The Human Brain

The Brain Is protected by the skull and three tough membranes known as meninges The spaces between the brain and the skull are filled with cerebrospinal fluid, which acts as a shock absorber. A concussion occurs if the brain is severely shaken and bumps against the skull.

The Brain, cont’d Is a gas guzzler - it comprises 2% of the total body weight, yet uses 25% of the oxygen taken in by the body.

Major Parts of the Brain Cerebrum - largest part of the brain (2/3), which sets humans apart from other animals. –It is divided into left and right hemispheres –The outer layer is called the cerebral cortex and is made of gray matter; the inner layer is white matter –The cerebral cortex carries out sensory functions, as well as memory, learning and thought

Two Hemispheres of Cerebrum (top view)

Cerebrum

Major Parts of the Brain Cerebellum - found at the back of the brain –It is also divided into left and right hemispheres with gray matter on the outside and white matter inside. –It controls all voluntary movements and plays a major role in balance and coordination

Cerebrum Cerebellum

Tumor between meninges and cerebral cortex

Major Parts of the Brain Medulla Oblongata - found at the base of the brain, below the cerebellum –It is made mainly of nerve fibers that connect the spinal cord to other parts of the brain. –It controls many involuntary actions such as breathing, heartbeat, blood flow, and coughing.

Cerebrum Cerebellum Medulla Oblongata

Major Parts of the Brain Corpus Callosum - found in the center of the cerebrum –It is a bundle of nerve fibers in the inner white matter. –It makes a bridge-like connection between the two hemispheres of the cerebrum so that information can pass between the two halves.

Cerebrum Cerebellum Medulla Oblongata Corpus Callosum

(bottom view)

Major Parts of the Brain Pons - found just above the medulla oblongata –It serves as a relay system, connecting the spinal cord, medulla oblongata, cerebellum and cerebrum

Cerebrum Cerebellum Medulla Oblongata Corpus Callosum Pons

Major Parts of the Brain Hypothalamus - found in the center of the cerebrum –It controls body temperature, blood pressure, sleep, and emotions. –It is associated with maintaining homeostasis. –It also plays a role in the functioning of the endocrine system.

Cerebrum Cerebellum Medulla Oblongata Corpus Callosum Pons Hypo- thalamus

Major Parts of the Brain Pituitary Gland - found below the hypothalamus. –It is referred to as the master gland because it controls all the other endocrine glands.

Cerebrum Cerebellum Medulla Oblongata Corpus Callosum Pons Hypo- thalamus Pituitary Gland