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...

thalamus.

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.

Diagram of Brain: thalamus.

The Thalamus

Diagram of Brain...

The Thalamus

The thalamus is sort of the hub for all sensory information in the brain, sort of like the mailroom in a large office building. Almost all signals that go into or come out of the brain pass through the thalamus. While the thalamus has long been thought to be just a relay station, new research suggests that it is much more complicated. For instance it is in some way related to sleep and wakefulness. Finally, the hypothalamus is the brain part that controls many hormones and regulates other important bodily functions including hunger, thirst, body temperature, and even breast feeding.

Diagram of brain....

diagram-of-brain-frontal-lobe

The Limbic System

The Limbic System
Diagram of Brain..
The brain parts that you do not often see in drawings is found deep within the brain. This brain part is called the limbic system and is involved in emotions and basic drives. Some refer to the limbic system as the lower brain, not only because of where it is located, but because it handles the things about us that are a bit less civilized. For example, the amygdala and nucleus accumbens are important for processing fear and reward. They are also involved in drug, alcohol and other addictions. The cingulate gyrus runs the day to day activities of the body that we do not directly control, like heart rate and blood pressure.

One interesting part of the limbic system that actually resides in the parietal cortex is called the hippocampus. The hippocampus is the brain part that forms memories. You have one of these on each side of the brain. If one hippocampus is injured, say by a stroke, the other one will still allow your brain to make memories. However, if both hippocampi are removed, as was once done through surgery, then you cannot form new memories! This horrible thing happened to a person that underwent surgery to prevent almost continuous, life-ruining seizures. After the surgery, it was found that the person could only remember things that happened prior to the surgery and could not make new memories. Each day, in fact each new moment was a confusing, perpetual question of “How did I get here?” Needless to say this surgery never happens anymore but this terribly unfortunate occurrence demonstrates the importance of the hippocampus in memory.

Diagram of Brain...

Diagram-of-brain-frontal-lobe

DIAGRAM OF BRAIN (Temporal Lobe)

DIAGRAM OF BRAIN

Temporal Lobe - There are two temporal lobes, one on each side of the brain located at about the level of the ears. These lobes allow a person to tell one smell from another and one sound from another. They also help in sorting new information and are believed to be responsible for short-term memory.

Right Lobe - Mainly involved in visual memory (i.e., memory for pictures and faces).

Left Lobe - Mainly involved in verbal memory (i.e., memory for words and names).

Diagram of Brain...