Ans these qns pls
1. A. Neural coordination
The neural system provides rapid coordination among the organs of the body. This coordination is in the form of electric impulses and is quick and short-lived. All the physiological processes in the body are closed linked and dependent upon each other. For example, during exercise, our body requires more oxygen and food. Hence, the breathing rate increases automatically and the heart beats faster. This leads to a faster supply of oxygenated blood to the muscles. Moreover, cellular functions require regulation continuously. These functions are carried out by hormones. Hence, the neural system along with the endocrine system control and coordinate the physiological processes.
B. Synapse is a junction between the axon terminal of one neuron and the dendrite of next neuron. It is separated by a small gap known as synaptic cleft. There are two types of synapses.
- Electrical synapse: In electrical synapses, the pre and post synaptic neurons lie in close proximity to each other. Hence, the impulse can move directly from one neuron to another across the synapse. This represents a faster method of impulse transmission.
- Chemical synapse: In chemical synapses, the pre and post-synaptic neurons are not in close proximity. They are separated by a synaptic cleft. The transmission of nerve impulses is carried out by chemicals such as neurotransmitters.
Dendrite is a small projection arising from the neuron. It conducts the nerve impulse toward the cell body.
Axon is a single, long projection that conducts the nerve impulse away from cell body to the next neuron.
Nissl’s granules are present in dendrites.
Nissl’s granules are absent from axons.
Dendrites are always non-myelinated.
Axons can be myelinated or non-myelinated.
C. Thalamus and Hypothalamus
Thalamus is the part of the forebrain that receives nerve impulses of pain, temperature, touch, etc., and conducts them to the cerebral hemisphere.
Hypothalamus is the part of the forebrain that controls involuntary functions such as hunger, thirst, sweating, sleep, fatigue, sexual desire, temperature regulation, etc.