Anatomy Flashcards
At what level does the the upper respiratory tract become the lower respiratory tract?
C6 at the lower border of the larynx
True or False: During development, growing lung buds grow inside the pleural cavity
False, they grow into but not inside the pleural cavity
What are the 2 layers of the pleura?
1) Parietal pleura - adherent to the structures of the mediastinum and the internal aspects of the chest wall 2) Visceral pleura - adherent to the developing lung bud
How many lobes does the right and left lung have?
Right: 3 (superior, middle & inferior)
Left: 2 (superior & inferior)
At what level is the horizontal fissure (right lung only)?
Rib 4
At what level are the oblique fissures (both lungs)?
Rib 6
How many bronchopulmonary segements does each lung have, and what is each served by?
10 bronchopulmonary segments each served by their own segmental bronchi
Which rib attaches at the sternal angle, and what else is found at this level?
Second rib. Aortic arch and pulmonary bifurcation are also found here
How many pairs of ribs are there?
12
Which riba are the true ribs?
1-7
Which ribs are the false ribs?
8-10
Which ribs are the floating ribs?
11 & 12
How do ribs articulate with the sternum?
- Head of the rib: articulates with the body of the vertebra of the same number & the body of the vertebra superiorly)
- Rib Tubercle: articulates with the transverse process of the vertebra of the same number
Costal groove
Groove found inferiorly on deep surface of the ribs for the intercostal NVB
What are the 3 joints of breathing?
1) Costovertebral joins: rib to vertebrae
2) Costochondral joints: rib to costal cartilages
3) Sternocostal joints: sternum to costal cartilage
What are the 3 layers of muscles between the ribs and within the intercosta spaces?
- external intercostal muscles
- these muscle fibres are at the angle as if putting hands in pockets
- internal intercostal muscles
- innermost intercostal muscles
- Both of these are at right angles
How many intercostal spaces are there?
11
What is the arterial supply and venous drainage of the anterior and posterior parts of the intercostal spaces?
- Anterior parts:
- Internal thoracic artery and veins
- Course vertically either side of the deep surface of the sternum
- These give off the bilateral anterior intercostal arteries which supply the chest wall
- Posterior parts:
- Posterior intercostal arteries branching from the thoracic aorta
- Azygous vein
What is the nerve supply to the intercostal spaces?
Intercostal nerves give sensory, motor and sympathetic supply. They arise from the anterior ramus of that level eg. T1-11
The diaphragm has holes to permit the travel of which structures through it?
- Oesophagal opening (T10 level): Transmits the oesophagus, vagus nerves, and oesophageal branches of the left gastric vessels.
- Aortic opening (T12 level): Transmits the aorta, thoracic duct (a large lymphatic vessel) and azygous vein.
- Caval opening (T8 level): Transmits the inferior vena cava.
What is unusual about the tendon of the diaphragm?
It is a central tendon
Which dome of the diaphragm is more superior?
The right, due to the presence of the liver
What is the nerve supply of the diaphragm?
phrenic nerve (C3,4 & 5 anterior rami)
“C3,4,5 keeps the diaphragm alive”
Where does the muscular part of the diaphragm articulate?
- the sternum
- the lower 6 ribs & costal cartilages
- L1-L3 vertebral bodies
What is the pathway of the phrenic nerve?
- Formed in the cerival plexus from anterior rami of C3, 4 and 5
- Found in the neck on the anterior surface of scalenus anterior
- In the chest it descends over the lateral aspect of the fibrous pericardium
- Supplies somatic sensory and sympathetic axons to the diaphragm & fibrous pericardium
- Supplies somatic motor axons to the diaphragm, to each respective half
What are the mechanical steps of inspiration?
- The diaphragm contracts and descends, increasing the chest cavity vertically
- the intercostal muscles contract, elevating the ribs and pulling the ribs laterally/anteriorly, increasing the A-P and lateral chest cavity dimensions
- The chest walls pull the lungs outwards with them due to: surface tension between the parietal and visceral pleurae created by the pleural fluid
- The lungs expand: lung P1V1 = lung P2V2
- Air flows into the lungs down a pressure gradient (between atmosphere & lungs)
What are the mechanical steps of expiration?
- The diaphragm relaxes and ascends, decreasing the vertical chest cavity dimension
- The intercostal muscles relax, returning the ribs to the resting position, decreasing the A-P and lateral chest cavity dimensions
- The chest walls return to the resting position, relaxing the stretch on the lungs
- Surface tension decrease and the lungs are permitted to elastically recoil
- The lunhs defalte: lung P1V1 = lung P2V2
- Air flows out of the lungs down a pressure gradient (between lungs and atmosphere)
What are the 4 quadrants of the breast?
- Superolateral
- Superomedial
- Inferolateral
- Inferomedial
What are the main components of the exterior breast?
- Areola
- Nipple
- Axillary tail
What is the arterial supply and venous drainage of the breast?
Subclavian > internal thoracic artery and vein
What is the lymphatic drainage of the breast?
- 2 lateral quadrants drain towards the axillary nodes –unilateral drainage
- While the medial quadrants drain towards the sternum (parasternal nodes)
- They drain to both the ipsilateral and contralateral nodes of the sternum
- And so are referred to as bilateral drainage
Winged scapula
If the long thoracic nerve if parylysed or compressed, then the serratus anterior is no longer anchoring the scapula onto the posterior wall so it starts to ‘float’
What stimulates coughing?
Occurs with stimulation of sensory receptors in:
- oropharyngeal mucosa
- laryngopharyngeal mucosa
- laryngeal mucosa
- mucosa of LRT
Which nerves transmit the stimulation signals of coughing to the medulla?
glossopharyngeal (CNIX) or vagus (X)
Carotid sheath
- A protective “tube” of cervical (neck) deep fascia
- Attaches superiorly to the bones of the base of the skull
- Blends inferiorly with the fascia of the mediastinum
- It contains:
- the vagus nerve
- the internal carotid artery
- the common carotid artery
- the internal jugular vein