Nervous system - Nerve cell Flashcards
What is an unmyelinated axon?
No myelin sheath
What is a myelinated axon?
Individual myelin sheaths around the nerve
What is the difference between myelinated and unmyelinated neurons?
A unmyelinated axon has a comparatively lower speed of conduction
What is a motor neuron?
carry signals from the CNS to the outer parts
What is a sensory neuron?
Carry signals from the outer parts of your body into the CNS
What do myelin sheaths contain?
Contains mitochondria to allow electrical impulses to transmit quickly and efficiently along the nerve cells
What are the periodic gaps between the myelin sheaths called?
Nodes of ranvier
What maintains the myelin sheath in the CNS?
Oligodendrocyte and astrocyte
What maintains the myelin sheath in the PNS?
Schwann cell
What are nerve synapses?
a small gap at the end of a neuron that allows a signal to pass from one neuron to the next
What are electrical synapses?
A gap junction that passes ions and signalling molecules directly between cells without passing through extracellular fluid
What are chemical synapses?
Neurotransmitters control the release of ions through channels
What is the process of the reflex arc?
Receptors in the skin detect sensation, this single travels along neurons into grey matter and relay neurons in the spine, then through motor neurons back to the muscle
