General Science - Skeletal System

(10-04-2025)

Skeletal System

The body's internal framework made of bones, cartilage, and connective tissues.

Bone

It provides structural support, protects organs, allows for movement, produces blood cells, and stores minerals.

Long, Short, Flat, and Irregular bones

4 Types of bones:

Long bones

This type of bone, carry our upper body’s weight; appendicular skeleton.

Short bones

This type of bone is cube shaped; wrist or ankles.

Flat bones

This type of bone protects our vital organs: skull and rib cage.

Irregular bones

This type of bone has complex shapes; spine

Axial and Appendicular skeleton

2 Main divisions of the skeletal system:

Axial skeleton

It is the backbone of the skeletal system; head part, thoracic cage, and spine (vertebral column).

Appendicular skeleton

126 bones, attached to the axial skeleton; arms and legs.

Cranium and Facial

2 parts of the skull:

Cranium

It is the brain case

Facial

It contains the Mandible

Mandible

The only moveable bone in the skeleton system.

Frontal, Parietal, Occipital, and Temporal

4 primary areas of the skull:

Frontal

The forehead part of the cranium:

Parietal

The top part of the cranium:

Occipital

The back part of the cranium:

Temporal

The side parts of the cranium:

Ribs and Sternum

2 Divisions of the Thoracic Cage:

Ribs

The 12 pairs of bones in the Thoracic Cage.

24 bones

The ribs contain how many bones?

Sternum

Also known as the “breast bone,” it is the middle part of the thoracic cage.

Spine

Also known as the “Vertebral Column” and It has 33 bones

Cervical

It is the neck part that contains 7 vertebraes in the spine:

Thoracic

It is the upper back part where the rib cage attaches; it contains 12 vertebraes in the spine:

Lumbar

It is the lower back part that contains 5 vertebraes in the spine:

Sacrum

The triangular section in the pelvis at the base of the spine that contains 5 vertebraes.

Coccyx

It is the tailbone part, located at the very end of the spine that contains 4 vertebraes.

Appendicular Skeleton

They are attached to the axial skeleton.

Clavicle and Scapula

2 parts that of the pectoral girdle:

Collarbone

The Clavicle is also known as:

Shoulder Blade

The Scapula is also known as:

Humerus, Radius, Ulna, Carpals, Metacarpals, and Phalanges

The upper extremities:

Humerus

The longest bone in the upper extremities:

Ulna

The longer bone in the forearm:

Radius

The shorter bone in the fore arm:

Carpals

Bones that makes up the wrist and contains 8 bones:

Metacarpals

Bones that makes up the palm of the hand and contains 5 bones:

Phalanges

Bones that makes up the finger and contains 14 bones:

Pelvic Girdle

It connects the lower limbs to the axial skeleton

Pelvis

Contains all the lower part of the spinal cords’ bones

Femur, Patella. Tibia, Fibula, Tarsals, Metatarsals, and Phalanges

The Lower Extremities:

Femur

The longest bone in the Human Body:

Patella

The knee cap.

Tibia

The longer part of the leg bones and contains 4 bones:

Fibula

The shorter part of the leg bones:

Tarsals

contains 7 bones of the foot

Metatarsals

contains 5 bones of the foot

Phalanges

contains 14 bones of the foot