Osteology

Function of the Human Skeleton

Musculoskeletal: as a tissue

• Support- structural and for organs

• Protection- ribs, sternum, clavicle protect important organs and vessels; vertebral column and skull protect central nervous system

Physiological: as an organ

• Hemopoiesis- red blood cells and produced in the red bone marrow of the epiphyses and metaphases

• Mineral and fat storage- calcium and phosphates stored in the bone; lipids (fats) stored in the yellow bone marlo

Can be observed microscopically

About Bone

One of the strongest biological materials in existence

• bears our weight + force

• Skeleton is 20% of our entire weight

Bone is a composite material

• Collagen- weight bearing, absorbs the energy

• Hydroxyapatite- what makes bones hard

Bone Anatomy

Types of bone:

• Spongy/Trabecular Bone- contains red bone marrow- blood forming

• Compact/Cortical bone- dense bone, creates medullary cavity which contains yellow bone marrow

Developmental Parts of the Bone:

• Diaphysis- shaft

• Epiphyses- end, articulation part

• Metaphases- growth plate, disappear as an adult

Membranes:

• Periosteum- Lines outside of surface bone

• Endosteum- lines internal cavities of bone

Bone Mechanics

Elasticity: the capacity of a material to completely return to its original shape after a load has been removed

Plasticity: The threshold at which the elastic limit has been reached and at least some permanent deformation occurs

Once in the plastic phase, the material is compromised microscopically and applying additional load can cause it to completely fail, which will result in fracture

Tooth Anatomy

Parts of Tooth

• crown

• Root

Tissue Types

• Enamel

• Dentin

• Cementum

• Pulp

Applications

• Demographics: age, sex, relatedness, statue

• Stress and Disease: patterns of lesions, hypoplasia, porosity

• Diet: remnants of food in calculus

• Activity: Occupation-specific patterns of wear and trauma, overall bone density, joint wear, muscles attachment sites

• Cultural Modifications: manipulations of bone to meet cultural standards of beauty

• Trauma: Blunt, sharp ballistic

  • Cause of Death- medico legal context

  • Past conflicts- archaeological context

Standard Anatomical Position

Standing, facing forward, feet together and flexed, palms rotates forward (no long bones crossing)

Anatomical Planes

Sagittarius Plane: cuts body into left and right portions

Coronal Plane: cuts body into front and bad portions

Transverse Plane: cuts body into upper and lower portion

Anatomical Directions

Medial: towards the midline of the body

Lateral: away from the midline of the body

Proximal: towards the body, along a limb

Distal: away from the body along a limb

Superior: towards the top, above

Inferior: towards the bottom, below

Posterior: towards the back of the body

Anterior: towards the front of the body

Cranial: skull

Post-cranial: everything from the neck down

Axial: everything but your limbs

Appendicular: limbs including pelvis, clavicle, and scapula

Segments of the Skull

Skull: brain case + face + mandible

Cranium: brain case + face

Calvaria: brain case

Calorie: top of the brain case without the base

Dental Directions and Parts

Parts of the Dentition:

• maxillary teeth/dentition- refers to teeth in the upper jaw

• Mandibular teeth/dentition- refers to teeth in the lower jaw

Dental Directions:

• Mesial- along arch toward midline

• Distal- along arch away from midline

• Labial- toward external face in lip area

• Buccal- toward external face in cheek area

• Lingual- toward tongue

• Incisal- edge of anterior teeth

• Occlusal- chewing surface of posterior teeth

Bones of the Skull

Unpaired:

• Frontal- superciliary arches/ supraorbital ridge supraorbital margins, glabella, temporal lines, coronal suture

• Occipital- foramen magnum, external occipital protuberance, uncalled lines/ crest, occipital condoles; also lambdoidal suture

• Vomer

• Ethmoid

• Sphenoid-butterfly feature behind orbital

• Mandible- lower jaw, mental eminence (chin)

• Hyoid

Paired:

• Parietals (2)- temporal lines and sagittal suture; contributes to the coronal suture, lambdoidal suture, and squamosal suture

• Temporal (2)-Mastoid process, external auditory meatus; also contributes to squamosal suture

• Auditory ossicles ( 3 × 2)

• Maxillae (2)- makes up most of face, contributes to the orbit, infraorbital foramen, where upper maxillary teeth are found

• Palatines (2)

• Inferior nasal conchae (2)

• Lacrimals (2)

• Nasals (2)- nose bridge

• Zygomatic’s (2)- upper cheek bones contribute to orbit base

Teeth

Four types of teeth:

• Incisors

• Canines

• Premolars

• Molars

Permanent dental formula;

• 2.1.2.3

Deciduous Dental Formula:

• 2.1.2

Post Cranial Skeleton:

Hyoid: only bone that doesn’t articulate with another (floating), critical for speaking

Vertebrae:

• Cervical (7) - forms the neck

• Thoracic (12)- rib articulation

• Lumbar (5)

Sacrum and Coccyx: Fused vertebrae at the base of the spinal column, sacrum articulates with ossa coxae, distributes force to legs

Spinal curvatures:

• Kyphotic- con canvas anterior sacral and thoracic

• Lordotic: conclaves posteriorly cervical and Lumbar

Normal but can become more extreme

Ribs: 12 pairs = 24 ribs

• 3 pairs of ribs

  • True

  • False

  • Floating

• articulate with thoracic vertebrae

Sternum:

• Manubrium

• Body

• Xiphoid process

Artichokes with ribs, rib cartilage and clavicles

Upper limb:

• scapula- shoulder blade

• Clavicle- collar bones

• Humerus- upper arm bone

  • Part of numeral head (shoulder joint)

  • Elbow join( capitulum, trochlea, olecranon fossa)

• Ulna- hooked, U-shaped articulate process like a wrench (olecranon process)

  • Medial forearm bone *anatomical position

• Radius- the lateral forearm bone (in anatomical position)

  • Contributes to elbow and wrist joint

• Elbow joint: distal humerus + proximal radius +proximal ulna

• Hands

  • Carpals (palm)

  • Metacarpals

  • Phalanges (fingers)

Lower Limb

• Ossa Coxae- made up of three bones that fuse during development

  • Acetabulum, agricultural surface, public symphysis

    • Llium, ischium, pubis

• femur- thigh bone, strongest bone in the body

  • Part of the hip join and knew joint, femoral head and lateral and medial condyles

• Patella- kneecap, anchors quads across knee joint, level for knee joint

• Tibia- shin bone, medial lower leg bone, part of knee and ankle joints

  • Medial malleolus

• Fibula- lateral lower leg bone, park of ankle joint

  • Lateral malleolus

• Feet- human have two arches, transverse and longitudinal; facilitates shock absorption and force distribution

  • Tarsals

  • Metatarsals

  • Phalanges