INSECT NERVOUS SYSTEM

Structure of the Nervous System

Consists of:

1. Protocerebrum

2. Tritocerebrum

3. Deutocerebrum

4. Thoracic ganglia

5. Abdominal ganglia

6. Connectives

Protocerebrum

• connects to the eyes

• allows insect to detect light

Deutocerebrum

• connects to the antennae

• used to collect information on tastes, smells, temperature, humidity

Tritocerebrum

• connects to the upper tip of insect’s mouth

Ganglia

Nerve that consists of cell bodies of interneurons and motor neurons

Neurons

Cellular building blocks that made up nervous system

• transmit information by electrical & shortrange chemical signaling (action potential)

• Chemical signaling occurs in synapses that connects with other neurons

Dendrites and Axon

Neuron consists of 3 parts; Soma, Axon, and Dendrites

• Soma - head of neuron

• Axon - take information away from soma

• Dendrites - bring information to soma

Neurons direction of information

1. Afferent (sensory) neurons - carry information towards central nervous system

2. Efferent (motor) neurons - conduct signals away from central nervous system

3. Internuncial (association) neurons - conducts signal within central nervous system

Ions in Axon

Voltage gated (positively-negatively charged)

Action Potential

A rapid sequence of changes in the voltage across membrane

Events at the Synapse

• Acetylcholine - neurotransmitter

• Neurotransmitter - chemical messengers, carries messages/ signals from one neuron (nerve cell) to other neurons

• Acetylcholinesterase - acetylcholine degrading enzyme