Nervous System Overview and Structure

Nervous System Overview

• The nervous system is a complex network of cells and organs coordinating bodily activities.
• It responds to internal and external stimuli, regulating functions, and enabling communication between body parts.
• This intricate system also controls movement, thoughts, emotions, and behaviors.

Neuron Structure and Function

• Neurons are the basic functional units.
• They carry messages to and from various body parts.
• Dendrites, branched structures, receive signals from other neurons.
• Nerve impulses are electrical signals travelling along axons.
• Synapses are junctions between neurons, enabling communication via neurotransmitters.

Nervous System Divisions

• The nervous system is divided into Central and Peripheral systems.
• The Central Nervous System (CNS) consists of the brain and spinal cord.
• It processes information, controls movement, and manages higher cognitive functions.
• The Peripheral Nervous System (PNS) includes nerves outside the CNS.
• Its somatic division controls voluntary movements (walking, picking things up).
• The autonomic division regulates involuntary functions (e.g., breathing, heart rate).

Brain Structures

• Cerebral cortex: The outermost brain layer, involved in complex functions (sensory perception, movement, language, memory).
• Corpus Callosum: Connects the brain's hemispheres, enabling information sharing.
• Medulla oblongata: Part of the brainstem, controls vital autonomic functions (breathing, heart rate, blood pressure).
• Cerebellum: Crucial for movement and coordination.
• Thalamus: Relays sensory and motor impulses to the cerebral cortex.
• Hypothalamus: Regulates body temperature and controls emotions and sensations.

Knee-Jerk Reflex

• The knee-jerk test (patellar reflex) assesses lower spinal cord function.
• It evaluates the reflex pathways.
• This test can diagnose conditions that affect the spinal cord, nerves, or muscles (e.g., nerve damage, spinal cord injury, multiple sclerosis).