CH 7,8,11

What are the total number of bones in the axial vs. appendicular skeleton?

Axial skeleton = 80 bones; Appendicular skeleton = 126 bones (Total = 206 bones).

How do the lower limb bones compare in size to the upper limb bones?

The bones of the lower extremity are much larger and more massive compared to the upper extremity to support the body's weight.

The bones of the pelvic girdle and lower limb are much more massive than their homologues of the upper limb

What are the primary functions of the pelvic girdle?

It supports and protects the lower viscera and the developing fetus in females.

What bones make up the pelvic girdle and lower limb?

Pelvic girdle: 2 ossa coxae (innominate bones). Lower limb: thigh (femur), kneecap (patella), leg (tibia and fibula), ankle (tarsals), and foot (metatarsals and phalanges).

Where do the two ossa coxae unite to form the pelvic girdle?

At the symphysis pubis and sacrum to form a girdle

What three separate bones fuse to form the os coxae (innominate bone)?

Ilium (llium), Ischium (posterior), and Pubis (anterior) (they unite at the acetabulum).

What’s the 2 things include in the Acetabulum

Acetabular Fossa

Acetabular notch

Which features are located on the lateral view of the Ilium?

Iliac crest, anterior/posterior/inferior gluteal lines, anterior superior iliac spine (ASIS), anterior inferior iliac spine (AIIS), posterior superior iliac spine (PSIS), and posterior inferior iliac spine (PIIS), greater sciatic notch, and inferior iliac notch

Which key landmarks are found on the lateral view of Ischium?

Ischial spine, lesser sciatic notch, ischial tuberosity (weight-bearing during sitting), and ischial ramus.

Which key landmarks are found on the lateral view of Pubis?

Superior ramus, inferior ramus,

What’s the medial view of the Pelvic girdle

Auricular surface for articulation with sacrum

Obturator foramen

Pectineal line

Pubic Tubercle

What is the function of the Auricular Surface of the ilium?

It articulates with the sacrum to form the sacro-iliac (sacroiliac) joint.

What is the Obturator Foramen?

A large opening created by the ischium and pubis rami through which nerves and blood vessels pass.

What lines mark the boundary of the pelvic brim on the medial surface?

The Arcuate line (on the ilium) and the Pectineal line (on the pubis).

What are the major features seen on the anterior view of the complete pelvis?

Sacrum, Coccyx, Sacro-iliac joints, Iliac fossa, Acetabulum, The Arcuate line, the Pectineal line, Obturator foramen, Pubic crest, Pubic symphysis, and Ischium.

What features are visible on the posterior view of the pelvis?

Sacrum, Median sacral crest, Sacral foramina, Coccyx, Posterior superior/inferior iliac spines, Greater sciatic notch, Ischial spine, and Ischial tuberosity.

True Pelvis vs. False Pelvis location

True pelvis = lower area of pelvis (below pelvic brim); False pelvis = upper area of pelvis (above pelvic brim / contains lower abdominal viscera).

Pelvic Inlet vs. Pelvic Outlet

Pelvic inlet = superior whole opening bounded by the pelvic brim; Pelvic outlet = inferior opening bounded by the ischial spines, pubic arch, and coccyx.

Characteristics of the Female Pelvis

Relatively broad/low pelvis, widely fanning ilia (project farther laterally), less curvature of sacrum/coccyx, wider, more circular pelvic inlet, enlarged pelvic outlet, and pubic angle > 100° (more rounded).

Characteristics of the Male Pelvis

Heavier/more prominent muscle markings, taller/narrower body. more curved sacrum/coccyx, and pubic angle ≤ 90° (curves in more).

What are the landmarks of the Femur Anterior?

Articular surface of head (medial), Less trochanter, greater trochanter, intertrochanteric line, shallow pit for the ligament of the femoral head.

Ligamentum Teres (Ligament of the femoral head)

Attaches to the shallow pit (fovea capitis) on the head of the femur to connect it into the acetabulum.

What are the landmarks of the Femur Anterior?

Intertrochanteric crest, gluteal tuberosity, Pectineal line, Line aspera, lateral epicondyle

Linea Aspera

A long ridge along the posterior shaft of the femur that splits at the top (into gluteal tuberosity and pectineal line) and serves as a major muscle attachment point.

Femur (Anterior vs. Posterior surface)

Anterior side is smooth; Posterior side is rough (contains line-like ridges like the linea aspera for muscle attachments).

Patella Anatomy

Sesamoid bone located within the quadriceps tendon; Pointy/Apex is located INFERIORLY; Base is SUPERIOR.

Tibial Tuberosity

A prominent bump on the anterior proximal tibia that serves as the attachment point for the patellar ligament.

What is the fibula and Tibia

Fibula: Slender lateral leg bone that supports very little weight; important for muscle attachments; distal end forms the lateral malleolus.

Tibia: Proximal end has articular condyles separated by intercondylar eminence. Also medial to the body.

Ligaments of the Hip Joint

Iliofemoral ligament, Ischiofemoral ligament, Pubofemoral ligament, Ligament of the femoral head, and Transverse acetabular ligament, Acetabular labrum.

Acetabular Labrum

A ring of fibrocartilage surrounding the rim of the acetabulum that deepens the socket for greater hip stability.

Hip Joint Capsule Mechanics

Extension tightens the joint ligaments/capsule; Flexion loosens the joint ligaments/capsule.

Type of Joint: Knee

Considered a hinge joint (permits flexion posteriorly and extension anteriorly, with slight rotation).

Quadriceps Tendon vs. Patellar Ligament

Quadriceps tendon attaches quadriceps muscles to the superior patella; Patellar ligament/tendon connects the inferior patella (apex) to the tibial tuberosity. Patellar retinaculae

4 ligament of the Knee Joint

Anterior cruciate ligament, Posterior cruciate ligament, Fibular collateral ligament, tibial collateral ligament

Fibular Collateral Ligament (LCL)

Located laterally on the knee; prevents varus movement (bow-legged displacement).

Tibial Collateral Ligament (MCL)

Located medially on the knee; prevents valgus movement (knock-kneed displacement).

Anterior Cruciate Ligament (ACL)

Crosses inside the knee joint; prevents anterior displacement (drawer) of the tibia relative to the femur.

Posterior Cruciate Ligament (PCL)

Crosses inside the knee joint; prevents posterior displacement (drawer) of the tibia relative to the femur (often injured in "dashboard injuries").

Menisci of the Knee (Medial & Lateral)

“C” shaped cushioning shock absorbers made of fibrocartilage (contains NO synovial fluid inside the cartilage itself).

Oblique and Arcuate Popliteal Ligaments

Ligaments located on the posterior (back) aspect of the knee capsule that stabilize posterior joint movement.

What and how many gluteal muscles are there

Gluteus Maximum, Gluteus medius, Gluteus minimus, tensor fasciae latae

What is the lliotibial band

Band of collagen fibers tense connective tissue that origins on the illiac crest and goes along the lateral surface of the thigh and inserts on the tibia. This tract braces the lateral surface of the knee and stabilizes the knee when a person balances on one foot. Gluteus Maximus and tensor fascia lata.

O/I/A of the Gluteus Maximus

O: Iliac crest, posterior gluteal line, and lateral surface of ilium; sacrum, coccyx, and thoracolumbar fascia

I: Iliotibial tract and gluteal tuberosity of femur

A: Extension and lateral rotation at hip; helps stabilize the extended knee; abduction at the hip (superior fibers only)

O/I/A of the gluteus medius

O: Anterior iliac crest, lateral surface of ilium between

posterior and anterior gluteal lines

I: Greater trochanter of femur

A: Abduction and medial rotation at hip

O/I/A of the gluteus minimus

O: Lateral surface of ilium between inferior and anterior gluteal lines

I: Greater trochanter of femur

A: Abduction and medial rotation at hip

O/I/A of the Tensor fasciae latae

O: Iliac crest and lateral surface of anterior superior iliac spine

I: Iliotibial tract

A: Extension of the knee and lateral rotation of the leg acting through the iliotibial tract; abduction* and medial rotation of the thigh