Thursday, August 25, 2011

What's in a brain?

In later posts I will be discussing brain damage and diseases. However, a basic understanding of brain structures and function is needed first. This post is meant to be a very basic version of brain anatomy that is easy to follow for people who are just learning about how the brain works.

The big three
A huamn brain has three main parts. The cerebrum, the cerebellum, and the brain stem.

The area that separates us from moose is called the cerebrum. Moose have a cerebrum, but it's about half the size and theoretically provides only about half the functioning ability. The cerebrum is the largest part of the human brain, and is also the outer layer of the brain. It has two parts: a right and a left hemisphere. (Pictured below is the left hemisphere.) The cerebrum is responsible for higher level functioning like  interpreting touch, vision, hearing, language, reasoning, emotions, learning, and fine control of movement.

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The cerebellum is responsible for balance, coordination, and posture. It is also the area of the brain where we keep our muscle memories. The cerebellum is what keeps me upright while downhill skiing. It also helps me remember how to play Blackbird on the guitar, and how to tie my shoes.

The brain stem is the part of the brain that connects the cerebellum and cerebrum to the spinal cord. It controls automatic functions like breathing, heart rate, swallowing, body temperature, vomiting, digestion, etc. Damage here is usually fatal.

Left brain vs. right brain

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The left and right hemispheres of the brain are connected by an information highway called the corpus callosum. The two hemispheres have a reputation for operating individually, but they really act in concert. This myth of independence may come from the fact that each hemisphere generally controls the movement on the opposite side of the body. For example, a stroke in the left hemisphere of the brain may result in weakness in the right arm.

The left hemisphere of the brain generally controls arithmetic, and language skills such as comprehension, writing, grammar and syntax. The right hemisphere of the brain generally controls artistic abilities, and recognition of non-verbal communication skills such as pitch, tone, and facial features. To have a meaningful conversation with someone, you must have both brain hemispheres working together to understand the words being said, and the manner in which those words are delivered.

Inside the brain

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Inside the brain are a series of structures that help determine emotional states, modify perceptions based on those states, and intiate involuntary movements.
The thalamus is an information relay center for the brain. It helps decide what to focus on, alerts us to pain, and starts memory formation.

The hypothalamus wakes us up in the morning, gives us adrenaline during a job interview, and regulates emotions.

The amygdala is the home of the "fight or flight" response. It is also involved in regulating emotions like anger and pleasure.

The olfactory bulb processes smell.

The thalamus, hypothalamus, amygdala and olfactory bulb all connect to the hippocampus. The hippocampus is a memory filing system. It stores long-term memories in the cerebrum, and then retrieves those memories later. In the above diagram, it's easy to see that memory is highly linked to emotions, attention, and smell.

Be good to your brain.
What's good for the...

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is good for the...
 
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Easy steps to take to keep your brain healthy and active...
(Below info borrowed from Alzheimer's Resource of Alaska)
  • Exercise - Walk or exercise moderately for at least 30 minutes per day.
  • Maintain a healthy, well-balanced diet - Eat brain-healthy foods and control portion sizes. A low-fat diet including vegetables, fruits, nuts and fish is recommended for brain health.
  • Keep your brain active - stimulate your brain with learning new things, or activities like crossword-puzzles and reading.
  • Socialize - you can even socialize while exercising.
  • Reduce stress and anxiety - you know what works best for you, but you may want to consult with a counselor.
  • Stop smoking.
  • Talk to your doctor if you have concerns about weight, cholesterol, blood pressure, or memory.

Sunday, August 21, 2011

Moose Brains

Those who know me may have heard rumors of moose brains...


Retrieved from: http://www.animalpictures.tk/wp-content/uploads/pictures/moose-843.jpg
The rumors are true!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

This semester I am studying Biological Bases of Behavior. My assigned topic is anatomy of the nervous system. However, studying anatomy in 2D is futile. So, my hunting hook-ups are bringing me a moose brain. Moose hunting season opened on August 20th, 2011. My moose brain will be delivered August 21st, 2011. Stay tuned for pictures and anatomical insights...

You may wonder if moose brains are anything like human brains. I wonder that too. However, Dr. Jill assures me that mammalian brains are pretty similar. Dr. Jill is a brain scientist who survived a stroke and wrote a book about her experience. Very cool stuff.

Dr. Jill says, "The portion of our brain that separates us from all other mammals is the outer undulated and convoluted cerebral cortex. Although other mammals do have a cerebral cortex, the human cortex has approximately twice the thickness and is believed to have twice the function (p. 15)."

Human cerebral cortex; Retrieved from: http://farm3.static.flickr.com/2012/1971826491_601f359b84.jpg
Dr. Jill says some other really interesting things. Of course being a stroke survivor, she says everyone should know the

WARNING SIGNS OF STROKE:

S = SPEECH, or any problems with language.
T = TINGLING, or any numbness in the body.
R = REMEMBER, or any problems with memory.
O = OFF BALANCE, problems with coordination.
K = KILLER HEADACHE.
E = EYES, or any problems with vision.

STROKE is a medical emergency. Call 9-1-1. 

Take care of yourself and your big, bad, beautiful brain!