Coordination

Nervous Coordination

Chemical/Hormonal Coordination

In this system the neurons release its neurotransmitter into one or a small group of specific cells

Neurons(sensory, associative, and motor), are the basic unit of structure and function. In addition, neurological cells are also present which provide nutrition and protection to the neurons

Nervous system uses electrical signaling(neural impulse)

Controlled and coordinated by the nervous
system

Endocrine system uses chemical signaling(hormones, produced by glands)

Controlled and coordinated by the endocrine system

The blood borne hormones bathe millions of cells indiscriminately and only a few respond to these hormones

Hormone producing cells and neuro secretory cells(such as those found in the hypothalamus), release hormones and are units of structure and function.

The chemical involved in this systems (the neurotransmitters or neuro hormones) are short lived i.e. broken down shortly after their release.Thus the effects of messengers sent by neurons tend to be of much shorter duration.

This has immediate effect or show response to a stimulus instantly

The hormones are the chemicals that remain active for a much longer duration within the blood, and thus have a much longer duration for their action.

They may have immediate effects(e.g. insulin) but mostly hormones have prolonged or delayed effects(for example growth hormone).

Coordination

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Importance of body coordination:

1.Enables our body organs to function as a unit to detect stimuli and respond towards them.

2.Controls coordination between stimuli and body responses.

3.Helping to avoid injuries or danger.

4.Enables us to adapt to the changes around us.


External stimuli are changes outside the body, or knowledge that is passed to us through our senses. This could be cold or hot weather, light levels, or danger. Internal stimuli are changes to conditions inside the body, such as dangerous food in the stomach, viruses in the body, or lack of food or water. Receptors are groups of specialized cells. They detect a change in the environment and stimulate electrical impulses in response. Sense organs contain groups of receptors that respond to specific stimuli.

What are external stimuli and receptors?

Sound waves are detected by ears
Light is detected by the eyes
Chemicals in air detected by the nose
Temperature and touch is detected by skin

Examples of Stimuli and receptors:

1.I was playing cricket and a ball is coming towards me in speed. First, my eyes will see the ball and send a message to the brain. The brain will calculate the speed and direction of the ball and will predict where should I move to catch the ball. The brain will then send a message to the muscles in my legs and arms to move, bringing me to the exact right place to catch the ball.


  1. I am sitting in my bedroom, and an aromatic smell comes into the room. My nose detects that the smell is of my favorite dish. Then it sends a signal to the brain, the brain receives the message and sends it to the salivary gland which then secretes the saliva. And as a result, my mouth starts to water.

3.When I eat something bitter, I spit it out. This happens when taste buds present on my tongue detects the taste and sends a signal to my brain. The brain after receiving the message sends a message to the muscles present in my mouth. Hence, I spit the bitter food.


  1. When it is hot outside, I sweat. This is also happening because my skin detects the temperature and sends a signal to my brain, which then sends a message to the sweat glands to produce sweat. As a result, my body cools down.


  1. When I am scared, I close my eyes. This is because my sense organs send a message to my brain if anything is suspicious. My brain then sends a message to close my eyes. Which helps me to relax.

Examples of coordination in between different organ systems in result of external stimuli: