Nervous System Physiology

The bony structure in the head of most vertebrates (in particular, craniates) that supports the structures of the face is called as the skull. It forms a protective cavity for the brain. The cranium and the mandible are the two parts of the skull. The skull forms the anterior most portion of the skeleton and is a product of encephalization, housing the brain, many sensory structures (eyes, ears, nasal cavity) and the feeding system.

The brain is the control center of the body. It consists of three main components- forebrain, brainstem, hindbrain. The brain is important in the human body, because it allows a person to think, feel and store memories, and it controls and coordinates the body's actions and reactions. The brain is an incredibly complex organ composed of many parts, including the cranium, the cerebrum, the brain stem and the cerebellum.

• A deep furrow divides the cerebrum into two halves, known as the left and right hemispheres. 
• The two hemispheres look mostly symmetrical yet it has been shown that each side functions slightly different than the other. 
• Sometimes, the right hemisphere is associated with creativity and the left hemispheres are associated with logic abilities. 
• The corpus callosum is a bundle of axons that connects these two hemispheres. 

• The thalamus is a part of the human brain situated between the cerebral cortex and midbrain. It has a number of functions. 
• Some of its functions include the relaying of the sensory and motor functions to the cerebral cortex. It processes the sensory information as well as relay it. 

• Underneath the limbic system in the brain stem. This structure is responsible for life functions such as breathing, blood pressure, etc.
•  Scientists say that this is the "simplest" part of human brains because animals' entire brains (such as reptiles) resemble our brain stem. 
• The brain stem is made of the midbrain, pons, and medulla. 

• 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. 

• 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.

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.