• Skull 28 (8 paired and 6 unpaired cranial and facial bones and 6 ossicles of the ears)
• Hyoid
• Vertebrae 26 bones
• Chest 25 bones
• Total 80

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Cortical (compact) bone represents almost 80% of the skeletal mass of the human body. It is called "compact" because it forms a protective outer layer around every bone in the body.

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Cancellous (spongy) bone represents only about 20% of the skeletal mass.

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appendicular skeleton

The appendicular skeleton has 126 bones and includes the bones of the upper and lower extremities.

• Upper extremities 64 bones
• Lower extremities 62 bones
• Total 126

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The space where the frontal angles of the parietal bones meet the two ununited halves of the frontal bone.

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At birth, the bones of the head are not completely formed. As a result, there is adequate space between them to allow the baby's head to be molded enough to fit through the birth canal. These 6 spaces are known as fontanels or “soft spots.”

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The space where the occipital angles of the parietal bones meet the occipital.

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An interval on either side of the head where the frontal angle of the temporal bone and greater wing of the sphenoid meet.

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An interval on either side of the head where the frontal angle of the temporal bone and greater wing of the sphenoid meet.

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Joins the frontal bone to the two parietal bones

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Bone that closes the anterior part of the cranial cavity and forms the skeleton of the forehead.

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Joins the two parietal bones to the occipital bone

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Bone situated at the posterior and inferior part of the cranium; articulating with the two parietal and two temporal bones.

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Bones forming part of the superior and lateral surfaces of the skull, and joining each other in the midline at the sagittal suture.

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Joins one parietal bone to the other parietal bone.

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Joins the parietal bones to the temporal bones.

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temporal bones

Bones forming part of the lateral surfaces and the base of the skull, and containing the organs of hearing.

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• frontal bone
• parietal bones
• occipital bone
• temporal bones

• coronal suture
• squamous suture
• lambdoid suture
• sagittal suture

1. coronal suture

2. sphenoid bone

3. nasal bone

4. frontal bone

5. temporal bone

6. nasal concha

7. maxilla

8. parietal bone

9. squamous suture

10. lambdoid suture

11. occipital bone

12. mastoid process

13. styloid process

14. condyloid process

15. coronoid process

16. supraorbital foramen

17. lacrimal bone

18. zygomatic bone

19. vomer

20. mandible

The vertebral column, or spine, consists of 26 total bones, differentiated below. The last lumbar vertebra connects to the sacrum, which connects to the coccyx (or tailbone).

• cervical vertebrae (7)
• atlas vertebra (the first cervical vertebra)
• axis vertebra (the second cervical vertebra)
• thoracic vertebrae (12)
• lumbar vertebrae (5)
• sacrum
• coccyx

The cervical spine contains 7 vertebrae located in the neck area. In medical reports this spine is abbreviated C1-C7. The cervical spine curve is concave. With the ability to raise the head and stand with erect posture comes the development of this curve, which is why infants are not born with the cervical spine curve.

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The thoracic spine contains 12 vertebrae located in the chest area, which connect to the ribs. In medical reports this spine is abbreviated T1-T12. The thoracic spine curve is convex and is already formed at the time of birth.

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The lumbar spine contains 5 vertebrae located in the lower back. The lumbar spine curve is concave. Like the thoracic spine, it is already formed at the time of birth.

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The sacral spine consists of 5 fused sacral vertebrae. It is easily distinguishable as an upside-down triangular shape. The two lateral surfaces (sides) are smooth for articulation (loose connection) with the iliac bones of the pelvis.

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The coccyx or “tailbone” is a single bone formed by fusion of 4-5 coccygeal vertebrae. When pressure is placed on the coccyx, it moves forward and acts like a shock absorber. Sitting down or falling on it too hard can cause it to become fractured. The adjectival form of coccyx is coccygeal.

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12 pairs of ribs

• true ribs (1–7)
• false ribs (8–10)
• floating (false) ribs (11–12)

There are 12 pairs of ribs in the human body. These are long, curved bones that attach posteriorly to the thoracic vertebrae. Anteriorly rib pairs 1–7 connect to the sternum and are called true ribs. Ribs 8–10 connect to cartilage anteriorly and are called false ribs. The remaining two ribs, 11–12, are also connected to the thoracic spine posteriorly, but are free from connection anteriorly. Although ribs 11–12 are technically considered false ribs, they are also called floating ribs.

sternum

• manubrium
• body
• xiphoid process
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Upper portion (handle) of the sternum.

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Middle section of the sternum.

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Distal portion of the sternum.

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Area of sternum where the manubrium and body join.

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Anteriorly rib pairs 1–7 connect to the sternum and are called true ribs.

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Ribs 8–10 connect to cartilage anteriorly and are called false ribs.

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Ribs 11–12, are also connected to the thoracic spine posteriorly, but are free from connection anteriorly. Although ribs 11–12 are technically considered false ribs, they are also called floating ribs.

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The appendicular skeleton gets its name from the fact that it consists of all the parts that append (hang on) to the axial skeleton.  In fact, the arms and legs are known as the appendages.

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collarbone

(1 per side for a total of 2)

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shoulder blade

(1 per side for a total of 2)

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upper arm

(1 per side for a total of 2)

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forearm

(1 per side for a total of 2)

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forearm located on the pinky side.

(1 per side for a total of 2)

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wrist bones

(8 per side for a total of 16)

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Carpals are generally made up of 2 rows of 4 bones each and are held in place by ligaments. The 8 carpal bones are the hamate, scaphoid, trapezium, pisiform, trapezoid, lunate, triquetrum, and capitate bones.

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hand

(5 per side for a total of 10)

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They consist of 5 bones that form the structure of the hand and articulate with the carpals. These metacarpals are numbered from 1–5, with the thumb being first and the little finger fifth.

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fingers

(14 per side for a total of 28)

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There are 5 fingers, and each has 3 phalanges (the distal, medial, and proximal phalanges), with the exception of the thumb, which has only 2.

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hip/pelvic bone

(1 per side for a total of 2)

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thigh

(1 per side for a total of 2)

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kneecap

(1 per side for a total of 2)

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largest of the two lower leg bones

(1 per side for a total of 2)

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long, skinny lower leg bone

(1 per side for a total of 2)

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ankle bones that support weight and act as shock absorbers

(7 per side for a total of 14)

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There are 7 tarsal bones in each foot: the talus, calcaneus, cuboid, navicular, and 1st, 2nd, and 3rd cuneiforms. The talus articulates with the tibia to bear weight from the legs. The medial malleolus (on the tibia) and the lateral malleolus (on the fibula) protect the talus on both sides.

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bones of the feet that sit upon arches

(5 per side for a total of 10)

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toe bones

(14 per side for a total of 28)

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The separations between the phalanges are identified as follows: the distal phalanx (tip of the toe), the middle phalanx, (in the middle) and the proximal phalanx (nearest the point of connection to the metatarsals). Notice that the medical term for toes is the same as for fingers.

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The end of the clavicle that is attached to the acromion.

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Process that helps form point of the shoulder.

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Process that helps form point of the shoulder.

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Cavity where the humerus rests.

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The large process at the proximal end of the ulna which projects behind the articulation with the humerus and forms the bony prominence of the elbow.

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wings of the hip bone

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lower part of the "eye mask" of the hip bone

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the portion of the hip bone between the "eyes"

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a groove in the hip bone

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1. Femur

2. patella

3. tibia

4. fibula

5. tarsals

6. metatarsals

7. phalanges

8. clavicle

9. scapula

10. humerous

11. radius

12. ulna

13. carpals

14. metacarpals

15. phalanges

There are two types of fibrous joints:

suture

syndesmosis

A fibrous joint has no joint cavity and, in general, does not move. Examples of fibrous joints include cranial sutures and tibiofibular joints.

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There are two types of cartilaginous joints:

synchondrosis

symphysis

Although a cartilaginous joint has no cavity, it is still somewhat moveable. Examples of cartilaginous joints are the growth zones in the arms and legs, and the disks between the vertebrae.

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There are four types of synovial joints:

plane

uniaxial

biaxial

multiaxial

A synovial joint has a joint cavity that is kept lubricated by synovial fluid. The looser the joint, the more unstable and susceptible it is to injury or other damage. The body compensates for the weakness in synovial joints with ligaments, tendons, and muscle overlays. In this way, joints can be strengthened and supported to a much higher degree, yet still be capable of functioning freely.

Plane joints are joints that glide where the flat ends of bones connect. Examples of plane joints are the intercarpal and intertarsal joints.

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Uniaxial joints allow movement around one axis only. Examples of uniaxial joints are the elbow joint and the interphalangeal joint.

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Biaxial joints allow movement around two axes. Examples of biaxial joints are the knee joint, the temporomandibular (jaw) joint, and the radiocarpal (wrist) joint.

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Multiaxial joints allow movement around three axes. Examples of multiaxial joints are the ball and socket joint found in the hip and shoulder, as well as the carpometacarpal joint of the thumb between the trapezium (base of thumb) and the first metacarpal. Ball-and-socket joints are the most freely moveable joints in the body.

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a band of white, fibrous, slightly elastic tissue that binds the ends of bones together. This binding prevents dislocations and stress that can cause fractures.

Most ligaments derive their names from the area where they are located, their shape, or the bones and/or structures near that area. For example, there is a carpal ligament in the wrist and a series of cervical ligaments in the neck

nuchal ligament

complete fracture