Nervous System Overview

Nervous System Overview

• The nervous system is responsible for integrating, processing, and coordinating sensory data and motor commands.
• The central nervous system (CNS) consists of the brain and spinal cord.
• The peripheral nervous system (PNS) includes all neural tissue outside the CNS.
• Information processing involves integration and distribution within the CNS.

Peripheral Nervous System (PNS)

• The sensory division of the PNS brings information to the CNS from receptors in peripheral tissues and organs.
• Somatic sensory receptors provide information about position, touch, pressure, pain, and temperature.
• Special sensory receptors provide information about smell, taste, vision, balance, and hearing.
• Visceral sensory receptors monitor internal organs.
• Receptors detect changes in the internal or external environment.

Motor Division of the PNS

• The motor division carries motor commands from the CNS to peripheral tissues and systems.
• The somatic nervous system controls skeletal muscle contractions.
• The autonomic nervous system regulates smooth muscle, cardiac muscle, glands, and adipose tissue.

Nerve Impulse

• A nerve impulse is an electrical message that travels down the axon of a neuron.
• The impulse regenerates along the axon.
• Speed of nerve impulses ranges from 1 m/s to 100 m/s.

Synapse

• A synapse is a junction between two neurons or a neuron and another cell.
• Neurotransmitters facilitate communication across the synaptic cleft, allowing signals to be passed and processed in the nervous system.

Receptors

• Receptors are specialized neural structures that detect specific types of stimuli, such as light, sound, temperature, and pressure.
• Receptors convert physical energy from the environment into neural signals.
• The brain interprets these signals as sensations.

Sensation

• Sensation is the process of receiving stimuli through the senses (vision, hearing, taste, touch, and smell), and conveying the information to the central nervous system for processing.

Motor Function

• Motor function refers to the nervous system's ability to control and coordinate muscles for movement.
• This includes simple reflexes and complex movements.
• Motor function is crucial for tasks such as walking, writing, and maintaining balance.

Upper and Lower Motor Neurons (UMNs and LMNs)

• Upper motor neurons (UMNs) originate in the brain and send signals to lower motor neurons (LMNs).
• Lower motor neurons (LMNs) directly innervate skeletal muscles, executing movements.
• Damage to UMNs can lead to conditions like spasticity, while LMN damage causes weakness and atrophy of muscles.

This quiz provides an overview of the nervous system, including the central and peripheral nervous systems. It highlights the roles of sensory and motor divisions, alongside various types of receptors. Test your knowledge on how these systems process and respond to internal and external stimuli.