[Biology Class Notes] on Control and Coordination – Nervous System Pdf

We, humans, are able to perform control and coordination processes through the nervous system. The process of sleeping, touching any object and changing our path on the road by listening to the honk, all are controlled by our nervous system. The same goes for animals too. Control and coordination in animals are as similar as humans. The nervous system helps in controlling and coordinating different activities of the human body. There are three types of nervous systems in our body- cranial nerves, spinal nerves and visceral nerves. All these run through our body sending and receiving messages.

What are Control and Coordination?

We humans have five senses of organs in our body, eyes, nose, tongue and skin, called receptors. In other words, control and coordination in humans’ take place through the nervous system and hormonal system called the Endocrine System. A receptor is a group of cells in the sense of an organ acting sensitive to a particular type of action or message in the form of light, sound or heat. All receptors send messages to our body system in the form of electrical impulses to the spinal cord and brain through sensory nerves. Then there are motor nerves transmitting a response from the brain and spinal cord to effectors. Here effectors are muscles and glands.

In layman’s language, the real meaning of control and coordination is the process of the body working in a systematic manner. Every small and big process happening in our body is quite complicated, and still, our body works efficiently. Our body nervous systems are connected to each other and send messages to every part of the body to conduct action.

What is a Nervous System?

The nervous system consists of nerve fibres and nerve cells transmitting messages to different parts of the body. It is a vital system found in animals and humans synchronizing its function by passing out signals to and from different parts of the body. This nervous system coordinates with the endocrine system. This system of control and coordination is brought after the involvement of various internal systems.

There are Three Types of Nerves Systems:

1. Sensory Nerve: It carries impulses from the sense organs to the brain

2. Motor Nerve: It brings messages from the brain to the sense organs

3. Relay Nerve: It works on both functions

Under the nervous system, there is a neuron acting as the structural and functional unit. It receives and transmits electrical nerve impulses. Neural control and coordination is an important part of human function. Neuron comprises of:

The cell body has a nucleus and granular cytoplasm called Nissl’s Granules. Dendrites carry several branches and look like finger projections transmitting nerve impulse towards the cell body. Axon arises from the cell body branched as the distal end. Cells of the axon are called Schwann cells covering myelin sheath.

Messages transmitted through this nervous system are in the form of electrical impulses and are called nerve impulses. In this process, dendrites pick messages and send them to the cell boy and then to the axon. The axon then sends these messages to neurons through a junction called a synapse.

This process of biology control and coordination happens in the friction of time making the person react to the situation.

Parts of the Nervous System:

• Central Nervous System (CNS)

CNS consists of the brain and spinal cord. There are multiple sensory emotions that take place in this area. Humans get thoughts and emotions from this system leading to the formation of memories. It gathers information throughout the body syncing with the activity. Apart from the sensory emotions, it controls the rate at which our heart rate beats and we breathe.

• Peripheral Nervous System

Everything apart from the brain and spinal cord comprise the Peripheral Nervous System. It covers the nerves that go down the spinal cord. PNS acts as the messenger from different parts of the body to the brain. Nerves in this PNS are called peripheral nerves and connect our sense organs to each other.

Organs of Human Nervous System

There are three different nervous systems in humans:

The brain is the major nervous system of our body controlling our actions. It receives and sends signals to and from sensory organs. The brain comprises of three parts:

1. Forebrain- It helps in the overall action of control and coordination of voluntary function and the thinking part of the brain.

2. Midbrain- It transmits signals from the hindbrain and forebrain

3. Hindbrain- Works on the control and coordination of heart rate, blood pressure and other activities.

The spinal cord is the thick nerve located at the backbone of the cavity area. The upper end of the spinal cord connects to the brain and is connected to all parts of the body through nerves and controls body functions.

It connects the brain and the spinal cord of the body.