Lesson 2 - Neurons

Question 1

Structure of a neuron

Answer 1

• The cell body/soma, contains the nucleus
• Dendrites carry impulses from neighbouring neurons to the cell body
• The axon carries impulses away from the cell body, and it is covered by a myelin sheath which protects the axon and speeds electrical transmission
• Nodes of Ranvier along the length of the myelin sheath force the impulse to jump across the gaps in the axon and speed up transmission

Question 2

Types of neurons

Answer 2

Sensory neurons - carry messages from the PNS to the CNS. LONG dendrites and SHORT axons

Relay neurons - they connect the sensory neurons to the motor neurons/other relay neurons. SHORT dendritic and SHORT axons

Motor neurons - they connect the CNS to effectors such as muscles and glands. SHORT dendrites and LONG axons

Question 3

Sensory neurons

Answer 3

Found in receptors such as eyes, ears, tongue, and skin, and carry impulses to the spinal cord and brain. Some neurons stop at the spinal cord allowing for quick reflex actions

Question 4

Relay neurons

Answer 4

Found in the brain and spinal cord and is an intermediary between sensory and motor neurons

Question 5

Motor neurons

Answer 5

Found in the CNS and control muscle movements. When they are stimulated, they release neurotransmitters that bind to receptors on muscles to trigger a response which leads to movement