The notion of peduncle appears in botany , zoology and anatomy . The term comes from the scientific Latin pedunculus , in turn derived from pedis (which translates as "foot" ).
In the field of botany, the peduncle refers to the small branch that supports the fruit , flower or leaf. It can be used, therefore, as a synonym for nipple .
The peduncle is similar to the stem . In addition to guaranteeing support, it allows the sap to reach the flowers . In some rare cases, the peduncle may have certain branches.
For zoology, a peduncle is a body extension that makes certain sedentary animals fix themselves to the ground, according to what is detailed by the Royal Spanish Academy ( RAE ) in its dictionary. The RAE offers the example of the barnacle , a crustacean that clings to coastal rocks through a fleshy peduncle.
In the anatomical field, meanwhile, the notion of peduncle is used to name the stem that links a terminal organ with the rest of the organism . In this sense we can talk about the cerebellar peduncles and the cerebral peduncles .
In the case of the cerebellum, it is attached to the brain stem through three pairs of peduncles through which all the nerve fibers that enter and leave it pass. The groups are divided into lower, middle and upper.
The inferior cerebellar peduncles are responsible for communicating the cerebellum with the medulla oblongata. The middle cerebellar peduncles , meanwhile, communicate the cerebellum with the annular pons, while the superior cerebellar peduncles do the same with the brain .
The middle cerebellar peduncles have a particular organization, since they are divided into three fascicles : the superior one, which arises from the transverse fibers located at the top of the pons; the lower one, which is formed by the fibers at the base of the pons; the deep one, with most of the deep fibers.
The cerebral peduncles , finally, join the pons to the cerebral hemispheres. These cords of white matter are separated from each other by gray matter, more specifically by the so-called interpeduncular fossa.
These two cylinder-shaped masses called cerebral peduncles are found in the upper area of the brain stem, above the annular pons, and end in the two hemispheres of the brain. Through the union of both hemispheres, they are responsible for keeping the brain and midbrain in communication, participating in the reflex control of eye movements and their coordination with the neck and head.
There are three common areas in which the cerebral peduncles originate, and they are the following: the cerebellum , the spinal cord and the cortex. Except for the tectum, we can affirm that the peduncles are entirely in the midbrain. This part includes the crus cerebrum, the pretectum and the tegmentum of the midbrain.
Another name by which cerebral peduncles are known is basis pedunculi . The large ventral bundle of efferent fibers, on the other hand, is called the pes pedunculi or crus cerebrum . There are a large number of nerve pathways found in this precise area of the brain stem .
We must point out that the cerebral peduncle circuit contains the fibers of the motor areas of the brain, which project to the cerebral peduncle as well as more than one thalamic nucleus.
Regarding the structure of the cerebral peduncles, we can say that it consists of nerve fibers, which include those of the corticopontine and corticospinal tracts, which connect the cortex with the pons of Varolio and the spinal cord, respectively.