THE APPENDICULAR SKELETON

Composed of 126 bones
Limbs (appendages)
 Pectoral girdle
 Pelvic girdle

THE APPENDICULAR SKELETON
acromion
Figure 5.6a
THE APPENDICULAR SKELETON
Figure 5.6b
THE PECTORAL (SHOULDER) GIRDLE

Composed of two bones
Clavicle—collarbone –slender bone; at risk to fracture
 Scapula—shoulder blade

These bones allow the upper limb to have
exceptionally free movement
 The clavicle serves as a brace to hold the arm
away from the top of the thorax…so there is no
problem with the arm clearing the widest
dimension of the thoracic cage.

BONES OF THE SHOULDER GIRDLE
Coracoid process
greater tubercle
Figure 5.21a
BONES OF THE SHOULDER GIRDLE
CLAVICLE (#2)
Figure 5.21b
BONES OF THE SHOULDER GIRDLE
*
SCAPULA (#1)
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*
*
Figure 5.21c–d
BONES OF THE UPPER LIMBS

Humerus
Forms the arm
 Single bone

BONES OF THE UPPER LIMBS
Humerus (#3)
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*
*
*
*
*
*
*
Figure 5.22a–b
BONES OF THE UPPER LIMBS

The forearm has two bones

Ulna


Medial bone in anatomical position
Radius

Lateral bone in anatomical position
BONES OF THE UPPER LIMBS
Radius (#4) & Ulna (#5)
*
*
*
*
Figure 5.22c
BONES OF THE UPPER LIMBS

The hand
Carpals—wrist 8 bones
 Metacarpals—palm
 Phalanges—fingers 14 bones

BONES OF THE UPPER LIMBS
Carpal (#6),
Metacarpals (#7),
Phalanges (#8)
Figure 5.23
BONES OF THE PELVIC GIRDLE
Formed by two coxal (ossa coxae) bones
 Composed of three pairs of fused bones

Ilium
 Ischium
 Pubis

Pectoral Girdle is more flexible
Pelvic Girdle is more secure and better able to bear weight
BONES OF THE PELVIC GIRDLE
The total weight of the upper body rests on the
pelvis…therefore, must be massive
 It protects several organs

Reproductive organs
 Urinary bladder
 Part of the large intestine


People instinctively curl over to protect internal
organs
THE PELVIS
More massive than 4 legged creatures because it
has to bear more weight.
Figure 5.24a
Illium = yellow bone #1
Ischium = Purple bone #2
Pubis = Red bone #3
THE PELVIS: RIGHT COXAL BONE
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*
*
*
*
*
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*
Figure 5.24b
GENDER DIFFERENCES
OF THE
PELVIS
The female inlet is larger and more circular
 The female pelvis as a whole is shallower, and
the bones are lighter and thinner
 The female ilia flare more laterally
 The female sacrum is shorter and less curved
 The female ischial spines are shorter and farther
apart; thus the outlet is larger
 The female pubic arch is more rounded because
the angle of the pubic arch is greater

GENDER DIFFERENCES
OF THE
PELVIS
Figure 5.24c
TRUE VS FALSE PELVIS
The greater or FALSE pelvis is located above the
pelvic brim- SUPERIOR; supports the abdominal
viscera the organs contained within the
abdominal cavity; they include the stomach,
intestines, liver, spleen, pancreas, and parts of
the urinary and reproductive tracts
 The lesser or TRUE pelvis below the brimINFERIOR; limits delivery of baby

BONES OF THE LOWER LIMBS

The thigh has one bone

Femur

The heaviest, strongest bone in the body
BONES OF THE LOWER LIMBS FEMUR #4
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*
*
Anterior view of right femur
*
*
Posterior view of right femur
*
Patella # 5
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*
Figure 5.25a–b
BONES OF THE LOWER LIMBS

The lower leg has two bones

Tibia
Shinbone
 Larger and medially oriented


Fibula

Thin and sticklike
BONES OF THE LOWER LIMBS
Fibula #6
Tibia #7
*
*
*
*
*
Figure 5.25c
BONES OF THE LOWER LIMBS

The foot

Tarsals



Two largest tarsals
 Calcaneus (heelbone)
 Talus
Metatarsals—sole
Phalanges—toes
BONES OF THE LOWER LIMB
Talus #8
Calcaneus #9
Metatarsals #10
Phalanges #11
Figure 5.26
ARCHES OF THE FOOT

Bones of the foot are arranged to form three
strong arches
Two longitudinal
 One transverse

ARCHES OF THE FOOT
Figure 5.27
FALLEN ARCHES
The ligament and tendons are
weakend, allowing bones to “fall”