Ulna: Features & Attachments

THE ULNA2ULNA:- Ulna is the medial bone of foream and is homologousto the lateral bone of leg- the fibula.TYPETypical long bone, developsSITE:- Medial bone ofby cartilagenous ossification.forearm.ANATOMICAL POSITION / SIDE DETERMINATIONDIPANNAR RAIUPPER END:-(i) Large and hook like (Trochlear rotch)(ii) Concavity of trochlear notch directed forwards.SHAFT :- Sharp and Crest like interosseous burder directed laterally.LOWER END :- (i) Smaller and carries head and Styloid process.(ii) Pointed Styloid process lies posteromedial torounded head (of Ulna).GENERAL FEATURESHuman Anaromy For Exam.-It consists of Shaft and 2 ends - Upper and Lower-THE UPPER ENDIt is hook shaped having -2 Proceess - Coronoid is Olecranon (ii) Norches 1 Trochlear & Radial(iii) Muscular Impressions 1 Ulnar Tuberosity & Supinator fossaOLECRANON PROCESS(i) Forms the uppermost part of ulna and upper part of the Trochiear notch.(ii) Bent forwards to form a prominent beak. (iii) Portion part is smooth ands(iv> It lodges into the Olecranonfossa of humerus (In full Extension) subscutaneous.CORONOID PROCESS(1) Projects forwards like a broad beak.(ii) Upper surface forms the lower part of Trochlear noteh.(iii) Anterior surface shows a rough area called - Ulnar Tuberosity(iv) Anterior border lodges into the Coronoid fussa of humerus (In full Flaxion)TROCHLEAR NOTEHLies on the lateral surface of coronoid process.(ii) It articulates with the circumference of head of radiusin supra radio ulnar joint. THE ULNA2RADIAL NOTCH(i) Lies on the lateral surface of Coronoid process(ii) Articulars with the circumference of head of radius inSuperior radio-ulnar jointULNAR TUBEROSITYDIMMEAR RAY(i) Rough area at the anterior surface of the Coronoid process.(ii) Receives the insertion of the brachialis muscle.SN PINATOR FOSSA & CRESTHUMAN ANATOMY FOR EXAM(i) Depressed area lying below radial notch-(ii) Bounded posteriorly by a sharp ridge called supinator erest.(iii) Supinator fossa and crest give origin to supinator muscle.THE SHAFTThick above but tappers towards the lower end.Its upper 3/4 is triangular in cross section while its lower1/4 is rounded.It has 3 Barders (Anterior, Interasseous & Posterior) and3 Surface ( Anterior, Medial & Posterior.)INTEROSSEOUS BORDER(i) Sharp directed laterally and gives attachment to the interosseousmembrane.(ii) Upper end is continuous with the supinator crest.ANTERIOR BORDER(i) Rounded and starts above at the lower end of medial borderof coronoid process(ii) Ends below at the base of the styloid process.POSTERIOR BORDER(i) Prominent and starts above at the apex of post surface ofOlecranon process.(ii) Subcutenous and ends below at the base of Styloid process.ANTERIOR SURFACEiBetween ant & Interasseous border(ii) Upper 1/3 presents a nutrient foramen (directed towards elbow). THE ULNA3MEDIAL SURFACE(i) Between anterior and post borders(ii) Smooth and featurelessPOSTERIOR SURFACE(i) Between the Interosseous and posterior borders.(ii) Oblique ridge - in upper 1/3 and vertical ridge - in Lower 2/3THE LOWER ENDSmaller process. than upper end & formed of head & StyloidTHE HEAD OF ULNADIPANKAR RAY,(i) Rounded, directed laterally & Can be feltSubsuteneously (in pronation)(iii) (ii) Lateral Lateral surface articulares - Ulnar notch (radius) Inf. Radio-ulnararticular surface disc. separated from carpal bones by triangular.joint]THE STYLOID PROCESS(in Posteriar surface separated from Styloid process by a grove.HUMAN. ANATOMY FOR EXAM(ii) subcutaneously (In Supination).(i) Can Projects be felt downwards from the posteromedial part of the head. THE ULNA4MUSCLES ATTACHMENTSMUSCLES (6) ATTACHED - UPPER ENDHUMAN ANATOMY FOR EAM(i) TRICEPS M:(ii) ANCONEUSInsertion - Posterior part of upper surface of Okeranon processM: Insertion - Lateral surface of Olecranon process andupper 1/4 of post surface.(iii) BRACHIALS M:Insertion - Ulnar tuberosity,DIPANNORMAY(iv) SUPINATOR M.Origin - Supinator fossa and crest.(v) FLEXOR DIGITORUM SUPERFICIALS (ULNAR HEAD)(vi) PRONATOR TERESOrigin - Medical(LIMAR HEAD)border ofcoronoid process.MUSCLES (2) ATTACHED - -ANTERIOR & MEDIAL SURFACEas FLEXOR DIGITORUM PROFUNDUSOriginUpper3 of ant & med surface.(ii) PRONATOR QUADRATUS :OriginLower 14 of the ant sunface of ulna.MUSCLES (3) - ORIGIN- POSTERIOR SURFACE(i) ABDUCTOR POLLICIS LONGUS(ii) EXTENSOR POLUCIS LONGUS(iii) EXTENSOR INDICISfrom upper 2/3 of the posteriorOrigin in that order (Above downwards)surfaceMUSCLES (3) - ORIGIN - POSTERIOR BORDER OF ULNA(i) FLEXOR CARPI ULNARISOrigin by Common Aponeurosis(ii) EXTENSOR CARPI ULNARIS:- Ulna aponeurosis from(iii) FLEXOR DIGTTORUM PROFUNDUS:-posterior border. STRUCTUREATTACHMENT TO RADIUSATTACHMENT TO ULNAattached to the neck of RadiusSurrounds the head and losselyArtached to the anterior & posteriorbarders of radial notch.Its lateral end is attached toIts medial end is attached justthe medial side of neck of Radius.below the radial notch.Attached just below theAttached to the lateralside of theOBUgue CORD.radial tuberosity.ulnar tuberosity below quadrateligamentRAY.Attached to Interasseous borderAttached to Interesscoves borderof radiusof Wna.CAFULLE JOINT. RADIOULNARYAttached around the articular surfaces ofLower end of radius & ulnaIts base-attached to InferiorOFIts apex-attached - to depressionRADIO.border of the ulnar hotchat base of the Styloid process.of radius.