Nervous System Overview

Organization

• The nervous system is a complex network of nerves and specialized cells transmitting signals throughout the body.
• This system coordinates bodily functions, responds to stimuli, and maintains homeostasis.
• It's broadly divided into the central nervous system (CNS) and the peripheral nervous system (PNS).
• The CNS consists of the brain and spinal cord, serving as the control center. The PNS consists of nerves branching from the CNS to connect it to the body.

Central Nervous System (CNS)

• The brain is the control center for higher-order functions like thought, memory, and emotion.
• The brain has specialized regions: the cerebrum for conscious thought and action, the cerebellum for coordination, and the brainstem for vital life functions.
• The spinal cord is a pathway for nerve signals between the brain and the rest of the body, controlling reflexes. It is encased and protected by the vertebrae of the spinal column.

Peripheral Nervous System (PNS)

• The PNS connects the CNS to the rest of the body.
• It includes sensory nerves (afferent) and motor nerves (efferent).
• Sensory nerves carry information from sensory receptors to the CNS. Motor nerves carry signals from the CNS to muscles and glands, controlling actions.

Types of Nerves

• Sensory nerves carry information from sense organs (eyes, ears, skin) to the CNS.
• Motor nerves carry signals from the CNS to muscles and glands, causing movement and other actions.
• Mixed nerves contain both sensory and motor fibers, enabling dual functionality.

Neuron Structure and Function

• Neurons are the fundamental units of the nervous system.
• Each neuron has a cell body, dendrites, and an axon.
• Dendrites receive signals from other neurons.
• The axon transmits signals away from the cell body to other neurons, muscles, or glands.
• Signals are transmitted as electrochemical impulses.
• The synapse is the junction between two neurons where communication happens across a gap.

Neurotransmitters

• Neurotransmitters are chemical messengers transmitting signals across synapses.
• Different neurotransmitters have varying effects on receiving neurons.
• Examples include dopamine, serotonin, norepinephrine, and acetylcholine, each with a specific role.

Nervous System Disorders

• Various disorders affect the nervous system, ranging from minor to severe.
• Conditions like stroke, multiple sclerosis, Alzheimer's disease, and Parkinson's disease cause neurological symptoms and deficits.
• These conditions present diagnostic and treatment challenges.

Nervous System Functions

• Sensory functions detect and process environmental information (e.g., touch, temperature, light).
• Motor functions initiate and control voluntary and involuntary movements.
• Integrative functions process sensory information, make decisions, and form memories.

Brain Regions

• Cerebrum: The largest part, responsible for higher-level thinking.
• Cerebellum: Crucial for motor coordination and balance.
• Brainstem: Contains vital centers controlling involuntary functions like breathing and heart rate.

Protective Structures

• The skull protects the brain.
• The vertebral column protects the spinal cord.

Autonomic Nervous System

• The autonomic nervous system regulates involuntary functions (heart rate, digestion, breathing).
• It's divided into the sympathetic nervous system (fight-or-flight) and the parasympathetic nervous system (rest-and-digest).
• These opposing systems maintain homeostasis through their actions.

This quiz explores the organization and functions of the nervous system, highlighting the roles of the central nervous system (CNS) and peripheral nervous system (PNS). Test your knowledge on the brain, spinal cord, and how they coordinate bodily functions and responses to stimuli.