DIAGRAM OF BRAIN VIDEO

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SKIN SENSATION











SKIN SENSATION
Diagram of Brain
If something lands on my left hand, this information will be transmitted to the right side of my brain. It goes to the area of the brain next to the area that deals with movement. The tactile area of the brain deals with physical sensation. Movement and feeling are closely related, so it makes sense that they are next to each other in the brain. Because movement and tactile areas are located close to each other, it is not uncommon for people with a brain injuries to lose both movement and feeling in parts of their body. Remember--tactile information from the left side of the body goes to the right brain, just like movement and vision.
diagram of brain.
Diagram of brain: hearing-and-language

MOVEMENT

MOVEMENT
Diagram of Brain
The area of the brain that controls movement is in a very narrow strip that goes from near the top of the head right down along where your ear is located. It's called the motor strip. If I injure that area, I'll have problems controlling half of my body. If I have a stroke in the left hemisphere of my brain, the right side of the body will stop working. If I have an injury to my right hemisphere in this area, the left side of my body stops working (remember, we have two brains). This is why one half of the face may droop when a person has had a stroke.
Diagram of Brain

GETTING INFORMATION IN AND OUT OF THE BRAIN

GETTING INFORMATION IN AND OUT OF THE BRAIN

How does information come into the brain? A lot of information comes in through the spinal cord at the base of the brain. Think of a spinal cord as a thick phone cable with thousands of phone lines. If you cut that spinal cord, you won't be able to move or feel anything in your body. Information goes OUT from the brain to make body parts (arms and legs) do their job. There is also a great deal of INCOMING information (hot, cold, pain, joint sensation, etc.). Vision and hearing do not go through the spinal cord but go directly into the brain. That’s why people can be completely paralyzed (unable to move their arms and legs) but still see and hear with no problems.

Information enters from the spinal cord and comes up the middle of the brain. It branches out like a tree and goes to the surface of the brain. The surface of the brain is gray due to the color of the cell bodies (that's why it's called the gray matter). The wires or axons have a coating on them that's colored white (called white matter).

IS THE BRAIN ONE BIG COMPUTER?

IS THE BRAIN ONE BIG COMPUTER?
Diagram of Brain
Is the brain like a big phone system or is it one big computer with ON or OFF states ? Neither of the above is correct.

Let's look at the brain as an orchestra. In an orchestra, you have different musical sections. There is a percussion section, a string section, a woodwind section, and so on. Each has its own job to do and must work closely with the other sections. When playing music, each section waits for the conductor. The conductor raises a baton and all the members of the orchestra begin playing at the same time playing on the same note. If the drum section hasn't been practicing, they don't play as well as the rest of the orchestra. The overall sound of the music seems "off" or plays poorly at certain times. This is a better model of how the brain works. We used to think of the brain as a big computer, but it's really like millions of little computers all working together.
Diagram of Brain

THE BRAIN: AN ELECTRICAL AND CHEMICAL MACHINE

THE BRAIN: AN ELECTRICAL AND CHEMICAL MACHINE
Diagram of Brain
Let's start looking at the building blocks of the brain. As previously stated, the brain consists of about 100 billion cells. Most of these cells are called neurons. A neuron is basically an on/off switch just like the one you use to control the lights in your home. It is either in a resting state (off) or it is shooting an electrical impulse down a wire (on). It has a cell body, a long little wire (the "wire" is called an axon), and at the very end it has a little part that shoots out a chemical. This chemical goes across a gap (synapse) where it triggers another neuron to send a message. There are a lot of these neurons sending messages down a wire (axon). By the way, each of these billions of axons is generating a small amount of electrical charge; this total power has been estimated to equal a 60 watt bulb. Doctors have learned that measuring this electrical activity can tell how the brain is working. A device that measures electrical activity in the brain is called an EEG (electroencephalograph).

Each of the billions of neurons "spit out" chemicals that trigger other neurons. Different neurons use different types of chemicals. These chemicals are called "transmitters" and are given names like epinephrine, norepinephrine, or dopamine.
Diagram of Brain

DIAGRAM OF BRAIN


DIAGRAM OF BRAIN

Dimensions and Sizes

  • Average dimensions of the adult brain: Width = 140 mm/5.5 in, Length = 167 mm/6.5 in, Height = 93 mm/3.6 in.
  • How much does human brain weigh? At birth our brains weigh and average of 350-400g (about 4/5 lbs), as adults the brain averages 1300-1400g (about 3 lbs).
  • If Stretched out the cerebral cortex would be 0.23 sq. m(2.5sq.ft), the area of a night table.
  • Total surface area of the cerebral cortex is 2,500 cm2 or 2.69 sq.ft.
  • Composition

  • The composition of the brain = 77-78% water, 10-12% lipids, 8% protein, 1% carbs, 2% soluble organics, 1% inorganic salt.
  • The breakdown of intracranial contents by volume (1,700 ml, 100%): brain = 1,400 ml (80%); blood = 150 ml (10%); cerebrospinal fluid = 150 ml (10%).
  • The cerebellum contains half of all the neurons in the brain but comprises only 10% of the brain.
  • The cerebral cortex is about 85% of the brain.
  • Percentage of total cerebral cortex volume = frontal lobe 41%, temporal lobe 22%, parietal lobe 19%, occipital lobe 18%.
  • There are about 100 billion neurons in the human brain, the same number of stars in our galaxy.
  • The left hemisphere of the brain has 186 million more neurons than the right hemisphere.
  • 750-1000ml of blood flow through the brain every minute or about 3 full soda cans.
  • In that minute the brain will consume 46cm3 (1/5 cups) of oxygen from that blood.
  • Of that oxygen consumed, 6% will be used by the brain's white matter and 94% by the grey matter.
  • Times

  • The brain can stay alive for 4 to 6 minutes without oxygen. After that cells begin die.
  • The slowest speed at which information travels between neurons is 416 km/h or 260 mph, thats as "slow" as todays supercar's top speed (the Bugatti EB 16.4 Veyron clocked at 253 mph).
  • 10 seconds is the amount of time until unconsciousness after the loss of blood supply to the brain.
  • Time until reflex loss after loss of blood supply to the brain, 40-110 seconds.
  • During early pregnancy the rate of neuron growth is 250,000 neurons a minute.
  • Other Fun Facts About The Human Brain

  • Results from cognitive tests show 30% of 80-year-olds perform as well as young adults.
  • Your brain is about 2% of your total body weight but uses 20% of your body's energy.
  • The energy used by the brain is enough to light a 25 watt bulb.
  • More electrical impulses are generated in one day by a single human brain than by all the telephones in the world.
  • How much does human brain think? 70,000 is the number of thoughts that it is estimated the human brain produces on an average day.
  • After age 30, the brain shrinks a quarter of a percent (0.25%) in mass each year.
  • Albert Einsteins brain weighed 1,230 grams (2.71 lbs), significantly less then the human average of 1,300g to 1,400g (3 lbs).
  • Each year Americans consume 50 billion aspirin tablets or 15.5 million tons.
  • 89.06 is the percentage of people who report normally writing with their right hand, 10.6% with their left and 0.34% with either hand.
Diagram of Brain

Diagram of Brain








DIAGRAM OF BRAIN

Brainstem - The lower extension of the brain where it connects to the spinal cord. Neurological functions located in the brainstem include those necessary for survival (breathing, digestion, heart rate, blood pressure) and for arousal (being awake and alert).

Most of the cranial nerves come from the brainstem. The brainstem is the pathway for all fiber tracts passing up and down from peripheral nerves and spinal cord to the highest parts of the brain.
Diagram of brain...

FRONTAL LOBES--Planning, Organizing, Controlling










FRONTAL LOBES--Planning, Organizing, Controlling
Diagram of Brain
The biggest and most advanced part of the brain is the frontal lobe. (It's called the frontal lobe because it's in the front part of brain.) One job of the frontal lobe is planning. You have probably heard of "frontal lobotomies." At the turn of the century, this surgery was done on people who were very violent or who were in a psychiatric hospital because they were very agitated. Doctors used surgery to damage this area of the brain. Following this surgery, people became very passive and less violent. At first, scientists saw this as a great thing. Neurosurgery could stop behavioral problems such as violence. The problem was that the patients stopped doing a lot of other things. They didn't take care of themselves and they stopped many activities of daily living. They basically sat there. In head injury, individuals with frontal lobe impairment seem to lack motivation and have difficulty doing any task that requires multiple steps (e.g., fixing a car or planning a meal). They have problems with planning.

The frontal lobe is also involved in organizing. For a lot of activities, we need to do step A, then step B, then step C. We have to do things in order. That's what the frontal lobes help us do. When the frontal lobe is injured, there is a breakdown in the ability to sequence and organize. A common example is people who cook and leave out a step in the sequence. They forget to add an important ingredient or they don't turn the stove off. I've met a lot of patients who've burned or melted a lot of pans.

Additionally, the frontal lobes also play a very important role in controlling emotions. Deep in the middle of the brain are sections that control emotions. They're very primitive emotions that deal with hunger, aggression, and sexual drive. These areas send messages to other parts of the brain to DO SOMETHING. If you're mad, hit something or someone. If you're hungry, grab something and eat it. The frontal lobes "manage" emotions. In general, the frontal lobe has a NO or STOP function. If your emotions tell you to punch your boss, it's the frontal lobes that say "STOP or you are going to lose your job." People have often said to me "a little thing will set me off and I'm really mad." The frontal lobes failed to stop or turn off the emotional system.

On the other hand, we have talked about how the frontal lobes plan activities. The frontal lobes may fail to plan for some types of emotion. For example, sexual interest involves some level of planning or preparation. Without this planning, there is a lack of sexual interest. A lack of planning can also affect the expression of anger. I've had some family members say "You know, the head injury actually improved him, he's not such a hot-head anymore." If you listen very carefully, you're also going to hear "he's not as motivated anymore." Remember, the frontal lobe plans activities as well as controls emotions.
Diagram of Brain

UNDERSTANDING HOW THE BRAIN WORKS














UNDERSTANDING HOW THE BRAIN WORKS

The human brain weighs only three pounds and is estimated to have more or less 100 billion cells. It is hard to get a handle on a number that large (or connections that small). Let's try to get an understanding of this complexity by comparing it with something humans have created--the entire phone system for the planet earth .
If we took all the phones in the world and all the wires (there are over four billion people on the planet), the number of connections and the trillions of messages per day would NOT equal the complexity or activity of a single human brain.
Now let's take a "small problem"--break every phone in Los Angeles and cut every wire in the state. How long would it take for the entire state (about 16 million people) to get phone service back? A week, a month, or several years? If you guessed several years, you are now beginning to see the complexity of recovering from a head injury. In the example LA residents would be without phone service while the rest of the world had phone service that worked fine. This is also true with people who have a head injury. Some parts of the brain will work fine while others are in need of repair or are slowly being reconnected.