THE SKELETAL SYSTEM Lab Objectives Students should be able to: 1. Recognize bones and bone markings for the axial and appendicular skeleton 2. Recognize bones disarticulated and/or articulated 3. Identify which bones articulate with one another Remember: Lab is considered a self-directed learning experience! Use your textbook, lab book, and atlas to identify all the bones and bone markings. If you have questions, then please feel free to ask the instructor. I. Bone Surface Markings (Divided into depressions and Processes or Projections) i. Depressions: (Openings allowing blood vessels and nerves to pass) 1. Fissure - narrow, slit-like opening 2. Foramen - round or oval opening through the bone 3. Fossa - shallow and may serve as an articular surface 4. Sulcus/meatus/canal - canal-like passageway 5. Groove - furrow ii. Processes: (Site of muscle and ligament attachment) 1. Tuberosity - large rounded projection 2. Crest - narrow ridge of bone 3. Trochanter - very large, blunt, irregulary shaped process 4. Line - narrow ridges of bone; less prominent than crest 5. Tubercle - small rounded projection 6. Epicondyle - raised area above a condyle 7. Spine - sharp, slender, often pointed iii. Processes: (Forms joints) 1. Head - bony expansion carried on a narrow neck 2. Facet - smooth and nearly flat articular surface 3. Condyle - rounded articular projection 4. Ramus arm-like bar of a bone II. Axial Skeleton (Skull, Thoracic Cage, and Vertebral Column) 1. Skull a. Cranial bones: Frontal, Parietal, Temporal, Occipital, Ethmoid, and Sphenoid b. Facial bones: nasal, zygomatic, maxilla, palatine, lacrimal, inferior concha, vomer and mandible c. Auditory Ossicles: malleus, incus, and stapes d. Hyoid e. Cranial bone markings: i. Frontal bone markings: 1. Frontal sinus 2. Supra-orbital margin (ridge)
3. Supra-orbital foramen (may look like a notch) 4. Coronal suture (between frontal and anterior border of parietals) 5. Glabella ii. Parietal bone markings: 1. Sagittal suture (between the two parietals) 2. Lambdoid suture (between posterior parietals and occipital bone) 3. Squamous suture (between parietals and squamous of temporal) iii. Occipital bone markings: 1. Occipital condyles 2. Foramen magnum 3. Superior and inferior nuchal lines 4. External occipital protuberance iv. Temporal bone markings: 1. External acoustic (auditory) meatus 2. Mastoid process 3. Styloid process 4. Petrous portion 5. Zygomatic process 6. Jugular foramen 7. Carotid canal 8. Internal acoustic meatus 9. Foramen lacerum v. Sphenoid bone makings 1. Greater and lesser wings 2. Sphenoid sinus 3. Pterygoid processes 4. Sella turcica (which houses the pituitary gland) 5. optic canal 6. foramen ovale 7. superior orbital fissure vi. Ethmoid 1. Perpendicular plate 2. Crista galli 3. Cribriform (horizontal) plate 4. Ethmoid sinus 5. Middle nasal concha 6. Superior nasal concha (visible only on sagittal head model) f. Facial bone markings: i. Nasal bones (with internasal suture) ii. Lacrimal bones (with nasolacrimal suture) iii. Zygomatic bones 1. Orbital process 2. Temporal process
3. Maxillary process iv. Maxilla 1. Alveolar margin 2. Infra-orbital foramen 3. Palatine processes 4. Inferior orbital fissure 5. Maxillary sinus v. Palatine bones vi. Mandible 1. Ramus 2. mandibular condyle 3. mandibular angle 4. body 5. coronoid process 6. alveolar margin 7. mental foramen vii. Vomer viii. Inferior nasal concha g. Auditory ossicles h. Hyoid bone 2. Thoracic Cage a. Ribs (True, false, and floating ribs) i. Head ii. Shaft iii. Tubercle b. Sternum i. Manubrium ii. Notch iii. Sternal angle iv. Body v. Xiphoid process vi. Clavicular notch 3. Vertebral Column a. Vertebrae: for each vertebrae be able to identify the following structures: lamina, pedicles, centrum (body), spinous process, superior and inferior articulating processes, transverse process, vertebral foramen, and intervertebral foramen. i. Cervical (7) have transverse foramina and first two are unique: C1 = atlas and C2 = axis with odontoid process (Dens) ii. Thoracic (12) have costal facets on the centrum (body) iii. Lumbar (5) do not have transverse foramina nor costal facets b. Sacrum: (5) fused bones to form the sacrum i. Sacral canal (not apparent on plastic models) ii. Sacroiliac joint (only observable on articulated models) iii. Sacral foramen iv. Median sacral crest
v. Sacral hiatus (only visible on real skeletons) vi. Sacral promontory vii. Apex viii. Ala c. Coccyx: (1-4) fused bones II. APPENDICULAR SKELETON (Pectoral Girdle, Arms, Pelvic Girdle, and Legs) 1. Pectoral Girdle a. Scapula i. Coracoid process ii. Acromion process iii. Spine iv. Supraspinous fossa v. Infraspinous fossa vi. Glenoid cavity (fossa) vii. Subscapular fossa viii. Suprascapular notch ix. Vertebral (medial) border x. Axillary (lateral) border xi. Inferior angle xii. Superior angle xiii. Lateral angle b. Clavicle i. Acromial end ii. Sternal end 2. Bones of upper extremity: arm and forearm (humerus, radius, ulna, carpals, metacarpals, and phalanges) a. Humerus i. Head of humerus ii. Neck of humerus: surgical and anatomical iii. Greater and lesser tubercles (tuberosities) iv. Iintertubercular sulcus (groove) v. Deltoid tuberosity vi. Medial and lateral epicondyles vii. Trochlea viii. Capitulum ix. Olecranon fossa x. Coronoid fossa b. Radius i. Head of radius ii. Neck of radius iii. Radial shaft iv. Styloid process v. Ulnar notch vi. Radial tuberosity
c. Ulna i. Olecranon process ii. Trochlear notch iii. Radial notch iv. Coronoid process v. Head of ulna vi. Styloid process d. Carpals i. Pisiform ii. Triquetral iii. Lunate iv. Hamate v. Trapezium vi. Trapezoid vii. Scaphoid viii. Capitate e. Metacarpals f. Phalanges i. Proximal ii. Middle (not present in the pollex) iii. Distal 3. Pelvic girdle (coxal bones = os coxae) a. Ilium i. Iliac crest ii. Anterior superior and inferior iliac spine (ASIS/AIIS) iii. Posterior superior and inferior iliac spine (PSIS/PIIS) iv. Iliac fossa v. Sacroiliac joint (only present in articulated skeleton) vi. Greater sciatic notch b. Ischium i. ischial spine ii. lesser sciatic notch iii. ischial tuberosity c. Pubis i. Pubic rami (superior and inferior) ii. Pubic symphysis iii. Acetabulum (acetabular fossa) iv. Obturator foramen 4. Bones of thigh and leg a. Femur i. Head of Femur ii. Fovea capitis iii. Neck of Femur iv. Greater and lesser trochanter v. Gluteal tuberosity vi. Shaft of Femur
vii. Linea aspera viii. Medial and lateral epicondyles ix. Medial and lateral condyles x. Intercondylar fossa xi. Patellar surface b. Tibia i. Tibial condyles (lateral and medial) ii. Intercondylar eminence iii. Medial malleolus iv. Shaft of Tibia v. Tibial tuberosity c. Fibula i. Head of Fibula ii. Fibula shaft iii. Lateral malleolus d. Patella e. Tarsals i. Talus ii. Calcaneus iii. Navicular iv. Medial cuneiform v. Intermediate cuneiform vi. lateral cuneiform vii. cuboid f. Metatarsals g. Phalanges i. Proximal ii. Middle (not present in the hallux) iii. Distal