by abhishek | Aug 21, 2020 | Nervous System
Reflex action is a sudden and involuntary response of effectors (muscles and organs) to a stimulus. Withdrawl of hands when touched by hot things, watering of mouth on seeing favourite food, coughing, sneezing and blinking of eyes are examples of reflex actions. The...
by abhishek | Aug 21, 2020 | Nervous System
The nervous system can be divided into three main divisions: The central nervous system (CNS) The peripheral nervous system (PNS) The autonomic nervous system (ANS) Central Nervous System The central nervous system consists of brain and spinal cord. Peripheral Nervous...
by abhishek | Aug 21, 2020 | Nervous System
In an insect, a long nerve cord is present which runs along the whole body. Like hydra, insects also do not have a brain. Instead of brain, many ganglia are present at intervals on the nerve cords. A ganglia is a mass of nerve cells. The largest ganglion is present in...
by abhishek | Aug 21, 2020 | Nervous System
Hydra is a small aquatic animal. It is found in fresh water ponds, rivers and lakes. It is predatory animal. Hydra is a simple multicellular animal and does not possess a brain. Hydra has a tubular body up to 10 mm long. Its mouth is surrounded by many thin, mobile...
by abhishek | Aug 21, 2020 | Nervous System
Neuron – Unit of Nervous System The nervous system of animals consists of a network of specialized cells called neurons or nerve cells. Function of neuron or nerve cells is to carry information from receptors to brain and then from brain to effectors in the form...
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