1CHAPTER 7-SKELTON FILL-IN NOTES 2 Axial skeleton: skull, vertebral column, thoracic cage 3 Fig. 7.1 pg. 199 4 I. Skull:two parts A. Cranium: Encloses and protects the brain - 8 bones B. Facial bones: 14 bones Cranium A.Frontal – Forehead (brain) Anterior part of the cranium forming the superior eye orbits then horizontal to form roof of eye and the floor of anterior cranial cavity 5 Figs. 7.4 A,Pg. 202 6 Figs. 7.4 b. 5,Pg. 202 7 Fig. 7. 5a, Pgs. 203 8 Fig. 7. 5b, Pg. 203 9 B. Parietal bones (2) bilateral posterior, lateral 2/3 of cranium (brain) fig. 7.5 a C. Occipital: (brain) posterior/inferior part of the cranium . D. Temporal: (2) bilateral, inferior to parietals 1. houses: external auditory meatus (ear canal), middle & internal ear 2. Zygomaticus: posterior part of zygomatic arch 10 Figures 7.5a; pg 2032 11 fig. 7.8; pg. 207 12 Sutures: major, “immoveable” serrated joints between previous cranial bones (we’ll get back to remaining 2 skull bones latter) Sagital sutures: lies in the mid-sagittal plane & separates the left & right parietals 13 Fig. 7.4b; pg. 202 14 B. Coronal suture: lies in coronal plane articulating both anterior parietals with the frontal bone C. Lamboid suture: posterior skull articulating both posterior parietals with the occipital bone. D. Squamous suture: articulates inferior border of parietals w/ superior border of the temporal bones . Cranial bones & sutures: prenatal & newborns Cranial bones cartilagenous [fontanelles] & sutures flexible - child birth 15 fig. 7.5 a pg. 203 16 Last two cranial bones – cranial floor E. Sphenoid – middle part of cranial floor 1.Weird, bat shhaped bone that articulates w/ all the other 7 cranial bones 2. Superior surface contains sella turcica (turk’s saddle) hold the pituitary gland (hypophysis) 3. Forms part of the cranial floor 4. Part of external skull, anterior to temporal bone (greater wing) 17 Fig. 7.6a; pg 2053 18 Fig. 7.7a; pg. 206 19 F. Ethmoid bone: another bizarre shaped bone. 1. Location: midline in anterior part of cranial floor medial to orbits 2. Includes the cribiform plate a. part of the roof of the nasal cavity b. foramina (holes) that carry olfactory nerves (smell) to brain 20 Figure 7.4a; page 202 21 Facial Bones A. Mandible – lower jaw bone 1. Coronoid (l) (crown shaped)“process” a. insertion of temporalis muscle – closes the jaw 2. mandibular condyle: articulates with mandibular fossa . of temporal bone – forms tempromandibular joint - TMJ. a. TMJ syndrome –symptoms from joint dysfunction 22 fig. 7.11 a pg. 210 23 fig. 7.5a pg. 203 24 B. Maxillary bones: upper jaw – 2,fused medially 1. “Keystone” articulate w/ all other facial bones 2. part of floor of orbit (eye) 3. most of hed palate (roof of mouth) 4. floor of nasal cavity C. Zygomatic bone: “Cheek bone” zygoma (L)” bar– lateral wall & floor of orbit (eye socket) 1. Forms zygomatic arch w/ zygomatic process of temporal bone4 25 Fig. 7.5a pg. 203 26 Fig. 7.6a&b pg. 205 26 Fig. 7.6a&b pg. 205 27 28 D. Nasal bones: Thin bones fused medially forming the bridge of the nose. a. Everything anterior to bridge is hyaline cartilage. E. Siuses: 1. Hollow, cavaties lined withmucous membranes – can become inflamed - allergies 2. Connect with nasal cavities 3. found in – frontal, sphenoid, ethmoid and maxillary bones 29 Figures 7.15 a page 216 30 Figure: 7.15 b page 216 31 Hyoid bone: A. Anchor for the tongue B. Horseshoe shaped C. Anchored to styloid proccesses by thin ligaments 32 Figure 7.12 pg 211 33 Vertebral Column/Spinal Column Spine 24 Vertebrae, sacrum & coccyx5Three regions 1.Cervical: 7 vertebrae ; C1-C7 2. Thoracic: 12 vertebrae; T1-T12 3. Lumbar: 5 Vertebrae; L1- L5 4. Sacrum: 5 fused segments segments 5.Coccyx: 4 fussed segments 3 Spinal Curves: 60 degrees 1.Cervical: forward curve & called a lordosis 2.Thoracic curve: reverse curve - kyphosis 3. Lumbar curve: forward curve – lordosis 34 Fig. 7.16; page 217 35 Fetus and newborns have one, thoracic (kyphotic) curve – 2 other curves develop as child develops and becomes active Perfect Posture (biomechanical) Digress Vertebrae Structure - 2 parts I. Body - large round thick bone disc a. Weight is transmitted from body to body c. Separated by intervertebral disc (“disc”) 36 Fig. 7.17 a; pg 218 37 Fig. 7.17 b; pg 218 38 Fig. 7.18; page 219 39 II. Posterior (neural) arch – posterior to body A. Pedicles: project posteriorly from the body forming the lamina which meet medially forming the vertebral foramina6B. Transverse foramina: extend laterally for muscle attachment w/ leverage (mechanical advantage) C. Spinous process : extends posteriorly for muscle attachment w/ leverage 1. Bumps down ones back 40 41 D. Inferior notch: notch for spinal nerve forming the intervertebral foramen E. articular processes: 1. Have a smooth articular face called facet 2. Each vertebra has a superior articular process and an inferior articular process 3. The inferior facet of a vertebrae will articulate (meet) with the superior facet of the vertebra just inferior to it. 4. Facet joint: Where the facets articulate (meet) 42 Fig. 7.20b; pg. 221 43 lII. Vertebral Regions A. Cervical vertebrae 1. C1 – Atlas – holds up the skull/head – Superior facets articulate w/ occipital condyles of skull a. No body or spinous process. Have anterior/posterior processes 2. C2 – Axis a. Has odontoid/dens, a post that acts as an axle/axis for atlas to rotate on b. Majority of cervical rotation between C1 &C2744 Fig. 7.19 a; pg. 220 45 Fig. 7.19 a&b; pg. 220 46 Fig. 7.19c; pg 220 47 3. All cervical vertebrae, C1-C7, have transverse foramina for vertebral