Estrutura do sistema nervoso | Saúde e medicina anatomia e fisiologia humana | Khan Academy

Summary

This video introduces the structure of the nervous system, highlighting its two main components: the central nervous system (CNS) and the peripheral nervous system (PNS). It details the brain's parts, including the cerebrum, brainstem, and cerebellum, explaining their embryonic origins. The video also covers the spinal cord, nerves, and ganglia in the PNS, explaining the roles of afferent and efferent neurons. It provides a thorough yet concise overview of how these structures connect and function to ensure communication within the body, preparing viewers for more in-depth learning in subsequent videos.

Takeaways

• 😀 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 and spinal cord. The brain is located in the head, and the spinal cord runs down the vertebral column.
• 😀 The brain is the largest part of the central nervous system and is divided into two hemispheres: left and right.
• 😀 The brain also includes the brainstem, which connects the brain to the spinal cord, and is divided into three parts: mesencephalon, pons, and medulla.
• 😀 The cerebellum, located behind the brainstem, is another key structure of the brain.
• 😀 The development of the brain in the embryo includes the prosencephalon (which becomes the brain), mesencephalon (which becomes the mesencephalon), and rhombencephalon (which becomes parts of the brainstem and cerebellum).
• 😀 The spinal cord resembles a long tube descending the spine and is connected to the peripheral nervous system through nerves.
• 😀 The peripheral nervous system consists of nerves and ganglia. Nerves carry axons of neurons, while ganglia contain the cell bodies of neurons.
• 😀 Afferent neurons carry information toward the central nervous system, while efferent neurons carry information away from it.
• 😀 Nerves can be cranial (originating from the brain) or spinal (originating from the spinal cord). Cranial nerves pass through the skull, while spinal nerves pass through the vertebral column.
• 😀 Spinal nerves are divided into two roots: the posterior root (carrying afferent neurons) and the anterior root (carrying efferent neurons). Most spinal nerves are mixed, containing both afferent and efferent neurons.
• 😀 Nerves branch repeatedly, becoming thinner as they travel throughout the body, with the distal branches being microscopic but essential for connecting the body to the central nervous system.

Q & A

What are the two main divisions of the nervous system?

The nervous system is divided into two main parts: the central nervous system (CNS) and the peripheral nervous system (PNS).

What structures make up the central nervous system?

The central nervous system is primarily composed of the brain and the spinal cord.

What is the role of the brain in the nervous system?

The brain is the largest part of the central nervous system and is responsible for processing information and controlling various functions of the body.

What are the two hemispheres of the brain called?

The brain is divided into two halves called the left and right cerebral hemispheres.

What is the function of the brainstem?

The brainstem connects the brain to the spinal cord and is responsible for basic life functions such as breathing and heartbeat.

What are the three parts of the brainstem?

The brainstem is divided into three parts: the mesencephalon (midbrain), the pons, and the medulla oblongata.

What part of the brain is responsible for movement coordination?

The cerebellum is responsible for coordinating movement and balance.

What is the difference between afferent and efferent neurons?

Afferent neurons carry information toward the central nervous system, while efferent neurons carry information away from the central nervous system to the peripheral body.

How are spinal nerves categorized?

Spinal nerves are categorized as either cranial nerves, which originate from the brain, or spinal nerves, which originate from the spinal cord.

What are the two types of roots in spinal nerves?

Spinal nerves have two roots: the dorsal root (posterior) that carries afferent neurons and the ventral root (anterior) that carries efferent neurons.