Transcript Pectoral Girdle

The Appendicular skeleton
Appendage = add on = limb
Why do I even want an appendicular
skeleton?
Appendicular Skeleton
• The appendicular skeleton is made up of the
bones of the limbs and their girdles
• Pectoral girdles attach the upper limbs to the
body trunk
• Pelvic girdle secures the lower limbs
• What the heck is a girdle?
• A girdle usually means a belt like structure
surrounding the body
Pectoral Girdles
• The pectoral girdles consist of the anterior
clavicles and the posterior scapulae
• They attach the upper limbs to the axial
skeleton
• The way its set upallows for maximum
movement
• They provide attachment points for muscles
that move the upper limbs
Maximum movement good or bad?
You tell me!
Good
• Lots of flexibility!
– Lots o’ movement
Bad
• Poorly reinforced
– Lots o’ dislocations
Glenohumerol joint
Figure 7.22a
Clavicles (Collarbones)
• Slender, “doubly curved” long bones lying
across the superior thorax
– Curve makes sense!
• attachment points for muscles
• act as braces to hold the scapulae and arms
out laterally - away from the body
Clavicle
You’ve got:
• The acromial (lateral) end articulates with the
scapula,
• The sternal (medial) end articulates with the
sternum (manubrium @ what notch??
• Conoid tubercle – near acromial end –
ligaments attach collar bone to 1st rib
Clavicles (Collarbones)
Figure 7.22b, c
Scapulae (Shoulder Blades)
• Moves quite freely across thorax
• Triangular, flat bones lying on the dorsal
surface of the rib cage
– between the second and seventh ribs
• Scapulae have three borders and three angles
– Superior – shortest & sharpest
– Medial – parallel to vertebral column
– Lateral – runs into armpit! (glenoid cavity)
Angles – superior, lateral, inferior
Scapula
• Anterior view = boring!
• Posterior view includes
1. Spine – palpated easily!
2. Acromion – region we learned (shoulder point)
a) Articulates with clavicle acromioclavicular joint
3. Coracoid process – bicep brachialis anchored here
4. Suprascapular notch – nerve passage helps bound
coracoid process – (laterally bounded by glenoid
cavity)
5. Infraspinous and 6. supraspinous fossae
• Major markings include the suprascapular
notch, the supraspinous and infraspinous
fossae, the spine, the acromion, and the
coracoid process
Scapulae (Shoulder Blades)
Figure 7.22d
Scapulae (Shoulder Blades)
Figure 7.22e
Scapulae (Shoulder Blades)
Figure 7.22f