*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE BRAIN

1. DEVELOPMENTAL & EMBRYOLOGICAL BASIS (SURGICAL RELEVANCE)

Understanding adult surgical anatomy requires embryologic orientation.

Neural Tube Formation

3rd week: Neural plate → neural groove → neural tube
Closure begins cervical region
Neuropore closure:
- Cranial: Day 25
- Caudal: Day 27

Failure results in:

Anencephaly
Encephalocele
Spina bifida

Primary Brain Vesicles

Week	Vesicle	Adult Derivative
4	Prosencephalon	Forebrain
4	Mesencephalon	Midbrain
4	Rhombencephalon	Hindbrain

Secondary Vesicles

Telencephalon → Cerebral hemispheres
Diencephalon → Thalamus, hypothalamus
Mesencephalon → Midbrain
Metencephalon → Pons, cerebellum
Myelencephalon → Medulla

Surgical importance:

Congenital malformations
Dandy–Walker malformation
Chiari malformations

2. MENINGES — SURGICAL LAYERS & SPACES

Dura Mater

Two layers:

Periosteal
Meningeal

Reflections:

Falx cerebri
Tentorium cerebelli
Falx cerebelli
Diaphragma sellae

Clinical:

Subfalcine herniation
Transtentorial (uncal) herniation
Tonsillar herniation

Venous Sinuses (Surgical Landmarks)

Superior sagittal sinus
Inferior sagittal sinus
Straight sinus
Transverse sinus
Sigmoid sinus
Cavernous sinus

Cavernous sinus contains:

ICA
CN III, IV, V1, V2, VI

Cavernous sinus thrombosis → ophthalmoplegia + fever

3. CEREBRAL HEMISPHERES — SURGICAL TOPOGRAPHY

Surface Landmarks

Key sulci:

Central sulcus
Lateral sulcus
Parieto-occipital sulcus

Frontal Lobe (Surgical Importance)

Contains:

Primary motor cortex
Premotor cortex
Supplementary motor area
Broca's area (dominant hemisphere)

Blood supply:

ACA (medial)
MCA (lateral)

Lesions:

Contralateral hemiplegia
Expressive aphasia

Parietal Lobe

Somatosensory cortex
Superior/inferior parietal lobule

Right-sided lesion:

Hemispatial neglect

Temporal Lobe

Structures:

Hippocampus
Amygdala
Wernicke's area

Surgical note: Temporal lobectomy for epilepsy

Occipital Lobe

Visual cortex

PCA territory

Lesion:

Homonymous hemianopia

4. INTERNAL CEREBRAL STRUCTURES

Corpus Callosum

Parts:

Rostrum
Genu
Body
Splenium

Lesion:

Disconnection syndrome

Basal Ganglia (Deep Brain Surgery Importance)

Components:

Caudate nucleus
Putamen
Globus pallidus
Subthalamic nucleus
Substantia nigra

Deep Brain Stimulation targets:

Subthalamic nucleus
Globus pallidus internus

5. DIENCEPHALON

Thalamus

Relay nucleus classification:

Ventral posterolateral (body sensation)
Ventral posteromedial (face sensation)
Lateral geniculate (vision)
Medial geniculate (hearing)

Thalamic stroke → pure sensory stroke

Hypothalamus

Functions:

Temperature
Hunger
Thirst
Endocrine control

Pituitary relation:

Infundibulum

Surgical relevance:

Pituitary adenoma approach (transsphenoidal)

6. BRAINSTEM (LIFE-CRITICAL ZONE)

MIDBRAIN

Structures:

Cerebral peduncles
Tectum
Red nucleus
Substantia nigra

Syndromes:

Weber syndrome
Benedikt syndrome

PONS

Contains:

Pontine nuclei
CN V–VIII nuclei

Lesion:

Locked-in syndrome

MEDULLA

Structures:

Pyramids
Olives
Nucleus gracilis
Nucleus cuneatus

Syndromes:

Lateral medullary (Wallenberg)
Medial medullary

7. VENTRICULAR SYSTEM

Lateral ventricles
Foramen of Monro
Third ventricle
Aqueduct of Sylvius
Fourth ventricle

Hydrocephalus types:

Communicating
Non-communicating

Shunt surgery relevance.

8. CEREBRAL BLOOD SUPPLY

Internal Carotid System

Branches:

Vertebrobasilar System

Vertebral arteries
Basilar artery
PCA

Circle of Willis

Common aneurysm sites:

Anterior communicating
Posterior communicating
MCA bifurcation

Subarachnoid hemorrhage → thunderclap headache

9. WHITE MATTER TRACTS

Projection fibers:

Internal capsule

Commissural fibers:

Corpus callosum

Association fibers:

Superior longitudinal fasciculus

Internal capsule lesion → dense contralateral hemiplegia

10. FUNCTIONAL MAPPING IN SURGERY

Broca
Wernicke
Motor cortex
Sensory cortex

Awake craniotomy used to preserve speech areas.

11. BRAIN HERNIATION SYNDROMES

Subfalcine
Uncal
Central
Tonsillar

Pupil dilation = CN III compression.

*- ULTRA-ADVANCED SURGICAL ANATOMY OF THE CRANIAL NERVES

(Neurosurgical, skull-base, ENT, vascular & operative relevance)

Overview of Cranial Nerves

The 12 cranial nerves emerge from the brain and brainstem, pass through skull base foramina, and supply the head, neck, and viscera.

They are classified by:

Functional components
Brainstem nuclei
Skull base exit
Parasympathetic ganglia
Surgical vulnerability

I. FUNCTIONAL COMPONENT CLASSIFICATION (Advanced)

Each cranial nerve contains one or more of the following fiber types:

Somatic Motor (GSE)

III, IV, VI, XII

Branchial Motor (SVE)

V3, VII, IX, X, XI

Parasympathetic (GVE)

III, VII, IX, X

General Sensory (GSA)

V (main), VII, IX, X

Special Sensory

I (smell)
II (vision)
VIII (hearing & balance)
VII, IX, X (taste)

Understanding these components is essential in brainstem lesion localization.

II. CRANIAL NERVE I — OLFACTORY NERVE

Anatomy

Origin:

Olfactory epithelium

Fibers pass through:

Cribriform plate

Terminate in:

Olfactory bulb → tract → limbic system

Unique features:

Only sensory system that bypasses thalamus initially.

Surgical Relevance

Anterior cranial fossa fractures → anosmia
CSF rhinorrhea after cribriform damage
Olfactory groove meningioma

III. CRANIAL NERVE II — OPTIC NERVE

Intracranial Course

Segments:

Intraocular
Intraorbital
Intracanalicular
Intracranial

Optic chiasm:

Nasal fibers decussate

Blood Supply

Ophthalmic artery
Central retinal artery

Surgical Relevance

Pituitary adenoma → bitemporal hemianopia
Craniopharyngioma
Optic neuritis
Raised ICP → papilledema

IV. OCULOMOTOR (III)

Nuclei (Midbrain Level)

Oculomotor nucleus
Edinger–Westphal nucleus (parasympathetic)

Course

Emerges from:

Interpeduncular fossa

Passes:

Between PCA and SCA
Through cavernous sinus
Enters orbit via superior orbital fissure

Functions

Motor:

All extraocular muscles except:
- Lateral rectus
- Superior oblique

Parasympathetic:

Pupil constriction
Accommodation

Clinical

Posterior communicating artery aneurysm → CN III palsy
Dilated pupil = surgical emergency.

V. TROCHLEAR (IV)

Only nerve:

Exits dorsal brainstem
Crosses completely

Supplies:

Superior oblique

Lesion:

Vertical diplopia
Worse when descending stairs

VI. TRIGEMINAL NERVE (V)

Root Entry Zone

Largest cranial nerve.

Emerges:

Lateral pons

Divisions:

V1 — Ophthalmic
V2 — Maxillary
V3 — Mandibular

Trigeminal Ganglion

Located in:

Meckel’s cave

Foramina

V1 → Superior orbital fissure
V2 → Foramen rotundum
V3 → Foramen ovale

Surgical Importance

Trigeminal neuralgia:

Usually vascular compression (SCA)
Treated by microvascular decompression

Cavernous sinus syndrome affects:

V1, V2

VII. ABDUCENS (VI)

Course

Emerges:

Pontomedullary junction

Long intracranial course.

Passes:

Through cavernous sinus
Superior orbital fissure

Vulnerability

Raised ICP → first nerve affected
Cavernous sinus thrombosis

Lesion:

Inability to abduct eye

VIII. FACIAL NERVE (VII)

Brainstem Origin

Motor nucleus
Superior salivatory nucleus
Solitary nucleus

Intratemporal Course

Segments:

Meatal
Labyrinthine
Tympanic
Mastoid

Branches

Greater petrosal nerve
Chorda tympani
Stylomastoid exit branches

Surgical Importance

Parotid surgery
Mastoid surgery
Bell’s palsy
Acoustic neuroma

Upper motor neuron lesion:

Forehead spared

Lower motor neuron lesion:

Entire side paralyzed

IX. VESTIBULOCOCHLEAR (VIII)

Two components:

Cochlear
Vestibular

Internal acoustic meatus.

Tumors:

Vestibular schwannoma

Symptoms:

Hearing loss
Tinnitus
Ataxia

X. GLOSSOPHARYNGEAL (IX)

Functions:

Taste posterior 1/3
Stylopharyngeus
Parotid gland (otic ganglion)

Clinical:

Glossopharyngeal neuralgia

XI. VAGUS (X)

Most extensive cranial nerve.

Emerges:

Medulla

Exits:

Jugular foramen

Branches

Pharyngeal
Superior laryngeal
Recurrent laryngeal

Surgical Importance

Thyroid surgery:

Recurrent laryngeal injury → hoarseness

Left recurrent laryngeal:

Loops under aortic arch

Right:

Loops under subclavian artery

XII. ACCESSORY (XI)

Spinal root:

C1–C5

Supplies:

SCM
Trapezius

Lesion:

Shoulder droop
Weak head rotation

XIII. HYPOGLOSSAL (XII)

Emerges:

Medulla

Exits:

Hypoglossal canal

Supplies:

Tongue muscles

Lesion:

Tongue deviates toward lesion

BRAINSTEM SYNDROME LOCALIZATION

Lateral Medullary (Wallenberg)

PICA lesion

Medial Medullary

ASA lesion

Millard-Gubler

Pontine lesion

CAVERNOUS SINUS SYNDROME

Contents:

Causes:

Thrombosis
Pituitary tumor
ICA aneurysm

SKULL BASE SURGICAL CORRIDORS

Anterior fossa:

Olfactory

Middle fossa:

Cavernous sinus nerves

Posterior fossa:

Lower cranial nerves

PARASYMPATHETIC GANGLIA

Ciliary (III)
Pterygopalatine (VII)
Submandibular (VII)
Otic (IX)

*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE KIDNEY & NEPHRON

(Urology, Transplant Surgery, Vascular Surgery, Interventional Radiology Level)

Gross Anatomy of the Kidney

The kidneys are paired retroperitoneal organs located in the posterior abdominal wall at the level of T12–L3 vertebrae.

Right kidney lies slightly lower due to the liver.
Weight: 120–170 g (adult)
Size: ~11 × 6 × 3 cm

1️⃣ SURGICAL RELATIONS

Posterior Relations

Diaphragm
12th rib (both sides), 11th rib (left side)
Psoas major
Quadratus lumborum
Transversus abdominis

Clinical relevance:

Percutaneous nephrolithotomy (PCNL)
Posterior approach avoids peritoneum

Anterior Relations

Right kidney:

Liver
Duodenum (2nd part)
Right colic flexure

Left kidney:

Stomach
Spleen
Pancreas
Left colic flexure

These relations are critical in:

Nephrectomy
Trauma surgery
Tumor resection

2️⃣ RENAL COVERINGS (SURGICAL LAYERS)

From inside outward:

Fibrous capsule
Perirenal fat
Renal fascia (Gerota’s fascia)
Pararenal fat

Gerota’s fascia encloses:

Kidney
Adrenal gland
Perirenal fat

Clinical:

Limits spread of infection
Perinephric abscess
Renal cell carcinoma extension

3️⃣ RENAL HILUM (CRITICAL SURGICAL LANDMARK)

From anterior to posterior:

Renal vein
Renal artery
Renal pelvis

Mnemonic: V-A-P

Left renal vein is longer and crosses anterior to aorta.

Nutcracker syndrome: Compression between SMA and aorta.

4️⃣ SEGMENTAL ANATOMY (TRANSPLANT & PARTIAL NEPHRECTOMY)

Kidney divided into 5 vascular segments:

Apical
Upper
Middle
Lower
Posterior

Each supplied by segmental arteries (end arteries).

No significant collateral supply → segmental resection possible.

5️⃣ ARTERIAL SUPPLY (DETAILED MICROVASCULAR PATHWAY)

Renal artery →
Segmental →
Interlobar →
Arcuate →
Interlobular →
Afferent arteriole →
Glomerulus →
Efferent arteriole →
Peritubular capillaries / Vasa recta

Important surgical note: Accessory renal arteries present in ~30% of individuals.

Transplant surgery must preserve all accessory arteries.

6️⃣ RENAL VEINS

Right renal vein:

Short
Direct to IVC

Left renal vein:

Longer
Receives:
- Left gonadal vein
- Left suprarenal vein
- Lumbar veins

This explains:

Left-sided varicocele (renal vein compression)

7️⃣ LYMPHATIC DRAINAGE

Drains into:

Para-aortic (lumbar) lymph nodes

Important in:

Renal carcinoma staging

8️⃣ NERVE SUPPLY

Renal plexus:

Sympathetic fibers (T10–L1)
Parasympathetic (vagus)

Pain:

Referred to flank and groin (T10–T12 dermatomes)

9️⃣ MICROSCOPIC SURGICAL ANATOMY — THE NEPHRON

Each kidney contains approximately 1–1.2 million nephrons.

Two types:

Cortical (85%)
Juxtamedullary (15%) — essential for urine concentration

🔬 GLOMERULUS (FILTRATION UNIT)

Components:

Fenestrated endothelium
Basement membrane
Podocytes

Filtration barrier layers:

Endothelial fenestrations
Glomerular basement membrane
Slit diaphragm

Clinical:

Nephrotic syndrome (podocyte injury)
Glomerulonephritis

🔬 JUxtaGLOMERULAR APPARATUS (JGA)

Components:

Macula densa
Juxtaglomerular cells
Extraglomerular mesangial cells

Function:

Renin secretion
Blood pressure regulation
RAAS activation

Critical in:

Renal artery stenosis
Hypertension

🔬 TUBULAR SYSTEM (FUNCTIONAL ZONES)

Proximal Convoluted Tubule (PCT)

Reabsorbs 65–70% of filtrate
Brush border
Highly vascular

Clinical:

Acute tubular necrosis

Loop of Henle

Descending limb:

Water permeable

Ascending limb:

Impermeable to water
Active Na-K-2Cl transport

Target of:

Loop diuretics

Distal Convoluted Tubule

Regulated by:

Aldosterone
Parathyroid hormone

Collecting Duct

Regulated by:

Final urine concentration occurs here.

🔟 RENAL MEDULLA & COUNTERCURRENT SYSTEM

Juxtamedullary nephrons create hyperosmotic medulla.

Vasa recta:

Prevents washout
Maintains gradient

Surgical importance: Medullary damage → inability to concentrate urine.

1️⃣1️⃣ SURGICAL APPROACHES

Open Nephrectomy

Flank incision
Retroperitoneal

Laparoscopic Nephrectomy

Transperitoneal
Retroperitoneoscopic

Partial Nephrectomy

Tumor resection with segment preservation

Warm ischemia time critical (<30 min preferred).

1️⃣2️⃣ RENAL TRANSPLANT ANATOMY

Donor kidney placed in:

Iliac fossa

Anastomosis:

Renal artery → external iliac artery
Renal vein → external iliac vein
Ureter → bladder

Accessory arteries complicate transplant.

1️⃣3️⃣ COMMON SURGICAL CONDITIONS

Renal Cell Carcinoma

Invades renal vein
Can extend to IVC

Wilms Tumor (Children)

Renal Artery Stenosis

Hydronephrosis

Nephrolithiasis

Common sites of obstruction:

Pelvi-ureteric junction
Pelvic brim
Vesicoureteric junction

1️⃣4️⃣ RENAL FASCIAL COMPARTMENTS

Gerota’s fascia separates:

Perinephric space
Paranephric space

Spread of infection is compartment-dependent.

1️⃣5️⃣ RADIOLOGICAL CORRELATION

CT scan phases:

Non-contrast
Corticomedullary
Nephrographic
Excretory

Essential for:

Tumor staging
Trauma grading

1️⃣6️⃣ TRAUMA CLASSIFICATION (AAST)

Grade I – Contusion
Grade II – Minor laceration
Grade III – Deep laceration
Grade IV – Collecting system involvement
Grade V – Shattered kidney

Management:

Conservative for most
Surgery for unstable patients

1️⃣7️⃣ EMBRYOLOGY (ADVANCED)

Three stages:

Pronephros
Mesonephros
Metanephros (definitive kidney)

Ascent: From pelvis → lumbar region.

Malrotation and ectopic kidney:

Horseshoe kidney
Pelvic kidney

1️⃣8️⃣ SURGICAL PEARLS

Clamp renal artery before vein during nephrectomy
Preserve adrenal gland if possible
Identify ureter early
Watch for lumbar veins

1️⃣9️⃣ KEY CLINICAL CORRELATIONS

Left renal vein compression → varicocele
Renal artery stenosis → secondary hypertension
Podocyte damage → proteinuria
Loop diuretics → act on thick ascending limb
ADH → collecting duct

*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE HAND

(Orthopedic Surgery, Plastic Surgery, Hand Surgery, Microvascular & Trauma Level)

Gross Overview of the Hand

The hand is the most functionally specialized structure of the upper limb, designed for:

Precision grip
Power grip
Fine motor coordination
Sensory discrimination

It consists of:

27 bones
29 joints
34 muscles (intrinsic + extrinsic)
Complex tendon pulley systems
Dense neurovascular networks

1️⃣ OSTEOLOGY (SURGICAL DETAIL)

A. Carpal Bones (8)

Proximal row (lateral → medial):

Scaphoid
Lunate
Triquetrum
Pisiform

Distal row:

Trapezium
Trapezoid
Capitate
Hamate

Surgical Relevance

🔹 Scaphoid fracture

Most commonly fractured carpal
Risk of avascular necrosis
Retrograde blood supply

🔹 Lunate dislocation

Median nerve compression

🔹 Hook of hamate fracture

Seen in athletes
Ulnar nerve injury risk

B. Metacarpals

5 bones numbered I–V.

Neck fractures:

5th metacarpal → Boxer’s fracture

C. Phalanges

14 total
Thumb has 2

Distal phalanx:

Mallet finger injury
FDP avulsion (Jersey finger)

2️⃣ JOINTS OF THE HAND

Radiocarpal Joint

Ellipsoid
Allows flexion, extension, abduction, adduction

Midcarpal Joint

Important for wrist motion.

Carpometacarpal (CMC) Joints

1st CMC (thumb):

Saddle joint
Highly mobile
Osteoarthritis common

Metacarpophalangeal (MCP)

Collateral ligaments:

Taut in flexion

Ulnar collateral ligament injury:

Gamekeeper’s thumb

Interphalangeal (IP)

Hinge joints
Flexion/extension only

3️⃣ FLEXOR COMPARTMENT (PALMAR SURGICAL ANATOMY)

Extrinsic Flexors

Flexor digitorum superficialis (FDS)
Flexor digitorum profundus (FDP)
Flexor pollicis longus (FPL)

All pass through: Carpal Tunnel

Carpal Tunnel Contents

Median nerve
FDS (4 tendons)
FDP (4 tendons)
FPL

Roof:

Flexor retinaculum

Carpal tunnel syndrome:

Median nerve compression
Thenar wasting
Surgical release involves dividing flexor retinaculum

4️⃣ TENDON PULLEY SYSTEM

Flexor tendons held by:

Annular pulleys:

A1–A5

Cruciform pulleys:

C1–C3

A2 and A4 are most critical.

Damage → bowstringing.

Trigger finger:

A1 pulley stenosis

5️⃣ PALMAR SPACES (INFECTION PATHWAYS)

Deep palmar spaces:

Thenar space
Midpalmar space

Communicate proximally with:

Parona’s space (forearm)

Felon:

Infection of distal pulp

6️⃣ EXTENSOR COMPARTMENT (DORSAL)

Extensor retinaculum divides tendons into 6 compartments:

APL, EPB
ECRL, ECRB
EPL
ED, EI
EDM
ECU

De Quervain’s tenosynovitis:

1st compartment inflammation

7️⃣ INTRINSIC MUSCLES (FINE CONTROL)

Thenar Muscles

Abductor pollicis brevis
Flexor pollicis brevis
Opponens pollicis

Median nerve supply.

Hypothenar Muscles

Abductor digiti minimi
Flexor digiti minimi
Opponens digiti minimi

Ulnar nerve supply.

Lumbricals

Flex MCP
Extend IP

Interossei

Dorsal:

Abduct (DAB)

Palmar:

Adduct (PAD)

Ulnar nerve lesion:

Claw hand

8️⃣ NEUROVASCULAR ANATOMY

Median Nerve

Motor:

Thenar muscles
Lumbricals (1,2)

Sensory:

Lateral 3½ fingers

Injury:

Ape thumb deformity

Ulnar Nerve

Motor:

Intrinsic muscles

Sensory:

Medial 1½ fingers

Injury:

Clawing of 4th & 5th digits

Radial Nerve

Motor:

Wrist extensors

Injury:

Wrist drop

9️⃣ ARTERIAL SUPPLY

From brachial → radial & ulnar arteries.

Form:

Superficial palmar arch (ulnar dominant)
Deep palmar arch (radial dominant)

Allen test:

Assesses collateral flow

🔟 MICROVASCULAR SURGERY

Digital arteries:

Run along sides of fingers

Digital nerve blocks:

Base of finger

Replantation surgery:

Requires arterial + venous repair
Tendon repair
Nerve repair

1️⃣1️⃣ FASCIAL COMPARTMENTS

Thenar compartment
Hypothenar compartment
Adductor compartment
Central compartment

Compartment syndrome:

Surgical emergency
Fasciotomy required

1️⃣2️⃣ TENDON INJURY ZONES (FLEXOR)

Zone I – Distal to FDS insertion
Zone II – “No man’s land”
Zone III – Palm
Zone IV – Carpal tunnel
Zone V – Forearm

Zone II historically difficult due to:

Dense pulley system

1️⃣3️⃣ FRACTURE BIOMECHANICS

Scaphoid:

Risk of AVN

Bennett fracture:

Base of 1st metacarpal

Rolando fracture:

Comminuted 1st metacarpal base

1️⃣4️⃣ CLINICAL DEFORMITIES

Claw hand
Ape hand
Mallet finger
Boutonnière deformity
Swan neck deformity

Each linked to specific tendon/nerve injury.

1️⃣5️⃣ EMBRYOLOGY

Upper limb bud:

Week 4

Digital rays:

Week 6

Failure of apoptosis:

Syndactyly

Extra rays:

Polydactyly

1️⃣6️⃣ SURGICAL PEARLS

Always check neurovascular status before anesthesia.
Repair tendons under magnification.
Preserve A2/A4 pulleys.
Avoid excessive flexor tendon tension.
Early physiotherapy prevents adhesions.

1️⃣7️⃣ FUNCTIONAL BIOMECHANICS

Power grip:

Flexors dominant

Precision grip:

Intrinsics dominant

Thumb opposition:

Essential for human dexterity

Loss of median nerve → loss of opposition.

1️⃣8️⃣ SUMMARY OF SURGICAL ALERTS

Structure	Risk
Scaphoid	AVN
Median nerve	Carpal tunnel
Ulnar nerve	Claw hand
A1 pulley	Trigger finger
1st CMC	Osteoarthritis

*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE FOOT

(Orthopedic Surgery, Trauma Surgery, Sports Medicine, Reconstructive & Vascular Level)

Gross Overview of the Foot

The foot is a highly specialized structure designed for:

Weight bearing
Shock absorption
Balance
Propulsion during gait

It contains:

26 bones
33 joints
100+ ligaments
20 intrinsic muscles
Complex neurovascular bundles

1️⃣ OSTEOLOGY (SURGICAL DETAIL)

A. Tarsal Bones (7)

Talus
Calcaneus
Navicular
Cuboid
Medial cuneiform
Intermediate cuneiform
Lateral cuneiform

Talus (Surgical Importance)

No muscular attachment
60% covered with articular cartilage
Blood supply vulnerable → AVN risk

Fracture of neck of talus:

Risk of avascular necrosis
Hawkins classification

Calcaneus

Most commonly fractured tarsal bone.

Important structures:

Sustentaculum tali
Achilles tendon insertion

Intra-articular fracture:

Alters subtalar joint mechanics

Metatarsals

5 bones.

5th metatarsal fractures:

Jones fracture (high risk of non-union)

Phalanges

14 bones.

Great toe critical for push-off phase of gait.

2️⃣ JOINTS OF THE FOOT

Ankle Joint (Talocrural Joint)

Type:

Hinge

Formed by:

Tibia
Fibula
Talus

Ligaments:

Medial (Deltoid ligament):

Strong
Rarely torn

Lateral ligaments:

ATFL (most commonly injured)
CFL
PTFL

Ankle sprain:

Usually inversion injury → ATFL tear

Subtalar Joint

Between:

Talus and calcaneus

Allows inversion and eversion.

Important in:

Flat foot deformity
Hindfoot reconstruction

Midtarsal Joint (Chopart joint)

Talonavicular
Calcaneocuboid

Tarsometatarsal Joint (Lisfranc joint)

Lisfranc injury:

Disruption between medial cuneiform and 2nd metatarsal
Often missed on X-ray
Surgical fixation required

3️⃣ ARCHES OF THE FOOT (BIOMECHANICAL CORE)

Medial Longitudinal Arch

Formed by:

Calcaneus
Talus
Navicular
Cuneiforms
1st–3rd metatarsals

Key support:

Plantar fascia
Tibialis posterior
Spring ligament

Collapse → Pes planus (flat foot)

Lateral Longitudinal Arch

Lower and more rigid.

Transverse Arch

Maintained by:

Peroneus longus
Interossei
Deep transverse metatarsal ligament

4️⃣ PLANTAR FASCIA

Thick aponeurosis extending from calcaneus to toes.

Functions:

Maintains arch
Windlass mechanism

Plantar fasciitis:

Most common cause of heel pain

5️⃣ COMPARTMENTS OF THE FOOT (SURGICAL IMPORTANCE)

There are 4 major plantar compartments:

Medial compartment
Central compartment
Lateral compartment
Interosseous compartments

Foot compartment syndrome:

Trauma
Crush injury
Requires fasciotomy

6️⃣ INTRINSIC MUSCLES

Layer 1

Abductor hallucis
Flexor digitorum brevis
Abductor digiti minimi

Layer 2

Quadratus plantae
Lumbricals

Layer 3

Flexor hallucis brevis
Adductor hallucis
Flexor digiti minimi

Layer 4

Interossei

Function:

Fine toe movement
Stabilization during gait

7️⃣ EXTRINSIC MUSCLES (FROM LEG)

Posterior compartment:

Gastrocnemius
Soleus
Tibialis posterior
Flexor hallucis longus
Flexor digitorum longus

Anterior compartment:

Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus

Lateral compartment:

Peroneus longus
Peroneus brevis

8️⃣ TARSAL TUNNEL

Located posterior to medial malleolus.

Contents (anterior → posterior):

Tibialis posterior tendon
Flexor digitorum longus
Posterior tibial artery
Tibial nerve
Flexor hallucis longus

Mnemonic: Tom, Dick, And Very Nervous Harry

Tarsal tunnel syndrome:

Tibial nerve compression
Burning plantar pain

9️⃣ BLOOD SUPPLY

Arteries

From popliteal →

Anterior tibial → dorsalis pedis
Posterior tibial → medial & lateral plantar arteries

Plantar arch formed by:

Lateral plantar artery + dorsalis pedis branch

Venous Drainage

Superficial:

Great saphenous vein

Deep:

Accompany arteries

🔟 NERVE SUPPLY

Tibial nerve

Medial plantar nerve
Lateral plantar nerve

Deep peroneal nerve

Between 1st & 2nd toes

Superficial peroneal nerve

Dorsum of foot

Common peroneal nerve injury:

Foot drop

1️⃣1️⃣ GAIT BIOMECHANICS

Phases:

Heel strike
Midstance
Toe-off

Great toe:

Essential for propulsion

Loss of hallux function:

Severe gait impairment

1️⃣2️⃣ COMMON SURGICAL CONDITIONS

Hallux Valgus

Lateral deviation of great toe
Bunion formation

Hammer Toe

Flexion deformity

Clubfoot (Talipes equinovarus)

Congenital
Requires early correction

Diabetic Foot

Neuropathy
Vascular compromise
Ulcer risk

1️⃣3️⃣ FRACTURES & TRAUMA

Calcaneal fracture:

From fall from height
Bohler angle reduced

Talus fracture:

Risk of AVN

Lisfranc fracture-dislocation:

High morbidity

1️⃣4️⃣ EMBRYOLOGY

Lower limb bud:

Week 4

Rotation:

Medial rotation 90°

Explains:

Dermatomal patterns
Muscle compartment orientation

1️⃣5️⃣ SURGICAL PEARLS

Always check dorsalis pedis pulse.
Beware of compartment syndrome.
Restore arch alignment in reconstruction.
Fix Lisfranc injuries early.
Preserve tibialis posterior tendon.

1️⃣6️⃣ SUMMARY TABLE

Structure	Clinical Importance
Talus	AVN risk
ATFL	Most common sprain
Plantar fascia	Heel pain
Tibial nerve	Tarsal tunnel
Lisfranc joint	Missed injury

*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE UPPER RESPIRATORY SYSTEM

(ENT Surgery, Head & Neck Surgery, Airway Management, Oncology Level)

Overview of the Upper Respiratory System

The upper respiratory system includes:

Nose
Nasal cavity
Paranasal sinuses
Pharynx
Larynx

Primary functions:

Air conduction
Humidification and warming
Olfaction
Phonation
Airway protection

1️⃣ NOSE & NASAL CAVITY (SURGICAL DETAIL)

External Nose

Framework:

Nasal bones
Septal cartilage
Upper & lower lateral cartilages

Blood supply:

Facial artery
Ophthalmic artery

Nasal Septum

Formed by:

Septal cartilage
Perpendicular plate of ethmoid
Vomer

Little’s area (Kiesselbach plexus): Common site of epistaxis.

Posterior epistaxis:

Sphenopalatine artery (surgical ligation may be required)

Septal deviation:

Causes obstruction
Treated by septoplasty

Lateral Wall of Nasal Cavity

Contains:

Superior turbinate
Middle turbinate
Inferior turbinate

Under middle turbinate:

Osteomeatal complex

Critical in:

Endoscopic sinus surgery (FESS)

2️⃣ PARANASAL SINUSES

Maxillary Sinus

Largest sinus.

Drainage:

Middle meatus

Relation:

Roots of upper molars

Dental infections → sinusitis.

Frontal Sinus

Drains via:

Frontonasal duct

Fracture risk:

CSF leak

Ethmoid Sinus

Anterior and posterior cells
Close to orbit

Lamina papyracea:

Thin medial orbital wall

Complication:

Orbital cellulitis

Sphenoid Sinus

Close to:

Optic nerve
ICA
Pituitary gland

Used in:

Transsphenoidal surgery

3️⃣ PHARYNX (SURGICAL ANATOMY)

Divided into:

Nasopharynx
Oropharynx
Laryngopharynx

Nasopharynx

Contains:

Pharyngeal tonsil
Opening of Eustachian tube

Nasopharyngeal carcinoma:

Common in some populations
Early lymph node spread

Oropharynx

Contains:

Palatine tonsils
Base of tongue

Tonsillectomy:

Risk of bleeding (tonsillar branch of facial artery)

Laryngopharynx

Piriform recess:

Foreign body lodgment site
Internal laryngeal nerve injury risk

4️⃣ LARYNX (CRITICAL AIRWAY STRUCTURE)

Located at C3–C6.

Functions:

Phonation
Airway protection
Respiration

Laryngeal Cartilages

Unpaired:

Thyroid
Cricoid
Epiglottis

Paired:

Arytenoid
Corniculate
Cuneiform

Cricoid:

Only complete ring
Landmark for cricothyrotomy

5️⃣ VOCAL CORDS

True vocal cords:

Stratified squamous epithelium

False cords:

Respiratory epithelium

Reinke’s space:

Edema causes hoarseness

6️⃣ LARYNGEAL NERVES (SURGICAL CRITICAL)

Superior Laryngeal Nerve

Internal branch:

Sensory above cords

External branch:

Motor to cricothyroid

Injury:

Voice fatigue

Recurrent Laryngeal Nerve

Right:

Loops under subclavian artery

Left:

Loops under aortic arch

Supplies:

All intrinsic muscles except cricothyroid

Bilateral injury:

Airway obstruction
Emergency tracheostomy

Commonly injured in:

Thyroidectomy

7️⃣ LARYNGEAL MUSCLES

Abductors:

Posterior cricoarytenoid (only abductor)

Adductors:

Lateral cricoarytenoid
Interarytenoid

Tensors:

Cricothyroid

Paralysis of posterior cricoarytenoid:

Life-threatening airway compromise

8️⃣ BLOOD SUPPLY

From:

Superior thyroid artery
Inferior thyroid artery

Venous drainage:

Thyroid venous plexus

9️⃣ LYMPHATIC DRAINAGE

Above vocal cords:

Upper deep cervical nodes

Below vocal cords:

Lower deep cervical nodes

Supraglottic cancers:

Early lymphatic spread

🔟 AIRWAY SURGICAL ACCESS

Cricothyrotomy

Performed:

Through cricothyroid membrane

Emergency airway access.

Tracheostomy

Usually between:

2nd–4th tracheal rings

Complications:

Bleeding
Tracheal stenosis
Recurrent laryngeal injury

1️⃣1️⃣ COMMON SURGICAL CONDITIONS

Deviated Nasal Septum

Chronic Sinusitis

Nasal Polyps

Laryngeal Carcinoma

Vocal Cord Nodules

Epiglottitis

1️⃣2️⃣ ONCOLOGICAL CORRELATION

Glottic cancer:

Early hoarseness

Supraglottic cancer:

Late symptoms
Early nodal spread

1️⃣3️⃣ EMBRYOLOGY

Pharyngeal arches:

1st arch → maxilla, mandible
2nd arch → hyoid
3rd arch → stylopharyngeus
4th/6th arch → laryngeal cartilages

Explains:

Nerve supply patterns

1️⃣4️⃣ SURGICAL PEARLS

Identify recurrent laryngeal nerve during thyroid surgery.
Control sphenopalatine artery in posterior epistaxis.
Protect lamina papyracea in sinus surgery.
Always assess vocal cord mobility pre- and post-thyroidectomy.

1️⃣5️⃣ SUMMARY TABLE

Structure	Clinical Risk
Little’s area	Epistaxis
Lamina papyracea	Orbital injury
RLN	Hoarseness
Cricothyroid membrane	Emergency airway
Sphenoid sinus	ICA injury

*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE GASTROINTESTINAL TRACT (GIT)

(General Surgery, Hepatobiliary Surgery, GI Oncology, Vascular Surgery Level)

Overview of the Gastrointestinal Tract

The gastrointestinal tract extends from the mouth to the anus and consists of:

Esophagus
Stomach
Small intestine
Large intestine
Rectum and anal canal

Associated organs:

Liver
Gallbladder
Pancreas

Primary functions:

Digestion
Absorption
Immunological defense
Endocrine regulation

1️⃣ ESOPHAGUS (SURGICAL DETAIL)

Length: ~25 cm
Begins: C6
Ends: T11 (cardia of stomach)

Anatomical Constrictions (Endoscopy Relevance)

Cricopharyngeal (C6)
Aortic arch (T4)
Left bronchus (T5)
Diaphragmatic hiatus (T10)

Common sites of:

Foreign body impaction
Carcinoma narrowing

Layers

Mucosa
Submucosa
Muscularis (upper 1/3 skeletal, lower smooth)
Adventitia (no serosa)

Clinical: No serosa → early spread of cancer.

Blood Supply

Upper:

Inferior thyroid artery

Middle:

Aortic branches

Lower:

Left gastric artery

Venous drainage:

Azygos system
Left gastric vein (portal)

Portal hypertension → esophageal varices.

2️⃣ STOMACH

Regions:

Cardia
Fundus
Body
Pylorus

Curvatures:

Greater
Lesser

Blood Supply (From Celiac Trunk)

Left gastric
Right gastric
Left gastroepiploic
Right gastroepiploic
Short gastric arteries

Important in:

Gastrectomy
Ulcer bleeding control

Lesser Sac (Omental Bursa)

Behind stomach.

Access via:

Epiploic foramen (Foramen of Winslow)

Critical in:

Pancreatic surgery

3️⃣ SMALL INTESTINE

Length: ~6 meters

Divided into:

Duodenum
Jejunum
Ileum

Duodenum (C-Shaped)

Parts:

Superior
Descending
Horizontal
Ascending

Ampulla of Vater:

Bile + pancreatic duct entry

Close relation:

Pancreatic head
SMA (3rd part anterior to aorta)

SMA syndrome:

Compression of 3rd part

Jejunum vs Ileum (Surgical Differences)

Jejunum:

Thick wall
More vascular
Fewer arcades

Ileum:

Thinner
Peyer patches
More arcades

4️⃣ MESENTERY (SURGICAL CORE)

Mesentery attaches small intestine to posterior wall.

Contains:

SMA
SMV
Lymphatics
Nerves

Root extends:

L2 → right iliac fossa

Critical in:

Bowel resection
Ischemia surgery

5️⃣ LARGE INTESTINE

Segments:

Cecum
Ascending colon
Transverse colon
Descending colon
Sigmoid colon
Rectum

Key Features

Taenia coli
Haustra
Epiploic appendages

Blood Supply

From:

SMA:

Cecum → proximal 2/3 transverse colon

IMA:

Distal 1/3 transverse → sigmoid

Watershed areas:

Splenic flexure (SMA–IMA junction)
Rectosigmoid junction

High risk of ischemia.

6️⃣ RECTUM & ANAL CANAL

Length:

Rectum: 12 cm
Anal canal: 4 cm

Anal Sphincters

Internal:

Smooth muscle

External:

Skeletal muscle

Venous Plexus

Internal hemorrhoids:

Above pectinate line

External hemorrhoids:

Below pectinate line

7️⃣ LIVER (SURGICAL ANATOMY)

Largest internal organ.

Divided functionally into:

Right and left lobes
8 Couinaud segments

Each segment:

Own portal triad branch
Own hepatic vein drainage

Allows segmental resection.

Portal Triad

Hepatic artery
Portal vein
Bile duct

Contained in:

Hepatoduodenal ligament

Pringle maneuver:

Clamping portal triad to control bleeding.

8️⃣ PORTAL VENOUS SYSTEM

Formed by:

SMV
Splenic vein

Portal hypertension causes:

Varices
Caput medusae
Hemorrhoids

Portocaval anastomoses:

Esophageal
Paraumbilical
Rectal
Retroperitoneal

9️⃣ PANCREAS (SURGICAL RELEVANCE)

Head:

In duodenal curve

Neck:

Anterior to portal vein formation

Body:

Crosses aorta

Tail:

Near spleen

Whipple procedure:

Pancreatic head
Duodenum
Bile duct

🔟 PERITONEAL REFLECTIONS

Intraperitoneal:

Stomach
Jejunum
Ileum
Transverse colon
Sigmoid colon

Retroperitoneal:

Duodenum (2–4)
Pancreas (except tail)
Ascending & descending colon

Important in:

Trauma
Infection spread

1️⃣1️⃣ LYMPHATIC DRAINAGE

Follows arterial supply.

Colon cancer staging:

Depends on nodal spread

1️⃣2️⃣ COMMON SURGICAL CONDITIONS

Appendicitis
Peptic ulcer perforation
Small bowel obstruction
Volvulus
Colon cancer
Diverticulitis
Hemorrhoids
Hepatocellular carcinoma

1️⃣3️⃣ SURGICAL PEARLS

Preserve marginal artery of Drummond.
Identify ureter during sigmoid surgery.
Control portal triad in liver trauma.
Recognize SMA ischemia early.
Always assess watershed areas.

1️⃣4️⃣ SUMMARY TABLE

Structure	Key Surgical Point
Esophagus	No serosa
Stomach	Celiac trunk supply
Duodenum	Close to SMA
Colon	Watershed zones
Liver	Segmental resection
Portal system	Varices

🎓 COMPLETE SERIES FINISHED

You now have:

Brain (Neurosurgical level)
Cranial nerves (Skull base & ENT level)
Kidney & nephron (Transplant & urology level)
Hand (Orthoplastic level)
Foot (Orthopedic trauma level)
Upper respiratory (ENT level)
GIT (General & hepatobiliary surgery level)

Ultra Advanced Surgical Anatomy Of The Different Parts Of The Body

*-ULTRA-ADVANCED SURGICAL ANATOMY OF THE BRAIN

1. DEVELOPMENTAL & EMBRYOLOGICAL BASIS (SURGICAL RELEVANCE)

Neural Tube Formation

Primary Brain Vesicles

Secondary Vesicles

2. MENINGES — SURGICAL LAYERS & SPACES

Dura Mater

Clinical:

Venous Sinuses (Surgical Landmarks)

3. CEREBRAL HEMISPHERES — SURGICAL TOPOGRAPHY

Surface Landmarks

Frontal Lobe (Surgical Importance)

Parietal Lobe

Temporal Lobe

Occipital Lobe

4. INTERNAL CEREBRAL STRUCTURES

Corpus Callosum

Basal Ganglia (Deep Brain Surgery Importance)

5. DIENCEPHALON

Thalamus

Hypothalamus

6. BRAINSTEM (LIFE-CRITICAL ZONE)

MIDBRAIN

PONS

MEDULLA

7. VENTRICULAR SYSTEM

8. CEREBRAL BLOOD SUPPLY

Internal Carotid System

Vertebrobasilar System

Circle of Willis

9. WHITE MATTER TRACTS

10. FUNCTIONAL MAPPING IN SURGERY

11. BRAIN HERNIATION SYNDROMES

*- ULTRA-ADVANCED SURGICAL ANATOMY OF THE CRANIAL NERVES

Overview of Cranial Nerves

I. FUNCTIONAL COMPONENT CLASSIFICATION (Advanced)

Somatic Motor (GSE)

Branchial Motor (SVE)

Parasympathetic (GVE)

General Sensory (GSA)

Special Sensory

II. CRANIAL NERVE I — OLFACTORY NERVE

Anatomy

Surgical Relevance

III. CRANIAL NERVE II — OPTIC NERVE

Intracranial Course

Blood Supply

Surgical Relevance

IV. OCULOMOTOR (III)

Nuclei (Midbrain Level)

Course

Functions

Clinical

V. TROCHLEAR (IV)

VI. TRIGEMINAL NERVE (V)

Root Entry Zone

Trigeminal Ganglion

Foramina

Surgical Importance

VII. ABDUCENS (VI)

Course

Vulnerability

VIII. FACIAL NERVE (VII)

Brainstem Origin

Intratemporal Course

Branches

Surgical Importance

IX. VESTIBULOCOCHLEAR (VIII)

X. GLOSSOPHARYNGEAL (IX)

XI. VAGUS (X)

Branches

Surgical Importance

XII. ACCESSORY (XI)

XIII. HYPOGLOSSAL (XII)

BRAINSTEM SYNDROME LOCALIZATION

Lateral Medullary (Wallenberg)

Medial Medullary

Millard-Gubler

CAVERNOUS SINUS SYNDROME