ANAT EXAM

MUSCOSKELETAL SYSTEM

Cranial Bones:

  • singular: frontal, ethmoid, sphenoid, occipital

  • paired: temporal, parietal

Cranial Sutures:

  1. Coronal suture (parietal and frontal)

  2. Sagittal suture (parietal x2)

  3. Lambdoid suture (parietal and occipital)

  4. Squamous suture (parietal and temporal)

  5. Pterion (frontal, parietal, temporal, sphenoid), associated with middle meningeal artery

Facial Bones:

  • Singular facial bone: Mandible, Vomer

  • Paired facial bones: Maxilla, Zygomatic, Nasal, Lacrimal, Palatine, Inferior nasal conchae

Oral cavity: bony base formed by maxilla and mandible

Nasal septum: vomer and ethmoid

Orbital cavities: frontal, zygomatic, maxilla bones

Mandible: condylar head articulates with temporal bone, alveolar processes for teeth

Temporomandibular joint: mandibular fossa and mandible condyle

  • synovial condyloid joint with articular disc of fibrocartilage

Mandible muscle attachments: elevate mandible

  1. Temporalis- temporal lines to coronoid process

  2. Masseter- zygomatic arch to ramus mandible

Frontal Bone:

  1. Supraorbital notch- supraorbital artery, vein, and nerve

  2. Supraorbital ridge- deep to eyebrows

Temporal Bones:

  1. Mandibular fossa

  2. Zygomatic process

  3. Mastoid process- neck muscle attachment

  4. External acoustic meatus opening- ear canal opening

Occipital bone:

  1. external occipital protuberance

  2. posterior wall and floor of skull

  3. occipital condyles- articulate with spine

  4. foramen magnum

Sphenoid bone: contains hypophyseal fossa

Ethmoid bone: perforations for olfactory nerves

Base of Cranium:

  1. anterior cranial fossa- lower frontal lobes

  2. middle cranial fossa- temporal lobes, cranial nerves

  3. posterior cranial fossa- cerebellum

  4. hypophysial fossa- pituitary gland

Kyphosis: posterior, convex curve

  • kyphosis spine sections- thoracic and sacral spine

Lordosis: anterior concave curvature, developed secondary

  • lordosis spine sections- cervical and lumbar spines

Regions of spine: cervical (7), thoracic (12), lumbar (5), fused sacral (5) and coccygeal (3-4)

Common vertebral features: articular processes form zygapophysial joints, intervertebral discs, intervertebral foramen and canal

C1 (ATLAS): no body, just hole; force from skull to cervical spine

Atlanto-occipital joint: convex occipital condyles and concave superior facet of atlas; flexion/extension of neck

C2 (AXIS): dens; no disc

Axis vertebra joints: dens and anterior arch of atlas; 2x lateral zygapophyseal joints; cervical rotation

C3 to C7 vertebrae: bifurcated spinous process for muscle attachment; transverse foramina for vertebral artery

Thoracic vertebrae: heart shaped body; spinous process directed inferiorly; long, thick transverse process; 2x costal demifacets for rib attachment (synovial)

Lumbar vertebrae: large body; horizontal spinous processes face posterior; transverse process for attachment; spinal cord ends at L1/L2

Sacrum: 5 fused vertebrae; inverted, concave triangle; sacroiliac joint

Sacrum features: 1) superior sacral canal and inferior sacral hiatus continuous with vertebral canal. 2) anterior and posterior foramina for anterior/posterior sacral nerves

Coccyx: varied number of vertebrae, coccygeal cornu articulates with sacrum

Interbody Joint: cartilaginous; between bodies of vertebrae; contains intervertebral disc; stability and mobility

Intervertebral disc components: Annulus fibrosus (outer, binds to bone) and Nucleus pulposus (inner pulp, high water)

Zygapophysial/Facet Joint: synovial plane joint; superior and inferior articular processes of vertebrae; guide movement EXCEPT C0 and C1

Cervical Zygapophysial Joint: 45 degrees, rotation, lateral movement

Thoracic Zygapophysial Joint: coronal plane, vertical; rotation and lateral flexion; restrict flexion/extension

Lumbar Zygapophysial Joint: sagittal plane; flexion/extension; limit rotation

Vertebral compression fractures associated with- kyphotic deformities

Anterior and Posterior longitudinal ligaments: from C3 down length of spine; attach at vertebral bodies and discs; restrict flexion/extension

Lining of vertebral column= Posterior longitudinal ligament

Ligamentum flava: connects laminae on either side of vertebrae; “yellow” due to high elastin

Ligamentum nuchae: external occipital protuberance to C7 (not whole spine); supports head and muscle attachments

Supraspinous ligament: C7 to sacrum; connect tips of spinous processes

Interspinous ligament: between spinous processes

Whiplash injury: hyperextension of neck; anterior longitudinal ligament stretched/torn; annulus of vertebral disc affected; potential “tear-drop” fracture of vertebrae

Posterior Vertebral Muscles: trapezius, splenius capitis, splenius cervicis, semispinalis capitis, semispinalis cervicis, erector spinae, multifidus

Capitis= attached to skull

Trapezius attachments: external occipital protuberance, ligamentum nuchae, spinous processes C7-T12

Trapezius functions: extends neck, lateral flexion, contribute to rotation (oblique fibers)

Splenius Capitis attachments: spinous processes to skull and mastoid process

Splenius Cervicis attachments: spinous processes to transverse processes

Splenius Capitis and Cervicis functions: extension, rotation (diagonal fibers)

Semispinalis Capitis attachments: transverse process to skull

Semispinalis Cervicis attachments: transverse processes to spinous processes

Semispinalis Cervicis and Capitis functions: rotation (left semispinalis- right rotation)

Erector spinae three parts: spinalis (medial), longissimus (intermediate), iliocostalis (lateral)

Erector spinae functions: extensions, lateral flexion, NO rotation (vert. fibres)

Multifundus attachments: spinous processes towards transverse processes (christmas tree)

Multifundus functions: extension, rotation of 2-4 vertebrae it crosses

Abdominal muscle layers:

  1. (anterior) Rectus Abdominis

  2. External oblique

  3. Internal oblique

  4. Transverse abdominis

Abdominal muscle attachments: ribs/costal cartilage, fascia to iliac crest and/or pubic symphysis

Rectus abdominis fibres: vertical (flexion)

External oblique fibres: laterally down towards midline- like hands in pockets

Internal oblique fibres: laterally and upwards- opposite to external oblique

Transverse abdominis fibres: transverse across

Lower limb tissue layers: 1. Bone, 2. Muscle, 3. Deep fascia (DFCT), 4. Superficial fascia (adipose), 5. Skin

Pubic tubercle and Anterior Superior Iliac Spine attachments: Inguinal ligament

Inguinal ligament: superior- inguinal canal (hernia); deep- femoral artery (catheterisation)

Iliac crest attachments: Erector muscles, gluteus maximus

Gluteal line attachments: gluteus medius and gluteus minimus

Ischial spine attachments: sacrospinous

Ischial tuberosity attachments: sacrotuberous, hamstrings

Greater sciatic notch: binds ilium and ischium

Obturator foramen: covered by obturatormembrane, obturator nerve/vessels pass through

Greater sciatic foramen exit site for: 1) Piriformis muscle, 2) Superior/inferior gluteal nerves/vessels, 3) Sciatic nerve

Pubic symphysis: cartilaginous joint, interpubic disc

Greater trochanter of femur: hip abductor muscles (gluteus medius/minimus)

Lesser trochanter of femur: hip flexors (iliopsoas)

Hip joint capsular ligaments: 1. iliofemoral, 2. ischiofemoral, 3. pubofemoral

Labrum= fibrocartilage on rim of acetabulum, increase SA for congruency

Anterior muscles of lower limb blood/nerve: femoral nerve, deep femoral artery/vein

Posterior muscles of lower limb blood/nerve: tibial nerve (EXCEPT gluteus max.), deep femoral artery/vein

Medial muscles of lower limb blood/nerve: obturator nerve, deep femoral artery/vein

External iliac artery becomes femoral artery as it passes under inguinal ligament

Malleolus= distal flaring of bone

Lateral collateral ankle ligament: tibia to talus and calcaneus; restricts INversion

Medial collateral ankle ligament: restricts Eversion

Gastrocnemius origin and insertion: medial/lateral femoral condyle to calcaneus

Gastrocnemius and Soleus form calcaneal (Achilles) tendon

Soleus origin and insertion: interosseous membrane of tibia/fibula to calcaneus

Retinacula= thickenings of deep fascia (DFCT) which hold tendons in place around joints

Tibialis posterior insertion: medial cuneiform and navicular

Flexor digitorium longus insertion: distal phalanges on toes 2-5

Flexor hallucius longus insertion: distal phalanx of hallux

Medial longitudinal arch support: tibialis anterior; tibialis posterior

Lateral longitudinally arch support: fibularis longus; fibularis brevis

Transverse arch support: fibularis longus; small intrinsic foot muscles

Ulnar artery becomes superficial palmar arch

Radial artery becomes deep palmar arch

Cephalic vein drains to subclavian vein

Basilic vein drains to brachial vein

Bicipital groove= “lady between two majors”: Pectoralis major, Latissimus dorsi, Teres major

Interphalangeal joints: synovial hinge; flexion/extension

Metacarpophalangeal joints: ellipsoid joints; circumduction

Carpometacarpal joint 1: saddle joint; opposition/reposition

Thenar muscles move thumb

Hypothenar muscles move 5th digit (pinky)

Palmar and dorsal interossei muscles: abduction/adduction of digits