Anatomy Flashcards
What is the Allantois?
Adult urachus
How can you identify a thyroglossal duct cyst?
Move on swallowing and tongue protrusion
Central mass
What is a Pyramidal lobe of the thyroid?
Normal variant due to thyroid tissue developing in the thyroglossal duct
What is the White line of Toldt?
Lateral reflection of posterior parietal peritoneum of abdomen over the mesentery of ascending and descending colon - avascular region
What are the 3 intercostal muscle layers?
External intercostal
Internal intercostal
Inner most intercostal
Where does the main neurovascular bundle lie in the intercostals?
In costal groove
Below rib
How do you surgically get access to mediastinal structures? And why?
Median sternotomy
Avoids intercostal muscles and neurovascular bundle, internal thoracic artery & vein
What delineates the safe zone for chest tube insertion?
Triangle of safety
Axillary folds
Posterior axillary fold: Latissimus dorsi & teres major
Anterior axillary fold: Pectoralis major & minor
Nipple line (4/5th ICS)
What is the access route for Percardiocentesis?
Minimally invasive needle insertion into the pericardial cavity Access via the anterior abdominal wall through the diaphragm
What is a risk of pericardiocentesis?
Pneumothorax
How do you get fast access to the heart or lungs?
Thoracotomy
Incision in 5th intercostal space from mid sternum to posterior axillary fold
Which compartments can be released by a lateral fasciotomy of the thigh?
Anterior and posterior compartments
What 2 fasciotomy incisions are performed in the leg?
Anterolateral fasciotomy incision: Access to anterior and lateral
compartments
Posteromedial fasciotomy incision: Access to superficial and deep
posterior compartments
What fasciotomy incisions can be performed in the forearm?
Dorsal
Volar (anterior)
How do you approach the femur?
Lateral thigh Skin Fat Tensor Fascia Lata Vastus lateralis
How do you approach the knee joint?
Antero medial approach
How do you approach the tibia?
Posterolateral approach
How is the ankle joint (e.g. head of talus) accessed?
Incision made midway between tibia & fibula heading towards 4th metatarsal base
What superficial nerves are present on the dorsum of the foot?
Deep & Superfical Fibular nerve
During an approach to the hip, which direction would you move piriformis?
Medially
To preserve the sciatic nerve
Where does the circumflex humeral artery run?
Run with axillary nerve, 5cm inferior to acromion
Where does the profunda brachii artery run?
With radial nerve along spiral groove within posterior compartment
Where does the axillary artery run?
Passes behind mid-clavicle, medial to coracoid process
Where does the cephalic vein run in relation to the shoulder joint?
In deltopectoral groove, anterior shoulder
What approach do you take to access the shoulder joint?
Anterolateral
Identity acromion and coracoid process
Line down the arm from the coracoid process
Identify cephalic vein which is superficial
Identify coracobrachialis, lateral to this is safe side, medial is “suicide”
What does lymph consist of?
Tissue fluid and plasma proteins
What are lymph nodes?
Filters with immune function
Describe the structure of a lymph node
Afferent lymphatics bring in fluid to Subcapsular sinus
Germinal Centres sit in Cortex with Paracortex surrounding it
High endothelial venules - blood supply
Medullary Cords where fluid collects back together the leaves via efferent lymphatics
Why do lymphatic vessels follow the arterial supply?
Lymphatic vessels similar to veins
Thin-walled & most contain valves
Arterial pulsation compresses lymph vessels aiding venous return
Develop with the vascular system
Which parts of the body drain lymph to the left subclavian vein?
Most of the body and the left upper lobe of the lung drain into the left subclavian vein via the thoracic duct
Which parts of the body drain to the right lymphatic duct?
Right upper limb
Most of lungs (all bar left upper lobe)
Right half of head and face
Right upper part of chest and back
What is an important thing to do when you see lymphangitis?
Check the distal part of the affected structure
Where do lymphatic vessels of the skin run?
With cutaneous veins to nodes located at the point of the vein passing through deep fascia
What could lymphangitis be confused with?
Thrombophlebitis
What drains to superficial inguinal lymph nodes?
Perineal region
Penis/clitoris glans
Lower anal/vaginal canal
Anterior labia majora / scrotal skin
What are the 2 groups of the superficial inguinal nodes?
Horizontal
Vertical
Where do the deep inguinal nodes run?
Sit along femoral vein
Cloquet node sits superiorly: sentinel node from lower limb and perineum
What do the deep inguinal nodes drain and where do they drain to?
Receive deep tissues and superficial node
Drain to external inguinal nodes
Where does abdo wall lymph drain to?
Axillary and inguinal lymph nodes
Regional split from umbilicus
Where does the umbilicus receive lymph drainage from?
Parasternal nodes
Axillary
Inguinal
Describe the route from the iliac vessels up to the left subclavian vein
Drain to cisterna chyli
Up thoracic duct
Into subclavian
Name some thoracic lymphatic trunks
Internal thoracic nodes: anterior
Intercostal lymph trunks: posterior
Right bronchomediastinal ducts: from anterior up to right lymphatic duct
What are the pre aortic node groups? And what do they drain?
Coeliac nodes: foregut
Superior mesenteric nodes: midgut
Inferior mesenteric nodes: hindgut
Where do mesenteric nodes sit and where do they drain to?
Sit in the mesentery around arteries supplying the gut tube
Drain to cisterna chyli
Through what structure does the cisterna chyli drain to the thoracic duct?
Aortic hiatus
Where is the cisterna chyli located?
R side of L1 & 2
What structures are at risk with Lymph node resection around the aorta?
Damage to sympathetic nerve plexi
What could be a result of damage after inferior mesenteric node resection in hindgut neoplasm metastasis?
Secretory phase of male ejaculation due to sympathetic nerve damage
Where does most of the tracheobronchial tree drain to? And what is the exception?
Right lymphatic duct
Left upper lobe drains to the thoracic duct
Describe lymph drainage from the lungs
Hilar/bronchopulmonary nodes drain to paratracheal nodes
Drain to bronchomediastinal duct then either to right lymphatic duct or thoracic duct depending on lung area
What symptoms might occur from mediastinal lymphadenopathy?
Dysphagia, tracheal compression, left recurrent laryngeal nerve damage: hoarse voice, superior vena cava obstruction
Which structures drain to iliac nodes?
Rectum
Anal canal above pectinate line
Uterus, cervix, proximal vagina
Bladder
Where do the ovaries drain to?
Para aortic nodes L2
Where does lymph from Scrotal/labial, penile & perineal skin drain to?
Superficial inguinal nodes
Where does lymph from the Glans of penis/clitoris drain to?
Deep inguinal nodes
Where does the corpus cavernosum lymph drain to?
Internal Iliac nodes
Where does lymph from the male urethra drain to?
Proximal spongy & membranous: internal iliac nodes
Distal spongy: deep inguinal nodes
Where does lymph from Prostate, seminal vesicles & ductus drain to?
Mainly internal iliac nodes
Where does lymph from Distal anal/vaginal canal drain to?
Superficial inguinal nodes
What do Axillary nodes drain?
Anterior thoracic wall & breast
Posterior thoracic wall
Upper limb
Name the Axillary lymph node groups
Apical Central Humeral Subscapular (posterior) Pectoral (anterior)
What lymph node groups can breast tissue drain to?
Anterior & central axillary nodes Interpectoral (Rotter) nodes Parasternal (internal thoracic) nodes Contralateral parasternal nodes Contralateral breast Subdiaphragmatic /hepatic nodes Inguinal lymph nodes
What can result from blockage/removal of lymph drainage route?
Lymphoedema
Where does breast skin drain to?
Axillary, deep cervical & infraclavicular nodes
Where do infraclavicular lymph nodes sit?
Deltopectoral triangle/ infraclavicular fossa
What is another name for the Inferior deep cervical nodes?
Jugulo-omohyoid nodes
Describe the direction of drainage of head and neck lymph nodes
Superficial to deep and from superior to inferior
What do submental lymph nodes drain?
Lower lip, lip of tongue
What do submandibular lymph nodes drain?
Lip, lateral body of tongue, nose, face
What do parotid lymph nodes drain? And what is their other name?
Temporal scalp & eye
Pre auricular
What do mastoid nodes drain? What is their other name?
EAM and pinna
Post auricular
What do occipital nodes drain?
Occipital scalp region to vertex
Where do the superficial cervical chain nodes run?
Run with EJV
What are the 3 groups of deep cervical nodes and what do they drain?
Jugulo-digastric: Tonsil, pharynx, posterior tongue
Deep Cervical Chain: Superficial node groups
Jugulo-omohyoid: Superficial node groups and central tongue
What areas may be affected with a unilateral lymphadenopathy of the right supraclavicular lymph nodes?
Intrathoracic structures
Oesophagus
Lung
Mediastinum
What areas may be affected with a unilateral lymphadenopathy of the left supraclavicular lymph nodes? And what other name do they have?
Virchow’s node
Stomach
Kidney
Ovary
What can be done to aid examination of supraclavicular lymph nodes?
Ask patient to valsalva
What are the constituents of waldeyers ring?
Pharyngeal: Adenoid
Tubal
Palatine
Lingual
What could result from a tubal lymphadenopathy which is common in children?
Secretory otitis media: glue ear
What is the significance of vascular watershed points from a surgical perspective?
Regions of poor healing
What are the superior and inferior boundaries of the neck?
Superior: Inferior mandible & base of skull: Pericraniocervical line
Inferior: Manubrium, Clavicle & Acromion–to-spinous process of C7
What are the supra hyoid muscles? what is their nerve supply? And what is their action?
Digastric anterior belly - CN Vc Mylohyoid - CN Vc Digastric posterior belly- CN VII Stylohyoid - CN VII Elevate the hyoid
What are the infra hyoid muscles? what is their action? And what is their nerve supply?
Thyrohyoid Sternothyroid Omohyoid (superior & inferior bellies) Sternohyoid Scalene muscles Depress hyoid Mostly ansa cervicalis (C1-3)
What are the posterior muscles of the neck and what is their nerve supply?
Subocciptial muscles = C1 posterior ramus
Levator scapulae = Dorsal scapula nerve and C3 &C4
Intrinsic vertebral column muscles = Posterior rami of spinal nerves
What are the boundaries of the anterior triangle of the neck?
Medial = Midline (Median Sagittal Plane) Lateral = Sternocleidomastoid (anterior border) Superior = Inferior margin of mandible
What are the boundaries of the posterior triangle of the neck?
Medial = Sternocleidomastoid (posterior border) Lateral = Trapezius (anterior border) Base = Clavicle (middle 1/3rd) Apex = Mastoid Process
What are the boundaries of the carotid triangle of the neck?
Ant. = Omohyoid (Superior Belly) Sup. = Digastric (Posterior Belly) Post. = Sternocleidomastoid
List some contents of the carotid triangle
Carotid, thyroid, facial & lingual arteries
Internal jugular & facial veins
CN X, XI, XII, VII (cervical branch)
Superior laryngeal nerve (internal & external branches)
Thyroid gland
What are the boundaries of the submandibular triangle?
Sup. = Inferior border of mandible Inf. = Digastric (ant. and post. bellies)
What are some key contents of the submandibular triangle?
Submandibular lymph nodes Submandibular salivary gland Hypoglossal nerve Lingual artery Facial artery & vein Marginal mandibular branch of CN VII
What are the boundaries of the submental triangle?
Inf. = Hyoid bone Lat. = Digastric (ant. belly) Med. = Midline, if halved
What are some key contents of the submental triangle?
Submental lymph nodes
Anterior jugular vein tributaries
What 2 triangles can the posterior triangle of the neck be divided into? And what divides it?
Omoclavicular/supraclavicular triangle
Occipital triangle
Inferior belly of omohyoid
Name some of the contents of the supraclavicular triangle
Subclavian artery & vein & Supraclavicular nodes
Suprascapular nerve – damaged by clavicle #
Anaesthetise brachial plexus here
What is in the lesser supraclavicular fossa and what can this be used for?
Internal jugular vein
Central venous access point
What key nerves sit in the posterior triangle?
Accessory nerve
Brachial plexus C5-6
Phrenic nerve
How can you identify the location of the brachial plexus in the neck?
Can feel groove between scalenus anterior and medius and use it to locate plexus – sits level with cricoid cartilage
What are Trapezius, sternomastoid and the infrahyoid muscles enclosed in?
Investing fascia
How many deep layers of fascia are there in the neck?
4
What are the deep layers of fascia in the neck?
Pretracheal fascia Buccopharyngeal fascia (Post. Pretracheal fascia) Carotid Sheath Alar fascia Prevertebral fascia
In what region does the sympathetic chain sit in the neck?
Danger space
Where does the vertebral compartment extend to?
From skull base to thoracic vertebrae
Where does the visceral compartment extend to?
Extends to fibrous pericardium
How far does the pre tracheal space extends?
Extends into superior mediastinum
How far does the retro pharyngeal space extend?
Communicates down to superior mediastinum level
How far does the danger space extend?
Communicate with posterior mediastinum to diaphragm level
What fascia covers the brachial plexus and where does this mean that infection can spread to?
Covered by layer of prevertebral fascia = axillary sheath
Continues with it into upper limb - Infection in vertebral compartment can spread to upper limb via axillary sheath
Plexus block via injection into axillary sheath
How can cervical vertebrae be approached surgically?
From an anterior perspective
What do submental lymph nodes drain?
Lower lip, lip of tongue
What do submandibular glands drain?
Lip, lateral body of tongue, nose, face
What do parotid or pre auricular lymph nodes drain?
Temporal scalp & eye
What do mastoid or post auricular lymph nodes drain?
EAM and pinna
What do occipital lymph nodes drain?
Occipital scalp region to vertex
Where do superficial cervical lymph nodes run?
Run with EJV
What do jugulo Digastric lymph nodes drain?
Tonsil, pharynx, posterior tongue
What do the deep cervical chain lymph nodes drain?
Superficial node groups
What do jugulo omohyoid lymph node groups drain?
Superficial node groups and central tongue
What are the 3 deep neck lymph node groups?
Jugulo-Digastric
Deep cervical chain
Jugulo-omohyoid
What do supraclavicular lymph nodes drain?
Lung & upper GI
Where does the carotid bifurcation occur?
Normally sits above thyroid cartilage lamina
At C3 in 45-62% of cases, Range C1-C5
What does the external carotid supply?
Neck & face
How can you distinguish the external carotid in the neck?
Multiple branches in the neck
What does the internal carotid supply?
Enters cranium to supply CNS
Where can you feel the carotid pulse?
In carotid triangle against C6 tubercle
Where does the common carotid travel in relation to the larynx and pharynx?
Lateral to larynx & pharynx
What sits close to the carotid bifurcation?
Carotid sinus and body
What can external pressure on a hypersensitive carotid sinus lead to?
Syncope – not a good place to take a pulse in patients with unexplained syncope or vascular disease
What does the carotid sinus sense?
Pressure
What does the carotid body sense?
PO2 but can also sense PCO2
What are the branches of the external carotid in the neck?
Superior thyroid artery: Runs close to external laryngeal nerve
Occipital artery: Supplies the occipital region. Runs over CNXII
Lingual artery: Mainly supplies the tongue
Maxillary artery: Deep facial tissues, nasal cavity, sinuses
What does the vertebral artery supply? And what foramen does it go through to enter cranium?
Brainstem, spinal cord & brain
Run through foramen transversarium
What does the internal thoracic artery supply?
Thoracic wall & breast
What does the thyrocervical artery supply?
Thyroid & neck tissues
Where do the EJV and IJV sit in relation to sternocleidomastoid?
IJV sits under sternomastoid
EJV sits above sternomastoid
Where does the internal jugular vein run?
Runs from jugular foramen to behind sternoclavicular joint
Sits lateral to common carotid artery
IJV Pulsation can be observed and increases with increased right sided venous pressure
Where does the external jugular vein run?
Runs from angle of mandible to lateral border where SCM meets clavicle
Sits under platysma
Injury can result in venous air embolus, Can be cannulated
How can the internal jugular be accessed?
Via the lesser supraclavicular fossa
Which veins in the neck feed into the anterior branch and then into the internal jugular vein?
Superficial temporal v. Maxillary v. Retromandibular v. Facial v. Common facial v.
Which veins of the neck feed into the posterior branch and then into the external jugular vein?
Superficial temporal v.
Maxillary v.
Retromandibular v.
Posterior auricular v.
Where does the thyroid begin its development?
Thyroid gland begins development on tongue at foramen
caecum
Therefore an epithelial endoderm-derived structure
Which pharyngeal arches does the tongue develop from?
Arches 1,3 & 4
Via what structure does the thyroid descend?
Thyroglossal duct
Why does the thyroglossal duct move during swallowing?
Thyroglossal duct attaches to hyoid bone, therefore duct moves during swallowing and tongue protrusion
How can you identify a thyroglossal duct cyst?
Can form anywhere along thyroglossal duct in midline neck
Move on swallowing and tongue protrusion
How might you distinguish a thyroglossal duct cyst from a thyroid gland enlargement?
Thyroid gland and lumps tends to move during swallowing but not always with tongue protrusion
What is a pyramidal lobe of the thyroid?
Normal variant due to thyroid tissue developing in thyroglossal duct
Where does the superior thyroid artery and vein run and what nerve are they close to?
From: external carotid
To: Internal jugular vein
artery runs close to the external branch of superior laryngeal nerve
Where does the inferior thyroid artery and vein run and which nerve do they run close to?
From: Thyrocervical trunk
To: Left brachiocephalic vein
artery runs close to recurrent laryngeal nerve
Where does the middle thyroid vein run to?
Internal jugular vein
Where does the isthmus of the thyroid sit?
Over tracheal rings 2-3 at C7
Where is the weak spot on the posterior pharynx?
Join between inferior constrictor and cricopharyngeus
Diverticula can form here
What could result from a bleed into pretracheal fascia?
Trachea could be compressed, airway obstruction
Where approximately do the parathyroid glands sit?
Posterior thyroid
2 at cricoid level
2 at inferior pole of thyroid
What can be injured in thyroid surgery leading to vocal fold paralysis?
Close relationship of recurrent laryngeal nerve to inferior thyroid arteries means that nerve is at risk of damage
What can thyroid gland enlargement result in which may be an emergency?
Compress the trachea causing stridor
Cause tracheal deviation
Affect swallowing
What may limit superior enlargement of the thyroid gland?
Strap muscles covering gland
What muscles and cartilage are formed from pharyngeal arch 1, CN V?
Mastication muscles, mylohyoid, anterior belly digastric, tensor tympani, tensor veli palatini
Malleus, incus, spine of sphenoid & sphenomandibular ligament
Maxilla, zygoma & mandible
What muscles and cartilages are formed from pharyngeal arch 2, CN VII?
Facial expression muscles, stapedius, stylohyoid, posterior belly of digastric
Stapes, styloid process, stylohyoid ligament
Lesser horn and upper body of hyoid
What muscles and cartilages are formed from pharyngeal arch 3, CN IX?
Stylopharyngeus
Greater horn & lower body of hyoid
What muscles and cartilages are formed from pharyngeal arch 4, CN X (sup laryngeal)?
Pharyngeal muscles, cricothyroid, levator veli palatini
Thyroid & cricoid cartilages
What muscles and cartilages are formed from pharyngeal arch 6, CN X (recurrent laryngeal)?
Intrinsic laryngeal muscles, pharyngeal muscles, striated muscle of oesophagus
Arytenoid cartilages
What does the external acoustic meatus develop from?
1st pharyngeal cleft
What forms from the 1st pharyngeal pouch?
Tympanic cavity & mastoid antrum
Pharyngotympanic tube
What does the tympanic membrane develop from?
Ectoderm & Endoderm of 1st Pouch & Cleft
What does the 2nd pharyngeal pouch develop into?
Palatine tonsillar crypts
Mesoderm under endoderm forms the tonsil
What does the 3rd pharyngeal pouch develop into?
Inferior parathyroid glands & thymus
What does the 4th pharyngeal pouch develop into?
Superior parathyroid glands & C-Cells of thyroid
What is the branchial sinus?
Space where pharyngeal arch 2 grows over lower arches
How does a branchial fistula form?
Branchial sinus should obliterate. If it remains open it can form a
branchial fistula that opens & discharges onto the lower neck
Where do branchial cysts usually form?
Branchial cysts often form on anterior border of
sternocleidomastoid
What nerves exit from the nerve point of the neck? (C2-4 emerge from posterior border of the middle 1/3 of sternocleidomastoid)
Lesser Occipital nerve Greater Auricular nerve Transverse Cervical nerve Spinal Accessory nerve (CN XI) Supraclavicular nerves
How can neck skin be anaesthetised?
What nerve is at risk here?
Anaesthetised via a nerve block around nerve point of neck, posterior border, middle 1/3 SCM
Can also anaesthetise phrenic nerve (C3-5)
What are the main functions of the cervical plexus?
Sensory to neck skin, and motor to strap muscles & diaphragm
Where do branches of the brachial plexus appear in the neck from?
Between anterior & middle scalenes
What are the main branches of the cervical plexus?
Transverse cervical Ansa cervicalis Supraclavicular Phrenic nerve Greater auricular Lesser occipital
Where does the hypoglossal nerve run in the neck? When therefore is it at risk of damage?
Lateral to carotid vessels & under occipital artery (or its
branch to sternocleidomastoid)
Passes into floor of mouth deep to mylohyoid
Nerve is at risk during carotid artery surgery or node removal
What can damage to the hypoglossal nerve result in?
Ipsilateral paralysis of tongue
Deviation of tongue towards damaged side on protrusion
What is the function of the glossopharyngeal nerve?
Sensory supply to the pharynx, tonsil, middle ear, pharyngotympanic tube and posterior 1/3rd of tongue
Where does the glossopharyngeal nerve run in the neck?
Nerve passes between carotid vessels
Enters pharynx between sup. & mid. constrictors
Note branch to carotid sinus & body
What can damage to the glossopharyngeal nerve result in?
Difficulty swallowing
Loss of taste on posterior tongue and pharynx
Loss of gag reflex
Increased risk of aspiration
Where does the accessory nerve run in the neck?
Exits via jugular foramen (in carotid sheath)
Emerges from under SCM 3-10cm below mastoid tip
Passes deep to trapezius 1-10cm above insertion of trapezius into clavicle
Runs through posterior triangle and is at risk during surgery in posterior triangle
What can damage to the accessory nerve result in?
Weakness of shrugging ipsilateral shoulder
Weakness of turning head to contralateral side
Long term – scoliosis, trapezius wasting and fasciculations
What are the nerve roots and function of the accessory nerve?
C1-5
Motor supply to SCM and Trapezius
What does the Ansa cervicalis supply?
Infrahyoid strap muscles of neck & omohyoid
What nerve roots form Ansa cervicalis?
Superior (C1) & inferior (C2,3) roots
Where does the thoracic duct travel as it heads towards the subclavian vein?
Passes posterior to IJV and enters SV near to junction with IJV
What are the 3 sympathetic chain ganglia in the neck?
Superior cervical ganglia (C1-4)
Middle cervical ganglia (C5-6)
Stellate ganglion/cervicothoracic (C7-C8)
What are the anterior and posterior relations of the sympathetic chain in the neck?
Sympathetic chain sits posterior to the carotid sheath and anterior to the prevertebral fascia
What damage results in horners syndrome?
Compression/laceration of sympathetic chain above T1
What are the symptoms of horners syndrome?
Miosis
Anhydrosis
Flushed skin (red & hot)
Partial ptosis
Name some causes of horners syndrome?
Neck tumours
Lymphadenopathy
Direct injury (trauma/iatrogenic)
Describe the anatomy of the lung hilum
Right pulmonary artery travels in front of the right main bronchus
Left pulmonary artery winds over top and then behind left main
bronchus
Look like pulmonary artery and veins crossing each other
What things should be looked at when analysing a chest X-ray?
Is it AP or PA? (scapulae clear of lungs?)
Is it the correct patient?
Is it adequately penetrated and exposed?
Is it rotated?
Compare upper, mid and lower zones
Look at apicies, lateral margin of lungs, hemidiaphragms
Look behind the heart and behind the hemidiaphragms and descending aorta
Asses hila
Look at soft tissue lines. Rt para tracheal, descending aorta
Look at the bones and soft tissue
Count ribs
Look at breasts
If you see multiple nodules on a chest X-ray, what might you be looking at?
Metastases Abscesses, histoplasmosis, hydatid AVMs (arteriovenous malformations) Multiple areas of consolidation-rare (Sarcoid, Lymphoma, Eosinophiliic pneumonia, Wegeners, Alveolar cell ca, Pulmonary emboli,PMF, Rradiation pneumonitis) Rheumatoid, caplans, wegeners
What things might you see on a chest X-ray in someone with a tension pneumothorax?
Mediastinal shift away
Flattening of hemidiaphragm, increased pressure causes decreased venous return and death/compromise
Supine position look for a deep sulcus sign and very sharp border: costophrenic angle abnormally deepened as air collects laterally
What is the cardiothoracic ratio?
A+B/C
Where A is from right heart border to midline
B is from left heart border to midline
C is the full width of the chest
What things can cause bilateral upper lobe fibrosis?
TB Radiation Extrinsic allergic Alveolitis Ankylosing spondylitis Sarcoid Histiocytosis
What is phlebotomy?
Sampling of blood usually from superficial veins
What is the preferred site for phlebotomy?
Upper limb over the cubital fossa
Which veins are most commonly used for phlebotomy?
Cephalic, basilic or median cubital veins
What are the borders of the cubital fossa?
Superior – Epicondylar line
Lateral – Brachioradialis
Medial – Pronator teres
Give some indications for cannulation
Short term venous access Intravenous infusion – fluid, blood, drugs Repeated drug administration Repeated sampling Measuring central venous pressure
What states need precaution or are contraindicated for cannulation?
Fluid overload
Cardiac failure – check for oedema
Renal failure
Skin sepsis or burns
List some possible complications of superficial venous cannulation
Venous inflammation Thrombosis Thrombophlebitis: Clot & inflammation Sepsis Tissue infusion
How many days can a superficial venous cannula be left in? After this time what should be used?
Up to 3 days use peripheral veins
Longer term use central/Hickman line
What are common locations for superficial venous cannulation?
Cubital fossa
Dorsal hand
Anatomical snuffbox
Medial ankle (cutdown)
Which nerves are at risk during cannulation in the cubital fossa?
Medial cutaneous nerve of the forearm
Lateral cutaneous nerve of the forearm
Where does the housemans vein run?
Passes over anatomical snuffbox roof from the lateral side of the dorsal venous network
Which tendons form the boundaries of the anatomical snuffbox?
Extensor Pollicis Longus
Extensor Pollicis Brevis
Abductor Pollicis
Which nerve runs in close proximity to the housemans vein and is at risk of damage during cannulation?
Superficial cutaneous branch of radial nerve
Describe the path of the great saphenous vein
Anterior to medial malleolus
Along posterior region of medial tibial border
Alongside saphenous cutaneous nerve
4 fingers breadth posterior to patella
Through saphenous opening 3cm inferior and lateral to pubic tubercle
Where does the short saphenous vein run?
Posterior to lateral malleolus
Ascends midline posterior leg
Alongside sural cutaneous nerve
Into popliteal fossa via crural fascia and into popliteal vein
Describe how you would carry out a venous cut down procedure to access the long saphenous vein
Identify medial malleolus
Identify great saphenous vein if possible (palpation)
Measure 1-1.5 cm anterior and superior to medial malleolus
Perform a transverse incision of up to 2.5cm from anterior toward posterior border of tibia
Where would you cannulate a child?
Cubital fossa Hand dorsum External jugular vein Scalp-especially babies NOT FEMORAL-hip joint Venous cutdown – saphenous, basilic Intraosseous-anterior tibia
What are indications for central venous system cannulation?
Need for long-term venous access Chemotherapeutic drug administration Total parenteral nutrition Access to the heart Peripheral veins inaccessible Central venous pressure measurement
List some possible complications of central venous system cannulation
Catheter occlusion - clot Air embolus Haemorrhage Displacement & tissue infiltration Infection
How is the central venous system accessed?
IJV line
Hickman (Subclavian) line
Where does the IJV run in the neck?
Deep to SCM from a point medial to mandibular ramus to sternoclavicular joint/ sternal end of clavicle
Sits lateral to pulsating common carotid artery
Where can the IJV be accessed in the neck?
Lesser supraclavicular fossa
Posterior border of sternocleidomastoid
How should the position of an inserted IJV central line be checked? What else should be checked?
Radiography
Check for pneumothorax
Where does the EJV run in the neck?
Runs from angle of mandible to lateral border of where SCM meets clavicle
Sits under platysma
What can injury to the EJV during central line insertion result in?
Venous air embolus
What nerves sit in close proximity to the EJV?
Accessory nerve (CN XI) Cutaneous branches of cervical plexus
How is the subclavian vein accessed?
Infraclavicular approach
Insertion point is the junction of middle and medial 1/3 of clavicle on the right hand side
Cannula is directed under clavicle and toward to jugular notch of sternum
What important structures are at risk of damage during a subclavian vein central line insertion?
Phrenic nerve
Vagus nerve
Recurrent laryngeal nerve
Lung apex
Dural venous sinuses in the cranium can be accessed in the neonate. Superior sagittal sinus sits deep to which structures via which it can be accessed?
Anterior and posterior fontanelles Soft spots (unossified regions) in newborn and young children
What vessels does an interosseous infusion access? How does the fluid then reach the central circulation?
Medullary cavity venous sinusoids
Absorbed within cancellous bone through nutrient and emissary veins, which drain into the systemic circulation
What are indications for arterial cannulation?
Acid base status Blood gasses Assessment of respiratory/cardiac/ renal failure Drug overdose Diabetic ketoacidosis (DKA) Lactic acidosis Cardiac catheterisation
What are possible complications of arterial cannulation?
Haematoma Arterial spasm – ischaemia Retrograde embolism Traumatic aneurysm Infection / spesis
Which arteries are commonly accessed for cannulation?
Brachial artery
Radial artery
Femoral artery
How is the radial artery accessed for arterial cannulation?
Lateral to flexor carpi radialis tendon
How is the ulnar artery accessed for arterial cannulation?
Lateral to pisiform and flexor carpi ulnaris at wrist
Sitsimmediately lateral to ulnar nerve
What structure ensures a consistent blood flow to the tissue of the hand?
Palmar anastomoses
List some uses for the radial artery
Harvested for grafts
Radiocephalic fistula can be used for haemodialysis
Radial artery can be cannulated
What test should be done to test the patency of each vessel of the wrist (normally the ulnar) prior to cannulation?
Allens test
Briefly describe the radial artery cannulation process
Confirm collateral supply using (Allen’s Test) Use a pre-heparinised syringe 5-10 mins pressure to ensure haemostasis Keep sample on ice (if possible) Minimise delay in analysis
How can the brachial artery be identified for an arterial stab?
Passes medial to biceps tendon and deep to its aponeurosis
Which nerve runs in close proximity to the brachial artery?
Median nerve runs medially
What are the boundaries of the femoral triangle?
Inguinal ligament
Sartorius
Adductor Longus
Where does the femoral nerve sit in the femoral triangle?
1cm lateral to the pulsating femoral artery
Where does the femoral artery enter the femoral triangle?
Midinguinal point ± 1.5cm (medial to lateral)
What can appear at the saphenous opening?
Femoral hernia
Varicosities can for on the saphenous vein at the opening
What are indications for a lumbar puncture?
CSF composition & pressure CNS infection (meningitis, encephalitis) Subarachnoid haemorrhage Multiple sclerosis Peripheral neuropathy (Guillian-Barre)
What are contraindications to lumbar puncture?
Patient refusal Raised intracranial pressure – Papilloedema Intracranial bleed Cord compression Coagulopathy Spinal fixation surgery Skin sepsis - exfoliation
What are possible complications of lumbar puncture?
Headache due to depressed brain position (raise foot of bed) Nerve root pain Bloody (traumatic) tap Brain or cerebellar herniation Meningitis Annulus laceration causing backache CN VI palsy/hearing loss Transient/persistent paraesthesia/anaesthesia
Where is the zone of spinal cord termination?
Ranges from middle 1/3rd of T11 to the middle 1/3rd of L3
What is the mean level of spinal cord termination?
Middle 1/3rd of L1 vertebral body
Corresponds with lower part of interspinous space between T12 and L1 spinous processes
Where is the zone of supracristal plane intersection with vertebral column?
Ranges from L2-L3 to L4-L5 junction/interspinous space
Where is the highest point of iliac crest and supracristal plane (Tuffier’s line)?
Intersects vertebral column from L4 to the L4/5 junction
Where does the subarachnoid space terminate in the spinal cord?
Usually S1 to S2 level
Can range from L5-S1 to S4
At what vertebral level is lumbar puncture performed in adults?
L3/4 to L5/S1 interspinous gap
At what vertebral level is lumbar puncture performed in children?
L4/L5 or L5-S1 interspinous gap
What is the filum terminale?
Continuation of pia mater in the spinal cord after termination of dura and arachnoid
What is the cauda equina?
Collection of lumbar and sacral spinal nerves
Supplies lower limbs, pelvic floor, urinary and anal sphincters
Damage to T11/T12 vertebra will affect which spinal nerves?
L1-L5
Damage to vertebra L1/2 will affect which spinal nerves?
S1-S5
What is located in the epidural space?
Fat and Veins
What angle is the needle inserted at during a lumbar puncture?
Anterosuperiorly
15° cephalad orientation
Why do you need to monitor O2 sats during lumbar puncture?
Compress diaphragm
Respiratory compromise
What layers are gone through during a lumbar puncture?
Skin Supraspinous and interspinous ligaments Ligamentum flavum Dura mater Arachnoid mater
Where is the epidural space located usually?
4.5-5.5cm from skin in lumbar region
What needle gauges should be used for lumbar puncture procedures?
Adult – 18/20 G
Child – 20 G
Neonate – 22G
What should you do if a lumbar puncture needle gets blocked?
Try rotating it
What different analyses can be performed on CSF?
Glucose and protein
Microscopy, Culture, Sensitivity
Cytology and cell counts
What problems can occur with a lumbar puncture procedure?
Dry tap
Traumatic tap
Herniation
Headache
Why might a dry tap occur when trying to perform a lumbar puncture?
When subarachnoid space is not entered or needle blocks
If a lumbar puncture needle passes of course, what may happen?
Dry tap
Possible nerve root damage
What might cause a lumbar puncture needle to pass off course?
Too little vertebral column flexion
Patient not perpendicular to bed
Why does a traumatic lumbar puncture tap occur?
Internal vertebral venous plexus is pierced
What makes a traumatic lumbar puncture tap more likely?
Increased number of attempts
Lateral deviation of needle
What cancer type could metastasise to Batsons plexus in the extradural space?
Prostate
Direct communication with pelvic veins - valveless
Why does headache occur after a lumbar puncture?
CSF loss results in a depressed brain, which pulls on sensitive meninges
Onset up to 48h post procedure
Accompanied by nausea, vomiting, tinnitus/hearing reduction
What factors increase the likelihood of headache post lumbar puncture?
Anything which increases CSF loss:
Multiple punctures
Bevel at wrong orientation - increases leakiness
Large needle
Which direction should the needle bevel face when performing a lumbar puncture?
Opening of bevel should be facing ceiling with patient lying in lateral decubitus position (on side)
Why can herniation occur as a result of a lumbar puncture? Why is it more likely with raised intra cranial pressure?
Removing CSF decreases pressure in vertebral canal & can result in inferior herniation of neural tissue
Predisposed to by high pressure gradient between cranium and vertebral canal
Pressure gradient causes transtenorial and cerebellar structures to move inferiorly
What is epidural anaesthesia used for?
Operative
Obstetrics
Orthopaedics
Pain management
Describe needle insertion for epidural anaesthesia
Almost exactly the same as for lumbar puncture – just stop in the epidural space
How can you increased the number of segments anaesthetised during an epidural?
Increased volume of anaesthetic inserted
To achieve up to a T10 block from an L3-4 injection of epidural anaesthetic, how much should be injected?
9-18ml
What difference is there between needle insertion in the lumbar region and thoracic region for epidural anaesthesia?
Needle needs to be angled more cephalad in thoracic region
Where is spinal anaesthesia performed?
L3/L4 to L5/S1
How can you control the level of spinal anaesthesia?
Volume, density and patient position
What is a combined spinal epidural? What is it used for?
Both a spinal and lumbar epidural are delivered
Used during labour
Ready for operative procedures (e.g. caesarian/episiotomy/ventouse)
What is caudal anaesthesia?
Injection into sacral epidural space via the sacral hiatus
Anaesthetises sacral spinal nerves: used to anaesthetise birth canal and perineum
Where is the sacral hiatus?
Inferior apex of an equilateral triangle measure between the posterior superior iliac spines
Describe needle insertion for a caudal anaesthesia
Introduced at oblique angle then directed cephalad and advanced
How long are the ureters and what 3 parts is it made from?
25-30 cm long and has three parts:
abdominal ureter: from renal pelvis to pelvic brim
pelvic ureter: from the pelvic brim to the bladder
intravesical or intramural ureter: within the bladder wall
Describe where the ureters run in the abdomen
Medial aspect of psoas Tips L2 – L5 transverse processes Pelvis – anterior to SI joints Down lateral pelvic sidewall Level ischial spine – turns anterior and medial Posterolateral wall of bladder Obliquely through bladder wall
What are common sites of obstruction of the ureters?
Pelvic-ureteric junction of renal pelvis and the ureter
As ureter enters pelvis and crosses over the common iliac bifurcation
At vesicoureteric junction as ureter obliquely enters bladder wall
To perform an ultrasound scan of the uterus, is it better for the bladder to be full or empty?
Transabdominal USS: full bladder as pushes uterus into view
Transvaginal USS: empty bladder so it doesn’t block view
Describe the blood supply to the female reproductive system
Ovaries – aorta (Right V – IVC Left V – L Renal V)
Branches of internal iliac:
Uterus – internal iliac
Fallopian Tubes – ovarian & uterine branches
Cervix – uterine branch
Vagina – internal iliac
What are the segments of the Fallopian tube?
Fimbriae Infundibulum Ampulla Isthmus Interstitial
What is a hysterosalpingogram?
X ray fluoroscopy and contrast used to look at uterus and Fallopian tubes to check for obstruction, usually in women who are struggling to get pregnant
What are fibroids? What symptoms might be present?
Non cancerous growths which develop in/around the uterus
Can cause heavy periods, abdominal pain/swelling and urinary problems
What is the function of puborectalis?
Maintain anorectal angle and therefore maintain faecal continence
