The+Appendicular+Skeleton
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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
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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)
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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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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
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Posterior view of right femur
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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
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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”