Home Jnr Science Biology
Cells organisation  Genetics jnr  Respiration Protein synthesis yr 10  Stem cells  Plant tropism  Offspring  Genetic Testing  Ethics  Cloning & Ethics  Neuron  Conditioning&Learning  Memory  Timeline 
Year 10 iGCSE - Biology

Everything you do today, from the unconscious actions of breathing and walking to the conscious actions like talking and decision making, all involve your brain. The brain is composed of neurons.

The Brain

Your brain is a bundle of neurons. It is essentially the control centre of your being. All thoughts, dreams and perceptions of reality occur here.

Even a simple animal like a flatworm has a brain. A very very simple brain, but a brain none the less. At the head of this organism is a bundle of nerves, responsible for the animals movement and sensory processes.

If you look at flat worm, the first thing you notice is just how simple they are. Their behaviour is nothing compared to ours.

Since our behaviour and actions are so complex, we need larger more sophisticated brains.

Billions of neurons in the brain communicate and work together to make you who you are.

Since our behaviour is so complicated, various parts of the brain are responsible for different actions.

Where are you right now? What are you doing right now?

Understanding where you are and who you are is consciousness. Consciousness requires your cerebral cortex.  

The cerebral cortex coats the brain, it is composed of folded grey matter and controls Language, intelligence and memory.

We know that the brain is responsible for your personality, actions and basic survival skills, but how do we know what parts of the brain control what.

Over the years scientists have studied

Brain damage studies.

Brain damage can be caused by strokes, disease, cancer, lobotomies or physical trauma.


Electrical stimulation

Scientists can stimulated different parts of the brain with a weak electrical current.

If the motor area is stimulated, the patient makes an involuntary movement.

If the visual area is stimulated, they may see a flash of colour.

The video to the right shows a rat, with an electrode attached to a pleasure spot in the brain.

MRI brain scans

Modern imaging methods such as MRI (Magnetic Resonance Imaging) scans show details of brain structure and function.

Patients perform various tasks while being scanned. Scientists can see which parts of the brain are active when the task is carried out, these are called functional MRI (fMRI) scans.

The video to the right shows a surgeon performing brain surgery. While actually working on the patient must be awake.

Using small electrical shocks, the surgeon stimulates parts of the motor strip.  

If an area of brain does not correspond with movement they can remove the tumour.

96% of football players had Chronic Traumatic Encephalopathy (CTE).

CTE is a progressive neurological illness caused from concussions and repeated blows to the head.

Death from Alzheimer’s and Lou Gehrig’s disease is four times higher among NFL players than the rest of the population.

CTE causes memory loss, depression, learning disability, mood disorders, and aggression.

Questions

Short Answer Questions

1. Using the following words, describe the brain. (Neurons, language, memory, Central Nervous System, movement and Conscious)


2. Explain the difference between a fly’s brain and ours


3. What is the function of the cerebral cortex


4. Explain the relationship between surface area and the structure of the brain.




5. Observe the fMRI scan to the right.
How can you tell who is the trained musician
and who isn’t?  







6. Observe the fMRI, is the individual seeing
or talking? Explain your answer




7. Explain why a knock to the back of the head can cause someone to see a flash of white light




8. The scan shows an image of an individual
who suffers depression, compared to a
healthy individual. What can you conclude
from this scan?






9. Explain how a stroke in Broca’s area will affect an individual.