1. Pectoral Girdle and Upper Limbs
Chapter 7
Pectoral Girdle and Upper Limbs

2. Pectoral Girdle
Composed of 2 clavicles (collar bones) and 2 scapulae (shoulder blades)
Supports upper limbs
Serves as an attachment point for muscles

3. Clavicles Slender, rod-like bones with elongated S-shapes
Run horizontally between the sternum and the shoulders
The sternal, or medial, ends articultate with the manubrium (of the sternum)
The acromial, or lateral, ends join the processes of the scapulae
Structurally very weak
Brace the scapulae and help to hold the shoulders in place
Provide attachments for muscles of the upper limbs, chest, and back

4. Scapulae Broad, triangular bones
Located on either side of the upper back
Have flat bodies with concave anterior surfaces
Three borders of the scapula are labeled as: superior border, axillary or lateral border, and veterbral or medial border

5. Scapulae Special features:
Posterior surface is divided into unequal portions by a spine
The spine leads to the acromion process that forms the tip of the shoulder, articulates with the clavicle, and provides attachments for muscles of the upper limbs and chest
The coracoid process curves anteriorly and inferiorly to the acromion process and also provides attachments for muscles of the upper limbs and chest
Between the two processes on the lateral surface is a depression called the glenoid cavity that articulates with the head of
the arm bone
Supraspinous fossa is located above the spine
Infraspinous fossa is located below the
spine

6. Upper Limb Bones of the arm, forearm, and hand
Includes humerus, radius, ulna, carpals, metacarpals, and phalanges
Provide attachments for muscles
Interact with muscles to move limb parts

7. Humerus Long bone that extends from the scapula to the elbow
Special features:
Head
Located at the upper end
Smooth and round
Fits into the glenoid cavity of the scapula
Greater tubercle and lesser tubercle
Located below the head (greater tubercle on the lateral side and lesser tubercle on the anterior side)
Serve as attachments for muscles that move the upper limb at the shoulder
Intertubular groove
Narrow furrow located between the two processes
Serve as a passage for a tendon that passes from the biceps brachii (a muscle in the arm) to the shoulder

8. Humerus Special Features (cont) Anatomical neck Surgical neck
Narrow depression along the lower margin of the head that separates it from the tubercules
Surgical neck
Tapering region just below the head and the tubercules
Deltoid tuberosity
Rough V-shaped area near the middle of the bony shaft on the lateral side
Provides an attachment for the deltoid muscle that raises the upper limb horizontally to the side

9. Humerus Special features (cont) Capitulum Trochlea Epicondyles
Knob-like condyle on the lateral side of the lower end of the humerus
Articulates with the radius at the elbow
Trochlea
Pulley-shaped condyle on the medial side of the lower end of the humerus
Articulates with the ulna at the elbow
Epicondyles
Located above the condyles on either side
Provide attachments for muscles and ligaments of the elbow
Coronoid fossa
Depression located between the epicondyles anteriorly
Receives the coronoid process of the ulna when the elbow bends
Olecranon foassa
Depression located between the epicondyles posteriotly
Receives the olecranon process when the elbow straightens

10. Radius Located on the thumb side of the forearm
A little bit shorter than the ulna
Crosses over the ulna when the hand is turned so that the palm faces backwards
Special features:
Head
Disc-like
Located at the upper end of the radius
Articulates with capitulum of the humerus and the radial notch of the ulna
Allows the radius to rotate
Radial tuberosity
Process located just below the head
Attachment for the biceps brachii which bends the upper limb at the elbow
Styloid
Located at the distal end
Provides attachments for ligaments of the wrist

11. Ulna Second bone in the forearm
Overlaps the end of the humerus posteriorly
Special features:
Head
Located at the distal end
Articulates laterally with the ulnar notch of the radius
Articualtes inferiorly with a disc of fibrocartilage which joins the triquetrum (wrist bone)
Trochlear (semilunal) notch
Wrenchlike opening located at the proximal end
Articultes with the trochea of the humerus

12. Ulna Special features (cont): Olecranon process Coronoid process
Located above the trochlear notch
Provides an attachment for the triceps brachii that straightens the upper limb at the elbow
Fits into the olecranon fossa of the humerus when the elbow is straightened
Coronoid process
Located just below the trochlear notch
Fits into the coronoid fossa of the humerus when the elbow is bent
Styloid process
Located at the distal end
Provides attachements for ligaments of the wrist

13. Hand Consists of the wrist, palm, and fingers Wrist:
Contains 8 small carpal bones
Carpal bones are arranged in 2 rows of 4 bones (with the resulting structure called a carpus)
The carpus is rounded on its proximal surface where it articulates with the radius and the fibrocartilaginous disc on the ulnar side
The carpus is concave anteriorly and forms a canal through which tendons and nerves extend to the palm
The distal surface of the carpus articulates with the metacarpal bones

14. Hand Palm (metacarpus)
Formed by 5 metacarpal bones (one in line with each finger)
Bones are cylindrical
Rounded distal ends of the bones form nuckles
Metacarpals articulate proximally with the carpals and distally with the phalanges
Lateral side of the metarcarpal is the most freely moveable, permitting the thumb to oppose the finger when grasping something
Bones are numbered 1 to 5, beginning with the metacarpal of the thumb

15. Hand Phalanges 14 Finger bones
3 in each finger (proximal, middle, and distal phalanx)
2 in the thumb (lacking a middle phalanx)