pulley
Sheave without a rope
A pulley is a wheel on an axle or shaft enabling a taut cable or belt passing over the wheel to move and change direction, or transfer power between itself and a shaft.
A pulley may have a groove or grooves between flan ...
) is a term in
anatomy
Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...
. It refers to a grooved structure reminiscent of a pulley's wheel.
Related to joints
Most commonly, trochleae bear the
articular surface
A joint or articulation (or articular surface) is the connection made between bones, ossicles, or other hard structures in the body which link an animal's skeletal system into a functional whole.Saladin, Ken. Anatomy & Physiology. 7th ed. McGraw- ...
of
saddle
A saddle is a supportive structure for a rider of an animal, fastened to an animal's back by a girth. The most common type is equestrian. However, specialized saddles have been created for oxen, camels and other animals.
It is not know ...
and other joints:
*
Trochlea of humerus
In the human arm, the humeral trochlea is the medial portion of the articular surface of the elbow joint which articulates with the trochlear notch on the ulna in the forearm.
Structure
In humans and other apes, it is trochleariform (or trochle ...
(part of the elbow hinge joint with the ulna)
* Trochlea of
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 ...
(forming the knee hinge joint with the patella)
* The trochlea tali in the superior surface of the
body of talus
The talus (; Latin for ankle or ankle bone; : tali), talus bone, astragalus (), or ankle bone is one of the group of foot bones known as the tarsus. The tarsus forms the lower part of the ankle joint. It transmits the entire weight of the body f ...
(part of the ankle hinge joint with the tibia)
*
Trochlear process
In humans and many other primates, the calcaneus (; from the Latin ''calcaneus'' or ''calcaneum'', meaning heel; : calcanei or calcanea) or heel bone is a bone of the tarsus of the foot which constitutes the heel. In some other animals, it is th ...
of the calcaneus
* In quadrupeds, the trochlea of
Radius (bone)
The radius or radial bone (: radii or radiuses) is one of the two large bones of the forearm, the other being the ulna. It extends from the Anatomical terms of location, lateral side of the Elbow-joint, elbow to the thumb side of the wrist and run ...
* The "knuckles" of the
tarsometatarsus
The tarsometatarsus is a bone that is only found in the lower leg of birds and some non-avian dinosaurs. It is formed from the fusion of several bird bones found in other types of animals, and homologous to the mammalian tarsus (ankle bones) a ...
which articulate with the
proximal phalanges
The phalanges (: phalanx ) are digital bones in the hands and feet of most vertebrates. In primates, the thumbs and big toes have two phalanges while the other digits have three phalanges. The phalanges are classed as long bones.
Struct ...
in a bird's foot
Related to muscles
It also can refer to structures which serve as a guide for muscles:
*
Trochlea of superior oblique
{{wiktionary
Trochlea (Latin for pulley) is a term in anatomy. It refers to a grooved structure reminiscent of a pulley's wheel.
Related to joints
Most commonly, trochleae bear the articular surface of saddle and other joints:
* Trochlea of hu ...
(see also
superior oblique muscle
The superior oblique muscle or obliquus oculi superior is a fusiform muscle originating in the upper, medial side of the orbit (anatomy), orbit (i.e. from beside the nose) which abducts, depresses and internally rotates the eye. It is the only e ...
), a mover of the eye which is supplied by the
trochlear nerve
The trochlear nerve (), ( lit. ''pulley-like'' nerve) also known as the fourth cranial nerve, cranial nerve IV, or CN IV, is a cranial nerve that innervates a single muscle - the superior oblique muscle of the eye (which operates through the pu ...