The human skeletal system: a 3D skeleton with the axial and appendicular bones labelled

The skeletal system is made of bone and cartilage. Bone, or osseous tissue, is a hard, dense connective tissue that forms most of the adult skeleton. Cartilage is a semi-rigid connective tissue found where flexibility and smooth surfaces are needed, such as in the rib cage and at joints. (OpenStax Anatomy and Physiology 2e, 6.1: The Functions of the Skeletal System.)

For adults, there are 206 bones in the skeleton. They are grouped into two divisions: the axial skeleton, which forms the vertical axis of the body, and the appendicular skeleton, which forms the limbs. (OpenStax Anatomy and Physiology 2e, 7.1: Divisions of the Skeletal System.)

Bones meet at joints, and ligaments tie bone to bone across many of them, so anatomy courses usually study bones, cartilages, joints and ligaments together. The joints themselves are covered on the types of joints page.

The skeleton has six main functions. It supports the body as a rigid framework. It allows movement, because muscles attach to bones that act as levers, with the joints as fulcrums. It protects internal organs: the ribs guard the heart and lungs, the vertebral column the spinal cord, and the cranium the brain. (OpenStax Anatomy and Physiology 2e, 6.1: The Functions of the Skeletal System.)

Bone also stores minerals, especially calcium and phosphorus, and releases them into the blood when the body needs them; calcium is essential for muscle contraction and for nerve impulses. Red bone marrow carries out haematopoiesis (hematopoiesis), making red blood cells, white blood cells and platelets. Yellow marrow stores fat, which can be used as an energy source. (OpenStax Anatomy and Physiology 2e, 6.1: The Functions of the Skeletal System.)

The axial skeleton includes all the bones of the head, neck, chest and back: 80 bones in the skull, vertebral column and thoracic cage. It protects the brain, spinal cord, heart and lungs, and anchors the muscles that move the head, neck and back and the muscles that act across the shoulder and hip joints. (OpenStax Anatomy and Physiology 2e, 7.1: Divisions of the Skeletal System.)

The appendicular skeleton includes all the bones of the upper and lower limbs, plus the bones that attach each limb to the axial skeleton. It has 126 bones in an adult. (OpenStax Anatomy and Physiology 2e, 7.1: Divisions of the Skeletal System.)

The bones that attach the limbs are the girdles. The pectoral girdle on each side consists of two bones, the scapula and the clavicle, and its only bony joint with the axial skeleton is the sternoclavicular joint. The pelvic girdle is formed by the hip bone (coxal bone) on each side, which meets the sacrum at the largely immobile sacroiliac joint. (OpenStax Anatomy and Physiology 2e, 8.1: The Pectoral Girdle.)

A common search is for the axillary skeleton, but there is no such division. Axillary refers to the axilla, the armpit region. The word students usually want is axial, the division that forms the central column of the body. (OpenStax Anatomy and Physiology 2e, 1.6: Anatomical Terminology.)

In the adult the skull consists of 22 bones, 21 of which are immobile and united into a single unit; the mandible, which forms the lower jaw, is the only movable bone of the skull. The brain case has eight bones: the paired parietal and temporal bones and the unpaired frontal, occipital, sphenoid and ethmoid bones. The 14 facial bones are the paired maxilla, palatine, zygomatic, nasal, lacrimal and inferior nasal conchae, and the unpaired vomer and mandible. (OpenStax Anatomy and Physiology 2e, 7.2: The Skull.)

Seven more bones are associated with the head: the hyoid bone, which does not touch any other bone, and the ear ossicles. (OpenStax Anatomy and Physiology 2e, 7.1: Divisions of the Skeletal System.)

The vertebral column starts in development as 33 vertebrae and is reduced in adults to 24 separate vertebrae plus the sacrum and coccyx: 7 cervical (C1 to C7), 12 thoracic (T1 to T12) and 5 lumbar (L1 to L5). The sacrum forms from five fused sacral vertebrae and the coccyx from four fused coccygeal vertebrae. The adult column has four curvatures: the thoracic and sacrococcygeal curves are primary, kept from the fetus, and the cervical and lumbar curves are secondary, developing after birth. (OpenStax Anatomy and Physiology 2e, 7.3: The Vertebral Column.)

The thoracic cage is made of the sternum and 12 pairs of ribs with their costal cartilages. The sternum has three parts: the manubrium, the body and the xiphoid process. Ribs 1 to 7 are true ribs, whose costal cartilages attach directly to the sternum; ribs 8 to 12 are false ribs, and ribs 11 and 12 are floating ribs that do not attach to the sternum at all. (OpenStax Anatomy and Physiology 2e, 7.4: The Thoracic Cage.)

There are 30 bones in each upper limb. The arm has a single bone, the humerus. The forearm has two: the ulna on the medial side and the radius on the lateral side. The wrist has eight carpal bones, the palm five metacarpal bones, and the thumb and fingers 14 phalanges. (OpenStax Anatomy and Physiology 2e, 8.2: Bones of the Upper Limb.)

Each lower limb also has 30 bones. The thigh has the femur, the longest and strongest bone of the body. The patella (kneecap) is a sesamoid bone at the knee. The leg has the large, weight-bearing tibia on the medial side and the thin fibula laterally. The foot has seven tarsal bones, five metatarsals and 14 phalanges. (OpenStax Anatomy and Physiology 2e, 8.4: Bones of the Lower Limb.)

Each adult hip bone forms from three bones, the ilium, ischium and pubis, which fuse together during the late teenage years. The two hip bones, the sacrum and the coccyx together make up the bony pelvis. (OpenStax Anatomy and Physiology 2e, 8.3: The Pelvic Girdle and Pelvis.)

Bones are classified by shape. A long bone is cylindrical and longer than it is wide, like the humerus, ulna, radius, femur, tibia and fibula. A short bone is cube-like, about equal in length, width and thickness; the only short bones are the carpals of the wrist and the tarsals of the ankle. (OpenStax Anatomy and Physiology 2e, 6.2: Bone Classification.)

Flat bones are thin and often curved, such as the cranial bones, scapulae, sternum and ribs, and they give broad areas for muscle attachment. Irregular bones have no easily described shape, such as the vertebrae and many facial bones. Sesamoid bones are small and round, shaped like a sesame seed, and form within tendons; the patellae are the only sesamoid bones that every person has. (OpenStax Anatomy and Physiology 2e, 6.2: Bone Classification.)

The surface of each bone carries features called bone markings or bony landmarks. They fall into three classes: articulations, where two bone surfaces come together; projections, which stand out from the surface and are the attachment points for tendons and ligaments; and holes, which are openings or grooves that let blood vessels and nerves enter or pass the bone. (OpenStax Anatomy and Physiology 2e, 6.3: Bone Structure.)

Learning the names of the markings makes every bone easier, because the same words repeat across the skeleton: a condyle is a rounded articular surface, a tubercle a small rounded projection, a tuberosity a rough projection, a crest a ridge, a fossa a shallow basin and a foramen a hole through bone. The table lists the common terms with an example of each. (OpenStax Anatomy and Physiology 2e, 6.3: Bone Structure.)

Women and men have the same bones, arranged in the same way: Petrie and colleagues describe the musculoskeletal anatomy of women and men as grossly similar, and sexual dimorphism in the human skeleton is apparent but more subtle than in many other species. The differences lie in overall size, robustness and the shape of particular bones. (Petrie KA et al. Considerations of Sex Differences in Musculoskeletal Anatomy Between Males and Females. In: The Active Female. Springer, 2023.)

The pelvis shows the clearest differences: because the female pelvis is adapted for childbirth, it is wider than the male pelvis. The bones of the female pelvis are lighter and thinner. The pelvic inlet is round or oval in females and heart-shaped in males, the subpubic angle is greater than 80 degrees in females and less than 70 degrees in males, and the greater sciatic notch is broader in females. The female sacrum is wider, shorter and less curved, the ischial tuberosities are farther apart, and the pelvic outlet is larger. OpenStax notes that the hip bone allows the most accurate sex determination of any bone. (OpenStax Anatomy and Physiology 2e, 8.3: The Pelvic Girdle and Pelvis.)

The skull also differs on average. Male crania tend to be larger, with rougher muscle markings, a more prominent glabella and supraorbital ridges, rounder and thicker upper margins of the orbits, a larger mastoid process and a more pronounced external occipital protuberance. The female chin tends to be narrower and more V-shaped, and the male chin squarer and broader. These traits overlap widely between individuals and populations, so no single feature is decisive. (Hall R, Beals K, Neumann H, et al. Introduction to Human Osteology, 2.6: Estimating Sex and Biological Affinity in the Skull.)

A 2023 study of 228 adult crania of known sex found that the glabellar and supraciliary (brow) region, the mastoid process and the nasal region were the most sexually dimorphic parts of the skull. These traits predicted sex with an accuracy of about 73%, rising to 77% when they were considered together, while the authors describe the pelvis as the most dimorphic structure in the human body. (Del Bove A et al. Mapping sexual dimorphism signal in the human cranium. Sci Rep. 2023.)

Because the skull alone is much less reliable than the pelvis, forensic anthropologists combine several areas. Hall and colleagues estimate about 80% accuracy from a cranium alone, about 90% with a well-preserved lower jaw, and 96% to 98% when the whole skeleton is available. (Hall R, Beals K, Neumann H, et al. Introduction to Human Osteology, 2.6: Estimating Sex and Biological Affinity in the Skull.)

Sex differences also exist at the level of tissue. Women and men differ in their collagenous, cartilage and bone tissues, differences that may predispose women to osteoarthritis and osteoporosis later in life. (Petrie KA et al. Considerations of Sex Differences in Musculoskeletal Anatomy Between Males and Females. In: The Active Female. Springer, 2023.)

The 3D skeleton on this page is built from BodyParts3D, a set of anatomical meshes of an adult male body. It is a male skeleton, so its pelvis has the narrow, heart-shaped inlet and the steeper subpubic angle described above. Every bone of the skull, vertebral column, rib cage and limbs is included as a separate, selectable part, together with the intervertebral discs, the upper costal cartilages, the interosseous membranes of the forearm and leg, and the long plantar ligament of the foot.

A few parts of the skeleton are not in the dataset: the coccyx, the auditory ossicles of the middle ear, and the costal cartilages of ribs 8 to 10. The coccyx, which is part of the vertebral column, forms from four fused coccygeal vertebrae below the sacrum. (OpenStax Anatomy and Physiology 2e, 7.3: The Vertebral Column.)

You can rotate the model to see it from the front (anterior view), back, either side or above, and click any bone to read about it. In medical imaging, an axial view means a horizontal slice through the body in the transverse plane, perpendicular to its long axis, which is different from the axial skeleton. (Radiopaedia: Radiographic positioning terminology.)

Atlas

The first cervical vertebra (C1), a ring-shaped bone that supports the skull.

Axis

The second cervical vertebra (C2), distinguished by a tooth-like upward projection called the dens.

Body of sternum

The long middle part of the sternum.

Calcaneus

The largest tarsal bone, forming the heel.

Capitate

The largest carpal bone, with a rounded head.

Clavicle

The collarbone, an S-shaped long bone running between the sternum and the shoulder.

Cuboid bone

A cube-shaped tarsal bone on the lateral side of the foot.

Distal phalanx of big toe

The end bone of the big toe (hallux), broad and stout.

Distal phalanx of fourth toe

The small end bone of the fourth toe (fourth digit of the foot).

Distal phalanx of index finger

The smallest, end bone of the index finger (second digit), supporting the fingertip and nail.

Distal phalanx of little finger

The smallest, end bone of the little finger (fifth digit), supporting the fingertip and nail.

Distal phalanx of little toe

The small end bone of the little toe (fifth digit of the foot).

Distal phalanx of middle finger

The smallest, end bone of the middle finger (third digit), supporting the fingertip and nail.

Distal phalanx of ring finger

The smallest, end bone of the ring finger (fourth digit), supporting the fingertip and nail.

Distal phalanx of second toe

The small end bone of the second toe (second digit of the foot).

Distal phalanx of third toe

The small end bone of the third toe (third digit of the foot).

Distal phalanx of thumb

The end bone of the thumb, supporting the nail and pulp.

Eighth rib

The eighth rib. A typical rib and the first of the false ribs.

Eighth thoracic vertebra

The eighth of the twelve thoracic vertebrae, labelled T8, which articulate with ribs.

Eleventh rib

The eleventh rib. A short floating rib with a pointed end and no neck or tubercle.

Eleventh thoracic vertebra

The eleventh of the twelve thoracic vertebrae, labelled T11, which articulate with ribs.

Ethmoid

A delicate cube-shaped bone between the orbits.

Femur

The thigh bone, the longest, heaviest and strongest bone in the body.

Fibula

The slender lateral bone of the leg.

Fifth cervical vertebra

The fifth of the seven cervical (neck) vertebrae, labelled C5.

Fifth costal cartilage

The bar of hyaline cartilage that connects the fifth rib to the sternum.

Fifth lumbar vertebra

The fifth of the five lumbar vertebrae, labelled L5, in the lower back.

Fifth metacarpal bone

The little finger metacarpal. One of the five long bones of the palm.

Fifth metatarsal bone

The metatarsal of the little toe. One of the five long bones of the forefoot.

Fifth rib

The fifth rib. A typical rib.

Fifth thoracic vertebra

The fifth of the twelve thoracic vertebrae, labelled T5, which articulate with ribs.

First costal cartilage

The bar of hyaline cartilage that connects the first rib to the sternum.

First lumbar vertebra

The first of the five lumbar vertebrae, labelled L1, in the lower back.

First metacarpal bone

The thumb metacarpal, shorter and stouter than the others. One of the five long bones of the palm.

First metatarsal bone

The shortest, thickest metatarsal, supporting the big toe. One of the five long bones of the forefoot.

First rib

The first rib. Usually the shortest, and the broadest and most strongly curved rib, flat from top to bottom.

First thoracic vertebra

The first of the twelve thoracic vertebrae, labelled T1, which articulate with ribs.

Fourth cervical vertebra

The fourth of the seven cervical (neck) vertebrae, labelled C4.

Fourth costal cartilage

The bar of hyaline cartilage that connects the fourth rib to the sternum.

Fourth lumbar vertebra

The fourth of the five lumbar vertebrae, labelled L4, in the lower back.

Fourth metacarpal bone

The ring finger metacarpal. One of the five long bones of the palm.

Fourth metatarsal bone

A lesser metatarsal on the lateral side of the foot. One of the five long bones of the forefoot.

Fourth rib

The fourth rib. A typical rib.

Fourth thoracic vertebra

The fourth of the twelve thoracic vertebrae, labelled T4, which articulate with ribs.

Frontal bone

The bone of the forehead and the roof of the orbits.

Hamate

A wedge-shaped carpal bone of the distal row with a hook.

Hip bone

The large irregular bone of the pelvis formed by the fusion of the ilium, ischium and pubis.

Humerus

The long bone of the upper arm.

Hyoid bone

A U-shaped bone in the neck.

Inferior nasal concha

A thin curved bone on the lateral wall of the nose.

Intermediate cuneiform bone

The smallest of the three cuneiform bones.

Interosseous membrane of forearm

A broad fibrous sheet joining the radius and ulna.

Interosseous membrane of leg

A broad fibrous sheet joining the tibia and fibula.

Intervertebral disk

A fibrocartilage cushion between two adjacent vertebral bodies, consisting of a gel-like nucleus pulposus inside a ring-like annulus fibrosus.

Intervertebral disk of axis

The intervertebral disc between C2 and C3 (the C2–C3 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of eighth thoracic vertebra

The intervertebral disc between T8 and T9 (the T8–T9 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of eleventh thoracic vertebra

The intervertebral disc between T11 and T12 (the T11–T12 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of fifth cervical vertebra

The intervertebral disc between C5 and C6 (the C5–C6 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of fifth lumbar vertebra

The intervertebral disc between L5 and S1 (the L5–S1 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of fifth thoracic vertebra

The intervertebral disc between T5 and T6 (the T5–T6 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of first lumbar vertebra

The intervertebral disc between L1 and L2 (the L1–L2 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of first thoracic vertebra

The intervertebral disc between T1 and T2 (the T1–T2 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of fourth cervical vertebra

The intervertebral disc between C4 and C5 (the C4–C5 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of fourth lumbar vertebra

The intervertebral disc between L4 and L5 (the L4–L5 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of fourth thoracic vertebra

The intervertebral disc between T4 and T5 (the T4–T5 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of ninth thoracic vertebra

The intervertebral disc between T9 and T10 (the T9–T10 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of second lumbar vertebra

The intervertebral disc between L2 and L3 (the L2–L3 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of second thoracic vertebra

The intervertebral disc between T2 and T3 (the T2–T3 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of seventh cervical vertebra

The intervertebral disc between C7 and T1 (the C7–T1 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of seventh thoracic vertebra

The intervertebral disc between T7 and T8 (the T7–T8 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of sixth cervical vertebra

The intervertebral disc between C6 and C7 (the C6–C7 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of sixth thoracic vertebra

The intervertebral disc between T6 and T7 (the T6–T7 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of tenth thoracic vertebra

The intervertebral disc between T10 and T11 (the T10–T11 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of third cervical vertebra

The intervertebral disc between C3 and C4 (the C3–C4 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of third lumbar vertebra

The intervertebral disc between L3 and L4 (the L3–L4 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Intervertebral disk of third thoracic vertebra

The intervertebral disc between T3 and T4 (the T3–T4 disc), a fibrocartilage pad with a gel-like nucleus pulposus inside a ring-like anulus fibrosus.

Lacrimal bone

A small, delicate bone of the medial orbit wall.

Lateral cuneiform bone

A wedge-shaped bone of the midfoot.

Long plantar ligament

The longest ligament of the sole of the foot.

Lunate

A crescent-shaped carpal bone in the middle of the proximal row.

Mandible

The lower jaw bone.

Manubrium

The upper part of the sternum.

Maxilla

The upper jaw bone, paired.

Medial cuneiform bone

The largest of the three cuneiform bones.

Middle phalanx of fourth toe

The middle phalanx of the fourth toe (fourth digit of the foot).

Middle phalanx of index finger

The middle of the three phalanges of the index finger (second digit).

Middle phalanx of little finger

The middle of the three phalanges of the little finger (fifth digit).

Middle phalanx of little toe

The middle phalanx of the little toe (fifth digit of the foot).

Middle phalanx of middle finger

The middle of the three phalanges of the middle finger (third digit).

Middle phalanx of ring finger

The middle of the three phalanges of the ring finger (fourth digit).

Middle phalanx of second toe

The middle phalanx of the second toe (second digit of the foot).

Middle phalanx of third toe

The middle phalanx of the third toe (third digit of the foot).

Nasal bone

A small, paired rectangular bone forming the bridge of the nose.

Navicular bone of foot

A boat-shaped tarsal bone on the medial side of the foot.

Ninth rib

The ninth rib. A typical rib in the false group.

Ninth thoracic vertebra

The ninth of the twelve thoracic vertebrae, labelled T9, which articulate with ribs.

Occipital bone

The bone forming the back and base of the skull.

Palatine bone

An L-shaped bone behind the maxilla.

Parietal bone

A paired, curved bone forming the roof and sides of the skull.

Patella

The kneecap, a triangular sesamoid bone in the tendon of quadriceps femoris.

Pisiform

A small, pea-shaped carpal bone on the palmar side of the triquetrum.

Proximal phalanx of big toe

The proximal of the two phalanges of the big toe (hallux).

Proximal phalanx of fourth toe

The first and longest phalanx of the fourth toe (fourth digit of the foot).

Proximal phalanx of index finger

The longest of the three phalanges of the index finger (second digit), nearest the palm.

Proximal phalanx of little finger

The longest of the three phalanges of the little finger (fifth digit), nearest the palm.

Proximal phalanx of little toe

The first and longest phalanx of the little toe (fifth digit of the foot).

Proximal phalanx of middle finger

The longest of the three phalanges of the middle finger (third digit), nearest the palm.

Proximal phalanx of ring finger

The longest of the three phalanges of the ring finger (fourth digit), nearest the palm.

Proximal phalanx of second toe

The first and longest phalanx of the second toe (second digit of the foot).

Proximal phalanx of third toe

The first and longest phalanx of the third toe (third digit of the foot).

Proximal phalanx of thumb

The first of the thumb's two phalanges.

Radius

The lateral bone of the forearm.

Sacrum

A triangular bone of five fused sacral vertebrae.

Scaphoid

The largest bone of the proximal carpal row, shaped like a boat.

Scapula

The shoulder blade, a flat triangular bone on the back of the thorax.

Second costal cartilage

The bar of hyaline cartilage that connects the second rib to the sternum.

Second lumbar vertebra

The second of the five lumbar vertebrae, labelled L2, in the lower back.

Second metacarpal bone

The index finger metacarpal, usually the longest. One of the five long bones of the palm.

Second metatarsal bone

The longest metatarsal in most people. One of the five long bones of the forefoot.

Second rib

The second rib. A thinner, longer rib than the first, with a flattened upper surface.

Second thoracic vertebra

The second of the twelve thoracic vertebrae, labelled T2, which articulate with ribs.

Sesamoid bone of foot

Small bone embedded in a tendon under the head of the first metatarsal.

Seventh cervical vertebra

The seventh of the seven cervical (neck) vertebrae, labelled C7.

Seventh costal cartilage

The bar of hyaline cartilage that connects the seventh rib to the sternum.

Seventh rib

The seventh rib. A typical rib and the last of the true ribs.

Seventh thoracic vertebra

The seventh of the twelve thoracic vertebrae, labelled T7, which articulate with ribs.

Sixth cervical vertebra

The sixth of the seven cervical (neck) vertebrae, labelled C6.

Sixth costal cartilage

The bar of hyaline cartilage that connects the sixth rib to the sternum.

Sixth rib

The sixth rib. A typical rib.

Sixth thoracic vertebra

The sixth of the twelve thoracic vertebrae, labelled T6, which articulate with ribs.

Sphenoid bone

A butterfly-shaped bone at the base of the skull.

Stylohyoid ligament

A fibrous band from the styloid process to the hyoid.

Talus

A tarsal bone that sits between the tibia and fibula above and the calcaneus below.

Temporal bone

A paired bone forming part of the side and base of the skull.

Tenth rib

The tenth rib. The last of the false ribs, with a single articular facet on its head.

Tenth thoracic vertebra

The tenth of the twelve thoracic vertebrae, labelled T10, which articulate with ribs.

Third cervical vertebra

The third of the seven cervical (neck) vertebrae, labelled C3.

Third costal cartilage

The bar of hyaline cartilage that connects the third rib to the sternum.

Third lumbar vertebra

The third of the five lumbar vertebrae, labelled L3, in the lower back.

Third metacarpal bone

The middle finger metacarpal. One of the five long bones of the palm.

Third metatarsal bone

The middle of the lesser metatarsals. One of the five long bones of the forefoot.

Third rib

The third rib. A typical rib.

Third thoracic vertebra

The third of the twelve thoracic vertebrae, labelled T3, which articulate with ribs.

Tibia

The shinbone, the medial and main weight-bearing bone of the leg.

Trapezium

A four-sided carpal bone at the thumb side of the distal row.

Trapezoid

A small wedge-shaped carpal bone of the distal row.

Triquetral

A pyramid-shaped carpal bone on the ulnar side of the proximal row.

Twelfth rib

The twelfth rib. The lowest floating rib, often very short, with no neck or tubercle.

Twelfth thoracic vertebra

The twelfth of the twelve thoracic vertebrae, labelled T12, which articulate with ribs.

Ulna

The medial bone of the forearm.

Vomer

A thin, flat bone of the nasal septum.

Xiphoid process

The small lowest part of the sternum.

Zygomatic bone

The cheekbone.