Anatomy

System-wise list of high-yield Anatomy points for NEET PG

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**UPPER LIMB**

* Brachial plexus roots are C5–T1; Erb’s palsy involves C5–C6, Klumpke’s palsy involves C8–T1

* Mnemonic for brachial plexus: Randy Travis Drinks Cold Beer (Roots, Trunks, Divisions, Cords, Branches)

* Supraspinatus is most commonly injured rotator cuff muscle

* Axillary nerve supplies deltoid and teres minor; injured in surgical neck fracture of humerus

* Median nerve injury causes ape thumb and carpal tunnel syndrome

* Ulnar nerve injury leads to claw hand; commonly compressed at medial epicondyle or Guyon's canal

* Radial nerve injury causes wrist drop; commonly injured in spiral groove of humerus

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**LOWER LIMB**

* Femoral triangle boundaries: inguinal ligament, sartorius, adductor longus

* Femoral triangle contents from lateral to medial: Nerve, Artery, Vein, Empty space, Lymphatics

* Sciatic nerve is the largest nerve; injury leads to foot drop

* Trendelenburg sign indicates superior gluteal nerve injury

* Popliteal fossa contents: popliteal artery, vein, tibial nerve

* Medial longitudinal arch is higher and more elastic than lateral arch

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**THORAX**

* Diaphragmatic openings: IVC at T8, esophagus at T10, aorta at T12 (Mnemonic: I 8 10 Eggs At 12)

* Azygos vein drains into SVC; accessory and hemiazygos drain left thorax

* Right border of heart is formed by right atrium, left border by left ventricle

* Transverse pericardial sinus lies between arteries and veins; important in cardiac surgery

* Right coronary artery supplies SA and AV nodes; LAD (from LCA) is the "widow maker"

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**ABDOMEN**

* Inguinal canal deep ring arises from transversalis fascia; superficial ring from external oblique

* Indirect inguinal hernia is lateral to inferior epigastric vessels; congenital

* Direct hernia is medial to inferior epigastric vessels; acquired

* Portosystemic anastomoses at esophagus (varices), umbilicus (caput medusae), rectum (hemorrhoids)

* Celiac trunk gives three branches: left gastric, splenic, and common hepatic

* McBurney’s point is 1/3rd from ASIS to umbilicus; site for appendicitis tenderness

* Retrocecal is the most common position of the appendix

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**PELVIS AND PERINEUM**

* Pudendal nerve (S2–S4) supplies perineum; blocked near ischial spine

* Pelvic diaphragm includes levator ani and coccygeus; supports pelvic viscera

* Ureter is crossed by vas deferens in males and uterine artery in females

* BPH occurs in transitional zone; prostate cancer in peripheral zone

* Ischiorectal fossa is fat-filled and prone to abscess formation

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**HEAD AND NECK**

* Facial nerve exits via stylomastoid foramen; damage leads to Bell’s palsy

* Optic canal transmits optic nerve and ophthalmic artery

* Superior orbital fissure transmits CN III, IV, V1, VI

* Foramen ovale transmits mandibular division (V3) of trigeminal nerve

* Cavernous sinus contains CN III, IV, V1, V2, VI and internal carotid artery

* Tongue anterior 2/3rd: taste via chorda tympani, sensation via lingual nerve

* Tongue posterior 1/3rd innervated by glossopharyngeal nerve

* Parotid duct pierces buccinator and opens opposite upper second molar

* Parotid gland secretomotor innervation via CN IX through otic ganglion

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**NEUROANATOMY**

* Circle of Willis is formed by ICA, ACA, ACoA, MCA, PCoA, PCA

* Berry aneurysms commonly occur at junction of ACA and ACoA

* Corticospinal tract decussates in medullary pyramids; lesion causes contralateral motor loss

* VPL nucleus of thalamus carries body sensation; VPM carries facial sensation

* Lateral geniculate nucleus handles vision; medial geniculate handles hearing

* CSF pathway: Lateral ventricles → foramen of Monro → 3rd ventricle → aqueduct → 4th ventricle → subarachnoid space

* Basal ganglia direct pathway facilitates movement; Parkinson’s involves loss of dopaminergic neurons in substantia nigra

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**EMBRYOLOGY**

* 1st pharyngeal arch forms maxilla, mandible; nerve supply by CN V

* 2nd arch forms stapes, styloid process; nerve supply by CN VII

* 3rd arch forms hyoid body; nerve supply by CN IX

* 4th and 6th arches contribute to laryngeal cartilages; supplied by CN X

* Aortic arch derivatives: 3rd forms carotids, 4th forms aortic arch (left) and subclavian (right), 6th forms pulmonary arteries

* Neural crest cells form DRG, melanocytes, Schwann cells, adrenal medulla

* Diaphragm develops from septum transversum, pleuroperitoneal membranes, body wall, and dorsal mesentery of esophagus

* Midgut rotates 270 degrees counterclockwise during development; herniates at 6 weeks, returns at 10 weeks

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