Table of ContentsView AllTable of ContentsLabeled Skeletal SystemAxial SkeletonAppendicular SkeletonFunctionConditionsDiagnosis

Table of ContentsView All

View All

Table of Contents

Labeled Skeletal System

Axial Skeleton

Appendicular Skeleton

Function

Conditions

Diagnosis

The skeletal system comprises 206 bones and has two main parts: the axial skeleton and the appendicular skeleton. The skeletal system includes your bones,ligamentsthat attach bone to bone, and cartilage that provides padding between yourbones.Bones fall into two main categories. Theaxial skeletoncontains the bones that support the middle of your body, and the appendicular skeletonincludes bones that make up your appendages (arms and legs) and bones that attach your limbs to your axial skeleton.Labeled Skeletal SystemIn order to visualize the human skeletal system, a digital interactive diagram with bones labeled and additional information can be helpful.The Skeletal System TourAxial SkeletonTheaxial skeletonforms the “axis” that runs down the center of the body. There are 80 bones that make up the axial skeleton.Skull (Cranium)Your skull (cranium) is made up of cranial and facial bones. Cranial bones protect your brain, while facial bones make up your facial structure. Skull bones include the following.Cranial bonesinclude:FrontalParietalOccipitalTemporalSphenoidEthmoidFacial bonesinclude:Maxillae (upper jaw)VomerMandible (lower jaw)LacrimalZygomatic (cheekbones)NasalPalatineInferior nasal conchaeAuditory OssiclesThe auditory ossicles consist of a total of six tiny bones, with three in each ear. They are located in the inner ear and are structures that help create sound in your body. The auditory ossicles include the following:MalleusIncusStapesHyoid BoneThehyoid boneis a horseshoe-shaped bone located in the throat. It is part of bodily functions like speaking, swallowing, and airway maintenance.Vertebral ColumnThe vertebral column (spine) protects your spinal cord, supports your head, and allows bodily movement. It contains the sacrum (made up of four bones) and coccyx (the tailbone, which is made up of five bones), and 24 vertebrae, including:Cervical vertebrae: Seven bones in the neck regionThoracic vertebrae: Twelve bones attached to the ribsLumbar vertebrae: Five bones in the low back regionThoraxThethoraxcontains thesternum (breastbone)and thethoracic (rib) cage. The thoracic cage comprises 12 pairs of ribs connecting to the thoracic vertebrae and the sternum. Your rib cage protects your heart.Appendicular SkeletonThe appendicular skeleton includes 126 bones that comprise your appendages—your arms and legs—and the bones that attach your limbs to your axial skeleton.Upper ExtremitiesYour upper extremities refer to your shoulders and arms. Bones in the upper extremities include:Scapula (shoulder blade)Clavicle (collarbone)Humerus (upper arm)Radius and ulna (forearm bones)Carpals (eight tiny bones in the wrist)Metacarpals (in the palm)Phalanges (bones of the fingers)Lower ExtremitiesBones in the lower extremities make up your hips and legs and include:PelvisFemur (thigh bone)Patella (kneecap)Tibia and fibula (lower leg bones)Tarsals (eight tiny bones in the ankle)Metatarsals (in the middle of the foot)Phalanges (bones of the toes)Which Bones Are Most Commonly Broken?The most commonly fractured bones include the distal radius on the thumb side of your wrist, the ankle, the femur (thigh bone), the humerus (upper arm bone), and the metacarpals (bones of the palms). With osteoporosis, the most commonly fractured bones are the vertebrae in the spine.Purpose and FunctionThe primary purpose of the skeletal system is to give the body its shape and to provide attachment points for the muscles that move the body.Other purposes of the skeletal system include:Storing minerals (such as calcium) and fats. Most of the body’s calcium is stored in your bones.Producing red blood cellsProtecting internal organsSDI Productions / Getty ImgaesAssociated ConditionsVarious conditions and injuries can affect the skeletal system. Examples include:Fractures (broken bones)Ligament sprainsOsteoarthritisOsteoporosisOsteopeniaOsteogenesis imperfectaScoliosisRicketsOsteomalaciaCancerPaget’s disease of boneOsteomyelitisAvascular necrosis (osteonecrosis)Marfan syndromeEhlers-Danlos syndromeOsteopetrosisAnkylosing spondylitisBone marrow diseasesSkeletal System TestsMany different tests can help diagnose conditions that affect the skeletal system.Imaging TestsHealthcare providers use various imaging tools to get detailed pictures of your bones. Depending on the reason for imaging, a healthcare provider will conduct one or more of the following tests:X-rays: This common test can help diagnose conditions that affect the bones and joints, such as fractures or arthritis.Computed tomography (CT scan): This test provides three-dimensional pictures that help diagnose fractures that aren’t clear on X-rays, or other bone conditions, such as cancer.Magnetic resonance imaging (MRI): This type of imaging often helps diagnose conditions that affect soft tissues of the skeletal system (ligaments, cartilage).Bone scintigraphy (bone scan): These scans can provide detailed information about a bone injury or condition, such as the staging of bone cancer.Positron emission tomography (PET scan): This test, which uses an injected radioactive tracer, can help stage bone (and other types of) cancer.Bone density test: These tests are primarily for determining how dense bones are—the key factor in diagnosing osteoporosis.Other Skeletal System TestsHealthcare providers may perform additional tests if they need further information about your bones or skeletal system. These tests may include:Joint aspiration: This test involves removing a sample of fluid from a joint to help diagnose infection.Biopsy: For the skeletal system, this procedure can involve removing a small sample of bone or bone marrow so that it can be tested for conditions such as cancer.Blood tests: These tests help diagnose infections that can affect the skeletal system.SummaryThe axial skeletal system includes the bones, ligaments, and cartilage that form the backbone and long axis of the body. The appendicular skeleton includes your arms and legs.While the main skeletal function is to provide structural support for the body, the system also stores important minerals, forms red blood cells, and protects your internal organs. Different injuries and diseases can affect the skeletal system. Imaging procedures, blood or biopsy tests, and bone density tests can help to diagnose these conditions.SDI Productions / Getty Imgaes

The skeletal system comprises 206 bones and has two main parts: the axial skeleton and the appendicular skeleton. The skeletal system includes your bones,ligamentsthat attach bone to bone, and cartilage that provides padding between yourbones.

Bones fall into two main categories. Theaxial skeletoncontains the bones that support the middle of your body, and the appendicular skeletonincludes bones that make up your appendages (arms and legs) and bones that attach your limbs to your axial skeleton.

In order to visualize the human skeletal system, a digital interactive diagram with bones labeled and additional information can be helpful.

The Skeletal System Tour

Theaxial skeletonforms the “axis” that runs down the center of the body. There are 80 bones that make up the axial skeleton.

Skull (Cranium)

Your skull (cranium) is made up of cranial and facial bones. Cranial bones protect your brain, while facial bones make up your facial structure. Skull bones include the following.

Cranial bonesinclude:

Facial bonesinclude:

Auditory Ossicles

The auditory ossicles consist of a total of six tiny bones, with three in each ear. They are located in the inner ear and are structures that help create sound in your body. The auditory ossicles include the following:

Hyoid Bone

Thehyoid boneis a horseshoe-shaped bone located in the throat. It is part of bodily functions like speaking, swallowing, and airway maintenance.

Vertebral Column

The vertebral column (spine) protects your spinal cord, supports your head, and allows bodily movement. It contains the sacrum (made up of four bones) and coccyx (the tailbone, which is made up of five bones), and 24 vertebrae, including:

Thorax

Thethoraxcontains thesternum (breastbone)and thethoracic (rib) cage. The thoracic cage comprises 12 pairs of ribs connecting to the thoracic vertebrae and the sternum. Your rib cage protects your heart.

The appendicular skeleton includes 126 bones that comprise your appendages—your arms and legs—and the bones that attach your limbs to your axial skeleton.

Upper Extremities

Your upper extremities refer to your shoulders and arms. Bones in the upper extremities include:

Lower Extremities

Bones in the lower extremities make up your hips and legs and include:

Which Bones Are Most Commonly Broken?The most commonly fractured bones include the distal radius on the thumb side of your wrist, the ankle, the femur (thigh bone), the humerus (upper arm bone), and the metacarpals (bones of the palms). With osteoporosis, the most commonly fractured bones are the vertebrae in the spine.

Which Bones Are Most Commonly Broken?

The most commonly fractured bones include the distal radius on the thumb side of your wrist, the ankle, the femur (thigh bone), the humerus (upper arm bone), and the metacarpals (bones of the palms). With osteoporosis, the most commonly fractured bones are the vertebrae in the spine.

Purpose and Function

The primary purpose of the skeletal system is to give the body its shape and to provide attachment points for the muscles that move the body.

Other purposes of the skeletal system include:

SDI Productions / Getty Imgaes

Woman teaching a class about the anatomy of the skeleton as students take notes

Associated Conditions

Various conditions and injuries can affect the skeletal system. Examples include:

Skeletal System Tests

Many different tests can help diagnose conditions that affect the skeletal system.

Imaging Tests

Healthcare providers use various imaging tools to get detailed pictures of your bones. Depending on the reason for imaging, a healthcare provider will conduct one or more of the following tests:

Other Skeletal System Tests

Healthcare providers may perform additional tests if they need further information about your bones or skeletal system. These tests may include:

Summary

The axial skeletal system includes the bones, ligaments, and cartilage that form the backbone and long axis of the body. The appendicular skeleton includes your arms and legs.

While the main skeletal function is to provide structural support for the body, the system also stores important minerals, forms red blood cells, and protects your internal organs. Different injuries and diseases can affect the skeletal system. Imaging procedures, blood or biopsy tests, and bone density tests can help to diagnose these conditions.

12 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Cancer Institute.Cranium.National Cancer Institute SEER Training Modules.Axial skeleton (80 bones).Fisher E, Austin D, Werner HM, et al.Hyoid bone fusion and bone density across the lifespan: prediction of age and sex.Forensic Sci Med Pathol. 2016;12(2):146-157. doi:10.1007/s12024-016-9769-xOsmosis from Elsevier.Bones of the vertebral column.National Cancer Institute SEER Training Modules.Appendicular skeleton (126 bones).American Academy of Orthopaedic Surgeons.Osteoporosis and spinal fractures.National Cancer Institute SEER Training Modules.Introduction to the skeletal system.MedlinePlus.Calcium and bones.National Institute of Arthritis and Musculoskeletal and Skin Diseases.Muscle and bone diseases.MedlinePlus.Diagnostic imaging.Institute for Quality and Efficiency in Health Care.Understanding tests used to detect bone problems.Johns Hopkins Medicine.Joint aspiration.

12 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.National Cancer Institute.Cranium.National Cancer Institute SEER Training Modules.Axial skeleton (80 bones).Fisher E, Austin D, Werner HM, et al.Hyoid bone fusion and bone density across the lifespan: prediction of age and sex.Forensic Sci Med Pathol. 2016;12(2):146-157. doi:10.1007/s12024-016-9769-xOsmosis from Elsevier.Bones of the vertebral column.National Cancer Institute SEER Training Modules.Appendicular skeleton (126 bones).American Academy of Orthopaedic Surgeons.Osteoporosis and spinal fractures.National Cancer Institute SEER Training Modules.Introduction to the skeletal system.MedlinePlus.Calcium and bones.National Institute of Arthritis and Musculoskeletal and Skin Diseases.Muscle and bone diseases.MedlinePlus.Diagnostic imaging.Institute for Quality and Efficiency in Health Care.Understanding tests used to detect bone problems.Johns Hopkins Medicine.Joint aspiration.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

National Cancer Institute.Cranium.National Cancer Institute SEER Training Modules.Axial skeleton (80 bones).Fisher E, Austin D, Werner HM, et al.Hyoid bone fusion and bone density across the lifespan: prediction of age and sex.Forensic Sci Med Pathol. 2016;12(2):146-157. doi:10.1007/s12024-016-9769-xOsmosis from Elsevier.Bones of the vertebral column.National Cancer Institute SEER Training Modules.Appendicular skeleton (126 bones).American Academy of Orthopaedic Surgeons.Osteoporosis and spinal fractures.National Cancer Institute SEER Training Modules.Introduction to the skeletal system.MedlinePlus.Calcium and bones.National Institute of Arthritis and Musculoskeletal and Skin Diseases.Muscle and bone diseases.MedlinePlus.Diagnostic imaging.Institute for Quality and Efficiency in Health Care.Understanding tests used to detect bone problems.Johns Hopkins Medicine.Joint aspiration.

National Cancer Institute.Cranium.

National Cancer Institute SEER Training Modules.Axial skeleton (80 bones).

Fisher E, Austin D, Werner HM, et al.Hyoid bone fusion and bone density across the lifespan: prediction of age and sex.Forensic Sci Med Pathol. 2016;12(2):146-157. doi:10.1007/s12024-016-9769-x

Osmosis from Elsevier.Bones of the vertebral column.

National Cancer Institute SEER Training Modules.Appendicular skeleton (126 bones).

American Academy of Orthopaedic Surgeons.Osteoporosis and spinal fractures.

National Cancer Institute SEER Training Modules.Introduction to the skeletal system.

MedlinePlus.Calcium and bones.

National Institute of Arthritis and Musculoskeletal and Skin Diseases.Muscle and bone diseases.

MedlinePlus.Diagnostic imaging.

Institute for Quality and Efficiency in Health Care.Understanding tests used to detect bone problems.

Johns Hopkins Medicine.Joint aspiration.

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