Cranial bones

Cranial bones

suturesagittal coronal lambdoid squamous

In practice 1. pterion: an H-shape confluence of the sutures of the frontal, parietal, sphenoid and temporal bones. The pterion overlies the speech area of the brain as well as the middle meningeal artery.2. Bregma3. lambda

In the very medial end of foramen lacerum is the opening of carotid canal.

Carotid canal

Sphenoid boneOptic canal: CN IIOphthalmic artery Central retinal veinSuperior orbital fissure: CN IIICN IVCN V1CN VISup. Ophthalmic veinForamen rotundum: V2Foramen ovale: V3Foramen spinosum: middle meningeal artery

Temporal and occipital bonesInternal auditory meatus: CN VIICNVIIIJugular foramen: CN IXCN XCN XISigmoid sinusInf. Petrosal sinusJugular veinCarotid canal: internal carotid arterysympathetic to head (on internal carotid artery)Hypoglossal canal: CN XIIForamen magnum: vertebral artery, spinal root of CN IX

In practiceCribriform plate fracture may result inDysosmiaRhinorrhea (CSF)

In practice: Jugular foramen syndromemay be caused by tumor pressing on CN IX, X, XI, which present with:Hoarseness and dysphagia: CN XLoss of sensation over the oropharynx and posterior one third of the tongue: CN IXTrapezius and SCM weakness: CN XIThe nearby CNXII may be involved producing tongue deviation to the lesioned sideYou leak your wound

Cranial bones

Sphenoid

Ethmoid bone

Temporal bone

Facial bones

Anterior Palatine Foramen Palatine Process of Maxilla Palatine Greater Palatine Foramen Lesser Palatine Foramen Pterygoid Processes of SphenoidZygomatic Process Squamous Part of Temporal BoneMandibular Fossa Styloid Process Stylomastoid Foramen Mastoid Process Mastoid Foramen Superior Nuchal LineExternal Occipital ProtruberanceMedian Nuchal LineInferior Nuchal LineForamen MagnumCondyloid CanalOccipital Condyle Hypoglossal CanalJugular ForamenCarotid CanalForamen SpinosumForamen OvaleForamen LacerumVomer Transverse Palatine SutureMedian Palatine Suture

Mandible

Base of the skull

Maxilla / palatine

Eye socket

Nasal cavity

Nasal cavity

Hyoid bone

Cervical and lumbar concave (bending forward), Thoracic and sacral convex (bending backward). Fetus has only one curvature, which is convex.

Intervertebral discAnulus fibrosus: fibrocartilageNucleus pulposus: semigelatinous fluid with very few, if any, cellsHerniation of nucleus pulposus is always posterolateral The intervertebral disc is reinforced:anteriorly and anterolaterally by the anterior longitudinal ligamentposteriorly by the posterior longitudinal ligament

Typical vertebra The body of the vertebrae has hemifacet to articulate with the head of ribs; Each rib head articulates with the body of the numerically corresponding vertebra and the one below it.Transverse process of thoracic vertebra has a facet for articular part of tubercle of the numerically corresponding rib

Cervical vertebra

Intervertebral foramen The intervertebral foramen is bounded superiorly and inferiorly by the pediclesAnteriorly by parts of bodies and intervertebral diskPosteriorly by facet joints (zygophyseal joint)Spinal nerve contained within the intervertebral foramen may be compressed by herniation or osteoarthritis of zygophyseal joint

Cervical vertebrae The first two vertebrae are atypical.All cervical vertebrae have openings in their transverse processes (transverse foramina)Vertebral artery and vein pass thorough transverse foramina

Atlas, Axis Atlas has no body.Axis has odontoid process

Interlaminar space is only found in lumbar region. Therefore, lumbar puncture can be done at lumbar. L4-L5 or L5-S1

The bottom of spinal cordIn adult: L1-L2in newborn: L3Sacral hiatus: if you pass a needle here, you reach epidural space, because subarachnoid space ends by S2

In practiceA neurovascular bundle traverse the inferior border of the rib in the order of vein-artery-nerve (VAN) from top to bottom

Appendicular skeleton

The most common dislocated bone: lunateUsually dislocate anteriorlyIt pressure median nerve in carpal tunnelThe most commonly fractured bone: scaphoidIncreased risk of avascular necrosis

For lumbar puncture use Iliac crest as landmark = L4for relieving pain during pregnancy block pudendal nerve by using ischial spine as landmark Appendix: 2/3 of the way from the umbilicus to the ant. sup. iliac spine = McBurneys point

pelvisGreater sciatic notch: blood vessels and the sciatic nerve use this area to leave the pelvic cavity and enter the posterior thigh region.Obturator foramen: blood vessels and nerves pass through the obturator foramen from the pelvic cavity into the anterior thigh.

In practiceThe most common form of ankle sprain (rupture of lig) is lateral (due to inversion and dorsiflexion of ankle)The calcaneofibular and ant. talofibular ligaments may tear, producing marked swelling and pain.These two ligaments plus post. talofibular ligament constitute the lateral ligament of the ankle

In practiceDeltoid ligament is a medial ligament of the ankle.Very strong one. Can be injured by eversion of the foot.