Tecido Nervoso - Histologia - Aula | Prof. Samuel Cunha

Summary

This educational video, presented by Professor Samuel Cunha, explores the nervous tissue, which is essential for transmitting signals and enabling interaction with the environment. The video covers the structure and functions of the central and peripheral nervous systems, including the roles of neurons and glial cells. Key topics include the classification of neurons, their specialized functions, and the role of glial cells in supporting neuronal health. The professor also delves into the physiological aspects of the nervous system, including the formation of the myelin sheath and how the nervous system interacts with other bodily systems. It's an informative guide to understanding how our nervous system works.

Takeaways

• 😀 The nervous system in vertebrates, especially humans, has evolved to be highly sophisticated, allowing us to interpret and respond to information effectively.
• 😀 Nervous tissue is exclusive to animals, and it differs from plants as it is responsible for interpreting stimuli, transmitting impulses, and storing information.
• 😀 The central nervous system (CNS) is divided into the brain and spinal cord, while the peripheral nervous system (PNS) consists of nerves and ganglia outside the CNS.
• 😀 The brain is subdivided into the cerebrum, cerebellum, and brainstem, with the spinal cord projecting from the brainstem.
• 😀 The CNS is protected by three membranes (pia mater, arachnoid, and dura mater), and cerebrospinal fluid (CSF) circulates between them to protect and nourish the nervous system.
• 😀 Nervous tissue originates from the ectoderm during embryonic development, and it contains very little or no extracellular material between the cells.
• 😀 Nervous tissue is highly specialized, with neurons being the most specialized cells, which leads to limited regeneration capacity.
• 😀 The tissue is highly vascularized to support its high metabolic activity and ensure a constant supply of oxygen and nutrients to neurons.
• 😀 Neurons are responsible for receiving, interpreting, and transmitting nerve impulses, and they have dendrites, a cell body, and an axon.
• 😀 Neurons are classified into sensory, motor, and associative (interneurons), each performing specific roles in transmitting impulses between the CNS and other parts of the body.
• 😀 Glial cells support neurons by providing nutrition, protection, and insulation (e.g., forming myelin), and include astrocytes, oligodendrocytes, Schwann cells, microglia, and ependymal cells.

Q & A

What are the main functions of nervous tissue?

Nervous tissue receives stimuli, interprets them, transmits responses, and stores information. It allows the body to react efficiently to the environment, such as feeling temperature or pain.

What is the difference between the central and peripheral nervous systems?

The central nervous system (CNS) consists of the brain and spinal cord, while the peripheral nervous system (PNS) includes all the nerves and ganglia outside the CNS.

What is the embryonic origin of nervous tissue?

Nervous tissue originates from the ectoderm during embryonic development.

Why is nervous tissue difficult to regenerate?

Nervous tissue is highly specialized, especially neurons, which results in a low capacity for regeneration.

What are the structural components of a neuron?

A neuron typically consists of dendrites, a cell body, and an axon. The dendrites receive signals, the axon transmits them, and the cell body processes information.

What role does the myelin sheath play in nerve conduction?

The myelin sheath, formed by glial cells like oligodendrocytes and Schwann cells, serves as an electrical insulator, increasing the speed of nerve impulse transmission by up to 100 times.

What are the different classifications of neurons based on morphology?

Neurons can be unipolar, bipolar, pseudo-unipolar, or multipolar, depending on the number and arrangement of projections (dendrites and axons) from the cell body.

What are the types of neurons based on their function?

Neurons can be sensory (afferent), motor (efferent), or associative (interneurons). Sensory neurons transmit signals to the CNS, motor neurons carry signals from the CNS to muscles, and associative neurons connect sensory and motor neurons.

What are glial cells, and what are their functions?

Glial cells support neurons by providing nutrition, protection, and structural support. They include astrocytes, oligodendrocytes, Schwann cells, microglia, and ependymal cells.

What is the role of astrocytes in the nervous system?

Astrocytes help nourish neurons, maintain physical structure, and aid in tissue repair after injury by replacing damaged neurons.