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
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