Question

Third ventricle of brain is also known as
A) Metacoel
B) Rhinocoel
C) Paracoel
D) Diacoel

Answer 1

Hint:The ventricles of the brain are a communicating network of cavities filled with a clear, colorless fluid that is cerebrospinal fluid (CSF). It is located within the brain parenchyma. It is 4 in number and allows the movement of CSF throughout the brain.

Complete answer:
Brain is called as the complex structure comprises various parts mainly cerebrum, cerebellum and medulla. Internally there is a presence of 4 interconnected ventricles present inside the brain that is lined with the choroid plexus responsible for the production and secretion of CSF. These 4 ventricles are:
The first and second ventricles are present in the cerebral hemisphere and are laterally present. These are known as paracoel.
The third ventricle of the brain is present in the diencephalon of the forebrain region between the right and left thalamus and thus it is also known as diocoel.
The fourth ventricle is present between the brainstem and the cerebellum and is called metacoel.

Additional information:The ventricles are guarded by several foramina that act as channels connecting all the 4 ventricles. There are basically 4 foramina present. These are:
The interventricular foramina known as foramen of Monro. It is present between the lateral 2 ventricles and the third ventricle.
The cerebral aqueduct is known as foramen of Sylvius connecting the third ventricle to the fourth ventricle.
The median aperture is known as foramen Magendie connecting the fourth ventricle to subarachnoid space via the cisterna magna.
The right and left lateral aperture is known as foramen Lushka connecting the fourth ventricle to the subarachnoid space via the cistern of great cerebral vein.

Hence the correct option is D i.e. Diacoel.

Note:These 4 foramina are present throughout the ventricles help in the flow of CSF throughout the central nervous system. In rabbits, Rhinocoel is the ventricle of the olfactory lobe in the brain that are hollow in nature. It is the first ventricle of the brain.