Types of Neurones | Biology for GCSE/IGCSE - Year 11 PDF Download

Neurone Diagrams

• There are three primary types of neurons: sensory, relay, and motor.
  • Sensory neurons transmit signals from sensory organs to the central nervous system (CNS), comprising the brain or spinal cord.
  • Relay neurons are situated within the CNS and serve as connectors between sensory and motor neurons.
  • Motor neurons convey signals from the CNS to effectors, such as muscles or glands.
• Neurons feature elongated fibers known as axons.
• This elongation minimizes time wastage in transmitting impulses between cells.
• The axon is enveloped by a fatty sheath, interrupted by small uninsulated segments called nodes.
• Consequently, the electrical impulse traverses the axon by jumping from one node to another.
• Neurons possess a cell body containing numerous extensions called dendrites.
• This structural aspect enables neurons to establish connections with multiple other neurons, facilitating the reception of impulses and forming a network for efficient communication.

Identifying the types of neurone

• Sensory neurons are characterized by their elongated structure, with a cell body branching off the middle of the axon.
• Relay neurons, in contrast, are relatively short and feature a small cell body at one end, from which numerous dendrites extend.
• Motor neurons exhibit a long configuration, with a prominent cell body at one end and extensive dendrites branching off it.