Anatomy and Pathology of the Nervous System – SG

Central Nervous System (CNS):

1. Brain: Processes information, controls voluntary and involuntary actions, generates thoughts and emotions, regulates bodily functions like breathing and heart rate.
2. Spinal Cord: Relays sensory information to the brain, transmits motor commands from the brain to muscles, controls reflex actions.

Peripheral Nervous System (PNS):

1. Somatic Nervous System: Controls voluntary movements of skeletal muscles and receives sensory information from the environment.
2. Autonomic Nervous System: Regulates involuntary functions such as heart rate, digestion, and respiratory rate.

• Sympathetic Division: Activates the “fight or flight” response in stressful situations.
• Parasympathetic Division: Promotes the “rest and digest” response, conserving energy.

Sensory Division:

1. Sensory Receptors: Specialized cells that detect stimuli (e.g., touch, temperature, pain, sound, light) and convert them into electrical signals.
2. Sensory Neurons: Transmit sensory signals from receptors to the central nervous system for processing.

Motor Division:

1. Motor Neurons: Transmit signals from the central nervous system to muscles and glands.

• Somatic Motor Neurons: Control voluntary muscle movements.
• Autonomic Motor Neurons: Control involuntary actions of organs.

Brain Structures and Functions:

1. Cerebrum: Higher cognitive functions such as thinking, memory, emotion, and conscious perception.
2. Cerebellum: Coordinates muscle movement, balance, and posture.
3. Brainstem: Regulates basic functions like breathing, heart rate, blood pressure, and digestion.
4. Thalamus: Relays sensory information to the appropriate areas of the brain for processing.
5. Hypothalamus: Regulates homeostasis, hunger, thirst, body temperature, and hormone secretion.
6. Limbic System: Involved in emotions, memory, and learning.

Autonomic Nervous System Divisions:

1. Sympathetic Division: Activates the body’s “fight or flight” response, preparing for stress or danger.
2. Parasympathetic Division: Promotes the body’s “rest and digest” state, conserving energy and promoting relaxation.

In summary, the nervous system is a complex network of interconnected parts that work together to control and coordinate various bodily functions. From the brain’s cognitive processes to the spinal cord’s rapid reflexes, and from the autonomic system’s regulation of vital functions to the somatic system’s control of voluntary movements, each part of the nervous system plays a critical role in maintaining overall health and facilitating our interactions with the world.