Forensic Anthropology

Bones of the Shoulder Girdle  The shoulder girdle provides support and anchor for the humerus and anchors a variety of muscles. It consists of the following bones: the clavicle and the scapula. pics/shoulder-joint.jpg

The clavicle - description The clavicle - description  S–shaped bone  Articulates medially with manubrium of sternum  Articulates laterally with acromion of the scapula

The clavicle – what to know  Superior surface Deltoid attachment Trapezius attachment  Inferior surface Acromial facet (lat) Trapezoid ridge (a/i) Conoid tubercle (p/i) Subclavian groove Costal pit (medial) annotation/webdocs/image_gal_files/miscellaneous/clavicl e.jpg

The clavicle – left from right  Superior surface smooth  Interior surface rough (sub clavian groove)  Lateral end flatter (art with scapula)  Medial curve – posterior  Lateral curve – anterior

The scapula - description  The body of the scapula is large and triangular  Flat side is anterior side (to slide over ribs)  Articulates with the humerus at the glenoid fossa  Articulates with the clavicle at the acromion /storypics/shoulder-joint.jpg

The scapula – what to know  Anterior/costal surface Body Body 3 borders 3 borders Medial/vertebralMedial/vertebral Lateral/axillaryLateral/axillary superiorsuperior Coracoid process (smaller, anterior) Coracoid process (smaller, anterior) Scapular notch (superior) Scapular notch (superior) Glenoid fossa Glenoid fossa

The scapula – what to know  Posterior/dorsal surface Scapular spine Scapular spine 3 borders 3 borders Medial/vertebralMedial/vertebral Lateral/axillaryLateral/axillary SuperiorSuperior Acromion process (higher and wider) Acromion process (higher and wider) Supraspinous and infraspinous processes Supraspinous and infraspinous processes 96.scapula.1.jpg

The scapula – left from right  Orient the spine posteriorly  Put the point down  Glenoid fossa is lateral

Bones of the thorax  The thorax (or chest) is like a cage made of cartilage and bone. This cage protects the main organs of the circulatory and respiratory systems, and is the base to which the upper limbs are attached.

The sternum - description  Manubrium – widened superior portion Jugular notch at top, art. w/ BOTH clavicles, cartilage of BOTH 1 st ribs attach only at manubrium Jugular notch at top, art. w/ BOTH clavicles, cartilage of BOTH 1 st ribs attach only at manubrium

The sternum - description  Body – long medium width bone attach at inferior portion of manubrium, cartilage of ribs 3-7 attache to body of sternum  Xiphoid process – small inferior portion of sternum – attachment for abdomen muscles htm

The sternum – what to know  Manubrium Jugular notch Jugular notch Clavicular notch Clavicular notch Costal notches Costal notches  Body of the sternum Costal notches  Xiphoid process Can be fused to sternal body in some cases

The ribs - description  24 total (though there may be variation in the number)  Function – protect thoracic organs  Each rib articulates with a thoracic vertebrae and has an extension of cartilage anteriorly Ribs 1-7 are true ribs (direct art. w/ sternum) Ribs 1-7 are true ribs (direct art. w/ sternum) Ribs 8-10 are false ribs (indirect art.) Ribs 8-10 are false ribs (indirect art.) Ribs are floating ribs (no art. w/ sternum) Ribs are floating ribs (no art. w/ sternum)

The ribs – what to know  Head – single or double facet Articulates with lateral vert body Articulates with lateral vert body  Neck  Tubercle – single facet Articulates with transverse process of vert (ribs 1-9/10) Articulates with transverse process of vert (ribs 1-9/10)  Shaft/body  Angle  Costal groove  Sternal end Ribs 1-7 wide, 8-10 tapered, flat Ribs 1-7 wide, 8-10 tapered, flat

The ribs – how to sort  Rib cage barrel-shaped  Easiest to sort… 1 st rib; short, flat, steep curve, long neck 1 st rib; short, flat, steep curve, long neck Inner surface inferior 11 th and 12 th ribs; fan-shaped head, no neck, tapered ends, 12 th VERY short 11 th and 12 th ribs; fan-shaped head, no neck, tapered ends, 12 th VERY short Inner surface superior

The ribs – sorting the rest  Head shape changes to fan shaped  Neck length shortens  Curvature changes – but each rib conforms to the curvature of adjacent ribs

The ribs - sorting  Figure 4.12b in book ~ 1-4 long necks ~ 1-4 long necks ~ 5-9 double faceted head ~ 5-9 double faceted head ~ 7-9 wide head ~ 7-9 wide head ~ 9-12 no neck ~ 9-12 no neck ~ no tubercle ~ no tubercle s.htm

The ribs – left from right  Head posterior – articulates with vertebrae  Sternal end anterior  Sharp ridge inferior

Skeletal anatomy of the arm Comprised of 3 bones Humerus Humerus Radius Radius Ulna Ulna Useful for ALL useful for age/growth Handedness Sex determination ? stature determination

The humerus - description  Longest, most robust bone of the arm  Contains the Ball of the Ball and socket joint  Articulations: Proximal – head of the humerus with the glenoid cavity of scapulaProximal – head of the humerus with the glenoid cavity of scapula Distal – radius and ulna with the capitulum and trochlea (resp.)Distal – radius and ulna with the capitulum and trochlea (resp.)  Shape = cylindrical shaft Round, articular proximal endRound, articular proximal end Broad, flattened distal endBroad, flattened distal end

The humerus – What to know  Proximal end: Head – points medially Head – points medially Greater tubercle – anterolaterally Greater tubercle – anterolaterally Lesser tubercle – anterior Lesser tubercle – anterior Neck – narrowest area Neck – narrowest area Deltoid tuberosity – lateral attach of deltoid m. Deltoid tuberosity – lateral attach of deltoid m.  Distal end: Medial and lateral epicondyle (Med. Larger) Fossas – named for what depression receives Olecranon – posterior Coronoid - anterior Capitulum – rounded Art. w/ radial head Joint - rotation Trochlea – large, spool-like Art. w/ ulna at olecranon process Joint – flexion/extension

Humerus – Right from left  Orient humeral head superior (points medially)  Make sure tubercles are anterior  Make sure trochlea and capitulum are anterior and distal  Olecranon fossa is posterior  Larger of the 2 epicondyles is MEDIAL

The radius - description  Lateral to the ulna, more robust  Responsible for ROTATION

The Radius  Shaft – teardrop X-section, broadens broadens Round head proximally Round head proximally Full-length interosseous Full-length interosseous ridge on medial surface  Articulations Proximal - radial head with capitulum of humerus AND radial notch of ulnaProximal - radial head with capitulum of humerus AND radial notch of ulna Distal - distal radial articular area with scaphoid and lunate AND ulnar notch of radius with distal ulnaDistal - distal radial articular area with scaphoid and lunate AND ulnar notch of radius with distal ulna

The Radius – What to know  Proximal End: Head – art. at capit and radial notch Head – art. at capit and radial notch Neck – narrow area Neck – narrow area Radial tuberosity – anterio-medially orient. attach of biceps m. Radial tuberosity – anterio-medially orient. attach of biceps m.  Distal End: Styloid process – lateral Ulnar notch – postero-medial area of art. w/ulna Dorsal tubercle – posterior Distal articular area art. w/ scaphoid and lunate

Radius – Right from left  Orient radial head superior  Make sure the radial tuberosity, ulnar notch and interosseous crest are medial (i.e. point toward the ulna and the interosseous space….)  Dorsal tubercle is posterior (i.e. dorsal….)  Styloid process is lateral

The Ulna - description  Medial to the radius, more slender; parallel to radius when arm supine  Responsible for flexion/extension AND stability at elbow joint

The Ulna  Articulations Proximal - Olecranon process with trochlea of humerus AND with radial head at radial notch of ulnaProximal - Olecranon process with trochlea of humerus AND with radial head at radial notch of ulna Distal - Ulnar head art. w/ ulnar notch of radius; ? Art. with lunate but separated by articular disk for ↑flexibilityDistal - Ulnar head art. w/ ulnar notch of radius; ? Art. with lunate but separated by articular disk for ↑flexibility  Shape = teardrop shaft Hook-shaped proximally Hook-shaped proximally Narrow head distally Narrow head distally

The Ulna – What to know  Proximally: Olecranon process Olecranon process Semilunar notch Semilunar notch Coronoid process – anteri-medial Coronoid process – anteri-medial Radial notch – lateral art. w/ radial head Radial notch – lateral art. w/ radial head  Distally: Head – art. w/ radial ulnar notch Styloid process – medial

The Ulna – Right from left  Orient the olecranon process superior and the semilunar notch is anterior  Make sure the radial notch and the interosseous crest are lateral  The head is distal  The styloid process is medial