Class 10 Science Important Biology
Diagrams
1. Neuron
Neurons or the nerve cells form the basic components of the nervous system. A typical
neuron possesses a cell body called as soma, hair like structures called as dendrites and
an axon. Dendrites are thin structures that arise from the cell body. These dendrites
acquire information from synapses via neurotransmitters and convert them into
electrical impulses. These impulses are further carried over to the cell body.
,2. Brain
A human brain is composed of three main parts- the forebrain, the midbrain and the
hindbrain. These three parts have specific functions.
• Forebrain: This consists of the cerebrum, hypothalamus, and thalamus.
• Midbrain: Consists of the tectum and tegmentum.
• Hindbrain: Is made of the cerebellum, medulla, and pons.
, 3. Reflex Arc
The pathway of a reflex action is called reflex arc. In a reflex arc the stimulus is received
by the receptors (sense organs) and it passes through the sensory nerves to the spinal
cord. From the spinal cord the information is passes through the motor nerves to the
effectors (muscles/glands) for the response.
Diagrams
1. Neuron
Neurons or the nerve cells form the basic components of the nervous system. A typical
neuron possesses a cell body called as soma, hair like structures called as dendrites and
an axon. Dendrites are thin structures that arise from the cell body. These dendrites
acquire information from synapses via neurotransmitters and convert them into
electrical impulses. These impulses are further carried over to the cell body.
,2. Brain
A human brain is composed of three main parts- the forebrain, the midbrain and the
hindbrain. These three parts have specific functions.
• Forebrain: This consists of the cerebrum, hypothalamus, and thalamus.
• Midbrain: Consists of the tectum and tegmentum.
• Hindbrain: Is made of the cerebellum, medulla, and pons.
, 3. Reflex Arc
The pathway of a reflex action is called reflex arc. In a reflex arc the stimulus is received
by the receptors (sense organs) and it passes through the sensory nerves to the spinal
cord. From the spinal cord the information is passes through the motor nerves to the
effectors (muscles/glands) for the response.
