Welcome!!

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Welcome!!

Warm-Up

On the sheet provided, label the

Neuron correctly… then explain the three types of Neurons on the bottom of the paper

Sensory, Motor, Inter

The Brain

The Brain

• 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

Brain Plasticity

Brain Plasticity

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.

Brain Plasticity

• 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.

Accidents

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

Lesions/Ablations

• Removal or destruction of some part of the damaged brain.

– Sometimes done intentionally

• Frontal Lobotomy

– Often used for mentally unstable patients

Warm-Up

• 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:

Brain Anatomy and Function

Brain Structures

The brain can be broken down into three areas:

1. Hindbrain

2. Midbrain

3. Forebrain

Hindbrain

• 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.

Medulla Oblongata

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

Pons

Located just above the medulla

• Relays information to other parts of the brain from the hindbrain

Cerebellum

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

Cerebellum

Midbrain

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

Forebrain

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.

Thalamus

• 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

The Limbic System

Sometimes called the emotional control

center of our brain

Contains Four Parts

Hypothalamus

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

Rat with an Implanted

Electrode in the pleasure center of Hypothalamus

Hippocampus

• Involved in the processing and storage of memories.

Not stored here, but it helps put them in the right places

Amygdala

• Handles emotional response to fear and aggression

• Also involved in handling basic emotions like anger and jealousy

Pituitary Gland

• “Master Gland”

• Responsible for the production and distribution of hormones

The Cerebral Cortex

• 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.

Corpus Callosum

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

Areas of the

Cerebral Cortex

The Brain’s Thinking, Calculating,

Organizing, and Creative Center

The Cerebral Cortex is made up of four Lobes.

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

Parietal Lobe

• 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

Motor and Sensory Cortexes

Homunculus

Occipital Lobe

• 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”

Temporal Lobe

• 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

Two Other Areas To Know

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

Association Areas

• 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??

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