forensic anthropology. bones of the shoulder girdle the shoulder girdle provides support and anchor...
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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.
http://www.kettering.edu/visitors/storypics/shoulder-joint.jpg
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)
http://www.sci.utah.edu/~simpson/documentation/projects/annotation/webdocs/image_gal_files/miscellaneous/clavicle.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
http://www.kettering.edu/visitors/storypics/shoulder-joint.jpg
The scapula – what to know
Anterior/costal surface Body 3 borders
• Medial/vertebral• Lateral/axillary• superior
Coracoid process (smaller, anterior)
Scapular notch (superior)
Glenoid fossa
http://www.alignmed.com/images/Scapula_1.jpg
The scapula – what to know Posterior/dorsal
surface Scapular spine 3 borders
• Medial/vertebral• Lateral/axillary• Superior
Acromion process (higher and wider)
Supraspinous and infraspinous processes http://content.answers.com/main/content/img/oxford/Oxford_Sports/
0199210896.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.
http://home.comcast.net/~wnor/thoraxbones.htm
The sternum - description Manubrium – widened
superior portion Jugular notch at top, art.
w/ BOTH clavicles, cartilage of BOTH 1st 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
http://home.comcast.net/~wnor/thoraxbones.htm
The sternum – what to know
Manubrium Jugular notch Clavicular notch 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 8-10 are false ribs (indirect art.) Ribs 11-12 are floating ribs (no art. w/ sternum)
The ribs – what to know Head – single or double facet
Articulates with lateral vert body Neck Tubercle – single facet
Articulates with transverse process of vert (ribs 1-9/10)
Shaft/body Angle Costal groove Sternal end
Ribs 1-7 wide, 8-10 tapered, 11-12 flat
The ribs – how to sort
Rib cage barrel-shaped Easiest to sort…
1st rib; short, flat, steep curve, long neckInner surface inferior
11th and 12th ribs; fan-shaped head, no neck, tapered ends, 12th 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 ~ 5-9 double faceted head ~ 7-9 wide head ~ 9-12 no neck ~ 11-12 no tubercle
http://home.comcast.net/~wnor/thoraxbones.htm
The ribs – left from right
Head posterior – articulates with vertebrae
Sternal end anterior
Sharp ridge inferior
Skeletal anatomy of the armComprised of 3 bones
Humerus Radius 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 scapula
• Distal – radius and ulna with the capitulum and trochlea (resp.)
Shape = cylindrical shaft• Round, articular proximal end• Broad, flattened distal end
The humerus – What to know Proximal end:
Head – points medially Greater tubercle –
anterolaterally Lesser tubercle – anterior Neck – narrowest area 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 Round head proximally Full-length interosseous ridge on medial surface
Articulations• Proximal - 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 ulna
The Radius – What to know
Proximal End: Head – art. at capit
and radial notch Neck – narrow area 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 ulna
• Distal - Ulnar head art. w/ ulnar notch of radius; ? Art. with lunate but separated by articular disk for ↑flexibility
Shape = teardrop shaft Hook-shaped proximally Narrow head distally
The Ulna – What to know
Proximally: Olecranon process Semilunar notch Coronoid process – anteri-medial 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