Lab 2.1 - Axial Skeleton

General

Axial skeleton is comprised of:

Bones along the central axis of the body, and is divided into:

• skull, vertebral column, and thoracic cage

Appendicular skeleton is comprised of:

Bones of the upper and lower extremities (limbs), and gridles of the bones that attach the upper and lower limbs to the axial

Vertebral column divisions

cervical, thoracic, lumbar, sacral, and coccygeal

Cervical vertebrae

7; small and light because they are not supporting a lot of weight and allow a lot fo movement of the neck

Thoracic vertebrae

12; provides articulation points for the ribs

Lumbar vertebrae

5; large, bulky vertebrae that are specialized for supporting the weight of the entire vertebrae column and body structures above them

Sacrum

5; consists of fused vertebrae, provides a stable anchoring point for the bones of the pelvic girdle

Coccyx

4; consists of three to five small vertebrae, which fuse together during development

• serves as an attachment point for several ligaments and for muscles of the pelvic floor

Spinal curvatures

1. cervical curve

2. thoracic curve

3. lumbar curve

4. sacral curve

Abnormal curvatures of the vertebrae

kyphosis, lordosis, and scoliosis

Kyphosis

exaggerated thoracic curvature that is directed posteriorly, making a hunchback look

• due to osteoporosis, maybe a compression fracture, osteomalacia, abnormal growth, or chronic contractions

Lordosis

exaggerated lumbar curvature; swayback, protrusion of the abdomen and buttocks

• same causes as kyphosis but may be due to abdominal weight

Scoliosis

abnormal lateral curvature that sometimes results during development when both the vertebral arch and body fail to form, or form incompletely, on one side of a vertebra

• due to unilateral muscular paralysis or spasm