Nervous system is very complex part of our body consists of brain, spinal cord, nerves; which helps coordinates in transmitting signals between different body parts.
For example, when the pin sticks into your skin, receptors send signals along nerves to your spinal cord and brain where those signals are analyzed, causing you to feel pain. Your nervous system enables you to move, think, feel, and controls all the activities going on inside your body.
Tell me more: nervous system
Brain: The control centre of your nervous system.
Nerves: Bundles of long neurons (nerve cells) that relay signals between all parts of the body, and the brain and spinal cord.
Cerebrum: The main part of the brain. It is divided into linked left and right halves (hemispheres).
Brain stem: Controls automatic activities such as heart and breathing rates.
Cerebellum: Co-ordinates muscle movement and balance.
Spinal cord: A downward extension of the brain that relays signals to and from the brain.
In numberes
2%
The weight of the brain compared to the weight of the body.
20%
The proportion of the body’s oxygen supply that is used by the brain.
100 billion
The number of neurons (nenve cells) in the brain.
83%
The proportion of the brain that the cerebrum makes up.
100 trillion
The number of connections between the brain’s neurons.
350 kph
(218 mph) The speed impulses travel along the fastest neurons.
2,500
The number of times the fastest neurons “tire” each second.
80%
How much of the brain is made up of water.
WEIRD OR WHAT?
An explosion shot a rod that went through mild-mannered Phineas Gage‘s left cheek and out through the front of his brain. He survived but became bad-tempered, proving that the front of the brain controls personality.
Tell me more: cerebral cortex
The cerebral cortex is the thin outer layer of each of the brain’s hemispheres. It is within the cortex that incoming information is processed and stored and instructions sent out. Each part of the cortex has a particular job to do.
- Auditory association cortex identifies sounds.
- Primary auditory cortex receives signals from the ears.
- Broca’s area controls speech production.
- Prefrontal cortex is involved in planning, problem solving, and thinking.
- Premotor cortex controls complex movements such as riding a bike.
- Motor cortex tells muscles to contract to move the body.
- Primary sensory cortex receives signals from receptors in the skin.
- Sensory association cortex interprets skin sensations.
- Wernicke’s area makes sense of written and spoken language.
- Visual association cortex forms images.
- Primary visual cortex receives signals from the eyes.
Four types of memory
You forget many of the things you experience, but important things are stored in long-term memory. Without memory you would not be able to learn, think, or create.
- Working (short-term) memory provides you with an awareness of your surroundings to help you function.
- Procedural memory stores skills such as riding a bike.
- Semantic memory deals with facts, learned words, and languages.
- Episodic memory remembers life events such as holidays and birthdays.
Left is right and right is left
The left cerebral hemisphere controls the right side of the body, and the right cerebral hemisphere controls the left. Each hemisphere also has its own specialities. The left side is usually dominant, which is why most people are right-handed.
Left hemisphere
Written and spoken language.
numbers and maths.
problem solving and logical thinking.
Right hemisphere
Thinking spatially (visually).
Appreciation of art and music.
recognizing faces and objects.
Top five types on intelligence
01: Spatial Intelligence
The ability to use the mind to turn around shapes. It is useful in map-reading and understanding how machines are put together.
02: Verbal intelligence
This measures how good someones writing and reading skills are, and how rapidly they can take in information.
03: Numerical intelligence
Someone who is good at mathematics, with a logical sort of mind that’s good at analyzing things, has a high level of numerical intelligence.
04: Lateral intelligence
With this aplenty, a person can easily solve problems using their imagination, and are probably also creative.
05: Emotional intelligence
Scoring well in this department means that you are good at understanding how other people think or feel.
How to: test your reflexes
Good reflex helps protect you from things that could harm you otherwise. Reflex actions are almost instantaneous actions in response to specific stimulus before it actually reach to your brain.
01. Locate a cactus with sharp spikes.
02. Touch a spike! This alerts receptors in your skin to send nerve impulses along sensory neurons to your spinal cord.
03. When the nerve signal hits your spinal cord, relay it to a motor neuron, plus send on to the brain.
04. Send the nerve message to your upper arm muscle through the motor neuron.
05. Before you realize what’s happening your upper arm muscle will automatically pull your hand away. Good reflexes!
06. Message reaches your brain and you feel pain. Ouch!
What about you?
Although it’s at the centre of your nervous system, your brain cannot feel pain. A headache is not your brain aching; headaches are commonly caused by muscle tension in the neck and under the skin of the scalp.
You won’t believe it!
A nerve impulse takes just one-hundredth of a second to travel from the spinal cord to the big toe.