• The most important structure in our bodies
• Controls most of human thought and emotion.
• From pain to pleasure it all comes from the brain.
The Brain
Made up of millions of densely packed neurons and actually it feels no pain.
Pain actually stops once something reaches the actual brain.
It was once commonly believed that if you damage brain cells (through drinking, smoking, hitting your head, or just holding your breath for a REALLY long time) they would never grow back
And you would be in big trouble...
There is some research now that points to the contrary.
• So, if you have some brain damage, do not worry...
– Some of our brain functions are flexible and if one part goes out, others will try to compensate and continue to function.
• This is called
• The idea that the brain, when damaged, will attempt to fix itself
• It does this by rerouting connections to avoid damaged areas
• Think of it this way…you are on the way for a romantic date when you find the highway flooded…
– Would you give up??
– No, you would use Mapquest to get new directions
• This is essentially what our brains try to do when damaged.
• Unfortunately, as we age the ability of brain plasticity working decreases.
– Children’s brains are more plastic than adults .
• The lesson here is…???
– if you are going to damage your brain, do it at a very young age.
Every so often someone gets smacked in the head REALLY hard and from that injury we learn about the brain.
The Phineas Gage Story
• Personality and behavior changed after damage to his
Frontal Cortex
What did this tell us?
– different parts of the brain control different aspects of who we are.
An ablation of a rat’s brain
• Removal or destruction of some part of the damaged brain.
– Sometimes done intentionally
• Frontal Lobotomy
– Often used for mentally unstable patients
• Explain what each part of the brain does and where it is located in a sentence on a sheet of paper:
– Medulla Oblongata
– Pons
– Cerebellum
– Thalamus
Ok, that was a piece of cake, now on to the heart of this unit:
The brain can be broken down into three areas:
1. Hindbrain
2. Midbrain
3. Forebrain
• Lowest part of the brain, on top of our spinal cord
• Controls most of our basic biological functions.
• i.e. heartbeat, breathing, ect.
The brain in purple makes up the hindbrain.
Located just above the spinal cord
Involved in control of
• blood pressure
• heart rate
• breathing.
If you get hurt in the MO you should just pack it in
Located just above the medulla
• Relays information to other parts of the brain from the hindbrain
Located at the bottom rear of the brain
• Looks like a mini version of the brain - “little brain”
• Controls balance, coordination, and fine muscle movement
Located in the middle of our brain and is the pathway that connect the hb and fb
• Most important structure in Midbrain is the
Reticular Formation
– controls arousal (no not that type of arousal)
If Destroyed
If stimulated
Wide awake coma
Largest part of the brain
– The most important part of the brain for this class
– What makes us human.
Made up of 3 parts
– Thalamus
– Limbic System
– Cerebral Cortex.
• The operator / switchboard of the brain (relay station)
• Any sensory information that comes into our bodies (sight, hearing, touch
and taste) goes to the Thalamus first from the spinal cord
– Every sense except smell
• It then sends them to other parts of the brain to get processed
Sometimes called the emotional control
center of our brain
Contains Four Parts
Maybe the most important and powerful structure in the brain
– Only the size of a pea
Often referred to as the “pleasure center”
Controls and regulates vital body functions
• Body temperature
• Sexual Arousal
• Hunger
• Thirst
• Endocrine System
• Involved in the processing and storage of memories.
– Not stored here, but it helps put them in the right places
• Handles emotional response to fear and aggression
• Also involved in handling basic emotions like anger and jealousy
• “Master Gland”
• Responsible for the production and distribution of hormones
• The most important part of the brain – “makes us human”
• Made up of densely packed neurons often called “gray matter”
• It is big and full of wrinkles called fissures.
• If I took out your cerebral cortex and ironed it, it would be as big as a large pizza (but would not taste as good)
The Cerebral Cortex is divided into two hemispheres
Lateralization:
•Division of functions between sides of the brain
•right controls left and vice versa
•Often one side is better at certain tasks than
In general =
The other side
Left Hemisphere : language abilities –speaking, reading, writing logical analysis - math
Right Hemisphere : understanding spatial relationships – puzzles, reading maps = recognizing faces and interpreting facial expressions and perceiving and expressing emotion
= likes art and music
Looking at the nose…
Smiling or Frowning???
Between the two hemispheres is a band of nerve fibers called the Corpus
Callosum
Divides the 2 hemispheres.
Helps the two sides communicate with each other
Sometimes this has to be removed
(usually seen in people with epilepsy)
Sometimes a whole side of the brain has to be removed
• hemispherectomy
They are then called Split Brain
Patients
They actually have two separate brains in their heads, and one brain has no idea what the other is doing
However, through plasticity most sbp will find ways to get their hemispheres to communicate
The Brain’s Thinking, Calculating,
Organizing, and Creative Center
REMEMBER!! We actually have 8 lobes!!
Frontal Lobe
Top part of our brain behind our eyes
• Higher mental functions
– thinking, planning, problem solving, decision making, and accessing memories
• Motor Cortex
– sends signals to our body controlling voluntary muscle movements
– Damage this area and you may not be able to move certain parts of your body
• Located in back of the frontal lobes on the top of our head
• Contains Sensory Cortex
– Process information relating to sensations of touch, pressure, temp. and pain
– Damage this area and it may result in an inability to integrate sensations
Homunculus
• Located in the very back of our brain
• Deals with vision.
• Contains Visual Cortex
– interprets messages from our eyes into images we can understand.
• Get hit here and you may “see stars”
• Located just above our ears on both sides of our head
• Contains the Auditory Cortex
• Process sound sensed by our ears
• NOT LATERALIZED – What??
Brain Activity when Hearing, Seeing, and Speaking Words
Broca’s Area
Responsible for transferring thoughts into audible spoken words
• Damage to Broca’s Area is called Broca’s
Aphasia : unable to make movements to talk.
Wernike's Area :
– Responsible for transforming spoken words into thoughts
• Wernike's Aphasia : unable to understand speech
• Any area NOT associated with receiving sensory information or coordinating muscle movements.
– But has some higher level purpose
• We are not so concerned with association areas
– But it does make up most of the cerebral cortex
Specialization and Integration in Language
How do we read and recite??