Skeletal System

Most abundant mineral in human body

Calcium

Difference between axial and appendicular skeleton

Axial skeleton is composed of bones found along the central axis of the body. Primary function is to protect vital organs and provide core structural support. Appendicular is the bones which attach to the central axis. Primary function is movement, locomotion, and manipulating the excitement.

Foramen

An opening or hole in a bone allowing passage of nerves or blood vessels.

Sesamoid

A small, rounded bone embedded within a tendon

Articular Cartilage

Hyaline cartilage covering joint surfaces; reduces friction and absorbs shock.

Osteoclast

Bone-resorbing cell that breaks down bone tissue

Osteon

Cylindrical structural unit of compact bone consisting of concentric layers.

Phalanges

Bones of the fingers and toes.

Atlas

First cervical vertebra (C1); supports the skull and permits nodding.

Synarthrosis

An essentially immovable joint.

Amphiarthrosis

A slightly movable joint.

diarthrosis

A freely movable joint; all synovial joints are diarthroses.

gomphosis

Fibrous joint anchoring a tooth within its alveolar socket.

articulation

A joint or location where two bones meet.

ROM

Range of motion; the extent a joint moves through its available movements.

rheumatism

General term for disorders causing joint, muscle, or connective-tissue pain.

What is located in the central canal of an osteon?

Blood vessels, nerves, and lymphatic vessels.

Where is the calcaneus?

The calcaneus is the heel bone, located in the posterior foot.

What bones make up the pelvis?

Two hip bones (ilium, ischium, pubis), sacrum, and coccyx.

cervical vertebrae #

7

Thoracic vertebrae #

12

Lumbar vertebrae #

5

Sacral vertebrae #

5 (fused)

Coccygeal vertebrae #

4 (fused, usually)

C1 vertebrae

Atlas; supports the skull.

C2 Vertebrae

Axis; contains the dens and permits head rotation.

What is the spinous process?

A posterior bony projection of a vertebra where muscles and ligaments attach.

What type of joint is the elbow and the hip?

Elbow: Hinge joint; primarily flexion and extension.

Hip: Ball-and-socket joint; multiaxial movement.

Gliding

Sliding the flat surfaces of two bones across each other

Flexion

Decreasing the angle between two bones, usually in the sagittal plane

Extension

Increasing the angle between two bones, usually in the sagital plane

ABduction

Moving a limb away from the bod midline in the frontal plane

ADDuction

Moving a limb toward the body midline in the frontal plane

Circumduction

Moving a limb or finger so that it describes a cone in space

Medial rotation

rotating toward the median plane

Lateral rotation

rotating away from the median plane

Retraction

Body part moves posteriorly.

Protraction

Body part moves anteriorly.

Supination

Forearm rotates palm anteriorly or upward.

Dorsiflexion

Foot moves upward toward the shin.

Plantar flexion

Foot points downward away from the shin.

Pronation

Forearm rotates palm posteriorly or downward.

Suture joint (type of fibrous)

Immovable fibrous joint between skull bones.

Synostosis Joint

Bones fused together by bone tissue.

Symphysis joint

Cartilaginous joint where bones are joined by fibrocartilage.

Synchondrosis

Cartilaginous joint where bones are joined by hyaline cartilage.

Syndesmosis

Fibrous joint connecting bones with ligaments or an interosseous membrane.

Fibrous joint

bones united by collagen fibers

• suture

• syndesmosis

• gomphosis

Cartilaginous Joint

Bone ends united by cartilage

• synchondrosis (hyaline)

• Symphysis (fibrocartilage)

Synovial Joint

bone ends covered with articular cartilage and enclosed within a capsule lined with a synovial membrane

• hinge

• plane

• pivot

• condyloid

• saddle

• ball and socket

Gomphosis

Fibrous joint connecting a tooth to its socket.

Marfan syndrome

Genetic connective-tissue disorder causing tall stature, long limbs, and cardiovascular abnormalities.

gigantism

Excess growth hormone during childhood before growth plates close, causing excessive height.

FOP

Fibrodysplasia ossificans progressiva; genetic disorder causing bone formation within muscles and connective tissues.

Hormones involved in blood Ca homeostasis

Parathyroid (PTH), Calcitriol (active vitamin D), Calcitonin, FGF23

Hormone released when blood Ca is low

Parathyroid Hormone (PTH)

Hormone released when blood Ca is high

Calcitonin