Presentation is loading. Please wait.

Presentation is loading. Please wait.

Chapter 7 Pectoral Girdle and Upper Limbs. Pectoral Girdle Composed of 2 clavicles (collar bones) and 2 scapulae (shoulder blades) Supports upper limbs.

Similar presentations


Presentation on theme: "Chapter 7 Pectoral Girdle and Upper Limbs. Pectoral Girdle Composed of 2 clavicles (collar bones) and 2 scapulae (shoulder blades) Supports upper limbs."— Presentation transcript:

1 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 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 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 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)


Download ppt "Chapter 7 Pectoral Girdle and Upper Limbs. Pectoral Girdle Composed of 2 clavicles (collar bones) and 2 scapulae (shoulder blades) Supports upper limbs."

Similar presentations


Ads by Google