Anatomy 2 Flashcards
What are the 5 parts of the brachial plexus and where are they?
Roots - from intervertebral foraminae in neck between anterior and medial scalene muscles
Trunks - base of posterior triangle of neck, over first rib behind 3rd part of subclavian artery
Divisions - posterior to middle 1/3 of clavicle
Cords - related to 2nd part axillary artery in axilla
Branches - related to 3rd part of axillary artery in axilla
Long thoracic nerve of bell innervates? Roots? What does it do?
Serratus anterior - C5-7 - lifts and rotates scapula
Nerve root medial cutaneous nerve of forearm?
C8
Nerve root medial cutaneous nerve of arm?
T1
Which cord of brachial plexus gives rise to the thoracordorsal nerve? Muscle supply?
Posterior cord - C6-8
Latissimus dorsi
Innervation of pectoralis major? Where do they come from?
Lateral (C5/6/7 - clavicular head) and medial (C8/T1 - sternocostal head) pectoral nerves, from lateral and medial cords respectively
Innervation of pectoralis minor?
Medial pectoral nerve
What is a Kulmpke’s palsy? How does it look?
Paralysis of lower trunk (C8/T1) of brachial plexus often related to birth trauma e.g. shoulder dystocia
Claw hand due to loss of intrinsic muscles of hand - flexed IP joints, hyperextended MCP joints
May also cause Horner’s
What is Erb’s palsy? How does it look?
Paralysis of upper trunk (C5/6) of plexus often related to acquired trauma e.g. motorcycle RTAs
Weak shoulder abductors, elbow flexors so arm is adducted and internally rotated with extended and pronated forearm
Boundaries of the quadrangular space?
Superiorly = teres minor Inferiorly = teres major Laterally = humerus Medially = long head of triceps
Boundaries of triangular space?
Superiorly = teres minor Inferiorly = teres major Laterally = long head of triceps
What goes through the quadrangular space?
Axillary nerve
Posterior circumflex humeral artery
Branches of the axillary artery?
3 parts and 6 branches - STLSAP
Superior thoracic
Thoracoacromial and Lateral thoracic
Subscapular, Anterior and Posterior circumflex humerals
Mid shaft humeral fracture will damage which nerve?
Radial - as it goes through spiral groove of humerus
What would damage to the radial nerve at mid shaft humerus cause?
Wrist drop and sensation loss in first webspace
Elbow extension preserved
Which 2 forearm muscles are supplied by the ulnar nerve?
Flexor carpi ulnaris and ulnar half of FDP
What does damage to ulnar nerve at the wrist cause? Why?
Sensory loss of medial 1 1/2 fingers
Motor weakness of intrinsic hand muscles leading to clawing of 4th and 5th digits
Worse clawing than if proximal, as FDP is spared
Where does the flexor retinaculum attach?
Carpal bones - proximally to pisiform and tubercle of scaphoid, distally to hook of hamate and trapezium
Contents of the carpal tunnel?
Median nerve
4x FDP tendons
4xFDS tendons
FPL tendon
What happens to sensation of thenar eminence in carpal tunnel?
Preserved, because palmar cutaneous branch of median nerve is given off before it enters and passes superficial to flexor retinaculum
What nerve innervates levator scapula and the rhomboids?
Dorsal scapular
What does the suprascapular nerve innervate?
Supraspinatus and infraspinatus
What is subscapularis innervated by?
Upper and lower subscapular nerves
Surface anatomy of breast?
2nd to 6th rib
Sternum to mid axillary line
Deep muscular relations of the breast?
Pectoralis major (2/3) Serratus anterior (1/3)
3 major constituents of breast tissue?
Fat
Glandular tissue
Fibrous tissue
How many lobules are there within the breast?
15-20, each drained by a lactiferous duct
What are Cooper’s ligaments? Clinical signifiance?
Suspensory ligaments of breast
Fibrous tissue from pectoral fascia to subcutaneous tissue separating lobules of the breast
Malignant infiltration causes puckering/induration - p’eau d’orange
Arterial blood supply to breast?
Internal thoracic/mammary artery - from SCA
Lateral thoracic - from axillary 2
Thoraco-acromial - from axillary 2
Intercostal arteries
Lymph drainage of breast?
Axillary lymph nodes - 3 levels with respect to pectoralis minor
Parasternal LNs - along internal thoracics
Posterior intercostal LNs
Sensory nerve supply to breast?
Anterior and lateral cutaneous branches of 4th-6th intercostal nerves
Which muscle separates subclavian artery from vein? Which is more anterior?
Anterior scalene - vein is more anterior
Describe how to insert a subclavian line?
Infraclavicular approach. Supine, aseptic technique, head to opposite side
US guidance ideally. Insert needle and syringe 1cm below junction between middle and medial 1/3 of clavicle
Aim medially and posteriorly towards suprasternal notch
Advance whilst withdrawing until get flash, then use seldinger to feed catheter in the vein
Which layers would you pass through when inserting a subclavian central line?
Skin Platysma Fascia Pectoralis major Subclavius SCV
Where should the catheter tip lie in a subclavian line?
SVC above pericardial reflection
What would you do if aspirated air during subclavian line insertion? Where would you try again?
Assume pleural breach - check for pneumothorax
Try on same side to avoid bilateral pneumothorax
4 structures at risk during subclavian line insertion?
Subclavian artery - haemothorax
Pleura - pneumothorax
Phrenic nerve - posterior to subclavian vein
If on left - thoracic duct leading to chylothorax
Where is the intercostal neurovascular bundle? What is its organisation?
Between innermost and internal intercostal muscles
In inferior notch of rib
From superior to inferior - Vein Artery Nerve
Nerve supply to pleura?
Parietal = intercostal and phrenic nerve Visceral = pulmonary plexus - autonomic from branches of vagus and symp trunk
What separates inferior from superior mediastinum?
Horizontal line drawn from angle of Louis posteriorly
What level is the sternal angle?
T4/5
From anterior to posterior what is in the superior mediastinum?
Thymus Great veins Great arteries Trachea Oesophagus
What does the thymus do?
Specialised immune organ which ensures self-T cells are eliminated and immune system doesn’t attack itself
What are the features of a typical rib?
Head with 2 articular demifacets
Tubercle for articulation with transverse process
Subcostal groove containing intercostal NV bundle
Which ribs are atypical in terms of facets/tubercles and why?
First - in horizontal plane, single facet and tubercle - scalene tubercle on inner border
Ribs 10-12 - only have 1 facet
Ribs 11 and 12 have no tubercle
What muscles do the breasts overlie?
Pec major medially
Serratus anterior laterally
Blood supply to breast?
Lateral thoracic artery
Internal thoracic
Posterior intercostals
Thoraco-acromial
What arteries supply the transverse colon?
Middle colic artery to 2/3
Left colic artery distally
What is the major anastomotic artery between the SMA and IMA?
Marginal artery of Drummond - in mesentery
What arteries are most commonly implicated in diverticular bleeds?
Sigmoid branches of IMA
Where does the inferior mesenteric vein drain?
Splenic vein
What forms the portal vein?
SMV and splenic vein
What positions can the appendix lie in?
Retrocaecal
Pelvic
Subcaecal
Anterior or posterior to terminal ileum
Blood supply to rectum?
Superior rectal artery from IMA
Middle rectal artery from internal iliac
Inferior rectal artery from internal pudendal
Describe nerve supply to rectum?
PNS = S2 3 4, causes bowel contraction and relaxation of internal sphincter
Symp from superior hypogastric plexus and lumbar splanchnic nerves = painful stimuli, contract internal sphincter
Is rectum retroperitoneal?
Yes - upper 1/3 has peritoneum over front and sides, middle 1/3 just over front and bottom 1/3 below peritoneal reflection
What are the 5 branches of the SMA?
Inferior pancreaticoduodenal artery Jejunal and ileal arteries Ileocolic artery Right colic artery Middle colic artery
What muscle is responsible for ptosis e.g. in Horner’s?
Superior tarsal
Structures passing through the foramen magnum?
Medulla Vertebral and ant/post spinal arteries Spinal roots of accessory nerve Tectorial membrane Apical ligament of dens
What passes through the jugular foramen?
IJV
CN9, 10 and 11 (cranial portion)
What passes through the carotid canal?
ICA
Sympathetic nerves
Intracranial course of the facial nerve?
Arises at pontomedullary junction between CN6 and CN8
Large motor and small sensory root
Traverses post fossa, through IAM (in petrous temporal bone)
Enters facial canal
Exits facial canal via stylomastoid foramen, just posterior to styloid process of temporal bone
What 3 branches does the facial nerve give off in the facial canal?
Chorda tympani
Nerve to stapedius
Greater petrosal nerve - PNS to mucous/lacrimal glands
What and where is the geniculate ganglion?
Collection of facial nerve cell bodies in the facial canal
Contents of superior orbital fissure?
Ophthalmic vein
Lacrimal and middle meningeal communicating arteries
Lacrimal, frontal, nasociliary (V1) and trochlear, oculomotor and abducens nerves
What goes through the foramen ovale?
Accessory meningeal artery
V3 of trigem
Lesser petrosal nerve
Where do the greater and lesser petrosal nerves come from and go?
Greater = from geniculate ganglion of CN7, given off in petrous bone facial canal to innervate lacrimal and mucous glands (PNS) Lesser = from CN9, goes through foramen ovale to innervate parotid (PNS) via otic ganglion
What goes through foramen spinosum?
MMA
Meningeal branch of mandibular nerve
What goes through foramen cecum?
Vein to superior sagittal sinus
What goes through the IAM?
CN7, 8 and labyrinthine artery
What goes through the foramen rotundum?
V2 of trigem - maxillary nerve
