The Brain

The Brain Stem The brain stem is the most basic part of the brain that regulates necessary life processes. It is a stalk that connects the spinal cord to the rest of the brain. Within the brain stem is the medulla, the pons, the reticular formation, and the thalamus. The medulla is a low bulge in the brain stem that regulates basic body functions like breathing, body pressure, and heart rate. The pons is just above the medulla and regulates the sleep and dreaming cycle. It connects the brain stem to the cerebellum.

The Brain Stem The reticular formation keeps the brain awake and alert, and acts as a filter to sensory information, only directing attention to important messages. The thalamus directs all incoming and outgoing sensory and motor information, except for olfaction (smell). It also seems to have a role in attention.

The Cerebellum The cerebellum lies at the back of the brain stem, and looked like another smaller brain. It controls the complex actions like walking, tying your shoe, dancing, without you consciously thinking about them. It's also thought to help us keep a series of events in order, such as listening to a sequence of notes in a melody. Research also shows it is involved in habitual responses on cue, like salivating at the sound of a lunch bell.

The Limbic System The limbic system is a diverse collection of structures that wrap around the thalamus. These structures give mammals greatly enhanced capacity for emotions and memory. The limbic system is made up of the hippocampus, the amygdala, hypothalamus,

Hippocampus There are two hippocampi, one on each side of the brain. The hippocampus's job is to help you remember things.

Amygdala The amygdala is involved in emotional processes, especially fear and aggression. It also seems to have a role in helping us to remember situations that are emotional to us.

Pleasure Centers In the brain there are "pleasure centers" that Goode feelings that accompany eating, sex, and other rewarding activities. Chocolate and roller coasters are examples of things that stimulate your pleasure centers.

Hypothalamus The hypothalamus's purpose is to keep the body at homeostasis, which is the tendency to be in a state equilibrium. It analyzes the blood by detecting small changes in body temperature, fluid levels, and nutrients, and then attempts to regulate the imbalances. It controls the pituitary gland, which is the master gland of the body and tells the pituitary gland to release however many hormones are required to reach equilibrium.

Cerebral Cortex The Cerebral Cortex is the largest part of the brain, known for its wrinkled appearance. The folding and wrinkling allow for a higher density of neurons in the brain. It is made up of lobes that each perform certain tasks.

The Frontal Lobes The frontal lobes are known to perform higher mental functions, like planning, deciding, and perceiving. Biological components of temperament and personality are also thought to come from the frontal lobes. The motor cortex is located in the back of the frontal lobe. It controls motor movement for the voluntary muscles. Commands from the motor cortex on one side of the brain control muscles on the other side of the body.

The Parietal Lobes The Parietal Lobes specialize in sensation, and allow us to feel temperature, pain, etc. It contains the somatosensory cortex, which processes sensations of touch, temperature, pain, and pressure, and keeps track of your body position. The parietal lobe also allows us to perceive spatial relationships, allows us to locate sources of speech sounds, and works with the temporal lobe to exact meaning from speech and writing.

The Occipital Lobe The Occipital Lobes are located at the back of the brain, and basically makes sense out of the info that your eyes see. The eyes send information to the visual cortex, which constructs the moving picture of the world.

The Temporal Lobes When you hear a sound it will register in the temporal lobes. The auditory cortex is located inside the temporal lobes, and it helps you understand the sounds. Parts of the temporal lobe help in storing long-term memories, not surprisingly because the hippocampus is right under it.

Throughout the brain there are areas that integrate and understand sensory information, collectively known as the association cortex. Broca's aphasia- loss of speech caused by damage to the brain. Broca's area- area of the brain involved in speech.

Cerebral Dominance Each side of the brain has different functions, and this tendency for each hemisphere to take on different tasks is called cerebral dominance, however both sides work together. For example, while the left side is usually dominant in speech, the right side will add the emotional tone to it. The left side of the brain is analytical and sequential, while the right side of the brain is processes more holistically and spatially.

Specialization of Hemispheres Left Hemisphere Regulates positive emotions Controls muscles used in speech Controls sequence of movements Understands speech/writing Memory of words and numbers Right Hemisphere Regulates negative emotions Responds to simple commands Interprets spatial relationships and visual images Recognizes faces