscle
Bronchioles can therefore constrict and dilate
Main requirements for adequate diffusion at alveolar wall? (5)
1 - Sufficient functioning lung tissue
2 - Sufficient O2 in air we breathe in
3 - No CO2 in air we breathe in
4 - Minimal thickness of walls of alveoli to facilitate gaseous diffusion
5 - Minimal tissue fluid in tissue spaces around alveolar capillaries
Main dangers to air moving freely through the URT and LRT?
Resp tract may become narrowed:
- Bronchioles constrict
- Swelling of mucosa lining resp tree & overproduction of mucus
- Growing tumour may externally compress
Foreign bodies being inhaled
- May stop breathing
How do we keep URT patent?
2 nasal cavities separated by nasal septum
Larynx consists of several cartilages which help maintain patency
Describe the nasal septum
Bony posterior part - ethmoid bone (superiorly) & vomer (inferiorly)
Cartilaginous part anterior
Larynx/ voice box consists of which cartilages?
Epiglottis
Thyroid cartilage
Cricoid cartilage
2 arytenoid cartilages
Functions of larynx?
- Cartilages help to maintain the patency of the URT
- Helps to prevent the entry of foreign bodies into the LRT (the vocal cords)
- Produces sound (the vocal cords)
What is the inferior continuation of the larynx?
Trachea
Narrowest part of larynx?
Rima glottidis
Airway protection - vocal chords?
- Vocal cords can approximate in midline, closing rima glottidis & preventing foreign body being inhaled into trachea
- Cough reflex then stimulated to expel foreign body via pharynx & oral cavity
Vocal ligaments & voice production?
- Phonation (producing sound) - expire air across vocal cords & cords vibrate to produce sound
- Articulation ( producing speech) - sound modified in nose, mouth
Describe how the air breathed in is normally warmed, humidified & “cleaned”
Conchae & respiratory mucosa
How do the conchae contribute to the air being warmed, humidified & cleaned?
Conchae
- Inc SA of lateral walls of nasal cavities
- Produce turbulent blood flow - brings air into contact with walls
How does resp mucosa contribute to the air being warmed, humidified & cleaned?
Good arterial blood supply - warmth
Produces mucous providing moisture - humidify
Sticky mucous traps infected particles - cleaned
Cilia waft mucous to pharynx to be swallowed into gastric acid
What else contributes to the cleaning process?
Tonsils located in mucosa lining pharynx
Anatomy of thoracic skeleton?
- 12 pairs of ribs
- Intercostal spaces
- Costal margin
- 12 thoracic vertebrae
- Clavicle & scapula
- Sternum
True ribs?
Ribs 1-7
Attach via their costal cartilage to sternum
False ribs?
Ribs 8-10
Attach via the costal cartilage above to the sternum
Floating ribs?
Ribs 11 & 12
No attachment to sternum
What does the sternum consist of?
Manubrium
Body
Xiphoid process
Sternal angle
Joints of thoracic skeleton?
Sternocostal joins - synovial
Costochondrial joints
Costovertebral joints
—> Limited movement
Costal margins?
Lower edge of the chest (thorax) formed by the bottom edge of the rib cage
Where do layers of intercostal muscles attach?
Between adjacent ribs
How do intercostal muscles make chest wall expand?
By pulling adjacent ribs upwards and outwards
