- Identify the location and function of the lobes of the brain
- Describe the functions of the midbrain and hindbrain
- Describe the function of the parts of the limbic system
The Central Nervous System: Looking at the Brain as a Whole
The brain is the largest single part of the central nervous system. It is here that most of your sensing, perception, thinking, awareness, emotions, and planning take place. The brain is so important, in fact, that it consumes 20% of the total oxygen and calories we consume even though it is only, on average, about 2% of our overall weight.
Sections of the Brain

Anatomists and neuroscientists often divide the brain into portions based on the location and function of various brain parts. Among the simplest ways to organize the brain is to describe it as having three basic sections:
- the forebrain,
- midbrain, and
- hindbrain.
Another way to organize the brain is to consider:
- the cerebrum, also called the cerebral cortex (the big part),
- the cerebellum (at the back), and
- the brain stem (that connects to the spinal cord).
- the limbic system (an area that is less regionally defined), that’s involved in a variety of functions such as emotion, behavior, memory, and smell.

We’ll start by looking at the big part—the forebrain.
Forebrain Structures
the forebrain

The forebrain is the largest part of the brain. The forebrain contains the cerebral cortex and a number of other structures that lie beneath the cortex (called subcortical structures). The cerebral cortex (also called the cerebrum) is the “newest,” most advanced portion of the brain associated with higher-level processes such as consciousness, thought, emotion, reasoning, language, and memory.
The surface of the brain is characterized by a distinctive pattern of folds or bumps, known as gyri (singular: gyrus), and grooves, known as sulci (singular: sulcus). The most prominent sulcus, known as the longitudinal fissure, is the deep groove that separates the brain into two halves or hemispheres: the left hemisphere and the right hemisphere.
These two hemispheres are connected to one another by a thick bundle of axons called the corpus callosum.