Learning MRCS A - anatomy

• - Lateral border – medial border of brachioradialis m.
• - Medial border – lateral border of pronator teres m.
• - Superior border – horizontal line drawn between the epicondyles of humerus
• - Roof – bicipital aponeurosis, fascia, subcutaneous fat and skin.
• - Floor – brachialis (proximally) and supinator (distally)

• - radial nerve
• - bicep tendon 
• - brachial artery 
• - medial nerve
• - roof: medial cubital vein 

Mnemonic for contents of the cubital fossa – Really Need (radial nerve) Beer To (biceps tendon) Be At (brachial artery) My Nicest (median nerve).

• - Radial n.: along lateral border of cubital fossa
•     + divides into superficial and deep branch
•     + motor + sensory f. (function) in posterior forearm and hand 

• - Biceps tendon: centrally through cubital fossa
•    + attaches to radial tuberosity (immediately distal to the radial neck)
•    + gives rise to bicipital aponeurosis -> contributes to roof of cubital fossa

• - Brachial artery: next
•    + bifurcates into the radial and ulnar arteries - at apex of cubital fossa
•    + brachial pulse: palpating medial to the biceps tendon

• - Medial nerve: medially through cubital fossa
•    + exiting by: between the two heads of the pronator trees
•    +  motor and sensory f. in the anterior forearm and hand

• * Roof: several superficial veins
•   - median cubital vein:
•      + connects basilic and cephalic veins
•      + common site for venepuncture

Mnemonic for contents of the cubital fossa – Really Need (radial nerve) Beer To (biceps tendon) Be At (brachial artery) My Nicest (median nerve).

• 1. fracture of distal humerus, typically transverse or oblique
• 2. FOOSH, more common in children 
• 3. contents of cubital fossa, esp.
• - brachial a. -> Volkmann's ischaemic contracture if not repair 
• - nerves:
•    + anterior interosseous (branch of median nerve)
•    + ulnar nerve
•    + radial nerve

• A) contents of the cubital fossa
•    + directly
•    + by soft tissue swelling following the trauma

• b) damage to brachial artery:
•    + if not repaired -> cause Volkmann’s ischaemic contracture
•    + (uncontrolled flexion of the hand) as the forearm flexor muscles become fibrotic and short

• c) test anterior interosseous nerve (branch of median n.)
•    + ask pt to make ‘OK’ sign - testing for weakness of flexor pollicis longus

• -Types
• Type 1 is minimally displaced
• Type 2 is displaced with but with an intact posterior cortex
• Type 3 is completely off-ended.

• - Mx:
•    + Type 1: conservative Mx w/ an above elbow cast 
•    + Types 2 and 3: typically - surgical fixation with crossed, bi-cortical k-wires.

• (Between ventricles and major vessles leaving heart)
• 1.Pulmonary valve: L 2nd intercostal space, upper sternal border
• 2.Aortic valve: R 2nd intercostal space, upper sternal border
• _{(1 pulm from R side - towards L to hear, 2 aortic from left - twisting outflow)}

• (Between atria + ventricles) 
• 3.Mitral valve: L 5th intercostal space, just medial to mid clavicular line  ((L side))
• 4.Tricuspid valve: L 5th intercostal space, at the lower left sternal border   ((R side heart))

Paired

• Superiorly – inferior border of the mandible (jawbone).
• Laterally – anterior border of the sternocleidomastoid.
• Medially – sagittal line down the midline of the neck.

• Roof - investing fascia 
• Floor - visceral fascia

-by hyoid bone, suprahyoid and infrahyoid muscles into four triangles

• Carotid triangle 
• Submental triangle 
• Submandibular triangle 
• Muscular triangle

- contents: include muscles, nerves, arteries, veins and lymph nodes

+muscles: in relation to hyoid bone -> suprahyoid / infrahyoid

• +important vascular strctures:
•      ⋄common carotid artery
•            -> bifurcates ⇾ external + internal carotid branches
•      ⋄internal jugular veins

+ cranial nerves: facial (VII), glossopharyngeal (IX - g ~9), accessory (XI), hypoglossal (XII)

- Special: doesn't articulate with other bones, suspended by muscles and ligaments

• - Structure:
•    + body: ant. convex, post. concave surface
•    + greater horn: projects post, superior lateral direction
•        ⋄ for attachment of neck muscles 
•    + lesser horn: from superior aspect, near origin of greater horn, projects superoposteriorly (toward styloid process of temporal bone) 
•       ⋄ stylohyoid ligament attaches to apex of lesser horn 

• TOSS My Gravy Spoon, Darling 
• (act to elevate hyoid bone, involve in swallowing -> food)

• Infrahyoid: 
• Thyrohyoid
• Omohyoid 
• Sternothyroid
• Sternohyoid 

• Suprahyoid: 
•   Mylohyoid
•   Geniohyoid
•   Stylohyoid
•   Digastric

- originate from the scapula and/or clavicle, and attach to the humerus

- 6: deltoid, teres major and rotator cuff (supraspinatus, infraspinus, subscapularis & teres minor)

• - Originates from scapula
• - Attaches to humeral head
• - collectively, resting tone - 'pull' humeral head into glenoid fossa -> additionally stability to glenohumeral joint

• - most to greater tubercle of humerus (supraspinatus, infraspinatus, teres minor)
• - except subscapularis (lesser tubercle of humerus)

• - supra + infra: suprascapular nerve 
• - subscapularis: upper and lower subscapular n. 
• - teres minor: axillary n. 

• _{((actually quite logical, related to position + name)} 
• _{teres minor - lowest, gan armpit -> axillary))}

• - supraspinatus: abducts arm 0-15 (i.e. initiating), assisting deltoid 15-90 
• - infraspinatus: laterally rotates arm
• - teres minor: laterally rotates arm (!! thay vi tri 1 ti))
• - subscapularis: medially rotates arm

- supraspinatus: rubs against coraco-acromial arch -> inflammation and degenerative changes in tendon

• - superificial: trapezius + latissimus dorsi 
• - deep: levator scapulae + 2 rhomboids

• adductor pollicis 
• palmaris brevis 
• interossei 
• lumbricals 
• thenar + hypothenar muscles

• - opponens pollicis, abductor brevis, flexor pollicis brevis 
• - all 3: median nerve 

(both short of ROM of thumb from that direction)

• - opponens digiti minimi, abductor digiti minimi, flexor digiti minimi brevis 
• - all 3: ulnar nerve

((little finger, only have 1 abductor, still the short one in this group))

• - opponens pollicis: largest, lies underneath the other 2
• - abductor pollicis brevis: anteriorly to OP and proximal to FPB 
• - flexor pollicis brevis: most distal 

(FP -fppppttt - xa nhat, most distal)

• - each tendon - originates from a tendon of FDP
• - insertion: passes dorsally + laterally around each finger, inserts into extension hood

• - 4
• - lateral (radial) 2 i.e. index + middle - median nerve, unipenate 
• - medial (ulnar) 2 i.e. ring + little - ulnar nerve, bipennate 

• ((index + middle - con giun manh, 1 dau thoi + ko đụng vô thumb
• ring + little - giun nho hon -> 2 dau)

flex MCPJ and extend IPJ

(mổ cò ăn giun)

• - 2 groups: dorsal + palmar
• - actions:
•     + MCPJ abduction (dorsal) + adduction (palmar) PAD DAB
•     + also assist lumbricals flex MCPJ + extend IPJ 

((dùng pad thoa mặt dab dab))

all - ulnar nerve

• - dorsal interossei: most superifical of all dorsal muscles
•    + 4
•    + from: med/lat aspects of metacarpals
•    + attach: into extensor hood + proximal phalanx each finger

(makes sense - middle abduct either way depending on prior position -> has 2; for index, middle + ring fingers (thumb + little have their own)

• - 3 (+/- 1 at base proximal phalanx of thumb) 
• - from medial / lateral of a metacarpal 
• - attaches to extensor hood + p1 of same finger

(this time, middle finger doesn't have 1 -> ring, little, index, insertion same to dorsal ones, med/lat depending on which finger position to midline)

• - large triangular muscle with 2 heads 
• - radial a. passes anteriorly between 2 head -> deep palmar arch

• - from:
•    + 1 head 3rd MC (transverse)
•    + (oblique) other: capitate + 2nd & 3rd MC
• - insert: both into base of P1 thumb 

• - palmaris brevis: 
•    + from palmar aponeurosis + flexor retinaculum
•    + skin dermis of ulnar margin of hand

• - palmaris brevis: wrinkle hypotenar, deepen curvature, ↑
• grip

- adductor pollicis: adduct thumb

• - thenar + hypothenar: median + ulnar n. 
• - lumbricals: radial 2 median; ulna 2 - ulnar n. 
• - interossei: all 7 (or 8) ulnar n. 
• - other 2: ulnar n.

6

• 1st: contributes to stapedial, maxillary and hyoid a. 
• 2nd: contributes to stapedial, maxillary and hyoid a. 
• 3rd: forms common carotid a. and part of proximal internal carotid a. 
• 4th: R arch forms R subclavian, L arch forms part of aorta
• 5th: never forms / incompletely and regress
• 6th: R arch R pulmary a., L arch from L pulmonary a. and ductus arteriosus 

((đảo thứ tự 1 chút, xong nhớ từ sup -> inf) 

• - each arch has a corresponding nerve during development 
• - most notable - recurrent laryngeal n. (branch from CN X)
• - associated with 6th arch
•    + R. recurrent laryngeal n.
•    + L. recurrent laryngeal n.
• both initially hookds around 6th aortic arch
• R: distal part R 6th arch disappear -> moves up to hook around R subclavian (4th arch)
• L: distal part L 6th arch persists as ductus arteriosum -> remains there => long course -> susceptive to pathology in chest 
• e.g. compression by aortic aneurysm

• (aortic arch 
•     + L common carrotid + L subclavian
•     + R brachiocephalic - R common carotid + R subclavian)

• - subclavian
• - axillary 
• - brachial 
• - radial
• - ulnar 

- terminal - digital arteries

• - begins R from brachiocephalic, vs L direct arch of aorta
• - laterally towards axilla

• - 3 parts: relative to anterior scalene muscle
•    + 1st: origin to medial border ant. scalene
•    + 2nd: post to ant. scalene 
•    + 3rd: lateral border of ant. scalene to lat. border of 1st rib 

- ends: enter axilla at border 1st rib -> axillary artery

• - position: deep to pectoralis major, enclosed in axillary sheath 
•     + (sheath: covers artery + 3 cords of brachial plexus) 

• - parts: relative to pec major
•     + 1st: proximal to pec major
•     + 2nd: post to pec major 
•     + 3rd: distal to pec major

- ends: lower border of teres major -> brachial artery

• - 1st part: superior thoracic a.
• - 2nd part: thoraco-acromial a., lateral thoracic a. 
• - 3rd part: subscapular a., anteror & post. circumflex a. 

(also easy 1st,2nd,3rd have 1,2,3 branches)

Ant. + Post. circumflex humeral arteries form anastomotic network around surgical neck of humerus -> could be damaged in cases of fracture

- what: dilation > twice original size

• - why important: 
•    + rare but serious
•    + can cause: 
•        ⋄ vascular compromise of upper limb 
•        ⋄ can compress brachia plexus -> neurological sx: paraesthesia + muscle weakness

• - treatment: definitive - surgical 
•    + involves excising aneurysm and reconstructing vessel wall using a vascular graft

• L2,3: 
• - hip flexion -  iliopsoas (lumbar plexus, femoral n.)
• - hip adduction - hip adductors (obturator n.)

(bắt đầu thì làm duyên, nhỏ hẹp flex + adduction))

• L2,3: 
• - hip flexion -  iliopsoas (lumbar plexus, femoral n.)
• - hip adduction - hip adductors (obturator n.)

(bắt đầu thì làm duyên, nhỏ hẹp flex + adduction))

• L4: 
• - knee extension - quadriceps (femoral n.)

• L4: 
• - knee extension - quadriceps (femoral n.)

• L5: 
• - ankle dorsiflex - tibialis anterior (deep peroneal n.)
• - foot inversion - tibialis posterior (tibial n.)
• - toe dorsiflexion - EHL (DPN), EDL (DPN)

• ((so far - going along L2,3 - L4, L5 proximal -> distal, now turn back a bit))
• - hip extension: hamstrings (tibial), gluteus max (inf. gluteal n.)
• - hip abduction: gluteus medius (sup. gluteal n.)

• L5: 
• - ankle dorsiflex - tibialis anterior (deep peroneal n.)
• - foot inversion - tibialis posterior (tibial n.)
• - toe dorsiflexion - EHL (DPN), EDL (DPN)

• ((so far - going along L2,3 - L4, L5 proximal -> distal, now turn back a bit))
• - hip extension: hamstrings (tibial), gluteus max (inf. gluteal n.)
• - hip abduction: gluteus medius (sup. gluteal n.)

• S1: 
• - foot plantar flexion - gastro, soleus (tibial n.)
• - foot eversion - roneals (SPN)

• S1: 
• - foot plantar flexion - gastro, soleus (tibial n.)
• - foot eversion - roneals (SPN)

• S2: 
• - toe plantar flexion - FHL (tibial n.), FDL (tibial n.)

• S2: 
• - toe plantar flexion - FHL (tibial n.), FDL (tibial n.)

• S3,4
• - bowel & bladder function - bladder muscle

L1 - iliac crest and groin

L2,3 - anterior and inner thigh

L4 - lateral thigh, anterior knee, medial leg

(đi chéo chéo)

L5 - lateral leg & dorsal foot

S1 - posterior leg

plantar foot

derivatives of 2nd pharyngeal arch

• - motor
• - sensory 
• - special sensory
• - parasympathetic

• - motor: 
•   + muscle of facial expression 
•   + post. belly of digastric 
•   + stylohyoid
•   + stapedius 

• (quite high up, rearrange: 
• suprahyoid - more post post digastric + stylohyoid part, facial expression, stapedius
• S for second arch - stapedius, 72)

small area around concha of external ear

taste senstion to anterior 2/3 of tongue via chord tympani

• many glands in head and neck, inc.
• - submandibular and sublingual salivary glands 
• - nasal, palatine and pharyngeal mucous glands (mũi họng mucous)
• - lacrimal glands

• - anterior 2/3
• - posterior 1/3

• - general sensation: by trigeminal nerve (CN V)
•    + specifically: lingual nerve, a branch of mandibular nerve (CN V3)
• - taste seation: facial nerve (CN VII) via chorda tympani
•   + in petrous part of temporal bone, CN VII facial nerve gives off 3 branches 
•       -> 1 is chorda tympani - through middle ear and onto tongue

both touch and taste - supply by glossopharyngeal nerve (CN IX)

(9 - glosso, tongue, behind (posterior) vì 9 lớn)

• Two Zebras Bit My Coccyx
• T: temporal
• Z: zygomatic
• B: buccal
• M: mandibula
• C: cervical 

Bị cắn nhăn mặt

names of skull foramina that 3 divisions of trigeminal nerve (CN V) pass through: 

Standing Room Only 

• S: superior orbital fissure (ophthalmic division)
• R: foramen rotundum (maxillary division)  ((ri - ro - ri - ro)
• O: foramen ovale (mandibular division) 

((miệng mở tròn tròn ovale, mandibular)

• depending on site of lesions
• - intracranial 
• - extracranial

• - course: proximal to stylomastoid foramen
• - damage
•    + muscles of facial expression: paralysed / severely weakened 
•    + other symptoms (depending on branches + location)
•       ⋄ chorda tympani: reduced salivation and loss of taste ipsilateral 2/3 of tongue 
•       ⋄ nerve to stapedius: ipsilateral hyperacusis (hypersensitive to sound)
•       ⋄ greater petrosal nerve: ipsilateral reduced lacrimal fluid production

• most common cause - infection related to external / middle ear
• if no def cause - Bell's palsy

only motor function of facial nerve affected -> paralysis / severe weakness of muscles of facial expression

• various
• - Parotid gland pathology – e.g a tumour, parotitis, surgery.
• - Infection of the nerve – particularly by the herpes virus.
• - Compression during forceps delivery – neonatal mastoid process is not fully developed ->  does not provide complete protection of the nerve
• - Idiopathic – If no definitive cause can be found then the disease is termed Bell’s palsy.

• - An oval, mobile cystic mass
• - between sternocleidomastoid muscle & pharynx
• - due to failure of obliteration of the second branchial cleft in embryonic development
• - Usually present in early adulthood

(b - bạc, second)

• - More common in  < 20 yo
• - usu.  midline, between isthmus of the thyroid & hyoid bone
• - Moves upwards with protrusion of the tongue
• - May be painful if infected

• - May be hypo-, eu- or hyperthyroid symptomatically
• - Moves upwards on swallowing

• - pulsatile lateral neck mass
• - doesn't move on swallowing

• - More common in adult females
• - Around 10% develop thoracic outlet syndrome

• - A congenital lymphatic lesion (lymphangioma)
• - typically in neck, classically on the left side
• - Most are evident at birth, around 90% present before 2 years of age

• - Rubbery, painless lymphadenopathy
• - pain whilst drinking alcohol is very uncommon
• - may be associated w/ night sweats and splenomegaly

• - begins in 4th & 5th week
• - pharyngeal arches: 
•     + growth of mesenchymal tissue (connective tissue)
•     + in cranial region of embryo -> formation of arches
• - pharyngeal clefts
•      + separated by clefts

• - pharyngeal pouches
•    + simultaneously - outpocketings on lateral wall of pharynx

• -> pouches separate arches on internal (endodermal) surface
•     cleft separate arches on external (ectodermal) surface

• - initially 4
• - only 1st -> permanent structure in adult - external auditory meatus 

• - 2nd, 3rd, 4th form temporary cervical sinues 
•  -> obliterated by rapidly proliferating 2nd pharyngeal arch

• - 6 - 5th regresses soon after forming
• - innervated by arch-associated cranial nerve 
• - components:
•    + muscular
•    + supporting skeletal and cartilaginous element
•    + vascular component

• - 1st arch: trigeminal nerve (CN V)
• - 2nd arch: facial nerve (CN VII)
• - 3rd arch: glossopharyngeal n. (CN IX)
• - 4th arch: vagus nerve (CN X)
• - 6th arch: recurrent laryngeal branch of vagus nerve (CN X)

MAP OF Sciatic

• - Medial compartment - Obturator nerve
• - Anterior compartment - Femoral nerve
• - Posterior compartment - Sciatic nerve

• L5
• - ankle dorsiflexion: tibialis anterior (deep peroneal n.)
• - toe dorsiflexion: EHL, EDL (DPN)
• - foot inversion: tibialis posterior (tibial n.)

• (toe dorsiflex thi di lien voi inversion (vs eversion, ngược ngạo) 
• ant. ((extension)) deep PN
• anything plantar-ish tibial n.

• S1
• - foot plantar flexion: gastroc, soleus (tibial n.) 
• - foot eversion: peroneals (SPN)

• innvervation - primary muscles lower leg
• S2: 
• - toe plantar flexion: FHL (tibial n.), FDL (tibial n.)

• - C2: occiput and top neck.
• - C3: lower part of neck to clavicle.
• - C4: just below the clavicle.

• Situated in the arms.
• - C5: lateral arm at & above elbow
• - C6: forearm and radial (thumb) side of hand
• - C7: middle finger
• - C8: medial aspect of hand
• - T1: medial side of forearm.

• The thoracic covers the axillary and chest region.
• - T3 to T12: chest and back to the hip girdle.
• - T4: nipples in the middle of T4
• - T10: at the umbilicus
• - T12: ends just above the hip girdle.

• - L1: the hip girdle and groin area
• - L2 and 3: front part of the thighs
• - L4: medial lower leg
• - L5: lateral the lower leg.

• - S1:heel and the middle back of leg
• - S2: back of the thighs
• - S3: medial side of buttocks
• - S4-5: perineal region.
• - S5 is of course the lowest dermatome and represents the skin immediately at and adjacent to the anus.

• - Elbow flexors/Biceps: C5
• - Wrist extensors: C6
• - Elbow extensors/Triceps: C7
• - Long finger flexors: C8
• - Small finger abductors: T1

• Ko theo thứ tự chi cả: C5 start at elbow OK, C6 nhảy qua wrist extensor then C7 vẫn là posterior up elbow/forearm -> C5-C7 arm
• - Xong tới hand: C8 long finger flexor (anterior trước), T1 small finger abductors

• - Hip flexors (psoas): L1 and L2
• - Knee extensors (quadriceps): L3
• - Ankle dorsiflexors (tibialis anterior): L4 and L5
• - Toe extensors (hallucis longus): L5
• - Ankle plantar flexors (gastrocnemius): S1

- The anal sphincter is innervated by S2,3,4

Femoral nerve - dorsal divisions of ventral rami of L2,3,4

Sciatic nerve - longest nerve, L4 - S3 of sacral plexus

(MAP OFScy)

• Femoral nerve
• iliopsoas (psoas - by L1,2,3)
• Sartorius
• Quadratus femoris: 3x vastus (lateralis, intermedius, medialis) + rectus femoris

+/- pectineus (sometimes of adductor)

Sciatic nerve

• Biceps femoris (long head - tibial n., short head- common fibular n. of sciatic n.)
• Semitendinosus + semimembranosus