1. THE SKELETAL SYSTEM Focus on the Pelvic Girdle and lower limb

2. General anatomical terms to know  Process  Ramus  Trochanter  Tuberosity  Tubercle  Crest  Line  Spine  Head  Neck  Condyle  Trochlea  Facet  Fossa  Sulcus  Foramen  Canal of meatus  Fissure  Sinus

3. Appendicular Skeleton  126 bones  Includes  bones of the limbs (appendages)  Supporting bones of the pectoral and pelvic girdles (connect limbs to axial skeleton)

4.  Includes sacrum, coccyx and coxal (hip) bones  Function: transfers weight of the upper body to the legs; designed for stability and locomotion more massive than the pectoral girdle more firmly attached to the axial skeleton  Sacroiliac joint = articulation of hip bone with sacrum  Hip joint = articulation of hip bone with femur (acetabulum) Pelvic Girdle

5. The Coxal Bones (2; hip bones)  TWO coxal bones  Each hip bone results from the fusion of three separate components which fuse together: 1. The ilium 2. The ischium 3. Pubis symphisis  The ilium, ischium and pubis together form a deep socket called the acetabulum which articulates with the head of the femur

9. The Ilium  Largest, most superior component of the coxal bone  Broad curved surface provides large surface area for attachment of muscles, tendons and ligaments  Iliac crest = “the hip”  Iliac spine can be seen is especially thin people

10. The ilium – superior portion of the hip  Iliac crest (superior)  ASIS = anterior superior iliac spine  PSIS = posterior superior iliac spine  Iliac fossa = wide depression  Ala = the other side of the iliac fossa  Arcuate line (medial)  Sacral articulation  Anterior, posterior and superior gluteal lines (attachments for gulteal muscles)  Greater sciatic notch

11. The Ischium  Most Inferior and strongest part of the coxal bone  Ischial tuberosity (inferior surface) supports the body’s weight when sitting; attachment site for hamstrings  Ischial Spine: separates the greater and lesser sciatic notch.  Obturator foramen – passageway for nerves and blood vessels from abdominal cavity to lower limbs  Lesser Sciatic Notch- smooth notch covered with cartilage- attachment for tendons

12. Pubis  Most anterior part of the coxal bone  Also called pubic bone

13. Acetabulum:  Latin for little cup of vinegar  Deep socket formed were the ilium, ischium and pubis bones articulate  Accepts the head of the femur to form the hip joint  Ball and socket joint

14. Male vs Female  Differences in shape and size result from variations in body size and muscle mass  Female pelvis: Smoother, lighter in mass and less prominent markings  Some differences are adaptations for child-bearing (to support the weight of the fetus and to ease passage of baby during birth)  Female pelvis: broad, low pelvis, larger pelvic outlet, broader pubic angle

15. Male vs Female

16. Male vs Female Pelvis  Female pelvis:  Pelvic weight- bones of the pelvis are lighter and thinner  Pelvic inlet(brim)- rounded and oval shaped  Pelvic outlet- rounded and larger  Subpubic angle- female greater than 80 degrees  Ischial spines- greater distance between the ischial spines  Lesser pelvic cavity- shorter and wider in females- this is why females tend to have broader hips.

18. Male vs Female

19. Bones of the Lower Limbs  Thigh = femur  Leg = tibia and fibula  Foot = tarsals, metatarsals and phalanges

20. The Femur  Heaviest strongest bone in the body  Structures to know: greater and lesser trochanters, intertrochanteric crest, gluteal tuberosity, lateral and medial condyles, intercondylar fossa (notch), patellar surface  Head of femur articulates with acetabulum of pelvis girdle  Neck of femur = common fracture site  Slants medially to join with the leg bones which brings the knees in line with the center of gravity

21.  Head- articulates with the acetabulum  Neck- weakest part of the femur-common area for fractures  Greater trochanter- insertion of gluteus muscles  Lesser trochanter- insertion of the psoas muscle

22.  Epicondyles- attachment of ligaments and muscles  Trochlear groove(patellar groove)- articulates with the patella  Condyles- articulate with the condyles of the tibia- distribute weight to the knee  Intercondylar fossa: separates the condyles of the femur- attaches the cruciate ligaments

23. The Femur head neck Greater trochanter Lesser trochanter Gluteal tuberosity Lateral condyle Medial condyle Patellar surface Intercondylar Fossa (notch) Intertrochanteric crest

24. Guess Who??

25. The Leg  Two bones connected by interosseous membrane  Tibia (shin) = larger, medial bone Forms knee joint with femur Medial malleolus forms the ankle  Fibula = thin and stick-like No part in forming knee joint lateral malleolus forms the ankle  Structures to know: medial and lateral condyles, intercondylar eminence, tibial tuberosity, medial and lateral malleolus, tibiofibular joints, anterior crest,

27. The Leg

28. The Foot  Two important functions:  Support of body weight  Serves as a lever to propel our body forward  Tarsals (7 bones)  Calcaneous = heel bone  Talus = “ankle” lies between the tibia and the calcaneous  Metatarsals (5 bones) = sole of foot  Phalanges (14 bones) = toes  Each toe has 3 phalanges except the big toe which has 2

29. The Foot

30. Arches of the Foot  3 arches  Two longitudinal (medial and lateral)  One transverse  Ligaments bind the foot bones together  Tendons help hold the bones firmly in the arched position  Weak arches = “flat feet” or “fallen arches”

32. Can you identify the following: