In the

skeleton A skeleton is the structural frame that supports the body of most animals. There are several types of skeletons, including the exoskeleton, which is a rigid outer shell that holds up an organism's shape; the endoskeleton, a rigid internal fra ...

of humans and other animals, a tubercle, tuberosity or apophysis is a protrusion or eminence that serves as an attachment for

skeletal muscle Skeletal muscle (commonly referred to as muscle) is one of the three types of vertebrate muscle tissue, the others being cardiac muscle and smooth muscle. They are part of the somatic nervous system, voluntary muscular system and typically are a ...

s. The muscles attach by

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

s, where the enthesis is the connective tissue between the tendon and

bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, ...

. A ''tuberosity'' is generally a larger

tubercle In anatomy, a tubercle (literally 'small tuber', Latin for 'lump') is any round nodule, small eminence, or warty outgrowth found on external or internal organs of a plant or an animal. In plants A tubercle is generally a wart-like projectio ...

Main tubercles

Humerus

The

humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of three sections. The humeral upper extrem ...

has two tubercles, the

greater tubercle The greater tubercle of the humerus is the outward part the upper end of that bone, adjacent to the large rounded prominence of the humerus head. It provides attachment points for the supraspinatus, infraspinatus, and teres minor muscles, th ...

and the

lesser tubercle The lesser tubercle of the humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius (bone), radius and ulna, and consists of thre ...

. These are situated at the

proximal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position prov ...

end of the bone, that is the end that connects with the

scapula The scapula (: scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either side ...

. The greater/lesser tubercule is located from the top of the

acromion In human anatomy, the acromion (from Greek: ''akros'', "highest", ''ōmos'', "shoulder", : acromia) or summit of the shoulder is a bony process on the scapula (shoulder blade). Together with the coracoid process, it extends laterally over the sh ...

laterally and inferiorly.

Radius

The radius has two, the

radial tuberosity Beneath the neck of the radius, on the medial side, is an eminence, the radial tuberosity; its surface is divided into: * a ''posterior, rough portion'', for the insertion of the tendon of the biceps brachii. * an ''anterior, smooth portion'', on ...

and Lister's tubercle.

Ribs

On a

rib In vertebrate anatomy, ribs () are the long curved bones which form the rib cage, part of the axial skeleton. In most tetrapods, ribs surround the thoracic cavity, enabling the lungs to expand and thus facilitate breathing by expanding the ...

, tubercle is an eminence on the back surface, at the junction between the neck and the body of the rib. It consists of an articular and a non-articular area. The lower and more medial articular area is a small oval surface for articulation with the transverse process of the lower of the two vertebrae which gives attachment to the head. The higher, non-articular area is a rough elevation which gives attachment to the ligament of the tubercle. The tubercle is much more prominent in the upper ribs than in the lower ribs.

Tibia

The most prominent tubercle of the

tibia The tibia (; : tibiae or tibias), also known as the shinbone or shankbone, is the larger, stronger, and anterior (frontal) of the two Leg bones, bones in the leg below the knee in vertebrates (the other being the fibula, behind and to the outsi ...

, a leg bone which is more commonly known as the shinbone or shankbone, is the tibial tuberosity. The tibial tuberosity is located on the tibia's

anterior Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

surface,

distal Standard anatomical terms of location are used to describe unambiguously the anatomy of humans and other animals. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provi ...

to the medial condyle. It creates a bony prominence just below the

patella The patella (: patellae or patellas), also known as the kneecap, is a flat, rounded triangular bone which articulates with the femur (thigh bone) and covers and protects the anterior articular surface of the knee joint. The patella is found in m ...

, and can be easily located with the fingers. It creates an attachment point for the

ligamentum patellae The patellar tendon is the distal portion of the common tendon of the quadriceps femoris, which is continued from the patella to the tibial tuberosity. It is also sometimes called the patellar ligament as it forms a bone to bone connection when ...

, or patellar ligament. Other tubercles of the tibia include the medial intercondylar tubercle, the lateral intercondylar tubercle, and

Gerdy's tubercle Gerdy's tubercle or anterolateral tibial tubercle, is a lateral tubercle of the tibia, located where the iliotibial tract inserts. It was named after French surgeon Pierre Nicolas Gerdy (1797–1856). Gerdy's tubercle is a smooth facet on the lat ...

Femur

A ''trochanter'' is one of up to three tubercles of the

femur The femur (; : femurs or femora ), or thigh bone is the only long bone, bone in the thigh — the region of the lower limb between the hip and the knee. In many quadrupeds, four-legged animals the femur is the upper bone of the hindleg. The Femo ...

: *

Greater trochanter The greater trochanter of the femur is a large, irregular, quadrilateral eminence and a part of the skeletal system. It is directed lateral and medially and slightly posterior. In the adult it is about 2–4 cm lower than the femoral head.Sta ...

Lesser trochanter In human anatomy, the lesser trochanter is a conical, posteromedial, bony projection from the shaft of the femur. It serves as the principal insertion site of the iliopsoas muscle. Structure The lesser trochanter is a conical posteromedial p ...

Third trochanter In human anatomy, the third trochanter is a bony projection occasionally present on the proximal femur near the superior border of the gluteal tuberosity. When present, it is oblong, rounded, or conical in shape and sometimes continuous with the ...

, which is occasionally present

Fifth metatarsal

$Proximal fractures of 5th metatarsal$ In the fifth metatarsal bone, the most proximal part of the bone is termed the "tuberosity", and the secondary

ossification center An ossification center is a point where ossification of the hyaline cartilage begins. The first step in ossification is that the chondrocytes at this point become hypertrophic and arrange themselves in rows. The matrix in which they are imbedd ...

that is normally present thereon in children is termed the "apophysis".

Related diseases and conditions

Fractures

The main type of fracture affecting tubercles is

avulsion fracture An avulsion fracture is a bone fracture which occurs when a fragment of bone tears away from the main mass of bone as a result of physical trauma. This can occur at the ligament by the application of forces external to the body (such as a fall ...

, by pulling the attached tendon.

Apophysitis

''Apophysitis'' is an

inflammation Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...

of a tubercle. It mainly affects growing children, with overuse of the affected tubercle. Examples include: *

Osgood–Schlatter disease Osgood–Schlatter disease (OSD) is inflammation of the patellar ligament at the tibial tuberosity (apophysitis) usually affecting adolescents during growth spurts. It is characterized by a painful bump just below the knee that is worse with act ...

(apophysitis of the tibial tubercle) * Sever's disease (apophysitis of the posterior tubercle of the heel) * Sinding-Larsen and Johansson syndrome (apophysitis of the inferior pole of the

)

Enthesitis

Enthesitis Enthesitis is inflammation of the entheses (singular: enthesis), the sites where tendons, ligaments and joint capsules attach to bones. It is a type of enthesopathy, meaning any pathologic condition of the entheses, with or without inflammati ...

'' is an anatomically close but separate condition, wherein there is inflammation of the

entheses The enthesis (plural entheses) is the connective tissue which attaches tendons or ligaments to a bone. There are two types of entheses: ''Fibrous tissue, fibrous entheses'' and ''fibrocartilaginous entheses''. In a fibrous enthesis, the collage ...

, the sites where tendons or ligaments insert into the bone. It is associated with HLA B27 arthropathies such as

ankylosing spondylitis Ankylosing spondylitis (AS) is a type of arthritis from the disease spectrum of axial spondyloarthritis. It is characterized by long-term inflammation of the joints of the spine, typically where the spine joins the pelvis. With AS, eye and bow ...

psoriatic arthritis Psoriatic arthritis (PsA) is a long-term inflammatory arthritis that may occur in some people affected by the autoimmune disease psoriasis. The classic features of psoriatic arthritis include dactylitis (sausage-like swelling of the fingers ...

, and

reactive arthritis Reactive arthritis, previously known as Reiter's syndrome, is a form of inflammatory arthritis that develops in response to an infection in another part of the body (cross-reactivity). Coming into contact with bacteria and developing an infect ...

References

{{reflist Skeletal system