Understanding the Human Brain

• The human brain is divided into three parts: the forebrain, the midbrain, and the hindbrain.
• The hindbrain includes the upper part of the spinal cord, the brain stem, and the cerebellum.
• The cerebellum coordinates movement and is involved in learned rote movements.
• The uppermost part of the brainstem is the midbrain, which controls some reflex actions and is part of the circuit involved in the control of eye movements and other voluntary movements.
• The forebrain is the largest and most highly developed part of the human brain: it consists primarily of the cerebrum and the structures hidden beneath it (see "The Inner Brain").
• When people see pictures of the brain it is usually the cerebrum that they notice.
• The cerebrum sits at the topmost part of the brain and is the source of intellectual activities.
• The cortex is the vital layer of tissue that coats the surface of the cerebrum and the cerebellum and is the source of most of the actual information processing in the brain.
• The cerebrum is divided into two halves (hemispheres) by a deep fissure.
• The cortex is gray because nerves in this area lack the insulation that makes most other parts of the brain appear to be white.
• The folds in the brain add to its surface area and therefore increase the amount of gray matter and the quantity of information that can be processed.
• Each cerebral hemisphere can be divided into sections, or lobes, each of which specializes in different functions.

The frontal lobes are located at the front of the brain and are responsible for many important functions, including thinking, planning, and problem solving. The frontal lobes are also involved in regulating our emotions.

The left frontal lobe is more involved in emotional processing than the right frontal lobe. Damage to the left frontal lobe can cause problems with decision making, planning, and problem solving.

The right frontal lobe is more involved in logical thinking and problem solving. Damage to the right frontal lobe can lead to problems with decision making, planning, and problem solving.

The frontal lobes are also involved in our sense of self. Damage to the frontal lobes can lead to a loss of self-awareness and an inability to understand and control one's own emotions.

The frontal lobes are important in our ability to think abstractly and solve problems. Damage to the frontal lobes can lead to problems with thinking abstractly and solving problems.

The frontal lobes are also involved in our ability to plan and organize our thoughts. Damage to the frontal lobes can lead to problems with planning and organizing our thoughts.

• The frontal lobes are located behind the forehead and are involved in short-term storage, reasoned arguments, and imagining the future.
• The motor cortex is located in the rearmost portion of each frontal lobe and helps plan, control, and execute voluntary movement.
• The parietal lobes are located behind the frontal lobes and are responsible for enjoying food, reading and arithmetic, and other functions.
• The somatosensory cortex is located in the forward parts of the frontal lobes and receives information about temperature, taste, touch, and movement from the rest of the body.
• The occipital lobes process images from the eyes and link that information with images stored in memory.
• The temporal lobes are located in front of the visual areas and are responsible for forming and retrieving memories, including those associated with music.
• The inner brain contains structures that determine our emotional state and modify our perceptions and responses.
• The neuron is the primary functional unit in the brain and consists of a cell body, dendrites, and the axon.

The frontal lobe is located behind the forehead and is responsible for short-term storage, reasoned arguments, and imagining the future. The motor cortex is located in the rearmost portion of each frontal lobe and helps plan, control, and execute voluntary movement. The parietal lobes are located behind the frontal lobes and are responsible for enjoying food, reading and arithmetic, and other functions. The somatosensory cortex is located in the forward parts of the frontal lobes and receives information about temperature, taste, touch, and movement from the rest of the body. The occipital lobes process images from the eyes and link that information with images stored in memory. The temporal lobes are located in front of the visual areas and are responsible for forming and retrieving memories, including those associated with music. The inner brain contains structures that determine our emotional state and modify our perceptions and responses. The neuron is the primary functional unit in the brain and consists of a cell body, dendrites, and the axon.

• Neurons are cells in the brain that communicate with other cells.
• The neuron has an extended cell body, called a nucleus, and many dendrites that receive messages from other cells.
• Signals pass from the dendrites through the cell body and may travel away from the cell body down an axon to another neuron, a muscle cell, or cells in some other organ.
• The neuron is usually surrounded by many support cells.
• Some types of cells wrap around the axon to form an insulating myelin sheath.
• Myelin is a fatty molecule which provides insulation for the axon and helps nerve signals travel faster and farther.
• Axons may be very short, such as those that carry signals from one cell in the cortex to another cell less than a hair’s width away. Or axons may be very long, such as those that carry messages from the brain all the way down the spinal cord.
• The synapse is the place where a signal passes from the neuron to another cell.
• When the signal reaches the end of the axon it stimulates the release of tiny vesicles.
• These structures release chemicals known as neurotransmitters into the synapse.
• The neurotransmitters cross the synapse and attach to receptors on the neighboring cell.
• These receptors can change the properties of the receiving cell.
• If the receiving cell is also a neuron, the signal can continue the transmission to the next cell.