Transcript appendicular skeleton

Appendicular
Skeleton
Appendicular Skeleton
• The appendicular skeleton consists of
the bones of the limbs and bones that
anchor the limbs to the axial skeleton.
• Pectoral girdle: scapula, clavicle.
• Upper limbs: humerus, radium, ulna,
carpals, metacarpals, phalanges.
• Pelvic girdle: coxal bones.
• Lower limbs: femur, tibia, fibula, patella,
tarsals, metatarsals, phalanges.
Figure 7.42
Pectoral Girdle
• Clavicles: collar bones that attach the
sternum to the shoulder anteriorly.
• Scapulae: shoulder blades with two
processes.
– Acromion process: tip of the shoulder.
– Coracoid process: attaches to the clavicle
and provides attachments for muscles.
– Glenoid fossa articulates with the humerus.
Upper limb
• Humerus: upper arm bone, articulates
with the glenoid fossa of the scapula
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Upper limb cont.
• Radius: thumb side of the forearm,
articulates with the capitulum of the
humerus and the radial notch of the ulna
• Ulna: longer bone of the forearm,
olecranon and coronoid processes
articulate with the humerus
Hand
• Carpal bones: eight small bones of the
wrist.
• Metacarpal bones: five bones, the
framework of the palm.
• Phalanges: finger bones, three in each
finger (proximal, middle, distal phalanx),
two in the thumb.
Figure 7.47
Pelvic Girdle
• Coxal bones: two hips bones composed
of three fused bones.
– Ilium: superior part of the coxal bone.
– Ischium: lowest portion of the coxal bone.
– Pubis: anterior part of the coxal bone. The
two pubic bones joint at the symphysis pubis.
Iliac crest
(bone) Pubis
Obturator foramen
Figure 7.49
Figure 7.49
Superior iliac notch
Inferior iliac notch
Pubic tubercle
Lesser sciatic notch
Male and Female Pelvis
• Female iliac bones are more flared. “Hips
are wide”
• female pubic arch angle is greater.
• The sacral curvature is shorter and flatter.
• greater distance between the ischial
spines and tuberosities in the female.
• The differences create a wider pelvic
cavity in all diameters
• Larger pelvic brim
WHY???
Figure 7.51
Lower Limb
• Femur: thigh bone, longest bone
• Patella: kneecap, located in a tendon,
femur, tibia, and patella form the knee joint
• Tibia: shinbone, lateral malleolus forms
the ankle
• Fibula: slender bone lateral to the tibia,
not part of the knee joint
Figure 7.52
Linea aspera
(posterior)
Popliteal surface
• Osgood schlatter disease
– Swelling of bony projection of tibia below knee
– Due to over use of thigh muslces
– More common in teens b/c of rapid bone
growth
Foot
• Tarsal bones: seven small bones in the
ankle. The calcaneus (heel bone) is the
largest, located below the talus.
• Metatarsal bones: elongated bones that
form the arch of the foot.
• Phalanges: each toe has three except the
great tow which has two.
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Figure 7.55
• Tarsus and metatarsus: arranged and
bound by ligaments to form arch
• Plantar fascitis: flat foot “fallen foot”
– Weakened tissue, constant or heavy weight
applied to foot
Life-Span Changes
• Calcium levels
fall through life
and the skeleton
loses strength.
• Osteoclasts
outnumber
osteoblasts.
Life-Span Changes
• By age 35,
everyone loses
bone mass.
Women lose
bone mass
faster between
menopause and
age seventy.
• Trabecular bone
is lost before
compact bone.