Control and Coordination

Chapter Summary

Control and Coordination

A living being responds to external environment.

These responses are controlled and coordinated by a system, especially in complex animals.


Neuron is the functional unit of nervous system.

Cyton and axon are the main parts of a neuron.

A neuron transmits nerve impulses in the form of electrical signals.

Nervous System

Nervous system has two main parts:

Central Nervous System

Peripheral Nervous System

Central Nervous System

It is composed of the brain and spinal cord.

The brain is similar to the CPU of a computer.

Peripheral Nervous System

Nerves arising from the spinal cord make the peripheral nervous system.

Peripheral nervous system has two parts: somatic and autonomous nervous system.

Human Brain

Human Brain has three parts:

Forebrain: Composed of the cerebrum.

Midbrain: Composed of the hypothalamus.

Hindbrain: Composed of the cerebellum, pons and medulla oblongata.

Reflex Action

When a voluntary organ is in the vicinity of a sudden danger, it is immediately pulled away from the danger to save itself.

Such an action is called reflex action.

Hormonal Control

Hormones also play important role in control and coordination.

Hormones reach even those organs which are not connected to neurons.

Coordination in Plants

Plants use chemical means for control and coordination.

Many plant hormones are responsible for various kinds of movements in plants.

Two types of movements in plants are tropic movement and nastic movement.