Download Chapter 8 The Appendicular Skeleton

Chapter 8
The Appendicular Skeleton
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Course objectives:
List the bones of the appendicular skeleton
Describe and identify the bones of the
pectoral girdle
Describe and identify the bones of the pelvic
girdle
Appendicular Skeleton
• Includes the bones of the upper limb and their
attachments to the axial skeleton at the pectoral
girdle.
• Includes the bones of the lower limb and their
attachments to the axial skeleton at the pelvic
girdle.
Pectoral Girdle
• scapula – “shoulder blade”
-(triangular flat bone) articulates with
humerus of arm at the glenoid fossa
• clavicle – “ collar bone"
-flat bone articulates with the acromion
process of scapula and the manubrium
of the sternum, thus forming the only
bony link with the axial skeleton and
pectoral appendicular skeleton
Scapula
• Thin triangular flat bone that forms the bulk of
the shoulder
• Articulates with the humerus of the arm at the
glenoid fossa
• Articulates with the clavicle at the acromion
process
Scapula landmarks
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Supraspinous and infraspinous fossae
Subscapular fossa
Acromion
Coracoid process
Glenoid cavity
Lateral and medial border
Clavicle landmarks
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Acromial end
Sternal end
Conoid tubercle
Costoclavicular tuberosity
The clavicle
The Upper Limb
• Consists of 30 bones
• Grouped into bones of the arm, forearm
and hand
• Arm = Humerus
• Forearm = Radius and Ulna
• Hand = Carpals (8), metacarpals (5) and
phalanges (5)
“Arm or Brachium”
Humerus landmarks
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Head and body of humerus
Greater and Lesser tubercles
Anatomical neck and Surgical neck
Medial and lateral supracondylar ridges
Medial and lateral epicondyle
Olecranon and radial fossa
Coronoid process
Deltoid tuberosity
Capitulum
Trochlea
Forearm “antebrachium”
• Consists of the Radius (lateral) and Ulna
(medial).
• Both are connected along their length by a
ligament (interosseous membrane)
Radius landmarks
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Head, neck and shaft
Radial tuberosity
Ulnar notch
Styloid process
Nutrient foramen
Ulna landmarks
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Olecranon process
Coronoid process
Trochlear notch
Radial notch
Head of the ulna
Styloid process of ulna
The Hand
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Consists of:
Carpals (8) “wrist”
Metacarpals (5) “palm”
Phalanges (5) “fingers”
Carpal bones
Eight bones makeup the wrist
Carpal bones
Metacarpals and Phalanges
• These bones are not named individually but are
numbered 1-5.
• The thumb “pollex” is number 1.
• They are all long bones
• The base of the metacarpals articulate with the
carpal bones at their base and the phalanges at
their head.
• The phalanges consist of a proximal, middle and
distal phalanx in all but the thumb .
Metacarpals and Phalanges
The Pelvic Girdle
• The “hips” form a much more solid and stable
connection for the lower limbs to the axial
skeleton than the pectoral girdle is to the upper
limbs.
• The pelvic girdle is formed by the coxal bones
(a.k.a. hip bones, os coxae) which fuse
posteriorly with the sacrum.
• The coxal bones are formed by the fusion of
three separate bones ( ilium, ischium and
pubis) during growth.
“Os Coxae” Hip bones
• Formed by the fusion of three bones
-1. ilium, 2. ischium, and 3. pubis
• Attaches to the lower limb and spine at sacroiliac joint
• Supports the pelvic organs or viscera
• Attached to the axial skeleton by strong ligaments
Os coxae landmarks
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Iliac crest
Anterior superior and ant. inferior iliac spine
Posterior superior and post. inferior iliac spine
Greater and lesser sciatic notch
Iliac fossa
Ischial spine and tuberosity; ramus of ischium
Obturator foramen
Superior and inferior ramus of pubis
Pubic symphysis and pubic arch
Acetabulum
Male vs Female Os coxae
• Significant differences exist between the male
and female pelvis.
– ♀ pelvic outlet is enlarged due to in part greater
separation of ischial spines
– ♀ less curvature of sacrum and coccyx which in
males ♂ arcs into pelvic outlet
– ♀ wider more circular pelvic inlet
– ♀ relatively broad, low pelvis
– A broader pubic angle in ♀ between pubic bones
> 100°
Male
Female
True vs. False pelvis
• False pelvis = area within entire pelvic girdle
• True pelvis = area below pelvic brim
Lower limb
Consists of:
• Femur “Thigh” = hip to the knee
• Tibia and fibula “Leg” = knee to foot
• Foot
Femur “Thigh” landmarks
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Longest, strongest, largest bone in body
Head
Neck
Greater and lesser trochanter
Medial and lateral condyle
Medial and lateral epicondyle
Linea aspera
Patella “knee cap” landmarks
• Base
• Apex
• Articular surfaces
Lower leg
• technically the distance between the knee and
ankle
• Bones of the leg: tibia (shin bone) and fibula
(lateral leg bone)
• Consists of the: Tibia (shin bone)
Fibula
• Interosseuos membrane connects tibia and
fibula along their length
Tibia landmarks
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Medial and lateral condyle
Tibial tuberosity
Medial malleolus (medial bulge of ankle)
Anterior border (crest) is the shin
Distal End of Tibia
Fibula landmarks
• Fibula is lateral bone of the leg
• Head
• Lateral malleolus (lateral bulge of ankle)
The foot
• Includes the bones of the;
-Tarsus
-Metatarsus
Phalanges
• Functions
-support of the body
-lever for walking or running
Tarsal bones
• Talus
• Calcaneous
Metatarsals and Phalanges
• Are all long bones
• Metatarsals numbered 1-5
• Phalanges consist of proximal, middle and
distal bones in all but big toe
• Big toe or great toe is Hallux
Tarsal bones (Ankle)