Respiratory Anatomy Flashcards
Features of thoracic vertebrae
Heart shaped body
Round vertebral foramen
Long, downward facing spinous process
Articulations of thoracic vertebrae
Transverse costal facet - tubercle of rib
Superior costal facet - head of rib
Inferior costal facet - top of head of the rib below
Costal groove (on rib) - intercostal vein, artery and nerve VAN
Atypical ribs
T1,2,11 and 12
1st rib
Short, wide
Only one facet on head for articulation (no thoracic vertebrae above)
Superior surface is lumpy - has two grooves for subclavian vein and artery
2nd rib
Longer and thinner than 1st rib
Roughened area on superior surface where serratus anterior attaches
11th and 12th ribs
No neck (like less curved typical ribs) Only one facet for articulation with corresponding vertebrae
Vagus and phrenic in thoracic inlet
Vagus more medial, by trachea
Phrenic next to, but more lateral
(2 of each)
Intervertebral joints
Secondary cartilaginous
Between vertebral bodies and intervertebral discs
Costovertebral joints
Synovial plane
Head of rib to SCF and ICF
Costotransverse joints
Synovial plane
Tubercle of rib to transverse process
Costochondral joints
Primary cartilaginous
Costal cartilage to sternal end of rib
Interchondral joints
Synovial plane
Between costal cartilages of 6-9th ribs
Sternocostal joints
1st - primary cartilagenous - costal cartilage to manubrium
2nd-7th - synovial plane - costal cartilage to sternum
Sternoclavicular joints
Synovial saddle
Clavicle to manubrium of sternum and 1st costal cartilage
Manubriosternal joints
Secondary cartilaginous
Manubrium to body of sternum
Xiphisternal joint
Primary cartilaginous
Xiphoid process to body of sternum
Vessels of thoracic wall
Aorta, posterior intercostal artery arises from here
Continues to front (lateral cutaneous branches off) to become anterior intercostal artery to join upward chain internal thoracic artery
VAN order (veins at top)
Nerves of thoracic wall
Innermost, internal then external intercostal nerves
Sympathetic trunk
Lies to right of aorta
Runs with azygous vein
(Thoracic duct to left, with hemiazygous vein)
Shingles
Caused by human herpes virus-3 (HHV-3)
Primary infection in childhood -> chickenpox
Then virus lies dormant in dorsal root ganglia of sensory nervous system
Then will flare up in single dermatome segment, usually on chest wall
Primary muscle of respiration
Diaphragm External intercostal (hands in pockets) Internal intercostal (opposite) Innermost intercostal (all directions, cross multiple rib spaces)
Accessory muscles of repiration
Sternocleidomastoid Anterior, middle and posterior scalenes Pectoralis major and minor Erector spinae Quadratus lumborum Latissimus dorsi Trapezius
- only if respiratory requirements increased, normal breathing just diaphragm
Surface anatomy of lungs
Apex 2cm above clavicle
Lower margin 2 ribs above pleural limit - 6th rib in midclavicular line, 8th in midaxillary, 10th at angle of ribs (back)
Oblique and horizontal fissures, surface anatomy
Oblique from spine of T4 to 6th rib in midclavicular line
Horizontal (only right) from 5th rib in midaxillary line to 4th costal cartilage at sternum
Surface anatomy of pleura, lower margin
Extend down to 8th rib in midclavicular line, 10th in midaxillary, 12th at angle of ribs
Structures passing through diaphragm at T8
Inferior vena cava (8) and phrenic nerves
- tendinous, or IVC would be compressed
Structures passing through diaphragm at T10
Oesophagus (10) and vagus, and oesophageal branch of left gastric vessels
- muscular, as helps peristalsis and stops reflux as aperture acts as sphincter
Structures passing through diaphragm at T12
Aorta and splanchnic nerves, and thoracic duct, azygous and hemiazygous veins
- behind diaphragm, or would be compressed through muscle
Diaphragmatic hernias
CONGENITAL
- when diaphragm not formed properly
- usually posterolateral, sometimes anterior
HIATUS
- acquired hernia, when oesophagus goes above diaphragm, rolls or slides
- acid reflux symptoms
- caused by excess strain on diaphragm or weakness
Pleural effusion - procedure
Pleural tap / chest drain to remove liquid
To prevent recurrence, can use a chemical powder to stick pleura together, prevent fluid build up
Pleura and innervation
Mesothelial membranes that line thoracic cavity and enclose pleural space (potential only)
Contain small amount of pleural fluid, to lubricate lung movements in breathing
PARIETAL
Costal - intercostal nerve
Diaphragmatic - phrenic nerve
Mediastinal - phrenic nerve
VISCERAL - vagus nerve
Mesothelioma
Thickened, pale, cream coloured pleura all around lung and into fissures - tumorous
Nearly always from past asbestos history (can be 40 years +)
Asbestos not broken down in body so WBCs accumulate
-> breathlessness as pleura constricts lung
Decompression of tension pneumothorax
One way valve is created, increase intra-thoracic pressure and organs shift away - can be fatal
1) Needle to 2nd intercostal space in midclavicular line - hear hiss
2) Chest drain to 5th intercostal space in midaxillary line
MUST be along superior border of rib, as neurovascular bundle lies immediately inferior
Types of epithelia down airway
Trachea - pseudostratified ciliated, with goblet cells
Bronchi - columnar ciliated with goblet cells
Bronchioles - ciliated simple columnar -> ciliated simple cuboidal (with club cells throughout)
Alveoli - simple sqaumous
Defence in respiratory tract
Filtered in nasopharynx Sneeze and cough reflex Epithelial barrier Mucociliary escalator Immune response, as loose lymphoid tissue drains to nodules
Left vs right bronchus
Right
- shorter, straighter - easier flow into
- 3 secondary bronchi
- less cartilage, more smooth muscle
Left
- right angle - harder flow in
- 2 secondary bronchi
- more cartilage, less smooth muscle
Major differences between trachea and bronchi
Bronchi:
- cartilage not continuous, hyaline plates instead
- columnar not pseudostratified epithelia
- fewer goblet cells
Club cells
In terminal bronchioles instead of goblet cells
Non-ciliated dome-shaped columnar cells
Microvilli
Protective and regenerative role
May act as stem cells for repair in bronchioles
Possible secretory role - surfactant, anti-proteases, oxidases to protect
Respiratory vs terminal bronchioles
- respiratory have less collagen, less smooth muscle
- respiratory have squamous epithelia, terminal have cuboidal
- alveolar ducts branch off respiratory
Histology of lobar pneumonia
Alveoli fill with pus, cannot fill with air, less gas exchange
Stretched and inflamed alveolar walls
Mostly dead neutrophils visible, some macrophages
Bones of nasal septum
Septal cartilage anterior
Then perpendicular plate of ethmoid at top, vomer at bottom
Openings of paranasal air sinuses - under superior concha
2
Posterior ethmoid + sphenoid (further back)
Openings of paranasal air sinuses - under middle concha
4
Frontal, middle and anterior ethmoid, maxillary (maxillary clearest, furthest back)
Openings of paranasal air sinuses - under inferior concha
1
Nasolacrimal duct
- eustachian orifice doesn’t open into nasal cavity, opens into nasopharynx
Maxillary sinus innervation
Maxillary division of trigeminal (V)
So sinusitis can be referred to upper jaw, teeth and skin of cheek
Sinusitis is an inflammation of membranous lining of sinuses -> pain, nasal discharge
Cranial nerves
O - olfactory O - optic O - occulomotor T - trochlear T - trigeminal A - abducens F - facial V - vestibulocochlear G - glossopharngeal V - vagus A - accessory H - hypoglossal
Epistaxis
Nose bleeds
Usually from damage to anterior-inferior part of nasal septum vessels - arterial anastamosis here
Obstruction in pharynx
Due to - adenoids, palatine tonsils, obstructive sleep apnoea -> snoring
-> STERTOR - (partial airway obstruction above the level of the larynx)
Obstruction in larynx
-> STRIDOR - (partial airway obstruction below the level of the larynx)
Vocal chord paralysis
From damage to recurrent laryngeal nerve through trauma
- > HOARSENESS - if unilateral
- > BREATHING DIFFICULTIES AND APHONIA - if bilateral
Nasopharynx
Opens into nasal cavity
Extends from base of skull to soft palate (C1)
Contains pharyngeal tonsils, eustachian tonsils, opening of auditory tube
Oropharynx
Opens into oral cavity
Extends from soft palate (C1) to tip of epiglottis (C3)
Contains palatine tonsils
Laryngopharynx
Opens into larynx
From tip of epiglottis (C3) to cricoid cartilage (C6)
Contains NOTHING, needs to be clear for air
Lymph tissue in pharynx
Pharyngeal tonsils and eustachian tonsils in nasopharynx
Palatine tonsils in oropharynx
Lingual tonsils under tongue
(Waldeyer’s ring)
-> drains to retropharyngeal then deep cervical nodes
Blood and nervous supply to pharynx
Arterial - from branches of facial, maxillary, laryngeal and lingual arteries
Veins - to internal jugular vein
Nerves - from pharyngeal plexus - glossopharyngeal for sensory and vagus for motor
Laryngeal cartilages
Thyroid - big Cricoid - signet ring Epiglottis - flap Arytenoids - move vocal chords Cuneiforms and corniculates - in quadrangular membrane under epiglottis
Vocal folds
False superior (vestibular fold) Then true vocal chords
Extrinsic muscles acting on larynx
Controlled by vagus
Move larynx as whole
Suprahyoid elevate for swallowing
Infrahyoid depress
Intrinsic muscles acting on larynx
Thyroarytenoid - relax vocal ligament
Lateral cricoarytenoid - adduct vocal folds
Cricothyroid muscle - stretch and tense vocal ligaments, needed for forceful speech
Transverse arytenoid - adduct arytenoid cartilages
Oblique arytenoid - adduct arytenoid cartilages
Posterior cricoarytenoid - abduct vocal folds
Nerve supply to larynx
Inferior laryngeal nerve - all intrinsic muscles (except cricothyroid), and mucosa below vocal folds
Superior laryngeal nerve - external - cricothyroid muscle, - internal - mucosa above vocal folds
- recurrent laryngeal nerve is very close to thyroid, may be damaged in surgery -> hoarseness
Intubation method
Stand behind patient head, extend neck fully, clear mouth
Laryngoscope lateral to tongue, tip in vallecula (above epiglottis)
Laryngoscope lifted to view vocal chords
Endotracheal tube inserted through chords into trachea
Balloon inflated to hold tube in place, ventilate
Check to ensure not in bronchus (only one lung inflating) or oesophagus
Cricothyroidotomy
In emergency situations
Small slit on cricothyroid membrane, insert endotracheal tube
Tracheostomy
For long term management
Inserted directly to trachea
Incision via anterior wall of neck in surgical procedure
To bypass air from obstruction eg laryngeal tumour
- cannot speak
Symptoms of lung cancer
Chronic cough Haemoptosis Persistent chest infections Breathlessness Loss of appetite, unexplained weight loss Clubbing Tiredness Aches/pains when breathing or coughing
Relations to trachea
Anterior - thyroid isthmus at 2nd/3rd tracheal cartilage, left brachiocephalic vein
Posterior - oesophagus
Lateral - lobes of thyroid gland, carotid sheath containing common carotid artery, internal jugular vein and vagus nerve
Bifurcation (carina) at T4/5, sternal angle, plane of louis
Lung segments
2 primary bronchi, then left has 2 lobar, right has 3 lobar.
Then, 10 bronchopulmonary segments on each side
Each segment has a tertiary bronchus and pulmonary artery branch
Segments separated by connective tissue septa - can surgically remove one segment, and can contain disease
- pulmonary veins do not accompany bronchi, run between segments
Polyphonic wheeze
High pitched, expiratory
Indicative of asthma - expiratory as further decreasing airway diameter as lung collapses
Vessels at hilum
Left lung - clockwise to front
A
B V
V
Right lung - A B A B V V (front is right, back is left)
Veins thicker than arteries, as pulmonary veins supply oxygenated blood
Back of lung is straight , front follows curved chest wall
Neurovasculature of lungs
Bronchial arteries, branches of descending aorta
Bronchial veins drain to azygous and hemiazygous veins
Lymph to bronchopulmonary nodes at hilum, then tracheobronchial nodes at mediastinum, then nodes along trachea (lung cancer spreads this way)
Autonomic innervation from sympathetic trunk and vagus nerves via pulmonary plexuses
- parasympathetic constricts bronchioles, sympathetic dilates
Examination results - pleural effusion
Position of trachea - central
Percussion note - stony dull
Breath sounds - reduced
Vocal resonance - reduced
Examination results - lobar pneumonia
Position of trachea - central
Percussion note - dull
Breath sounds - reduced
Vocal resonance - increased
Examination results - collapsed lung (atelectasis)
Position of trachea - towards
Percussion note - dull
Breath sounds - reduced
Vocal resonance - reduced
Examination results - pneumothorax
Position of trachea - central
Percussion note - hyper-resonant
Breath sounds - reduced
Vocal resonance - reduced
Examination results - tension pneumothorax
Position of trachea - away
Percussion note - hyper-resonant
Breath sounds - reduced
Vocal resonance - reduced
Anterior auscultation
Apex - superior to medial third of clavicle
Superior lobe - 2nd intercostal space
Middle lobe (right) - 4th IC space
Inferior lobe - 6th IC space
Posterior auscultation
Apex - superior to medial third of clavicle
Superior lobe - 2nd IC space
Inferior lobe - triangle - bordered by trapezius, latissimus dorsi, medial border of scapula
