Lecture 1 & 2- Anatomy of the lungs Flashcards
the respiratory system develops as a
diverticulum from the pharynx
paranasal sinuses
Empty spaces around the bone.
Bones in the skull are very thin to allow the brain, eyes, sinuses to be larger (compression of the bone).
function of the nasal cavity
- Smell (olfactory epithelium)
- Induce turbulent flow (nasal conchae)
- Conditioning the air that goes to the lungs- warms and moistens
- Recover water from expired air
- Speech production (phonation)
the floor of the nasal cavity is in the ………………..plane
horizontal
How do we not inhale food all the time
The pharynx and larynx work together to ensure food and air enter the oesophagus and trachea respectively- epiglottitis of the larynx covers the trachea when swallowing
function of the pharynx
Pharynx’s coordinates swallow so we don’t aspirate
function of the larynx
Also Stops food going into the airway. The epiglottitis blocks the trachea when we swallow.
do the lungs have the same number of lobes
NOOOOO
the right lung has …… lobes
3 lobes (3 lobar bronchi)
the left lung has ………. lobes
2 lobes (2 lobar bronchi)
the upper airway is known as the
conducting airway
what is the sturcture of the treache
- horseshoe shape ring of cartilage
Would be uncomfortable to swallow if it went all the way round
list the order of the respiratory system
- nose/mouth
- trachea
- primary (main) bronchi
- secondary (lobar) bronchi
- tertiary (segmental) bronchi
- bronchioles
- terminal bronchioles
- respiratory bronchioles
- alveoli
bones of the throacic cavity
what separates the lungs
mediastinum and heart
the diaphragm separates the
abdominal and throacic cavity (although they can be thought of as a single cavity)
Movement of thorax occurs due to
the demi facet joints, supported by various ligaments
- Ribs move out laterally to increase volume of chest
- Due to
bucket handle movement
- Ribs move outwards and up
- due to
Pump handle movement
- Diaphragm contracts and flattens to
to increase volume of the thorax
flattening of the diaphragm causes
- Causes a drop in intrathoracic pressure which causes air to be drawn in
- Alveolar pressure must be lower than atmospheric pressure for air to enter the alveoli
Innervation of the diaphragm
- The phrenic (left and right) (Cervical C3 C4 C5 keeps the diaphragm alive)
- Motor and sensory (sensory to pericardium too)
- The Vagus (left and right) (Cranial 10)
the intercostal muscles are
- Less significant to ventilation (accept when exercising’s)
- External intercostal (anteroinferior direction)
- Internal “” (perpendicular to external intercostal)
- Innermost (same direction of internal)
neurovascular supply of the intercostal muscle exists between the
- the internal and innermost intercostal muscles
outline the anatomy of the neurovascualr supply to the intercostal muscles
- Major bundle below each rib
- Minor bundle above each rib
Intercostal arteries come round from the back from the aorta. Also intercostal arteries coming from the intercostal vessels –> dual blood supplies (risk of bleeding)
chest drains and major/minor bundles
- If doing a chest drain (5th intercostal) you want to avoid these bundles (esp the major)
- Therefore go above the rib (smaller bundle)- above the 6th rib to avoid the major bundle of the 5th rib
The diaphragm-……… major holes at three different levels (T8,T10, T12)
three
- vena cava
- oesophagus
- aortic hitatus
vena cava level of hole in diaphragm
T8
oesophagus level of hole in diaphragm
T10
aortic hiatus level of hole in diaphragm
T12
Accessory muscles
- Scalene
- Trapz
- SCM
- Pec major
- External intercostal
When we are out of breath we start to use our accessory muscles like the pectoral muscles
chest drain is from
from drain T5
Venous drainage of the thorax
Azygous vein does not
have an artery
- Azygos vein drains intercostal right intercostal and accessory hemiazygos drain from the left
fissures of the the right lung
2
- horizontal fissure
- oblique fissure
fissures of the the left lung
just the oblique
right vs left bronchi
Right main bronchus sits at a much straighter angle than the left main bronchus- this means- if there is an inhaled foreign body it would probably be down the right main bronchus (T4)
Media stinum
Sub divided into the superior mediastinum and the inferior mediastinum
what separates the superior emdiastinum and the inferior mediastinum
plain of Louis (T4/5)
The pleura
Serous membrane with visceral and parietal layer
in between these layers is the pleural cavity– potnetial space with a small amount of pleural fluid
parietal pleura and pain
Parietal pleura has a somatic innervation and feels pain
Visceral pleura x
Visceral pleura invests the lung and goes down into the fissures. Autonomic innervation. Does not feel pain like the parietal pleura.
where does the pleura cover
Visceral pleura invests the lung and goes down into the fissures. Autonomic innervation. Does not feel pain like the parietal pleura.
blood supply of the lungs
Dual blood supply
- Bronchial artery (branch of the aorta)
- Bronchial vein
- Pulmonary artery
- Pulmonary vein
surface anatomy of the respiratory system
- Dome of the diaphragm extends up to the 4th intercostal space
- Left extends lower to the 5th intercostal at its peak due to the liver
