Skeletal System 7.9

pectoral girdle

pectoral girdle

aka shoulder girdle

composed of four parts: two clavicles and two scapulae

incomplete ring; open in the back between the scapulae and sternum separates its bones in front

pectoral girdle function

supports the upper limbs and is an attachment for several muscles that move them

clavicles

aka collerbones

slender, rodlike bones with elongated S shapes

located at the base of the neck

clavicles function

brace the freely movable scapulae

help hold shoulders in place

provide attachments for muscles of the upper limbs, chest, and back

scapulae

shoulder blades

broad, triangular bones located in either side of the upper back

scapulae anatomy

the spine divides the posterior surface into unequal portions

spine leads to an acromion process that forms the tip of the shoulder

acromion process articulates with the clavicle and provides attachments for muscles of the upper limb and chest

coracoid process curves anteriorly and interiorly to the clavicle + provides attachment for upper limb and chest muscles

glenoid cavity on lateral surface that articulates with humerus head

what articulates with the clavicles and the costal cartilages

sternum / manubrium

on the scapula, the ___ forms the top of the shoulder and articulates with the clavicle, while the __ projects anteriorly for muscle attachment

acromion process; coracoid process

the indentation on the scapula where the head of the humerus articulates is called the

glenoid cavity or fossa

A - coracoid process

B - acromion process