MSAK 1 Trunk Bones PDF

Friday, January 21, 2022 MSAK 1 Trunk Bones —The Axial Skeleton (center bones of body) - Vertebral column - Vertebral column — made up of 26 connected vertebrae ( exible, ridged) Lose 50% of mobility in vertebral column as we age Muscles in vertebral column help maintain spinal curve V...

Friday, January 21, 2022 MSAK 1 Trunk Bones —The Axial Skeleton (center bones of body) - Vertebral column - Vertebral column — made up of 26 connected vertebrae ( exible, ridged) Lose 50% of mobility in vertebral column as we age Muscles in vertebral column help maintain spinal curve Vertebrae increase in size descending down vertebral column — has more pressure to withstand - 3 Pillars: (makes up vertebral column) (1) Major pillar—anterior; stacked vertebral bodies (weight bearing part of vertebrae) (2) Minor pillars—posterior left & right; stacked articular processes - Intervertebral discs - Intervertebral disc — cartilage between each vertebrae Holds vertebrae together Shock absorbent increase stability/strength - Herniation — Jelly/watery substance in the middle of disc; slides and bulges out bulging goes into intervertebral foreman When bulging is too much; lls up foreman and compresses the nerve Bulging gets worse and worse if untreated… - starts w/ pins & needles/ numbness/ burning sensation - ends w/ weakness of muscle —> paralyzed; if nerve gets completely compressed / cut - Typical Vertebra - 2 major parts: 1. Vertebral body (anteriorly) 2. Vertebral arch (posteriorly) Common features to all vertebrae: - (1) Vertebral body — large, thick base - (1) Vertebral arch — Arch of vertebra inside foramen —without body - Floor = back of vertebra - Walls = pedicles - Roof = where laminae join - (1) Vertebral foramen — Hole made between the body and vertebral arch - Houses spinal nerve Spinal nerve named by the vertebral sitting above them - Ex. foreman of L1 (& upper L2) : nerve would be called “ Spinal Nerve L1” - (1) Spinal cord — inside vertebral foremen and canal fi fl  - Nerve branches o spinal cord and exits vertebral canal through intervertebral foreman - (1) Canal — multiple foramen stacked together - (2) Pedicles — 2 arms branching o the body (2) Superior vertebral notch — notch forming lower margin of intervertebral foreman (2) Inferior vertebral notch — notch forming upper margin of intervertebral foreman - (2) Laminae — 2 arms branching o the pedicles - (1) Spinous process — 2 lamina coming together creating sharp process on midline (posterior) - (2) Transverse processes — 1 Pedicle and 1 Lamina coming together forming long process - (4) Articular processes (Superior/ Inferior) — hands @ the junctions of pedicles/laminae holding onto the adjacent vertebrae’s above/below (4) Articular facet — facet covered by cartilage on each end of articular process - Joints: Disc joint — between 2 adjacent bodies @ intervertebral discs (less mobile than Z-joint) Zygo-pophyseal joint (Z joint) — between articular facets of articular processes; responsible for majority of movement in spine - Spinal curves (curvatures) Curves are ‘developmental’ - gradually taking weight of the body as we grow - Primary curve —Fetus born with 1 single spinal curve convexity (Kyphosis curvatures) - Thoracic curve — remains unchanged - Sacral curve — remains unchanged - Secondary curves — develop as baby grows (Lordosis curvatures) - Cervical curve — appears @2-3 months - Lumbar curve — appears @1 year (once baby starts walking) Abnormal curves: - Scoliosis — Abnormal curves in Thoratic/ Cervical/ Lumbar; to right or left - Can be due to a poor posture OR Congenital (born with it) - if severe…. Must be xed with surgery - if mild…. Can be xed with a splint - Hyper-Kyphosis — Exaggerated curve in Thoracic spine (posterior convexity) —hunchback - Fix with surgery —must break bones and put rod inside - can’t x in elderly due to osteoporosis - Hyper-Lordosis — Exaggerated curve in Lumbar spine (posterior concavity) —bum stick-out - Result of weakness of core muscles - Typically temporary; from posture - Common in pregnant woman fi ff fi fi ff ff - Cervical Vertebrae (Neck region) - ( 7 ) Cervical vertebrae in region (CI - CVII) Typical = C3,C4,C5,C6 Atypical = C1,C2,C7 Most mobile region (#1) Convex forward Small body Triangular vertebral foramen Typical features of Cervical vertebrae: - Bifurcated spinous process — split end (except #1, #7) - Transverse foramen — a hole on transverse process making 2 arms (*biggest tell of C-spine*) Vertebral artery — inside transverse foremen (important artery for brain blood supply) - Uncus (Uncinate process)— 2 Lips / edges on superior lateral body - Anterior / Posterior tubercles — tubercles on transverse processes lateral to the foremen - Articular facets — superior and inferior - Joints: Uncovertebral joint — 2 Uncus joining together Z- joint — transverse-oblique oriented Disc Joint —between intervertebral discs Atypical features of Cervical Vertebrae (C1,C2,C7) C1 Vertebrae: Atlas - No body ( No… laminae / pedicles / uncus ) - No spinous process - Large vertebral foremen - Anterior arch — Smaller Anterior tubercle —in mid point of arch Articular surface for Dens— inside anterior arch - opposite to tubercle - Posterior arch — Bigger Posterior tubercle —in mid point of arch - Lateral masses — 2; on either side Articular surface for occipital condyle — on superior/inferior surfaces Superior articular facets - large bean shaped (occipital bone rests on facet) Inferior articular facets - smaller circular - Joint: Atlanto occipital joint — skull & superior-articular-facet joining; for movement of exion/extension (nodding “yes”) of head fl  C2 Vertebrae: Axis - Dens (Odontoid process) — Tooth-shaped tubercle on body - below anterior arch of atlas acts as a pivot; allows rotation of atlas on axis bone. - If dens dislocates = it will cut spinal cord (partially or completely) - injury of dense = Everything below neck is paralyzed Anterior articular facet — on dens; for anterior arch of atlas Posterior articular facet — on dens; for transverse ligament of atlas - Lateral masses — 2; one on both sides - Superior articular facets - larger; for atlas - Inferior articular facets - smaller; for C3 - Tubercle — Fused Tubercles on transverse processes — No anterior/posterior - Joint: Atlanto axial joint — Dens joining with anterior arch of atlas; for movement of rotation (“no” nod) of head (dens dislocation) C7 Vertebrae: - Spinous process — NOT bifurcated - Size — Larger than the rest of the cervical spine - Transverse foramen — smaller than the rest of the cervical spine (does not transmit vertebral artery) - Vertebral prominent: C7 is typically the longest (sometimes T1)—important to locate to use as a reference to count and nd the other vertebrae ( ex neck to prove which vertebrae) - Thoracic Vertebrae (Mid region) - ( 12 ) Thoratic vertebrae in region (TI - TXII) Typical = T2,T3,T4,T5,T6,T7,T8 Atypical = T1,T9,T10,T11,T12, Least Mobile region (#3) ( Ribs & Z-joints) Concave forward Typical features of Thoracic vertebrae: - Costal facet — rigged ridge on the sides of the vertebral body; where head of ribs articulate - 4 on body: (2 Right/ Left … 2 Superior/ Inferior) Semi-Costal facet — half facets ( Ribs articulate with 2 semi facets [above & below] to = 1 full facet ) Transverse-Costal facet — on each transverse process; articulation Rib tubercles - Spinous process —Sharp pointy long, inclined downward - Ribs — attach to body & transverse process - Body — heart-shaped / increase in size from above downward - Vertebral foramen — Round, small (size of middle nger) fi fl fi  - Facet of Superior articular process — face backward and laterally - Facet of Inferior articular process — face forward and medially. Joints: - Z-joint — Frontal plane (side- exion: mobile … exion/extension/rotation: limited) - Disc Joint — between intervertebral discs RIB ARTICULATION : with 2 ribs; 1 of same T#, 1 of the T# below - ex. Rib #6 — Articulates with superior semi-costal facet of T5 and inferior semi-costal facet of T6. The tubercle of rib also articulates with transverse process of T6 Atypical features of Thoracic Vertebrae T1 Vertebrae: - Articulates with 4 ribs - (1) Superior facet: FULL — for head of Ribs#1 - (1) Inferior facet: SEMI — for upper half of head of Ribs#2 - Body — broad transverse; concave upper surface, lipped on both sides. - Spinous process — thick, long, horizontal - YES transverse costal facet T9 Vertebrae: - Articulates with 2 ribs - (1) Superior facet: SEMI — for head of Ribs #9 - No semi-facets below - YES transverse costal facet T10 Vertebrae: - Articulate with 2 ribs - (1) Articular facet: FULL —for head of Ribs#10 - No semi-facets below - YES transverse costal facet T11 Vertebra: - Articulate with 2 ribs - (1) Articular facets: FULL — for head of Ribs#11 — large, above pedicles - No semi-facets below - NO transverse costal facet — (no articulation with rib 11) T12 Vertebra: - Articulate with 2 ribs - (1) Articular facet: FULL —for head of Ribs#12 - No semi-facets below - NO transverse costal facet — (no articulation with rib 12) - Inferior articular Facet —faces laterally - RIB ARTICULATION : 2 ribs , 1 of same #, 1 of the # below fl fl  ex. Rib #10 — Articulates with full-costal facet of T10. The tubercle of rib also articulates with transverse process of T10 - Lumbar Vertebrae (Lower region) - ( 5 ) Lumbar vertebrae in region (LI - LV) Convex anteriorly Largest vertebrae All Typical ! Moderately Mobile region (#2) L5 has the most pressure/ weight/ compression - Discs absorb lots of shock/pressure/force — very thick - These discs are more at risk of injury — thick and strong Has no facets for articulation with ribs and no foramina in transverse processes (Obviously!). Common features of Lumbar vertebrae: - Body — massive & bean-shaped. - Pedicles — strong & directed postero-laterally. - Laminae — thick - Vertebral foramina — large & triangular - Transverse processes — long & slender. - Articular processes — sagital plane - Spinous process — short, at, rectangle-shaped; projects directly backward - Accessory process — Bump on root of transverse process; posterior surface - Mammillary process — bump on posterior part of the superior articular processes - Superior articular facet — face medially - Inferior articular facet — face laterally - Inter-vertebral foreman —stacking 2 adjacent foreman; making a hole in between body & inferior articular processes (& superior articular surface of bottom vertebrae) - Foreman reduced in size when disc is compressed - Made by: Inferior vertebral notch Superior vertebral notch Joints: - Z-joint — sagittal plane orientated (side- exion/rotation: limited… exion/extension: very mobile) - Disc Joint — between intervertebral discs fl fl fl - Sacral Vertebrae (bottom region) - ( 5 ) vertebrae in sacral region (SI - SV) 4-5 vertebrae fused together; 1 single wedge-shaped bone - (used to be separated as fetus) Concave anteriorly Triangular shape Disc — last disc in vertebral column L5 - S1 - Injury is very common, lots of pressure Common features of Sacral vertebrae: - Body of S1 — upper border; articulates with the body of L5 vertebra Anterior surface — smooth Inferior surface — Curved, convex, bumy Auricular surface — Laterally joints with 2 hip bones; Sacroiliac joints - ”Auricle” = ear ; ear shaped - Sacral Canal — inside anterior surface; formed by vertebral foramina - All sacral nerves inside canal - Quada equina (horse tail) — nerves inside the sacral canal - Sacral ridge/crest — 5 crests on posterior surface; median (1) / intermediate (2) / lateral (2) 1. Median Sacral Crest — 1 middle bony ridge; fusion of spinous processes - Remnants of spinous processes of embryonic segments 2. Intermediate Sacral Crest (medial crest) — 2 bony ridges; left/right sides of medial sacral crest - Remnant of articular processes 3. Lateral sacral crest — 2 bony ridges lateral to the 4 pairs of posterior sacral foramina - Sacral foramina — holes; 4 on right/4 left sides; for passing nerves - passage for posterior rami of Sacral nerves - connected together by transverse ridges - represent the remnant of intervertebral discs - Promontory of sacrum — anterior edge of the body of S1 - bulges out like big rock - Sacral ala (wing) — 2 triangular at surfaces (left/right) superior side of S1 lateral to the promontory - Helps form the ‘Superior Aperture’ - Sacral hiatus — Bottom of sacral canal; Laminae of S5 (sometimes S4 too), fails to meet in the midline - Last part of nerves exit through here - Sacral Cornu — connects with coccygeal horn by ligaments - Disc —Last disc in vertebral column L5 - S1 Joints: - Z-joint — last Z-joint in vertebral column fl  - Lumbo-Sacral joint — between L5 and S1 disc - Sacroiliac joints— between sacrum - Coccygeal Vertebrae (last region) - ( 4 ) Coccygeal vertebrae region (TI - TXII) 3-4 vertebrae fused together; 1 single bone Bones were separated as fetus Small triangular bone 1st coccygeal vertebra — commonly un-fused (or partially fused) with sacral vertebra Transverse process — On both sides of 1st coccygeal segment Coccygeal Cornu — 2 processes arising from 1st coccygeal segment toward sacrum - Ribs - ( 12 ) Ribs in axial skeleton Long, twisted, at bone Attached to vertebrae; ( the body & transverse process ) Costal cartilage — articulates with rib on Sternum Superior border — rounded, smooth Inferior border — sharp, thin - has costal groove Lateral surface — convex (on outside, can touch) Medial surface — concave (on inside, toward lung) Typical rib: (T 3, 4, 5, 6, 7, 8, 9 ) - Head — attaches to costal facet of body of T- spine; Has 2 semi-facets for articulation with # corresponding vertebral body & vertebra below Separated by interarticular crest - (Ex. Rib #7)— Head articulates with vertebrae #6 & 7 - Neck — constricted portion between the head and tubercle. - Tubercle — on outside surface at junction of neck & shaft - (Ex. Rib #7)—tubercle articulates with transverse process of vertebrae #7 Articular portion — facet for articulation with transverse process of # corresponding vertebra. Non-articular portion — gives attachment to ligaments - Shaft/ Body — thin, attened, twisted on long axis. Its inferior border has the costal groove. Anterior end —attached to corresponding costal cartilage Posterior end — curvature with the head and facets; attaches to body of T-spine - Costal Angle — where shaft bends sharply forward fl fl  - Costal groove — houses intercostal nerve/ artery/ vein ; where inferior border overhangs Atypical rib: (T 1, 2, 10, 11, 12 ) - 1st Rib: - Important — close to brachial plexus & main vessels of arms Orientent in horizontal plane - Flattened Superior surface & Inferior surface - not medial / lateral Scalene Tubercle — on superior surface; close to medial boarder (2) Grooves — in-front & behind tubercle - houses subclavian vein & artery Head —only 1 single articular facet for body of T1 No angle No costal groove - 2nd Rib: Orientent in Oblique plane No costal groove - 10th Rib: Head — only 1 single articular facet for body of T10 - 11th Rib: Head — only 1 single articular facet for body of T11 No neck No tubercle Slight angle Shallow costal groove - 12th Rib: Head — only 1 single articular facet for body of T12 No neck No tubercle No angle No costal groove - Sternum - Flat bone - Divided into 3 parts : 1) Manubrium 2) Body 3) Xiphoid process - The Manubrium: Upper section sternum Lies opposite to T3 & T4 vertebrae Suprasternal notch (Jugular notch) — large dip on superior middle sternum Clavicular notch — where clavicle articulates and joins with the sternum Sternal angle — where manubrium meets with body of sternum - landmark for Rib #2 - Sternal angle (Angle of Louis) — formed by the junction of manubrium and body in the form of a cartilaginous joint - Later becomes bony and the manubrium and body fuse at this angle Manubriosternal joint. - Palpable, important Articular facets — 2 notches on each lateral side; for the True Ribs - Full-facet for Rib #1 - Semi-facet for Rib #2 - The Body: Superior body — articulates with manubrium Inferior body — articulates with xiphoid process Articular notches —for articulation with inferior costal cartilage of Rib #2, 3 - 7th costal cartilages Articular facets — 7 lateral notches for True Ribs ****** - The Xiphoid Process: Lowest & smallest part of the sternum Triangular Divides the infra-sternal angle to left / right halves Marks approximate level of 2nd pair of costal cartilages & level of intervertebral disc between T4 / T5. - Xiphi-sternal joint — has set boundaries by transverse ridge. - Rib Cage (Rib categorization) - Chest Cavity: - True ribs — Ribs attached to sternum directly; via their own costal cartilage — Ribs # 1-7 - False ribs — Ribs attached to sternum indirectly; via — Ribs # 8-12 False oating ribs — Ribs not attached to sternum at all — Ribs # 11,12 Can be True and Atypical (Rib # 1 , 2) Can be False and Typical (Rib # 10) Can be False and Typical (Rib # 8 , 9) Can be False and oating (Rib # 11, 12) fl fl - 12 pairs of ribs; all articulated posteriorly to the thoracic vertebrae. - Ribs #8-10 — attached anteriorly to Rib#7 by costal cartilages & small synovial joints ( false ribs). - Ribs #11-12 — no anterior attachment (False oating/free ribs). - Intercostal spaces—The spaces between the ribs on each side of the thoracic cage - lled by intercostal muscles - carry intercostal nerve / vessels. - Hip (coxal) bone — going more in depth with lower limb bones - ( 2 ) Coxal Flat bone Quadrangle-shaped Twisted — borders are in di erent planes - Composed of 3 bones: - Ilium - Ischium - Pubis - 3 bones are Completely fused after puberty Anterior border — ASIS / AIIS / pubic tubercle Posterior border — boarder below greater sciatic notch Inferior border — ????????? Superior border — iliac crest Common features: - Acetabulum — deep fossa on lateral surface of body - for leg - Obturator foremen — Big wide foreman; inferior to acetabulum (second widest foreman in body) - Greater sciatic notch — Deep notch beginning the posterior border - Iliac crest — part of ilium; prominent top boarder of hip bone - Ischial tuberosity — part of ischium; Bottom bone protuberance “sit bone” - Anterior Superior iliac Spine (ASIS) — part of ilium; anterior end of iliac crest - Anterior Inferior iliac Spine (AIIS) — part of ilium; anterior end of iliac crest - Pubic tubercle — part of pubis; top boney bump across from obturator foreman - Symphysis pubis — rough articular surface for 2 anterior hipbones ; below Pubic tubercle - Pubic crest — small sharp border between Pubic tubercle and Symphysis pubis - Joints: Symphysis pubis joint — both hip bones join together anteriorly Sacroiliac joint — both hip bones join with sacrum posteriorly - fuses at age: 50-55 female (more exible longer; birth compensation) / 45-50 in male ff fl fl fi - Thoratic Apertures - 2 Apertures : Superior Thoratic Aperture— Neck to chest; fully open (esophagus, trachea pass through) - bony ring comprised of jugular notch, clavicular notch, Rib#1, body of T1 - Borders: Posterior — Body of T1 Lateral — Medial border of Rib #1 / Costal cartilage of Rib #1 Anterior —Manubrium (clavicular notch, jugular notch) Inferior thoratic aperture— end of chest; not-fully open— separates chest and abdomen - formed by xiphoid process, costal margin (costal cartilages of Ribs #7-10), tip of Rib#11, whole Rib#12, & T12 vertebra. Closed by diaphragm - Borders: Posterior — Body of T12 Lateral — costal cartilages of Ribs #7-10 / tip of Rib#11 / all of Rib#12 Anterior — End of xiphoid process -