The cranium

The brain is protected by a bony covering called the cranium (with the bones of the face, they together make up the skull). Inside the cranium, the brain is surrounded by an area of tissue called the meninges. The meninges is made up of 3 layers:

• Pia mater – this is the layer closest to the surface of the brain
• Arachnoid membrane – this is the middle layer of tissue
• Dura mater – this is the outer-most layer closest to the bone

 

The cerebrum – the front of the brain

The largest part of the brain is located in the front. It is called the cerebrum. The cerebrum is responsible for:

• Problem solving
• Learning
• Reasoning
• Judgment
• Hearing
• Vision
• Movement
• Body temperature
• Emotions
• Touch

The cerebrum is separated into 2 parts: the right and the left hemispheres. These are both connected together within their bottom areas, and also have a deep groove between them. In general, the right hemisphere controls the left side of the body, and the left hemisphere controls the right. The right side is involved with creativity, musical and artistic abilities. The left side is important for logic, math and rational thinking.

Further still, the hemispheres of the cerebrum are divided into lobes, or broad regions of the brain. Each lobe is responsible for a variety of bodily functions:

• Frontal lobes are involved with speech, personality, and motor development
• Temporal lobes are responsible for language, memory,  and speech functions
• Parietal lobes are associated with physical sensations
• Occipital lobes are the primary centers for vision

In appearance, the surface of the cerebrum looks wrinkled and is made up of deep grooves (called sulci) and bumps or folds (called gyri). The outer part of the cerebrum is called gray matter and contains nerve cells. The inner part is called white matter and contains connections of neurons.

The brainstem – the middle of the brain

The brainstem is located directly in front of the cerebellum. This area can be likened to the hard-drive of a computer. It is also the main area of the brain which allows for messages  to be passed between the body and the brain. The cerebrum, the cerebellum, and the spinal cord are also all connected to the brainstem.

The brainstem itself has three main parts called the midbrain, the pons, and the medulla oblongata.

The brainstem controls vital functions of the body, including:

• Breathing
• Swallowing
• Cardiac function
• Movement of the eyes and mouth
• Involuntary muscle movements
• Hunger
• Relaying sensory messages (pain, heat, noise, etc.)

The cerebellum – the back of the brain

Behind the cerebrum at the back of the head is an area called the cerebellum. Physically, it is a smaller area of the brain, but it contains more nerve cells than both hemispheres combined. The primary function of the cerebellum is as a movement control center, responsible for:

• Voluntary muscle movements
• Fine motor skills
• Maintaining balance, posture, and equilibrium

Unlike the cerebrum, the left cerebellum controls the left side of the body, and the right cerebellum controls the right side of the body.

 

Other Important Parts Of The Brain

 

The Ventricular system

Contrary to popular opinion, the brain is not a solid organ. There are many fluid-filled cavities within it called ventricles. These ventricles are important in providing nourishment to the brain. The ventricular system produces and processes cerebrospinal fluid which is a clear, watery substance that flows around the brain to help protect it.

 

Cranial nerves

The brain also contains 12 pairs of cranial nerves each responsible for specific functions in the body:

• Olfactory nerve – smell

• Optic nerve – vision

• Hypoglossal – tongue movement

• Accessory – neck and shoulder muscles

• Glossopharyngeal – taste, swallowing

• Abducens – eye movements

• Trochlear – eye movements

• Vestibulocochlear – hearing, balance

• Vagus – swallowing, taste

• Trigeminal – facial sensations, chewing

• Oculomotor – eye movements, eyelid opening

• Facial – taste, facial expressions

Pituitary gland

The pituitary gland is located in the center of the brain and is about the size of a pea. It is often called the “master gland” because it is responsible for many functions, including the production of hormones for the thyroid and adrenal glands, as well as the hormones responsible for normal growth and sexual maturation.