t he a ppendicular s keleton composed of 126 bones limbs (appendages) pectoral girdle pelvic girdle
TRANSCRIPT
THE APPENDICULAR SKELETON
Composed of 126 bones Limbs (appendages) Pectoral girdle Pelvic girdle
THE APPENDICULAR SKELETON
Figure 5.6a
acromion
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
Figure 5.21a
Coracoid process
greater tubercle
BONES OF THE SHOULDER GIRDLE
Figure 5.21b
CLAVICLE (#2)
BONES OF THE SHOULDER GIRDLE
Figure 5.21c–d
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SCAPULA (#1)
BONES OF THE UPPER LIMBS
Humerus Forms the arm Single bone
BONES OF THE UPPER LIMBS
Figure 5.22a–b
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Humerus (#3)
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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
Figure 5.22c
Radius (#4) & Ulna (#5)
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BONES OF THE UPPER LIMBS
The hand Carpals—wrist 8 bones Metacarpals—palm Phalanges—fingers 14 bones
BONES OF THE UPPER LIMBS
Figure 5.23
Carpal (#6), Metacarpals (#7), Phalanges (#8)
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 flexiblePelvic 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
Figure 5.24a
More massive than 4 legged creatures because it has to bear more weight.
THE PELVIS: RIGHT COXAL BONE
Figure 5.24b
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Illium = yellow bone #1Ischium = Purple bone #2Pubis = Red bone #3
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 brim- INFERIOR; 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
Figure 5.25a–b
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Anterior view of right femur
Posterior view of right femur
Patella # 5
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
Figure 5.25c
Fibula #6Tibia #7
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BONES OF THE LOWER LIMBS
The foot Tarsals
Two largest tarsals Calcaneus (heelbone) Talus
Metatarsals—sole Phalanges—toes
BONES OF THE LOWER LIMB
Figure 5.26
Talus #8Calcaneus #9Metatarsals #10Phalanges #11
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”