Nervous Tissue | Structural Organization in Animals | Anatomy | Inter 2nd year Class 11 Biology

Summary

This script delves into the nervous system, highlighting its critical role in communication within the body. It details the structure and function of neurons, including the cyton (cell body), axon, and dendrites, and explains the significance of the myelin sheath and Schwann cells. The script also explores nerve impulses, neurotransmitters, and the synaptic junction, and distinguishes between nerve cells and neuroglia. It further categorizes neurons based on their structure, myelin sheath, and function, providing a comprehensive understanding of the nervous system's complexity.

Takeaways

• 🧠 The nervous system is crucial for fast communication throughout the body, composed of neurons and nervous tissues.
• 🌐 Neurons consist of two main parts: the cyton (cell body) and the axon (nerve fibre), with the nucleus located in the cyton.
• 🔬 Dendrites are the branching structures that project from the cyton, while the axon is a long fiber insulated by the myelin layer.
• 🚀 Nerve impulses are transmitted quickly in the form of electrochemical flows, facilitated by synaptic junctions between neurons.
• 💊 Neurotransmitters are chemicals that assist in the transmission of impulses at the synapses.
• 🔍 There are two types of cells in the nervous system: nerve cells (neurons) that transmit impulses, and neuroglia that do not.
• 🌿 Neurons are the functional units of the nervous system, with the ability to generate and transmit electrical disturbances along their plasma membrane.
• 🌱 The cell body, or cyton, contains granules and a large nucleus, and is the site of Nissl’s structures.
• 🌿 Dendrites are the small, branched structures that surround the cell body and are involved in receiving signals.
• 🔋 The axon is a long, cylindrical structure that carries impulses to other neurons and muscle fibers, forming synaptic connections.
• 🔄 There are different types of neurons based on their structure and function, including unipolar, bipolar, and multipolar neurons.
• 🛡️ Myelinated axons are covered by a myelin sheath for faster impulse transmission, while non-myelinated axons lack this insulating layer.
• 🔌 Sensory neurons transmit signals from sensory organs to the CNS, motor neurons send signals to effectors, and interneurons connect within the CNS.

Q & A

What is the nervous system responsible for?

The nervous system is responsible for establishing fast communication between different body parts.

What are the two main components of the nervous system?

The two main components of the nervous system are neurons and nervous tissues.

What are the two parts of a neuron?

A neuron is made up of the cyton, also known as the cell body, and the axon, also known as the nervous fibre.

What is the cyton and where is the nucleus located?

The cyton is the broad part of the neuron and is also known as the cell body. The nucleus is located within the cyton.

What is the function of the axon and what is its protective layer called?

The axon is the long fibre of the neuron responsible for transmitting nerve impulses. It is protected by a fatty layer called the Myelin layer.

What is the role of the dendrites in a neuron?

Dendrites are the edges of the cyton that project out and are involved in the reception of signals from other neurons.

What is a nerve impulse and how does it occur?

A nerve impulse is the quick transmission that occurs in the nervous system in the form of an electrochemical flow.

What is the synaptic junction and its relation to neural transmission?

The synaptic junction is the area between two neuron ends and it helps in the transmission of impulses between neurons.

What are neurotransmitters and their role in the nervous system?

Neurotransmitters are chemicals that assist in the transmission of nerve impulses up to the synapse.

What are the two types of cells found in the nervous system and their functions?

The two types of cells in the nervous system are nerve cells (neurons), which transmit impulses, and neuroglia, which do not transmit impulses but provide support and protection.

What is the Node of Ranvier and its significance?

The Node of Ranvier is the part of the axon not surrounded by the Schwann cell and myelin, and it plays a role in the rapid transmission of electrical impulses along the neuron.

What are the types of neurons based on their structure and function?

Neurons can be classified based on structure as unipolar, bipolar, and multipolar neurons, and based on function as sensory neurons, motor neurons, and interneurons.

What is the Myelin sheath and its importance in the nervous system?

The Myelin sheath is a protective covering around the axons, produced by Schwann cells in the PNS and oligodendrocytes in the CNS, which acts as an electric insulator and aids in the speed of nerve impulse transmission.

What is a nerve and its components in the peripheral nervous system?

A nerve in the PNS is a collection of axons bundled together, covered by connective tissue layers such as endoneurium, perineurium, and epineurium.