brachial plexus roots trunks divisions cords anatomy diagram

epidural space subarachnoid space spinal anatomy cross section

brachial plexus terminal nerves median ulnar radial musculocutaneous axillary

spinal meninges dura mater arachnoid pia mater layers anatomy

ls -la /home/daytona/workspace/ 2>/dev/null | head -20; mkdir -p /home/daytona/w…

~/neuro-anatomy-ppt/build.js

const pptxgen = require("pptxgenjs");

const pres = new pptxgen();
pres.layout = "LAYOUT_16x9";
pres.title = "Anatomy of Brachial Plexus, Subarachnoid & Epidural Spaces";
pres.author = "Medical Education";

// ─── PALETTE ────────────────────────────────────────────────────────────────
const C = {
  navy:     "0D1B2A",   // dominant dark bg
  midnight: "162032",   // alt dark bg
  teal:     "1B8FA8",   // primary accent
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  white:    "F0F4F8",   // body text
  lightgray:"B8C8D8",   // subtext / caption
  headerbg: "0A3A52",   // section header bars
  divider:  "1B8FA8",
};

// ─── HELPERS ─────────────────────────────────────────────────────────────────
function bg(slide, color) {
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function bullets(slide, items, opts = {}) {
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}

function imgCaption(slide, url, caption, imgX, imgY, imgW, imgH) {
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}

function colHeader(slide, leftLabel, rightLabel) {
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function sectionDivider(slide, sectionTitle, subtitle_text) {
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function footer(slide, pageNum) {
  slide.addShape(pres.ShapeType.rect, { x: 0, y: 5.3, w: 10, h: 0.325, fill: { color: C.headerbg }, line: { type: "none" } });
  slide.addText("Neuroanatomy — Brachial Plexus · Subarachnoid & Epidural Spaces", {
    x: 0.2, y: 5.3, w: 8.5, h: 0.325,
    fontSize: 9, color: C.lightgray, align: "left", valign: "middle", fontFace: "Calibri", margin: 0
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    fontSize: 9, color: C.teal, align: "right", valign: "middle", fontFace: "Calibri", bold: true, margin: 0
  });
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 1 — TITLE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
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  // full-width decorative band
  s.addShape(pres.ShapeType.rect, { x: 0, y: 1.5, w: 10, h: 0.06, fill: { color: C.teal }, line: { type: "none" } });
  s.addShape(pres.ShapeType.rect, { x: 0, y: 3.65, w: 10, h: 0.06, fill: { color: C.teal }, line: { type: "none" } });
  s.addText("Anatomy of the", { x: 0.6, y: 1.65, w: 8.8, h: 0.6, fontSize: 22, color: C.lightgray, fontFace: "Calibri", align: "center" });
  s.addText("Brachial Plexus", { x: 0.6, y: 2.15, w: 8.8, h: 0.75, fontSize: 40, bold: true, color: C.amber, fontFace: "Calibri", align: "center" });
  s.addText("Subarachnoid Space & Epidural Space", { x: 0.6, y: 2.92, w: 8.8, h: 0.62, fontSize: 22, bold: true, color: C.teal, fontFace: "Calibri", align: "center" });
  s.addText("A Comprehensive Neuroanatomy Review", { x: 0.6, y: 3.78, w: 8.8, h: 0.45, fontSize: 15, color: C.lightgray, fontFace: "Calibri", align: "center", italic: true });
  footer(s, 1);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 2 — TABLE OF CONTENTS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Table of Contents");
  rule(s);
  twocol(s,
    [
      "PART 1 — Brachial Plexus",
      "  Overview & Formation",
      "  Roots (C5–T1)",
      "  Trunks",
      "  Divisions",
      "  Cords",
      "  Terminal Branches",
      "  Branches from Roots & Trunks",
      "  Pre-fixed & Post-fixed variants",
      "  Clinical relevance & injuries",
    ],
    [
      "PART 2 — Subarachnoid Space",
      "  Spinal meninges overview",
      "  Boundaries & extent",
      "  CSF contents & flow",
      "  Pia mater & denticulate ligament",
      "PART 3 — Epidural Space",
      "  Boundaries & compartments",
      "  Contents (fat, veins, nerves)",
      "  Clinical applications",
      "  Comparative summary",
    ],
    { fontSize: 13, y: 1.08, colH: 4.1 }
  );
  footer(s, 2);
}

// ════════════════════════════════════════════════════════════════════════════
// SECTION DIVIDER — BRACHIAL PLEXUS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "PART 1", "Brachial Plexus");
  footer(s, 3);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 4 — OVERVIEW & FORMATION
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Brachial Plexus — Overview");
  rule(s);
  bullets(s, [
    "Network of somatic nerves formed by anterior rami of C5, C6, C7, C8 and T1",
    "Originates in the posterior triangle of the neck, crosses the first rib, enters the axilla",
    "Supplies ALL motor and most sensory innervation to the upper limb",
    "Organized into five sequential segments: Roots → Trunks → Divisions → Cords → Terminal Branches  (mnemonic: 'Really Tired? Drink Coffee Twice')",
    "Enclosed in a fascial sheath (prevertebral fascia) — the interscalene fascial sheath proximally, the axillary sheath distally",
    "Closely related to subclavian and axillary arteries throughout its course",
  ], { fontSize: 15 });
  footer(s, 4);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 5 — ROOTS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Roots of the Brachial Plexus");
  rule(s);
  twocol(s,
    [
      "Composed of anterior (ventral) rami of C5–C8 and most of T1",
      "Emerge from intervertebral foramina and travel in grooves of transverse processes",
      "Pass between anterior scalene and middle scalene muscles (interscalene triangle)",
      "Lie superior and posterior to the subclavian artery",
      "Each root receives gray rami communicantes from the sympathetic trunk",
      "C5 also contributes to the phrenic nerve",
    ],
    [
      "Branches from roots:",
      "  • Dorsal scapular nerve (C5) — innervates rhomboids",
      "  • Long thoracic nerve (C5, C6, C7) — innervates serratus anterior",
      "  • Small segmental branches to cervical muscles",
      "  • Contribution to phrenic nerve (C5)",
      "",
      "Pre-fixed plexus: C4–C8 dominant",
      "Post-fixed plexus: C6–T2 dominant",
    ],
    { fontSize: 13, colH: 4.0, y: 1.08 }
  );
  colHeader(s, "Anatomy", "Key Branches");
  footer(s, 5);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 6 — TRUNKS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Trunks of the Brachial Plexus");
  rule(s);

  // table-like layout
  const headers = ["Trunk", "Formation", "Position", "Branches"];
  const rows = [
    ["Superior (Upper)", "C5 + C6", "Lies superior; above subclavian artery", "Suprascapular nerve, Nerve to subclavius"],
    ["Middle", "C7 alone", "Between superior & inferior trunks", "None (no direct trunk branches)"],
    ["Inferior (Lower)", "C8 + T1", "On rib I; posterior to subclavian artery", "None (no direct trunk branches)"],
  ];

  // header row
  const hX = [0.25, 2.35, 4.45, 6.55];
  const hW = [1.9, 2.0, 2.0, 3.2];
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  });
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  s.addText("All three trunks pass inferolaterally over the first rib and are palpable in the supraclavicular fossa.", {
    x: 0.25, y: 4.15, w: 9.5, h: 0.55, fontSize: 13, italic: true, color: C.lightgray, fontFace: "Calibri", align: "left"
  });
  footer(s, 6);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 7 — DIVISIONS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Divisions of the Brachial Plexus");
  rule(s);
  twocol(s,
    [
      "Each trunk bifurcates into an anterior and a posterior division at the lateral border of the first rib",
      "Occur deep to (behind) the clavicle — infraclavicular region",
      "Six total divisions: 3 anterior + 3 posterior",
      "No peripheral nerves originate directly from divisions",
      "Anterior divisions → innervate ANTERIOR (flexor) compartments",
      "Posterior divisions → innervate POSTERIOR (extensor) compartments",
    ],
    [
      "Anterior divisions:",
      "  • Superior anterior + Middle anterior → form Lateral cord",
      "  • Inferior anterior → forms Medial cord",
      "",
      "Posterior divisions:",
      "  • All three (Superior + Middle + Inferior) → unite to form Posterior cord",
      "",
      "Key point: Posterior cord is the only cord with contributions from ALL spinal levels (C5–T1)",
    ],
    { fontSize: 13, colH: 4.0, y: 1.08 }
  );
  colHeader(s, "Structure & Location", "Formation of Cords");
  footer(s, 7);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 8 — CORDS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Cords of the Brachial Plexus");
  rule(s);

  const headers2 = ["Cord", "Formation", "Spinal Levels", "Position", "Key Terminal Branches"];
  const rows2 = [
    ["Lateral", "Ant. div. Superior + Middle trunks", "C5, C6, C7", "Lateral to axillary artery", "Musculocutaneous N.; Lateral root of Median N."],
    ["Medial", "Ant. div. Inferior trunk", "C8, T1", "Medial to axillary artery", "Ulnar N.; Medial root of Median N.; Medial cutaneous nerves"],
    ["Posterior", "Post. div. ALL three trunks", "C5–T1", "Posterior to axillary artery", "Radial N.; Axillary N.; Thoracodorsal N.; Subscapular N."],
  ];

  const hX2 = [0.18, 1.7, 3.22, 4.74, 6.48];
  const hW2 = [1.4, 1.42, 1.42, 1.6, 3.15];
  headers2.forEach((h, i) => {
    s.addShape(pres.ShapeType.rect, { x: hX2[i], y: 1.06, w: hW2[i], h: 0.38, fill: { color: C.headerbg }, line: { type: "none" } });
    s.addText(h, { x: hX2[i], y: 1.06, w: hW2[i], h: 0.38, fontSize: 10.5, bold: true, color: C.amber, align: "center", valign: "middle", fontFace: "Calibri", margin: 0 });
  });
  rows2.forEach((row, ri) => {
    const rowY = 1.44 + ri * 1.1;
    const rowC = ri % 2 === 0 ? "0E2136" : "12293F";
    hX2.forEach((x, ci) => {
      s.addShape(pres.ShapeType.rect, { x, y: rowY, w: hW2[ci], h: 1.02, fill: { color: rowC }, line: { type: "none" } });
      s.addText(row[ci], { x, y: rowY, w: hW2[ci], h: 1.02, fontSize: 10.5, color: C.white, align: "center", valign: "middle", fontFace: "Calibri", margin: 2 });
    });
  });

  footer(s, 8);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 9 — IMAGE: Brachial Plexus Schematic
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Brachial Plexus — Structural Schematic");
  rule(s);
  s.addImage({
    path: "https://cdn.orris.care/cdss_images/HARRISON_1763034978151_dcfec64f-4894-46b6-94bd-ba17fd6a8314.png",
    x: 0.5, y: 1.0, w: 9.0, h: 4.15
  });
  s.addText("Schematic: Roots → Trunks → Divisions → Cords → Terminal Nerves (Harrison's Principles of Internal Medicine)", {
    x: 0.3, y: 5.1, w: 9.4, h: 0.25, fontSize: 8.5, italic: true, color: C.lightgray, fontFace: "Calibri", align: "center"
  });
  footer(s, 9);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 10 — TERMINAL BRANCHES
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Terminal Branches of the Brachial Plexus");
  rule(s);
  twocol(s,
    [
      "5 major terminal branches arise just beyond pectoralis minor",
      "",
      "MUSCULOCUTANEOUS (C5–C7) — Lateral cord",
      "  • Pierces coracobrachialis; supplies anterior arm muscles",
      "  • Continues as lateral cutaneous nerve of forearm",
      "",
      "MEDIAN (C5–T1) — Lateral + Medial cords",
      "  • Passes through cubital fossa, carpal tunnel",
      "  • Supplies most forearm flexors, thenar muscles",
      "  • Sensory: lateral 3½ digits (palmar aspect)",
    ],
    [
      "ULNAR (C8, T1) — Medial cord",
      "  • Passes posterior to medial epicondyle",
      "  • Supplies intrinsic hand muscles (except thenar)",
      "  • Sensory: medial 1½ digits",
      "",
      "RADIAL (C5–T1) — Posterior cord",
      "  • Largest branch; winds round radial groove of humerus",
      "  • Supplies ALL posterior compartment muscles (arm + forearm)",
      "  • Sensory: posterior arm, dorsal hand",
      "",
      "AXILLARY (C5, C6) — Posterior cord",
      "  • Exits quadrangular space; supplies deltoid & teres minor",
      "  • Sensory: 'regimental badge' area of shoulder",
    ],
    { fontSize: 12, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Anterior Compartment Nerves", "Posterior Compartment Nerves");
  footer(s, 10);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 11 — BRANCHES FROM ROOTS & TRUNKS (detailed)
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Branches from Roots & Trunks");
  rule(s);
  bullets(s, [
    "DORSAL SCAPULAR NERVE (C5) — from C5 root; pierces middle scalene; runs along medial scapular border; innervates rhomboids major & minor",
    "LONG THORACIC NERVE (C5, C6, C7) — descends through neck, through axillary inlet, along medial axillary wall; innervates serratus anterior",
    "  → Injury causes 'winging of the scapula' (serratus anterior palsy)",
    "SUPRASCAPULAR NERVE (C5, C6) — from upper trunk; passes through suprascapular notch; innervates supraspinatus & infraspinatus",
    "NERVE TO SUBCLAVIUS (C5, C6) — from upper trunk; innervates subclavius muscle; rarely of clinical significance",
    "MEDIAL PECTORAL NERVE (C8, T1) — from medial cord; innervates pectoralis minor and part of pectoralis major",
    "LATERAL PECTORAL NERVE (C5–C7) — from lateral cord; innervates pectoralis major",
    "UPPER SUBSCAPULAR (C5, C6), LOWER SUBSCAPULAR (C5, C6), THORACODORSAL (C6–C8) — from posterior cord",
  ], { fontSize: 14 });
  footer(s, 11);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 12 — RELATIONS & TOPOGRAPHY
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Topography & Relations");
  rule(s);
  twocol(s,
    [
      "SUPRACLAVICULAR PART (roots & trunks):",
      "  • Between anterior & middle scalene muscles",
      "  • Posterior triangle of the neck",
      "  • Above the subclavian artery",
      "  • Phrenic nerve descends on anterior scalene (medial relation)",
      "",
      "AT THE CLAVICLE:",
      "  • Divisions pass posterior to the clavicle and subclavian artery",
      "  • Subclavian vein lies anterior to anterior scalene",
    ],
    [
      "INFRACLAVICULAR PART (cords & terminal branches):",
      "  • Cords cluster around axillary artery (2nd part)",
      "  • Lateral cord: lateral to artery",
      "  • Medial cord: medial to artery",
      "  • Posterior cord: posterior to artery",
      "  • Terminal branches emerge distal to pectoralis minor",
      "",
      "Key relations: Axillary vein medial, Axillary artery central, Cords around artery",
    ],
    { fontSize: 13, colH: 4.05, y: 1.08 }
  );
  colHeader(s, "Supraclavicular", "Infraclavicular");
  footer(s, 12);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 13 — MRI IMAGE of Brachial Plexus
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Brachial Plexus — MRI Anatomy");
  rule(s);
  s.addImage({
    path: "https://cdn.orris.care/cdss_images/pmc_clinical_VQA_84a54033dbc8ecad8a5f6bc966a49c2e9eb53fa9ac67b2835fa0f5cdb82d3651.jpg",
    x: 0.4, y: 1.0, w: 9.2, h: 4.1
  });
  s.addText("MRI: Interscalene triangle (sagittal/axial T1) and coronal oblique tracing Roots (R) → Trunks (T) → Divisions (D) → Cords (C)", {
    x: 0.3, y: 5.1, w: 9.4, h: 0.25, fontSize: 8.5, italic: true, color: C.lightgray, fontFace: "Calibri", align: "center"
  });
  footer(s, 13);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 14 — BRACHIAL PLEXUS INJURIES
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Clinical Correlates — Brachial Plexus Injuries");
  rule(s);
  twocol(s,
    [
      "ERB'S PALSY (Upper trunk — C5, C6):",
      "  • Caused by excessive lateral neck–shoulder stretch",
      "  • Loss: abduction, lateral rotation, elbow flexion, supination",
      "  • Posture: 'waiter's tip' — adduction, medial rotation, pronation",
      "  • Affects: deltoid, biceps, brachialis, brachioradialis",
      "",
      "KLUMPKE'S PALSY (Lower trunk — C8, T1):",
      "  • Caused by forceful arm traction upward",
      "  • Loss: intrinsic hand muscles → 'claw hand'",
      "  • + Horner's syndrome if T1 rami affected (ptosis, miosis, anhidrosis)",
    ],
    [
      "LONG THORACIC NERVE INJURY (C5–C7):",
      "  • Serratus anterior palsy → winged scapula",
      "  • Cannot push / punch forward against resistance",
      "",
      "AXILLARY NERVE INJURY (C5, C6):",
      "  • Fracture of surgical neck of humerus",
      "  • Deltoid paralysis, loss of shoulder abduction (initial 15°)",
      "  • Loss of sensation over 'regimental badge' area",
      "",
      "RADIAL NERVE INJURY:",
      "  • Midshaft humeral # → wrist drop",
      "  • Posterior interosseous injury → finger drop only",
    ],
    { fontSize: 12, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Upper / Middle Plexus", "Lower Plexus & Distal");
  footer(s, 14);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 15 — Pre-fixed / Post-fixed / Variants
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Plexus Variants & Cutaneous Innervation");
  rule(s);
  twocol(s,
    [
      "PLEXUS VARIANTS:",
      "  • Pre-fixed: C4 contributes to C5 — plexus 'higher' than usual",
      "  • Post-fixed: T2 contributes to T1 — plexus 'lower', Horner's syndrome risk ↑",
      "  • Affects anesthetic spread and surgical risk assessment",
      "",
      "SYMPATHETIC CONTRIBUTION:",
      "  • Gray rami communicantes from sympathetic trunk join roots",
      "  • Provide postganglionic sympathetic fibers to periphery",
      "  • Damage to C8–T1 roots or T1 rami → Horner's syndrome",
    ],
    [
      "CUTANEOUS INNERVATION OF UPPER LIMB (summary):",
      "  • Lateral arm: Axillary nerve",
      "  • Medial arm: Medial brachial cutaneous (T1)",
      "  • Posterior arm: Radial nerve",
      "  • Lateral forearm: Musculocutaneous (lateral cutaneous)",
      "  • Medial forearm: Medial antebrachial cutaneous",
      "  • Thumb, index, middle: Median nerve",
      "  • Ring (lateral half) and little finger: Ulnar nerve",
      "  • Dorsum lateral: Radial nerve",
    ],
    { fontSize: 12.5, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Variants & Sympathetics", "Cutaneous Innervation");
  footer(s, 15);
}

// ════════════════════════════════════════════════════════════════════════════
// SECTION DIVIDER — SUBARACHNOID SPACE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "PART 2", "Subarachnoid Space");
  footer(s, 16);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 17 — SPINAL MENINGES OVERVIEW
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Spinal Meninges — Overview");
  rule(s);
  bullets(s, [
    "The spinal cord is enclosed within THREE meningeal layers (from outer to inner):",
    "  1. DURA MATER ('hard mother') — thick fibrous outer layer; extends from foramen magnum to ~S2",
    "  2. ARACHNOID MATER ('spider mother') — thin, delicate intermediate layer; two portions: compact laminar layer + trabecular web",
    "  3. PIA MATER ('soft mother') — vascular inner layer; firmly adherent to spinal cord surface",
    "",
    "SPACES between the layers:",
    "  • Epidural space: between vertebral canal walls and OUTER surface of dura mater",
    "  • Potential subdural space: between dura and arachnoid (normally virtual)",
    "  • Subarachnoid space: between arachnoid and pia mater — contains CSF",
    "",
    "The arachnoid (not the dura) is the primary barrier to drug movement through the meninges — due to tight intercellular junctions",
  ], { fontSize: 14 });
  footer(s, 17);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 18 — SUBARACHNOID SPACE BOUNDARIES
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Subarachnoid Space — Boundaries & Extent");
  rule(s);
  twocol(s,
    [
      "SUPERIOR LIMIT:",
      "  • Continuous with cranial subarachnoid space at the foramen magnum",
      "",
      "INFERIOR LIMIT:",
      "  • Terminates at the lower border of vertebra S2",
      "  • Dural sac ends here, fusing with filum terminale",
      "",
      "KEY FEATURE — Lumbar Cistern:",
      "  • Spinal cord ends at L1–L2 disc level (conus medullaris)",
      "  • Subarachnoid space continues to S2",
      "  • This region (L2–S2) surrounds the cauda equina",
      "  • Safest site for CSF withdrawal (lumbar puncture) — no cord risk",
    ],
    [
      "CONTENTS:",
      "  • Cerebrospinal fluid (CSF) — 100–160 mL total in adults",
      "  • Arachnoid trabeculae — delicate strands connecting arachnoid to pia",
      "  • Large blood vessels — suspended by pial/arachnoid strands",
      "  • Nerve roots traversing to foramina",
      "  • Cauda equina in lower lumbar region",
      "",
      "CLINICAL USE:",
      "  • Spinal anaesthesia (intrathecal injection)",
      "  • Lumbar puncture (diagnostic CSF sampling)",
      "  • Myelography (contrast injection)",
    ],
    { fontSize: 12.5, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Extent & Cisterns", "Contents & Clinical Use");
  footer(s, 18);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 19 — DURA MATER (detailed)
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Dura Mater — Structure & Relations");
  rule(s);
  bullets(s, [
    "Thickest, outermost meningeal layer — 270–280 μm thick",
    "Composed of ~80 lamellae of fine collagen fibers arranged in multiple directions",
    "External (epidural) surface: bands of collagen in varying directions + thick elastic fibers",
    "Inner (arachnoid-facing) surface: fine fibers that fuse with arachnoid",
    "Extends from foramen magnum → fuses with filum terminale at approximately S2",
    "Extends laterally along each nerve root, fusing with epineurium near intervertebral foramina (creates 'nerve root sleeves')",
    "Potential SUBDURAL SPACE between dura and arachnoid — rarely, drugs or needles may misplace here",
    "The dural sac intermittently abuts bony/ligamentous structures — epidural space is DISCONTINUOUS",
  ], { fontSize: 15 });
  footer(s, 19);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 20 — ARACHNOID MATER & PIA MATER
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Arachnoid Mater & Pia Mater");
  rule(s);
  twocol(s,
    [
      "ARACHNOID MATER:",
      "  • Two portions:",
      "    – Outer: compact laminar layer of flattened epithelial-like cells closely applied to dura",
      "    – Inner: trabecular web-like portion extending to pia",
      "  • Specialized intercellular junctions → selective permeability",
      "  • PRIMARY barrier to drug movement (not the dura)",
      "  • Arachnoid granulations: protrude through dura → CSF/material exit sites",
      "  • Low permeability keeps CSF in subarachnoid (not subdural) space",
    ],
    [
      "PIA MATER:",
      "  • Innermost layer; vascular and firmly adherent to cord surface",
      "  • Extends into anterior median fissure",
      "  • Forms sleeve-like coatings on nerve rootlets crossing subarachnoid space",
      "  • Pial fenestrations present along lumbar cord and nerve roots",
      "",
      "DENTICULATE LIGAMENT:",
      "  • Longitudinal sheet of pia extending laterally from cord",
      "  • 21 pairs of lateral triangular extensions anchoring to dura",
      "  • Positions and stabilizes the spinal cord centrally",
      "  • Located between posterior and anterior rootlet exit points",
    ],
    { fontSize: 12, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Arachnoid", "Pia & Denticulate Ligament");
  footer(s, 20);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 21 — CSF
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Cerebrospinal Fluid (CSF)");
  rule(s);
  twocol(s,
    [
      "COMPOSITION:",
      "  • 99% water",
      "  • Protein, glucose, electrolytes, neurotransmitters",
      "  • Normal protein: 15–45 mg/dL",
      "  • Normal glucose: 50–80 mg/dL (60–70% plasma glucose)",
      "  • Clear, colourless",
      "",
      "VOLUME & PRESSURE:",
      "  • Total volume: 100–160 mL (adults)",
      "  • Normal opening pressure: 7–18 cmH₂O",
      "  • Replaced 3–4 times per day (~500 mL/day produced)",
    ],
    [
      "PRODUCTION & REABSORPTION (revised understanding):",
      "  • NOT solely produced by choroid plexus",
      "  • Both CSF and interstitial fluid (IF) mainly produced and absorbed at parenchymal capillaries",
      "  • Lymphatic system also absorbs considerable CSF",
      "  • Flow is not unidirectional — cardiac oscillations produce local mixing",
      "  • Solutes reabsorbed across capillary membranes",
      "",
      "CLINICAL: CSF analysis used for meningitis, SAH ('xanthochromia'), Guillain-Barré, MS",
    ],
    { fontSize: 12.5, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Composition & Volume", "Production & Reabsorption");
  footer(s, 21);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 22 — MENINGES IMAGE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Spinal Meninges — Anatomy Diagram");
  rule(s);
  s.addImage({
    path: "https://cdn.orris.care/cdss_images/pmc_clinical_VQA_c4396d50a486d522e5a4959694c9ffdc8b37e71d753adec2f54d6a7e5c4bf845.jpg",
    x: 0.7, y: 1.0, w: 8.6, h: 4.1
  });
  s.addText("Cranial meningeal layers: (a) dura mater (b) arachnoid mater (c) subarachnoid space (d) pia mater (e) brain tissue — showing arachnoid trabeculae and blood vessels", {
    x: 0.3, y: 5.1, w: 9.4, h: 0.25, fontSize: 8.5, italic: true, color: C.lightgray, fontFace: "Calibri", align: "center"
  });
  footer(s, 22);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 23 — LUMBAR PUNCTURE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Lumbar Puncture & Spinal Anaesthesia — Access to Subarachnoid Space");
  rule(s);
  bullets(s, [
    "TARGET: L3–L4 or L4–L5 interspinous space (below conus medullaris at L1–L2)",
    "LAYERS TRAVERSED (skin → subarachnoid): Skin → Subcutaneous fat → Supraspinous ligament → Interspinous ligament → Ligamentum flavum → Epidural space → Dura mater → Arachnoid mater → Subarachnoid space",
    "NEEDLE TIP position confirmed by free flow of clear CSF",
    "Spinal anaesthesia: hyperbaric local anaesthetic (e.g., bupivacaine) injected into CSF; onset within 3–5 min",
    "Position of patient affects spread: baricity determines level — baricity + position determine dermatomal spread",
    "COMPLICATIONS: Post-dural puncture headache (PDPH) — CSF leak through dural hole; treated with bed rest, caffeine, epidural blood patch",
    "Contraindications: raised ICP, coagulopathy, infection at site, patient refusal",
  ], { fontSize: 14.5 });
  footer(s, 23);
}

// ════════════════════════════════════════════════════════════════════════════
// SECTION DIVIDER — EPIDURAL SPACE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  sectionDivider(s, "PART 3", "Epidural Space");
  footer(s, 24);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 25 — EPIDURAL SPACE: BOUNDARIES
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Epidural Space — Boundaries & Extent");
  rule(s);
  twocol(s,
    [
      "DEFINITION:",
      "  • Lies WITHIN the vertebral canal but OUTSIDE the dural sac",
      "  • Potential (real) space — discontinuous due to dura abutting structures",
      "",
      "VERTICAL EXTENT:",
      "  • Superior: foramen magnum (where dura attaches to skull base)",
      "  • Inferior: sacrococcygeal membrane / end of dural sac at S2",
      "",
      "BOUNDARIES:",
      "  • Anterior: posterior longitudinal ligament (PLL)",
      "  • Posterior: laminae + ligamentum flavum",
      "  • Lateral: pedicles — communicates with paravertebral space via intervertebral foramina",
    ],
    [
      "REGIONAL FEATURES:",
      "  • Cervical: NO epidural fat; dura closely adherent",
      "  • Thoracic: narrow posteriorly",
      "  • Lumbar: widest posteriorly (~6 mm at L2–L3); most fat",
      "",
      "LIGAMENTUM FLAVUM:",
      "  • Yellow elastic ligament connecting adjacent laminae",
      "  • Posterior boundary of epidural space",
      "  • Has midline gap — clinically relevant for needle insertion",
      "  • Normal thickness: 2–3 mm lumbar, thinner cervical/thoracic",
      "",
      "DEPTH from skin: ~4–6 cm (lumbar, adult average)',",
    ],
    { fontSize: 12.5, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Limits & Walls", "Regional Variations");
  footer(s, 25);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 26 — EPIDURAL SPACE: CONTENTS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Epidural Space — Contents");
  rule(s);
  bullets(s, [
    "1. EPIDURAL FAT:",
    "  • Discontinuous, metameric fat-filled pockets (NOT continuous)",
    "  • Predominantly in posterior and anterior epidural space (lumbar region)",
    "  • Cervical epidural space contains NO fat",
    "  • Fat plays important role in kinetics of epidural medications (drug binding, slow release)",
    "",
    "2. EPIDURAL VEINS (Batson's plexus):",
    "  • Located mostly in the ANTERIOR epidural space",
    "  • Valveless — connects intrathoracic, intra-abdominal, pelvic veins",
    "  • Communicate via intervertebral foramina with paravertebral veins",
    "  • Pregnancy → raised intra-abdominal pressure → venous engorgement → higher risk of inadvertent venous cannulation during epidural placement; also narrows epidural space → greater spread of injected drug",
    "",
    "3. NERVE ROOTS (within dural sleeves): traverse epidural space as they exit intervertebral foramina",
    "4. LYMPHATICS & small arteries (segmental spinal arteries)",
  ], { fontSize: 14 });
  footer(s, 26);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 27 — EPIDURAL SPACE IMAGE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Epidural Space — MRI Cross-Section");
  rule(s);
  s.addImage({
    path: "https://cdn.orris.care/cdss_images/pmc_clinical_VQA_e721b23638e92195e7534d9cc8c6db83410e32ec47c3c60a9c5cce3875a38b96.jpg",
    x: 0.5, y: 1.0, w: 9.0, h: 4.1
  });
  s.addText("MRI: Colour-coded spinal canal compartments — intramedullary (green), intradural (yellow), dorsal epidural space (purple). PLL & ligamentum flavum boundaries marked.", {
    x: 0.3, y: 5.1, w: 9.4, h: 0.25, fontSize: 8.5, italic: true, color: C.lightgray, fontFace: "Calibri", align: "center"
  });
  footer(s, 27);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 28 — EPIDURAL ANAESTHESIA
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Epidural Anaesthesia — Technique & Pharmacology");
  rule(s);
  twocol(s,
    [
      "LAYERS TRAVERSED (lumbar approach):",
      "  Skin → Subcutaneous fat → Supraspinous lig → Interspinous lig → Ligamentum flavum → EPIDURAL SPACE",
      "  (Needle does NOT enter subarachnoid space)",
      "",
      "IDENTIFICATION of epidural space:",
      "  • Loss of resistance technique (LOR) — to air or saline",
      "  • Hanging drop technique (less common)",
      "  • Ultrasound guidance (experienced practitioners)",
      "",
      "NEEDLE: Tuohy needle (17G or 18G) — curved bevel to guide catheter",
    ],
    [
      "DRUG ACTION MECHANISM:",
      "  • Drugs diffuse through dura/arachnoid into CSF → nerve roots",
      "  • Also act directly on nerve roots in epidural space",
      "  • Fat sequestration prolongs drug action",
      "  • Epidural veins provide vascular absorption pathway",
      "",
      "AGENTS: Bupivacaine, Ropivacaine, Levobupivacaine + Opioids (fentanyl, morphine)",
      "",
      "USES: Labour analgesia, surgical anaesthesia, post-op pain (e.g. thoracotomy, colectomy), chronic pain management, cancer pain",
      "",
      "COMPLICATIONS: Dural puncture, inadvertent intravascular injection, epidural haematoma, abscess, high block",
    ],
    { fontSize: 12, colH: 4.1, y: 1.08 }
  );
  colHeader(s, "Technique", "Pharmacology & Clinical Uses");
  footer(s, 28);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 29 — COMPARISON TABLE
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s);
  title(s, "Subarachnoid vs Epidural Space — Comparison");
  rule(s);

  const ch = ["Feature", "Subarachnoid Space", "Epidural Space"];
  const cr = [
    ["Location", "Between arachnoid and pia mater", "Between vertebral canal walls and dura mater"],
    ["Extent", "Foramen magnum → S2 (dural sac)", "Foramen magnum → S2 sacrococcygeal membrane"],
    ["Contents", "CSF, arachnoid trabeculae, nerve roots, blood vessels", "Fat, veins (Batson's), nerve roots in dural sleeves, lymphatics"],
    ["Real or potential?", "Real space (contains CSF)", "Potential space — discontinuous, fat pockets"],
    ["Clinical access", "Spinal anaesthesia, LP, myelography", "Epidural anaesthesia/analgesia, steroid injection"],
    ["Onset of block", "Rapid (3–5 min)", "Slower (15–30 min)"],
    ["Drug volume needed", "Small (1.5–4 mL)", "Large (10–20 mL)"],
    ["Dura puncture?", "Yes — intentional", "No — dura not pierced"],
  ];

  const cX = [0.2, 2.3, 5.3];
  const cW = [1.95, 2.85, 4.5];
  ch.forEach((h, i) => {
    s.addShape(pres.ShapeType.rect, { x: cX[i], y: 1.05, w: cW[i], h: 0.38, fill: { color: C.headerbg }, line: { type: "none" } });
    s.addText(h, { x: cX[i], y: 1.05, w: cW[i], h: 0.38, fontSize: 11.5, bold: true, color: C.amber, align: "center", valign: "middle", fontFace: "Calibri", margin: 0 });
  });
  cr.forEach((row, ri) => {
    const ry = 1.43 + ri * 0.48;
    const rc = ri % 2 === 0 ? "0E2136" : "12293F";
    cX.forEach((x, ci) => {
      s.addShape(pres.ShapeType.rect, { x, y: ry, w: cW[ci], h: 0.44, fill: { color: rc }, line: { type: "none" } });
      s.addText(row[ci], { x, y: ry, w: cW[ci], h: 0.44, fontSize: 10.5, color: C.white, align: "center", valign: "middle", fontFace: "Calibri", margin: 1 });
    });
  });

  footer(s, 29);
}

// ════════════════════════════════════════════════════════════════════════════
// SLIDE 30 — KEY TAKEAWAYS
// ════════════════════════════════════════════════════════════════════════════
{
  const s = pres.addSlide();
  bg(s, C.midnight);
  s.addShape(pres.ShapeType.rect, { x: 0, y: 0, w: 0.35, h: 5.625, fill: { color: C.teal }, line: { type: "none" } });
  title(s, "Key Takeaways", 0.2);
  rule(s, 0.88);
  bullets(s, [
    "BRACHIAL PLEXUS: Anterior rami C5–T1 → Roots → Trunks → Divisions → Cords → 5 terminal nerves (musculocutaneous, median, ulnar, radial, axillary)",
    "Remember: Upper trunk = C5+C6 (Erb's); Lower trunk = C8+T1 (Klumpke's)",
    "Cords are named for their relation to the axillary artery (lateral, medial, posterior)",
    "SUBARACHNOID SPACE: Between arachnoid and pia; contains CSF; extends foramen magnum → S2; lumbar cistern (L2–S2) is safe for LP (no cord)",
    "ARACHNOID is the true barrier to drug diffusion — not the dura",
    "EPIDURAL SPACE: Outside dura; extends foramen magnum → S2; DISCONTINUOUS fat pockets; veins mostly anterior; NO fat at cervical level",
    "Epidural block: Loss of resistance → Tuohy needle enters epidural space (dura not pierced); larger drug volumes, slower onset than spinal",
    "Pregnancy narrows epidural space & engorges veins → altered drug kinetics",
  ], { x: 0.55, y: 1.0, w: 9.1, h: 4.35, fontSize: 14 });
  footer(s, 30);
}

// ════════════════════════════════════════════════════════════════════════════
// WRITE FILE
// ════════════════════════════════════════════════════════════════════════════
pres.writeFile({ fileName: "/home/daytona/workspace/neuro-anatomy-ppt/Neuro_Anatomy_Brachial_Epidural_Subarachnoid.pptx" })
  .then(() => console.log("✅ PPTX written successfully"))
  .catch(err => { console.error("❌ Error:", err); process.exit(1); });

cd /home/daytona/workspace/neuro-anatomy-ppt && node build.js 2>&1