Types of Bones
Long bones ~ Longer than they are wide and work as levers. The bones of the upper and lower extremities are of this type.
Short bones ~ Short, cube-shaped, and found in the wrists and ankles.
Flat bones ~ Broad surfaces for protection of organs and attachment of muscles.
Irregular bones ~ All others that do not fall into the previous categories. They have varied shapes, sizes, and surfaces features and include the bones of the vertebrae and a few in the skull.

Cranial Bones
The cranial bones makeup the protective frame of bone around the brain.

Frontal ~ Forms part of the cranial cavity as well as the forehead, the brow ridges and the nasal cavity.

Left/Right Parietal ~ Forms much of the superior and lateral portions of the cranium.

Left/Right Temporal ~ Form the lateral walls of the cranium as well as housing the external ear.

Occipital ~ Forms the posterior and inferior portions of the cranium. Many neck muscles attach here as this is the point of articulation with the neck.

Sphenoid ~ Forms part of the eye orbit and helps to form the floor of the cranium.

Ethmoid ~ Forms the medial portions of the orbits and the roof of the nasal cavity.

The joints between bones of the skull are immovable and called sutures. The parietal bones are joined by the sagittal suture. Where the parietal bones meet the frontal is referred to as the coronal suture. The parietals and the occipital meet at the lambdoidal suture. The suture between the parietals and the temporal bone is referred to as the squamous suture. These sites are the common location of fontanelles or "soft spots" on a baby’s head.

Facial Bones
The facial bones makeup the upper and lower jaw and other facial structures.

Mandible ~ The lower jawbone. It articulates with the temporal bones at the temporomandibular joints. This forms the only freely moveable joint in the head. It provides the chewing motion.

Left/Right Maxilla ~ The upper jaw bones. They form part of the nose, orbits, and roof of the mouth.

Left/Right Palatine ~ Forms a portion of the nasal cavity and the posterior portion of the roof of the mouth.

Left/Right Zygomatic ~ The cheek bones. They form portions of the orbits as well.

Left/Right Nasal ~ Form the superior portion of the bridge of the nose.

Left/Right Lacrimal ~ Help to form the orbits.

Vomer ~ Forms part of the nasal septum (the divider between the nostrils).

Left/Right Inferior Turbinate ~ Forms the lateral walls of the nose and increase the surface area of the nasal cavity.

The Sternum
The sternum is a flat, dagger shaped bone located in the middle of the chest. Along with the ribs, the sternum forms the rib cage that protects the heart, lungs, and major blood vessels from damage. The three segments of the sternum are usually fused in adults. The sternum serves an important function in the body. The ribs are connected to it by the costal cartilage. Without the sternum, there would be a hole in the bone structure in the middle of the chest, right above the heart and lungs. The sternum protects this vital area and completes the circle of the rib cage.

Manubrim (aka “Handle”) ~ Located at the top of the sternum and moves slightly. It is connected to the first two ribs.

Body (aka “Blade” or “Gladiolus”) ~ Located in the middle of the sternum and connects the third to seventh ribs directly and the eighth through tenth ribs indirectly.

Xiphoid process (aka “Tip”) ~ Located on the bottom of the sternum. It is often cartilaginous (cartilage), but does become bony in later years.

The Ribs
The ribs are thin, flat, curved bones that form a protective cage around the organs in the upper body. They are comprised 24 bones arranged in 12 pairs. The ribs form a kind of cage that encloses the upper body. They give the chest its familiar shape. The ribs protect the heart and lungs from injuries and shocks that might damage them. Ribs also protect parts of the stomach, spleen, and kidneys. The ribs help in breathing. As a person inhales, the muscles in between the ribs lift the rib cage up, allowing the lungs to expand. When the person exhales, the rib cage moves down again, squeezing the air out of the lungs.

True Ribs ~ The first seven bones. These bones are connected to the spine (the backbone) in back. In the front, the true ribs are connected directly to the breastbone or sternum by a strip of cartilage called the costal cartilage.

False Ribs ~ The next three pairs of bones. These bones are slightly shorter than the true ribs and are connected to the spine in back. However, instead of being attached directly to the sternum in front, the false ribs are attached to the lowest true rib.

Floating Ribs ~ The last two sets of rib bones. Floating ribs are smaller than both the true ribs and the false ribs. They are attached to the spine at the back, but are not connected to anything in the front.

The Vertebral Column
Also called the backbone, spine, or spinal column, the vertebral column consists of a series of 33 irregularly shaped bones, called vertebrae. These 33 bones are divided into five categories depending on where they are located in the backbone. These bones compose the vertebral column, resulting in a total of 26 movable parts in an adult. In between the vertebrae are intervertebral discs made of fibrous cartilage that act as shock absorbers and allow the back to move. As a person ages, these discs compress and shrink, resulting in a distinct loss of height (generally between 0.5 and 2.0cm) between the ages of 50 and 55.

When looked at from the side, the spine forms four curves. These curves are called the cervical, thoracic, lumbar, and pelvic curves. These curves allow human beings to stand upright and help to maintain the balance of the upper body. The cervical and lumbar curves are not present in an infant. The cervical curves forms around the age of 3 months when an infant begins to hold its head up and the lumbar curve develops when a child begins to walk.

In addition to allowing humans to stand upright and maintain their balance, the vertebral column serves several other important functions. It helps to support the head and arms, while permitting freedom of movement. It also provides attachment for many muscles, the ribs, and some of the organs and protects the spinal cord, which controls most bodily functions.

Cervical Vertebrae ~ The first seven vertebrae. Located at the top of the spinal column, these bones form a flexible framework for the neck and support the head. The first cervical vertebra is called the atlas and the second is called the axis. The atlas' shape allows the head to nod "yes" and the axis' shape allows the head to shake "no".

Thoracic Vertebrae ~ The next twelve vertebrae. These bones move with the ribs to form the rear anchor of the rib cage. Thoracic vertebrae are larger than cervical vertebrae and increase in size from top to bottom.

Lumbar Vertebrae ~ After the thoracic vertebrae. These five bones are the largest vertebrae in the spinal column. These vertebrae support most of the body's weight and are attached to many of the back muscles.

Sacrum ~ A triangular bone located just below the lumbar vertebrae. It consists of four or five sacral vertebrae in a child, which become fused into a single bone after age 26. The sacrum forms the back wall of the pelvic girdle and moves with it.

Coccyx (aka “Tailbone”) ~ The bottom of the spinal column. It consists of 3-5 bones that are fused together in an adult. Many muscles connect to the coccyx.

Arm (aka “Brachium”) ~ Technically only the region between the shoulder and elbow. It consists of a single long bone called the humerus. The humerus is the longest bone in the upper extremity. The top, or head, is large, smooth, and rounded and fits into the scapula in the shoulder. On the bottom of the humerus, are two depressions where the humerus connects to the ulna and radius of the forearm. The radius is connected on the side away from the body (lateral side) and the ulna is connected on the side towards the body (medial side) when standing in the anatomical position. Together, the humerus and the ulna make up the elbow. The bottom of the humerus protects the ulnar nerve and is commonly known as the "funny bone" because striking the elbow on a hard surface stimulates the ulnar nerve and produces a tingling sensation.

Forearm ~ The region between the elbow and the wrist. It is formed by the radius on the lateral side and the ulna on the medial side when the forearm is viewed in the anatomical position. The ulna is longer than the radius and connected more firmly to the humerus. The radius, however, contributes more to the movement of the wrist and hand than the ulna. When the hand is turned over so that the palm is facing downwards, the radius crosses over the ulna. The top of each bone connects to the humerus of the arm and the bottom of each connects to the bones of the hand.

Hand ~ The hand consists of three parts (the wrist, palm, and five fingers) and 27 bones.

• Wrist (aka “Carpus”) ~ Consists of eight small bones called the carpal bones that are tightly bound by ligaments. These bones are arranged in two rows of four bones each. The top row (the row closest to the forearm) from the lateral (thumb) side to the medial side contains the scaphoid, lunate, triquetral, and pisiform bones. The second row from lateral to medial contains the trapezium, trapezoid, capitate, and hamate. The scaphoid and lunate connect to the bottom of the radius.
• Palm (aka “Metacarpus”) ~ Consists of five metacarpal bones, one aligned with each of the fingers. The metacarpal bones are not named but are numbered I to V starting with the thumb. The bases of the metacarpal bones are connected to the wrist bones and the heads are connected to the bones of the fingers. The heads of the metacarpals form the knuckles of a clenched fist.
• Fingers (aka “Phalanges”) ~ The fingers are made up of 14 bones called phalanges. A single finger bone is called a phalanx. The phalanges are arranged in three rows. The first row (the closest to the metacarpals) is called the proximal row, the second row is the middle row, and the farthest row is called the distal row. Each finger has a proximal phalanx, a middle phalanx, and a distal phalanx, except the thumb (also called the pollex) which does not have a middle phalanx. The digits are also numbered I to V starting from the thumb.

Thigh ~ The thigh is the region between the hip and the knee and is composed of a single bone called the femur or thighbone. The femur is the longest, largest, and strongest bone in the body.

Leg ~ Technically only the region from the knee to the ankle. It is formed by the fibula on the side away from the body (lateral side) and the tibia, also called the shin bone, on the side nearest the body (medial side). The tibia connects to the femur to form the knee joint and with the talus, a foot bone, to allow the ankle to flex and extend. The tibia is larger than the fibula because it bears most of the weight, while the fibula serves as an area for muscle attachment.

Foot (aka “Pes”) ~ The foot contains the 26 bones of the ankle, instep, and the five toes.

• Ankle (aka “Tarsus”) ~ Composed of the 7 tarsal bones which correspond to the carpals in the wrist. The largest tarsal bone is called the calcaneus or heel bone. The talus rests on top of the calcaneus and is connected to the tibia. Directly in front of the talus is the navicular bone. The remaining bones from medial to lateral are the medial, intermediate, the lateral cuneiform bones, and the cuboid bone.
• Toes ~ The metatarsal and phalanges bones of the foot are similar in number and position to the metacarpal and phalanges bones of the hand. The five metatarsal bones are numbered I to V starting on the medial side with the big toe. The first metatarsal bone is larger than the others because it plays a major role in supporting the body's weight. The 14 phalanges of the foot, as with the hand, are arranged in a proximal row, a middle row, and a distal row, with the big toe, or hallux, having only a proximal and distal phalanx.
• Instep ~ The foot's two arches are formed by the structure and arrangement of the bones and are maintained by tendons and ligaments. The arches give when weight is placed on the foot and spring back when the weight is lifted off of the foot. The arches may fall due to a weakening of the ligaments and tendons in the foot.

The Shoulder Girdle (aka “Pectoral Girdle”)
Composed of four bones: two clavicles and two scapulae. Usually, a "girdle" refers to something that encircles or is a complete ring. However, the shoulder girdle is an incomplete ring. In the front, the clavicles are separated by the sternum. In the back, there is a gap between the two scapulae. The primary function of the pectoral girdle is to provide an attachment point for the numerous muscles that allow the shoulder and elbow joints to move. It also provides the connection between the upper extremities (the arms) and the axial skeleton.

Clavical (aka “Collarbone”) ~A slender S-shaped bone that connects the upper arm to the trunk of the body and holds the shoulder joint away from the body to allow for greater freedom of movement. One end of the clavicle is connected to the sternum and one end is connected to the scapula.

Scapula (aka “Shoulder Blade”) ~ A large, triangular, flat bone on the back side of the rib cage. It overlays the second through seventh ribs and serves as an attachment for several muscles. It has a shallow depression called the glenoid cavity that the head of the humerus (upper arm bone) fits into.

The pelvic girdle differs between men and woman. In a man, the pelvis is more massive and the iliac crests are closer together. In a woman, the pelvis is more delicate and the iliac crests are farther apart. These differences reflect the woman's role in pregnancy and delivery of children. When a child is born, it must pass through its mother's pelvis. If the opening is too small, a cesarean section may be necessary.

Coxal Bones (aka “Hip” Bones) ~ The coxal bones are also called the ossa coxae or innominate bones. During childhood, each coxal bone consists of three separate parts: the ilium, the ischium, and the pubis. In an adult, these three bones are firmly fused into a single bone.