TLDR;
This video provides a concise overview of the nervous system, detailing its components, functions, and divisions. It explains how the nervous system collects and integrates sensory stimuli to produce coordinated responses, and its structural organisation into the central and peripheral nervous systems. The video also touches on the types of cells that constitute nervous tissue, namely neurons and glial cells, and their respective roles.
- The nervous system consists of the brain, spinal cord, nerves, and ganglia.
- It is divided into the central nervous system (brain and spinal cord) and the peripheral nervous system (nerves and ganglia).
- Neurons and glial cells are the primary components of nervous tissue, responsible for transmitting and supporting nerve impulses, respectively.
Introduction to the Nervous System [0:01]
The video introduces the nervous system and its crucial role in the body. It highlights that the nervous system is composed of the brain, spinal cord, nerves, and ganglia. The main function of the nervous system is to gather sensory stimuli from various parts of the body, integrate this information, and generate an appropriate, coordinated response.
Function of the Nervous System [0:09]
The nervous system is responsible for collecting sensory stimuli from the body, integrating them, and producing a coordinated response. For example, when touching a hot surface, sensory receptors in the skin send signals to the central nervous system. The central nervous system interprets these signals as danger and sends an immediate response signal to the hand muscles, causing them to withdraw instinctively from the heat source.
Divisions of the Nervous System [1:06]
The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system consists of the brain, which is protected by the cranium, and the spinal cord, which is housed within the vertebral column. The CNS coordinates incoming information and formulates responses. The peripheral nervous system comprises nerves (long nerve fibres) and ganglia. Nerves carry nerve impulses from sensory organs to the CNS and transmit processed impulses from the CNS to muscles and glands. Ganglia are small clusters of nerve cell bodies.
Relationship with the Endocrine System and Nervous Tissue [2:37]
The nervous system works alongside the endocrine system to regulate bodily functions. The organs of the nervous system are largely composed of nervous tissue. This tissue consists of two types of cells: nerve cells (neurons) and glial cells. Neurons are capable of receiving stimuli as electrical signals and transmitting them to other nerve, muscle, or gland cells. Glial cells do not generate or conduct nerve impulses but protect, isolate, and support the neurons.
Neurons and Glial Cells [3:28]
Neurons consist of a cell body containing the nucleus and cellular organelles. Extending from the cell body are dendrites (short, highly branched extensions) and an axon (a long, thick fibre that branches only at its terminal end). Glial cells, such as Schwann cells, wrap around the axons of neurons in the peripheral nervous system, forming the myelin sheath. The myelin sheath is a white, dense substance that protects and nourishes the neuron.
