The Skeletal System

Flashcards covering the types of skeletal systems, bone anatomy, the human axial and appendicular skeletons, and common skeletal diseases.

Hydrostatic Skeleton

Organisms without a hard skeletal structure that have body cavities filled with fluid under high pressure, where muscles act against the fluid to bring about movement.

Exoskeleton

A hard outer layer that supports and protects the internal organs and does not grow with the organism.

Endoskeleton

An internal support system consisting of bones, muscles, tendons, and ligaments found in all vertebrates.

Cartilage

An elastic tissue usually found in association with bones that reduces friction and acts as a shock absorber.

Tendon

A tough, fibrous connection that attaches a muscle to a bone to carry tension created by the muscle.

Ligament

Elastic connective tissue that keeps bone attached to other bones and allows for movement under tension.

Vertebrae

Thirty-three bones that form the vertebral column and encase the spinal cord.

Cranial bones

The bones that surround and protect the brain.

Patella

The bone that forms part of the knee.

Clavicle

The scientific name for the collarbone.

Foramen magnum

An opening in the skull through which the spinal cord passes to enter the cranium.

Bipedal

Having an upright posture and the ability to walk on only two legs.

Canines

Large, pointed teeth found in African apes used for tearing food.

Femur

The longest bone in the human body.

Axial skeleton

The part of the skeleton made up of bones around the axis of the body, including the skull, vertebral column, and thoracic cage.

Appendicular skeleton

The part of the skeleton consisting of the upper and lower limbs, as well as the shoulder (pectoral) and pelvic girdles.

Atlas

The first cervical vertebra which allows for nodding movements.

Axis

The second cervical vertebra which allows for rotation of the head.

S-shaped spine

The shape of the human vertebral column that evolved to allow for shock absorption and support for an upright skull.

C-shaped spine

The shape of the spine typically found in apes.

Rib cage

A structure consisting of $12$ thoracic vertebrae, $12$ pairs of ribs, and the sternum that protects organs in the thoracic cavity.

Humerus

The longest bone in the arm which articulates with the scapula, radius, and ulna.

Phalanges

Bones making up the fingers (three each) and the thumb (two each).

Synovial membrane

A membrane that produces synovial fluid to lubricate a joint.

Antagonistic muscles

Pairs of muscles that work together where one must relax while the other contracts, such as the biceps and triceps.

Rickets

A condition caused by a lack of Vitamin D in children, resulting in soft and deformed bones.

Osteomalacia

A Vitamin D deficiency in adults that causes bones to weaken and potentially fracture.

Osteoporosis

A condition caused by calcium not being replaced in bone, making them brittle and porous.

Osteoarthritis

A condition where cartilage starts to break down without associated inflammation, making movement difficult.

Rheumatoid arthritis

An auto-immune system disorder where the body attacks the joints, causing inflammation and pain.

Strain

Damage or tearing of a muscle.

Sprain

Damage or tearing of a ligament around a joint.

Fractures

Broken bones which can be incomplete (hairline/greenstick) or complete (simple/multi-fragmentary).

Dislocation

When a bone is over-extended out of its joint.