Some are psychological, i.e. the fear response causes them to faint, or physical, such as the fainting that occurs when we over exert ourselves. Vagal nerve fainting (also known as vasovagal syncope) is quite simply any loss of consciousness caused by the vagus nerve. The vagus nerve runs directly from the brain stem, in front of the ears and down the neck towards the chest and abdomen. It branches off in several places to provide communication with the brain to a number of organs, such as the heart and the stomach.
The floor of the third ventricle is formed by a number of structures including the hypothalamus, subthalamus, mammilary bodies, infundibulum (pituitary stalk), and the tectum of the midbrain. The lateral walls of the third ventricle are formed by the walls of the left and right thalamus.
The lateral ventricles are the largest of the four ventricles. The ventricles are chambers in the core of the brain and brainstem that are filled with a watery substance called cerebrospinal fluid (CSF).The ventricles are the red structures in the picture below.he sketch below is the inside of the right half of the brain with the head facing to the left. The corpus callosum can be seen in the center of the brain. The corpus callosum is a communication link between the left and right hemispheres of the brain that forms the roof of the lateral ventricles.