Nervous System Physiology

• The brain has three divisions, i.e., forebrain, midbrain, and hindbrain. The forebrain consists of the cerebrum, thalamus, and hypothalamus. 
• The midbrain has decreased in size during vertebrate evolution and the forebrain has gradually acquired much of its function, while the hindbrain consists of medulla, cerebellum and the pons. 

Three layers of protective tissue that surround the brain and spinal cord are called meninges. These three layers are dura mater, arachnoid mater, and pia mater.

• Superior colliculi is a part of the midbrain. There are paired structures that are responsible for controlling eye movement. 
• There are one colliculi in each side of the brain which is responsible for creating a map of the visible area. 
• The fixation of the vision and the tracking of any object is controlled and regulated by this region of the brain. 

The meninges from the outermost to the innermost layer are the dura mater, the arachnoid mater, and the pia mater. This sequence provides protection to the brain.

The lateral ventricles are connected to the third ventricle via the interventricular foramen (foramen of Monro). Since this is not listed in the options, 'None of the above' is the correct choice.

The pons varolii is a major structure in the brainstem that acts as a bridge, containing neural tracts that connect the cerebrum with the cerebellum. It coordinates communication between these regions to help regulate motor control and balance.

The ventricles of the brain are lined by a specialized epithelial tissue called ependyma, which is involved in the production and circulation of cerebrospinal fluid.

Different regions of the brain are responsible for specific functions. For example, the medulla oblongata is responsible for regulating heart beat and many other involuntary actions. The Broca region is responsible for speech and language etc. So, the correct answer is option A.

• The limbic system often referred to as the "emotional brain", is found buried within the cerebrum. 
• Like the cerebellum, evolutionarily the structure is rather old. This system contains the thalamus, hypothalamus, amygdala, and hippocampus. 

The cerebrum or cortex is the largest part of the human brain, associated with higher brain function such as thought and action. The cerebral cortex is divided into four sections, called "lobes". The frontal lobe, parietal lobe, occipital lobe, and temporal lobe. 

• Hippocampus is the portion of the cerebral hemispheres in basal medial part of the temporal lobe. 
• This part of the brain is important for learning and memory, for converting short term memory to more permanent memory and for recalling spatial relationships in the world about us. 

• Amygdala is a part of the telencephalon, located in the temporal lobe, involved in memory, emotion, and fear. 
• The amygdala is both large and just beneath the surface of the front, medial part of the temporal lobe where it causes the bulge on the surface called the uncus. 
• This is a component of the limbic system. 

• Pons is a part of the metencephalon in the hindbrain. It is involved in motor control and sensory analysis. 
• For example, information from the ear first enters the brain in the pons. It has parts that are important for the level of consciousness and for sleep. 
• Some structures within the pons are linked to the cerebellum, thus are involved in movement. 

The meninges are the layers that are closely present around the brain. The dura mater is an outermost tough and fibrous layer. It closely lines the cranium. It is followed by the arachnoid mater that forms the middle meninx. The piamater is the innermost meninx which adheres closely to the surface of the brain. It is highly vascular due to the rich supply of the blood vessels. So, it provides oxygen and nutrients to the cells of the brain.