Anatomy of Thorax Flashcards
Sternal Angle
T4/5
Spinal nerve posterior rami
Supply skin + muscles posterior to vertebral column
Spinal nerve anterior rami
Intercostal nerves innervating the intercostal muscles and the skin that overlies them
Pectoralis Major Action
Flexion, medial rotation + adduction of arm
Aids inspiration- accessory muscle
Pec Major Innervation
Pectoral nerves (C5-T1) from brachial plexus
Pectoralis Minor Action
Helps elevate rib cage
Inspiration
Pec Minor place
Coming from Coracoid Process superiorly down to the 3/4/5th rib
Pec minor innervation
Pectoral nerves (C5-T1) from brachial plexus
Sternocleidomastoid place
From mastoid process superiorly
Attaches to sternum and clavicle
Sternocleidomastoid action
Elevates chest
Inspiration
Sternocleidomastoid innervation
Spinal Accessory Nerve XI
Serratus anterior placement
Underside of scapula
Wraps around chest to insert onto ribs
Makes up medial wall of axilla
Serratus anterior innervation
Long thoracic (C5-C7) superficial to the muscle
Long thoracic damage
Scapular winging
Rectus abdominis placement
Attaches to costal margin
Runs down front of abdomen
Attaches to pubic symphysis
Recuts abdominis action
Pulls down ribcage
Aids forced expiration
Rectus abdominis innervation
Intercostal and subcostal nerves T7-T12
External intercostal muscles
Hands in pockets
Pulls ribcage up and out
Elevates rib cage –> inspiration
Internal intercostal muscles
Hands on shoulders
Depressing ribcage –> expiration
Innermost intercostal muscles
Hands on shoulders
Depressing ribcage –> expiration
Muscles of respiration innervation
T2-11
Neurovascular bundle
Between internal and innermost intercostals in costal groove
Intercostal nerves innervation
Anterior rami of thoracic spinal nerves
Thoracocentesis
Sample pleural fluid- in costophrenic recess
9th intercostal space in mid-axillary line
Superior to rib
Thoracocentesis risk
Lacerate liver
Pneumothorax
Haemothorax
Chest Drain
Case of pneumothorax
5th intercostal space in mid-axillary line
Axilla Safe triangle
Apex below axilla
Anterior border of Lat. Dorsi
Lateral border of pec. Major
nipple level
Diaphragm
Phrenic nerve- C3,4,5
Medial part is tendinous
Peripheral part is muscular
IVC passes through diaphragm
T8
Oesophagus passes through diaphragm
T10
Aortic hiatus passes through diaphragm
T12
Visceral pleura innervation
Sympathetic nerves
Same as lung tissue
Parietal pleura innervation- laterally
Intercostal nerves T2-12
Parietal pleura innervation- mediastinal surface
Phrenic nerve- C3,4,5
Parietal pleura innervation- diaphragmatic surface
Intercostal nerves and phrenic
Lung tumour
Visceral pleura- no pain
Parietal pleura- lots of pain
Blunted costophrenic angle
Fluid in lungs
Inferior border of lungs
Mid clavicular- 6th rib
Mid axillary- 8th rib
Posteriorly- 10th rib
Inferior border of pleura
Mid clavicular- 8th rib
Mid axillary- 10th rib
Posteriorly- 12th rib
Left Lung
2 lobes
Superior + inferior
Divided by oblique fissure
Right lung
3 lobes
Superior, middle and inferior
Superior + middle- horizontal fissure
Middle + inferior - oblique fissure
Medial surface of lungs
Pulmonary arteries always higher than pulmonary veins
Traches bifurcation
Carina
T4
Lobar Bronchi
Left- 2
Right- 3
Airway sequence
Trachea Main bronchus Lobar bronchus Segmental bronchi Conducting bronchioles Terminal bronchioles Respiratory bronchioles Alveolar ducts Alveolar sacs
Hyper-expansion
Lungs have become hyper-expanded and compress the diaphragm
More ribs in lung field
Emphysema
One of commonest reasons for hyper-expansion
Destruction of alveolar walls
Loss of elastic tissue so less recoil of lungs
Emphysema hyper-expansion
Less elastic recoil
Alveoli collapse + air trapped in them
Air trapped –> hyper-expansion –> compressed diaphragm
Superior mediastinum location
Above angle of louis
superior mediastinum content
Thymus Great vessels Oesophagus Trachea Phrenic nerves Vagus nerves Recurrent laryngeal nerves Thoracic duct
inferior mediastinum location
below level of sternal angle
Inferior mediastinum content
Anterior- everything anterior to heart
Middle- heart + pericardium
Posterior- posterior to heart
Left recurrent laryngeal
Branch of left vagus
Loops under aortic arch + travels up to larynx
Right recurrent laryngeal
Branch of right vagus
Loop under right subclavian artery and runs back up to larynx
Recurrent laryngeal
Innervate intrinsic muscles that move vocal cords
Damage to 1- hoarse voice
Damage to voice- can’t speak
Posterior mediastinum
4 birds (3 goose + 1 duck) Azygos Vagus Oesophagus Thoracic Duct
Sympathetic Trunk
T1-L2
Fight or flight response
Runs either side of posterior mediastinum
Head and neck
cervical ganglion/stellate ganglion
Above T1 and below L2
Sympathetic innervation
