The Appendicular SkeletonThe Appendicular Skeleton

Slide 5.32aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The Appendicular SkeletonThe Appendicular Skeleton

Slide 5.32aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Limbs (appendages) – arms & legs

Pectoral girdle (shoulders)

Pelvic girdle (hips)

Bones of the Shoulder GirdleBones of the Shoulder Girdle

Slide 5.34aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.20a, b

The Pectoral (Shoulder) GirdleThe Pectoral (Shoulder) Girdle Composed of 2 bones: clavicle & scapula

Clavicle (collarbone)

attaches to sternum & to the scapula

keeps shoulder from dislocating and the arm from flopping forward onto chest

Scapula (shoulder blade)

Only attaches to the axial skeleton at the clavicle, so allows lots of movement

Drawbacks: clavicle breaks; scapula dislocates

Slide 5.34bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.20c, d

The ScapulaThe Scapula Scapula

Has 3 important landmarks or areas: acromion process, coracoid process & glenoid cavity

Acromion process – where clavicle connects

Coracoid process – forms top of shoulders & gives arm muscles a place to attach

Glenoid cavity – shallow socket where humerus fits (ball & joint)

Bones of the Upper LimbBones of the Upper Limb

Slide 5.35aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Humerus = upper arm

Round at the top for shoulder joint

2 depressions at lower end to allow ulna to move freely

Figure 5.21a, b

Bones of the Upper LimbBones of the Upper Limb

Slide 5.35bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

• The forearm has two bones: ulna & radius

• Radius is on thumb side

• Ulan & radius touch at top & bottom (radioulnar joints) & are joined in the middle by interosseous membrane

• Radius allows arm to rotate Figure 5.21c

Bones of the Upper LimbBones of the Upper Limb

Slide 5.36Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The hand:

Carpals – wrist, 8 bones – 2 rows of 4

Metacarpals – palm; 5 total, #1 = thumb

Phalanges – fingers; 14 total (3 per finger except the thumb)

Figure 5.22

Slide 5.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The PelvisThe Pelvis

Slide 5.38aCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.23a

Slide 5.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The PelvisThe Pelvis

Slide 5.38bCopyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.23b

Bones of the Pelvic GirdleBones of the Pelvic Girdle

Slide 5.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Composed of 2 hip bones (coxal bones) Does not include the sacrum & coccyx Composed of three pair of fused bones

Ilium – large upper part, most of the hip bone Ischium – lower back part, what you sit on Pubic bone – lower front part

All 3 are heavy bones with deep sockets & lots of ligament

Attaches to the axial skeleton & entire weight of body rests on the pelvis

Bones of the Pelvic GirdleBones of the Pelvic Girdle

Slide 5.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

2 main functions Bear weight is the main function Second function is to protects several organ

Reproductive organs Urinary bladder Part of the large intestine

Several differences between male & female pelvic girdles so can easily tell gender on a skeleton

One big difference is the size of the interior cavity since women give birth

Gender Differences of the PelvisGender Differences of the Pelvis

Slide 5.39

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 5.23c

Bones of the Lower LimbsBones of the Lower Limbs

Slide 5.40a

Carry our entire weight when erect, so large & thick compared to arms

Femur - thigh bone

Only bone in the thigh

Lower leg

Tibia & fibula Figure 5.35a, b

FemurFemur

Slide 5.37Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The largest and strongest bone in the body The top has a large head (to fit into pelvis), a

neck and the greater & lesser trochanters (for muscle attachment)

The neck is a common fracture site, especially in older people

Femur slants medially or toward the inside as it goes down toward the knee – more pronounced in women

Two condyles or bumps at the distal end of femur to rest on the tibia below

Big groove between the condyles where the patella moves back and forth with movement

Bones of the Lower LegBones of the Lower Leg

Slide 5.40b

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

The leg has two bones: tibia & fibula

Very similar to ulna and radius

Tibia (shinbone) is bigger & medial – upper end is where patella attaches; lower end forms ankle

Figure 5.35c

Bones of the FootBones of the Foot

Slide 5.41

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Three parts like the hand

Tarsus – ankle

Metatarsals – sole

Phalanges – toes

2 jobs: support weight & act as a lever to help us move forward Figure 5.25

Arches of the FootArches of the Foot

Slide 5.42

Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Bones of the foot are arranged to form three strong arches

Two longitudinal

One transverse

Allows flexibility and springiness

Figure 5.26