Appendicular Skeleton Ch 8. Flashcards
1
Q
The Appendicular Skeleton
A
- Pectoral girdle: attaches the upper limbs to the upper trunk
- Pelvic girdle: attaches the lower limbs to the lower trunk
- Upper and lower limbs differ in function but share a similar structural plan
2
Q
The Pectoral Girdle
A
- Consists of the clavicleand the scapula
- Pectoral girdles do not encircle the body completely
- Scapulae are positioned on superior posterior thorax and do not join each other or articulate with the axial skeleton
- Clavicles extend horizontally across superior anterior thorax
- Medially: sternal endof each clavicle articulates with the manubrium and first rib of the axial skeleton
- Tuberosity for costoclavicular ligament is near sternal end of clavicle
- Laterally: acromium end of the clavicle joins the scapula at the acromioclavicular joint
3
Q
The Pectoral Girdle
A
- Provides attachment for many muscles that move the upper limb
- Girdle is very light and upper limbs are mobile
- Socket of the shoulder joint (glenoid cavity of scapula) is shallow and provides for good flexibility, but relatively poor stability
4
Q
Clavicles
A
- Provide attachment for muscles
- Articulate with the scapulae laterally
- Articulate with sternum medially
- Transmit compression forces from the upper limbs to the axial skeleton
5
Q
Scapulae
A
•Lie on the superior dorsal surface of rib cage •Located between ribs 2–7 •Have three borders –Superior –Medial (vertebral) –Lateral (axillary) •Have three angles –Lateral (location of glenoid cavity) –Superior –Inferior
6
Q
Scapula
A
- Subscapular fossa (anterior surface)
- Supraspinous fossa (posterior surface)
- Suprascapular notch
- Spine (posterior surface)
- Infraspinous fossa (posterior surface)
- Acromium attaches to clavicle
- Glenoid cavity attaches to humerus head
- Coracoid process
7
Q
The Upper Limb
A
•30 bones form each upper limb •Grouped into bones of the: –Arm: 1 bone (humerus) –Forearm: 2 bones (radius and ulnar) –Hand/wrist: 27 bones
8
Q
Arm = region between shoulder & elbow Humerus is only bone in arm
A
- Longest and strongest bone of the upper limb
- Articulates with the scapula at the shoulder
- Articulates with the radius and ulna at the elbow
SLIDE 19 the humerus bone on the left is anterior view the bone on the right is posterior view
9
Q
Proximal humerus structures
A
- Humerus head
- Greater tubercle
- Lesser tubercle
- Intertubercular sulcus: in between lesser and greater tubercles on anterior side of bone
- Anatomical neck: slight constriction inferior to the head
- Surgical neck: inferior to the tubercles and is a frequent site of humerus fracture
10
Q
Mid-humerus structures
A
- Deltoid tuberosity: on lateral surface of shaft
* Radial groove: on posterior surface of shaft marks course of radial nerve
11
Q
Arm: Humerus
A
- Many structures of the humerus provide sites for muscle attachment
- Other structures of the humerus provide articulation sites for other bones
- Condyle: “knuckle”or rounded projection at the distal end of a bone that articulates with another bone
- Epicondyle: A rounded projection at the end of a bone, located on or above a condyle and usually serving as a place of attachment of ligaments and tendons
12
Q
Distal Humerus structures
A
- Medial epicondyle
- Lateral epicondyle
- Medial supracondylar ridge
- Lateral supracondylar ridge
- Trochlea
- Capitulum (anterior)
- Radial fossa (anterior)
- Coronoid fossa (anterior)
- Olecranon fossa (posterior)
13
Q
Forearm =region between elbow & wrist
A
- Formed from the radius and ulna bones
- Proximal ends articulate with the humerus
- Distal ends articulate with carpal bones
14
Q
Proximal radius bone interface with distal humerus
A
- Head of proximal radius boneinterfaces with capitulumof distal humerus
- Radial tuberosity below head of radius
- With elbow flexion, radial head moves into radial fossa of distal humerus
15
Q
Proximal ulna bone interface with distal humerus
A
- Main bone responsible for forming the elbow hinge joint with the humerus
- Anterior coronoid process andposterior olecranon process of ulna interfaces with trochleaof distal humerus
- With elbow flexion, coronoid process of ulna moves into coronoid fossa of distal humerus
- With elbow extension, olecranon process of ulna moves into olecranon fossa of distal humerus
16
Q
Forearm:radius and ulna articulate with each other
A
- At the proximal & distal radioulnar joints
- Proximal ulna has radial notch
- Distal radius has ulnar notch
- The interosseous membraneinterconnects radius and ulna
- In anatomical position (palms facing forward), radius is lateral& ulna is medial
17
Q
Distal Ulna with ulnar head & styloid process
A
- Distal ulna is separated from carpal bones by fibrocartilage
- Plays little to no role in hand movement
18
Q
Distal radius
A
- Distal radius articulates with carpal bones of the wrist
- Articulation with scaphoid boneof hand
- Articulation with lunate boneof hand
- When radius moves, the hand moves with it
- Ulnar notch of distal radius articulates with ulnar bone
- Styloid process