CLASSIFICATION

Location

1. Axial – skull, vertebral column, rib cage

2. Appendicular – girdles and limbs

Categories of bones

1. Long bones – longer than wider; most bones of limbs, including fingers

2. Short bones – cube like; wrist and ankle; mostly spongy bone

-a. Sesamoid – like patella; within tendon; variety

3. Flat bones – skull (most), ribs, and sternum

4. Irregular bone – do not fit other classes; vertebrae and hip bones

BONE MARKINGS

Bone markings

1. Bone markings – bulges, depressions, holes; attachment, articulation, passage

2. Attachment sites – usually a projection; tendon or ligament

-a. Tuberosity – large rounded projection; deltoid tuberosity

-b. Crest – narrow ridge of bone; iliac crest; abdominal muscles

-c. Trochanter – large, blunt, irregular; femur; some muscles of hip joint

-d. Line – narrow ridge of bone; Linea aspera; thigh muscles

-e. Tubercule – mall rounded projection; humerus; muscle attachment

-f. Epicondoyle – projection above condyle

-g. Spine – sharp pointed process; scapula; muscle attachment

-h. Process – any prominence; spinous process

3. Articulating surfaces – projections, flatting, depression

-a. Head – bony expansion; narrow neck; head of femur

-b. Facet – smooth articulating surfaces; thoracic vertebrae

-c. Condyle – rounded articulating projection

-d. Ramus – arm like; mandible

-e. Fossa – depression; articulating surface

4. Passage – blood vessels; nerves; other opening

-a. Sinus – cavity in bone; lined with mucus membrane; air

-b. Groove – furrow; intertubercular groove humerus; tendon biceps

-c. Fissure – narrow slit like opening; superior orbital fissure

-d. Foramen – hole; mental foramen of mandible

-e. Meatus – cannal; auditory meatus

AXIAL SKELETON

Skull: cranium

1. Cranium – portion of the skull which protects the brain

2. Sutures – where cranial bones articulate with other cranial bones

-a. Coronal – joins the parietal and frontal bone

-b. Sagittal – joins the two parietal bones

-c. Lamboidal – joins the parietal bones to the occipital bone

-d. Squamous – joins the parietal bones to the temporal bones

-e. Occipitomastoid suture – between occipital and temporal bones

3. Frontal bone – anterior portions of cranium

-a. Supraorbital foramen – nerve, artery passage

-b. Frontal sinus – air filled space

4. Parietal bone – superiolateral bones of cranium

5. Occipital bone – posterior wall and base of cranium

-a. Foramen magnum – spinal cord meets the brain

-b. Occipital condyle – two; articulate with first vertebrae

-c. External occipital protuberence – bump on back of head

6. Temporal bone – inferiolateral bones of the cranium

-a. Zygomatic process – zygomatic bone; cheek bone

-b. Mandibular fossa – articulation with madible

-c. External auditory (acoustic) meatus – external ear canal

-d. Styloid process – tongue neck muscle attachment

-e. Mastoid process – neck muscle attachment

-f. Jugular foramen – at junction with occipital; internal jugular vein; 3 cranial nerves

-g. Carotid canal – anterior to above; internal carotid

-h. Internal acoustic meatus – facial and vestibulocochlear nerves

7. Sphenoid bone – middle of cranium inferiorly; articulates, all bones of the cranium

-a. Sphenoid sinuses – paired; in body of the sphenoid

-b. Sella turcica – pituitary gland

-c. Greater wing – orbit; cranial fossa; external wall

-d. Lesser wing – orbit; cranial fossa

-e. Optic foramen – optic nerve

-f. Superior orbital fissure – between greater and lesser wings; eye muscle control

8. Ethmoid bone – anterior to sphenoid bone; much of the medial orbit and nasal cavities.

-a. Cribiform plate – roof of nasal cavities; olfactory foramina

-b. Crista galli – dura matter attached; secures brain

-c. Perpendicular plate – superior part of the nasal septum

-d. Lateral masses – left and right

-e. Ethmoid sinuses – in the lateral masses

-f. Nasal concha (turbinate) – superior and medial

9. Cranial fossae – floor of cranium; three distinct ridges

-a. Posterior cranial fossa – occipital bone

-b. Middle cranial fossa – sphenoid and part of the temporal

-c. Anterior cranial fossa – mostly frontal; ethmoid

10. Cranial vault (calvaria) – superior, lateral, and posterior of skull

Skull: facial bones

1. Mandible – lower jaw

-a. Body – forms the chin

-b. Ramus – the uprights

-c. Mandibular angle – where ramus meets angle

-d. Coronoid process – chewing muscle insertion; temporalis muscle

-e. Mandibular condyle – to madibular fossa temporal bone; temporomandibular joint

-f. Alveolar margin – body; part which contains sockets (alveoli)

-g. Mandibular foramina – medial side of each ramus; nerve; teeth; Novocain

-h. Mental foramina – blood and nerves to chin, lower lip

2. Maxillary bone – upper jaw; this bone articulates with most other facial bones

-a. Alveolar margin – upper teeth

-b. Palatine process – anterior 2/3^rd of the hard palate

-c. Maxillary sinuses – largest; most inferior

3. Zygomatic bone – cheek and inferiolateral orbit; temporal, frontal, and maxillary

4. Nasal bone – fused paired bones; bridge of nose

5. Lacrimal bone – anteriomedial aspect of the orbit;

-a. Lacrimal fossa – tears to nasal cavity; lacrimal puncta; sac; canal; nasolacrimal duct

6. Palatine bone – forms the posterior portion of the hard palate

7. Vomer – forms the inferior portion of the nasal septum

8. Inferior nasal concha – shelf-like projections form the lateral wall of the nasal cavity

Skull: orbit

1. Orbit – houses eyes, ocular muscles, and tear glands; formed by seven bones

2. Frontal bone – forms superior wall of the orbit

3. Lacrimal bone – forms the anteriomedial aspect of the orbit

4. Sphenoid bone – forms the dorsal aspect of the orbit

-a. Optic foramen – optic nerve passes through

-b. Superior orbital fissure – between greater and lesser wing

5. Ethmoid bone – between lacrimal and sphenoid bones

6. Zygomatic bone – inferiolateral portion of the orbit

7. Maxillary bone – inferiomedial portion of the orbit

8. Palatine bone – forms small part of the inferior wall

Skull: nasal cavity

1. Roof – cribiform plate (ethmoid)

2. Lateral walls – from superior to inferior

-a. Superior concha – from ethmoid

-b. Middle concha – from ethmoid

-c. Inferior nasal concha – separate bone

-d. Perpendicular plate – palatine bone

3. Floor – roof of oral cavity

-a. Palatine process – maxillary bone

-b. Palatine bone – posterior to above

4. Nasal septum – several components

-a. Vomer – posterior and inferior

-b. Perpendicular plate (ethmoid) – posterior and superior

-c. Cartilage – anteriorly

Skull: Paranasal sinuses

1. Paranasal sinuses – openings in skull; all paired; to nasal cavity via small canals

2. Functions – lighten skull; warm inspired air; resonate voice

3. Frontal sinus – most superior

4. Sphenoid – anterior to the ethmoid; found in body

5. Ethmoid – two lateral masses are riddled with openings

6. Maxillary – the largest and most inferior

Hyoid bone

1. Hyoid bone – does not articulate with other bones; anchor for several muscles

2. Larynx – suspended by hyoid bone

Fontanels

1. Fontanels – remnants of unossified remnants; compressed during birth

2. Anterior fontanel – between frontal and parietal; 1.5 to 2 years after birth; superior

3. Anterolateral fontanel – sphenoid, temporal, frontal, and parietal; lateral

4. Posterolateral fontanel – temporal, occipital, and parietal; lateral

5. Posterior fontanel – between parietal and occipital

Vertebral column: ligaments

1. Ligaments – support the vertebral column

2. Anterior longitudinal ligament – resist hyperextension; bending too far back

3. Posterior longitudinal ligament – resist hyperflextion bending to far forward

4. Other ligaments – such as the supraspinous ligament

Vertebral column: intervertebral disc

1. Intervertebral discs – forms cushions between the body of each vertebra

2. Nucleus pulposus – inner semifluid portion; elasticity and compressibility

3. Annulus fibrosis – ring, fibrocartilage; connects vertebrae holds in nucleus pulposus

4. Herniated disc – annulus fibrosis, ruptured; nucleus pulposus protrudes; pressing on

Vertebral column: divisions

1. Cervical – contains 7 vertebrae

2. Thoracic – contains 12 vertebrae

3. Lumbar – contains 5 vertebrae

4. Sacrum – contains 5 fused vertebrae; articulates with the pelvis

5. Coccyx – four fused vertebrae

Vertebral column: curvatures

1. S shaped – in appearance

2. Function – springiness

3. Cervical – concave to the posterior

4. Thoracic – convex to the posterior

5. Lumbar – concave to the posterior

6. Sacrum – convex to the posterior

7. Primary curvatures – thoracic and sacral in fetus

8. Secondary curvatures – cervical and lumbar after birth

9. Abnormalities – congenital, poor posture, disease, and unequal muscle pull

-a. Scoliosis – lateral curvature; most often in the thoracic region; girls; body braces

-b. Kyphosis – or hunchback dorsally exaggerated thoracic curvature; osteoporosis

-c. Lordosis – exaggerated lumbar curvature; pregnant women; men, beer bellies

Vertebral column: vertebral structure

1. Body – anterior weight bearing, disc shaped structure

2. Vertebral arch – posterior arch of bone

3. Vertebral foramen – opening between arch and body

4. Vertebral canal – successive vertebral foramina; spinal cord

5. Spinous process – posteriorly projection

6. Transverse process – two extend laterally from each arch

7. Articular surfaces – two superior and two inferior

Vertebral column: atlas and axis

1. Atlas – C1; no body or spinous process; articulates with occipital condyles

-a. Function – up and down movement of the skull

2. Axis – C2

-a. Odentoid process (dens) – knob like structure

-b. Function – rotates head; like saying ‘no’

Vertebral column: regional characteristics

1. Cervical vertebrae – characteristics

-a. Spinous process – short, split; straight back; most

-b. Transverse foramina – vertebral artery; in transverse process

2. Thoracic vertebrae – characteristics

-a. Spinous process – long; points inferiorly

-b. Facets – on transverse processes; articulating with ribs

3. Lumbar vertebrae – characteristics

-a. Spinous process – short, blunt, directly to posterior

4. Sacrum – 5 fused

-a. Superior articular processes – articulate wit L5

-b. Auricular surface – with ilium to make sacroiliac joint

-c. Sacroilliac joint – articulates with pelvic girdle

-d. Sacral promontory – anteriosuperior margin of first sacral vertebrae

-e. Sacral foramina – ventral and dorsal; blood vessel and nerves

-f. Sacral crests – 2 lateral; 1 medial; remnants of transverse and spinous processes

-g. Sacral canal – extension of spinal canal

-h. Sacral hiatus – enlarged opening; sometimes; extension of canal

5. Coccyx – tail bone; 5; 3 or 6; fused together; tail bone

Bony thorax

1. Sternum – breast bone; anterior midline of thorax

-a. Manubrium – superior; knot; articulates with clavicles; clavicular notch

-b. Body – main part; articulates with rib cartilage

-c. Xiphoid process – small inferior end; hyaline cartilage; abdominal muscles

2. Ribs – 12 pairs; all articulate with vertebrae posteriorly

-a. True ribs – 1 to 7; attach to sternum by own cartilage

-b. False ribs – 8 to 12; indirect cartilage attachment, or not at all

-c. Floating ribs – 11 and 12; no attachment to sternum