Understanding The Brain

WARNING!!!

THIS IS ABOUT TO GET EXTREMELY COMPLEX!

The brain weighs three and a half pounds and has over ten billion cells.  Pretty crazy right!

We have three layers to our brain, these are:

The Central Core:  Structures deep within our brain and is involved in the processes of breathing, digestion and heart rate.

The Limbic System:  This is located within the central core and plays a role in the emotional & sexual behaviour.

AND

The Cerebral Cortex:  This is the outer layer of the brain which allows us to plan, reason and make decisions.

Within the central core are five structures:

THE MEDULLA

This is located just above the spinal cord and is responsible for our reflexes, heart rate, respiration and digestion.  It is considered to be the cross over point allowing the transition from the spinal cord to the brain stem.  

This is why the left side controls the right side!

THE PONS

This is situated just above the Medulla and acts like a bridge for nerve fibres to connect to the cerebellum.  This controls our motor control and sensory analysis nuclei found in the pons which wrap around the base of the cerebellum.  Our Medulla and Pons contain our reticular activating system (RAS).  This is a network of neurons involved in arousal, attention and regulated sleep.  

THALAMUS

This is found deep within the brain.  It is our relay station and what I mean by that is it receives sensory information from our nervous system and is responsible for transmitting information to other parts of the brain.  All our sensory information apart from smell passes through here before entering our cerebral cortex.

CEREBELLUM

This large structure is known as our 'little brain'.  It is situated behind the Medulla and Pons and damage to this structure can have a significant affect on our motor responses, balance and coordination.  It integrates sensory information with information about muscle movement.

The Limbic System

The consists of three structures; our amygdala, hippocampus and hypothalamus.  The limbic system allows our body to keep a thermostat, scientifically known as homeostasis.  It also regulates our blood sugar level, body temperature and blood pressure.

AMYGDALA

This is located deep within our temporal lobe and controls our rage.  This structure receives important sensory information such as smell, sight and sound.  

HIPPOCAMPUS

This is the largest structure in the limbic system and helps with our memory skills, specifically our long term memory.

HYPOTHALAMUS

This is located below the thalamus and is approximately the size of a pea.  It is the most IMPORTANT part of the limbic system.  It regulates our hormonal system by controlling the pituitary gland which is attached to the base of the hypothalamus.

The Cerebral Cortex

This is one eight of an inch thick and contains billions of neurons.  This is responsible for the opposite sides of the body.  The hemispheres are connected by a band of nerves called the corpus collosum.  This transfers the information from one side of the brain to the other.  Our cerebral hemispheres occupy our general sensory input, visual input, and interpretation

FISSURES

We have three fissures that help divide the brain into four regions.

-  Longitudinal - separates the two hemispheres.
-  Central - runs along the top of the brain and separates into front and back.
-  Lateral - runs along the side of the brain and divides the hemispheres into top and bottom.

REGIONS OF THE BRAIN

Frontal Lobe - located at the front of the brain directly in front of the central fissure (our emotions, personality & problem solving skills operate here).

Parietal Lobe - located behind the central fissure & above the lateral fissure at the top of the brain (controls our sensory information).

Temporal Lobe - side of each hemisphere below below lateral fissure (controls our speech).

Occipital Lobe - located at the back of the brain (controls our vision).