Anatomy and Function of the Human Brain

Parts of the Brain

A human brain is composed of several parts, each with its own function. The parts of the brain include the cerebrum, the cerebellum, the brain stem, and the pituitary gland. The brain structure is protected by the skull, which is composed of the cranium and the bones of the face. Layers of tissue between the cranium and brain cover the brain anatomy, which is cushioned by a clear liquid called cerebrospinal fluid. The brain anatomy is discussed in more detail in the following sections.

Cerebrum

The cerebrum, which controls thought and voluntary muscle actions, is the largest part of the brain. The cerebrum is divided into two halves, called hemispheres, which are connected by a structure called the corpus callosum. Each hemisphere of the outer layer of the cerebrum, the cortex, is composed of four lobes: the frontal lobe, the parietal lobe, the temporal lobe, and the occipital lobe. The four lobes of the cerebrum are shown in the diagram.

The cerebrum, a part of the brain, is composed of four lobes

The cerebrum controls a wide range of functions, including memory, speech and language, personality, voluntary muscle movements, and interpreting information gathered from the senses. The two hemispheres of the cerebrum control opposite sides of the body; the left hemisphere controls the right side of the body, and the right hemisphere controls the left side of the body. Both hemispheres also control many different functions, but the left hemisphere generally controls speech, language, and mathematics, while the right hemisphere controls more creative pursuits, such as music or art.

One of the functions of the cerebrum is controlling voluntary muscle movement. The frontal lobe of the cerebrum makes a plan and sends a message through the nerves, along the spinal cord, and to the muscles. The cerebrum is also collecting data from the senses to control and adjust the movements of the muscles as needed.

Cerebellum

The cerebellum is located behind the cerebrum and on top of the brain stem. The main cerebellum function is to control coordination, posture, and balance. Although the cerebellum is not responsible for initiating muscle movement, it does organize and coordinate the movements of different muscle groups. The cerebellum also plays a key role in the development of muscle memory, which results from practice and allows people to perform actions such as riding a bike without consciously thinking through each step.

Brain Stem

The brain stem is located at the base of the brain, and it connects the brain to the spinal cord. There are three parts to the brain stem: the midbrain, the pons, and the medulla oblongata. The brain stem controls involuntary muscle movements, and it is responsible for such important life functions as breathing, heart rate, blood pressure, and sleep. A person's heart continues beating and respiration continues, even while the person is asleep, thanks to the work of the brain stem. The brain stem sends signals to the muscles that control breathing, which ensures people continue to inhale and exhale while asleep or unconscious. All messages relayed from the body to the rest of the brain, and vice versa, travel through the brain stem.

Pituitary Gland

The pituitary gland is a small gland located near the center of the brain, behind the nose, that is in charge of producing and releasing hormones. Hormones are chemical messengers that regulate the body's functions. Hormones from the pituitary gland are responsible for physical growth and development, the function of organs such as the kidneys and uterus, and the function of various other glands throughout the body. The pituitary gland is referred to as the "master gland" because of its importance in the body.

Brain Function

The brain functions as the control center of the body. There are two types of cells in the brain: neurons and glial cells. Neurons are the cells responsible for sending and receiving signals, while the glial cells are responsible for providing support and nutrition to the brain and nervous system. The brain's neurons can send and receive communications, both chemical and electrical, within the brain itself. Neurons also receive messages from the five senses and send signals throughout the body, using the brain stem and spinal cord as pathways.

Brain Diagram

The labeled diagram shows the main parts of the brain, including the cerebrum, the cerebellum, the brain stem, and the pituitary gland.

The diagram shows the brain anatomy with labeled parts of the human brain

Lesson Summary

The brain is the control center of the body. It is in charge of everything from thought, memory, and motor skills to emotion, breathing, and the senses. The brain is divided into different parts, each with a specific purpose, and together the brain's structures coordinate the body's vital functions. Neurons are the cells responsible for sending and receiving messages within the brain itself, and between the brain and the rest of the body.

The cerebrum, which controls thought and voluntary muscle actions, is the largest part of the brain. The cerebrum is divided into two halves, called hemispheres. The cerebrum controls a wide range of functions, including memory, speech and language, personality, voluntary muscle movements, and interpreting information gathered from the senses. The cerebellum is located behind the cerebrum and on top of the brain stem. The main cerebellum function is to control coordination, posture, and balance. The brain stem is located at the base of the brain, and it connects the brain to the spinal cord. The brain stem controls involuntary muscle movements, and it is responsible for such important life functions as breathing, heart rate, blood pressure, and sleep. The pituitary gland is a small gland located near the center of the brain, behind the nose, that is in charge of producing and releasing hormones.