Neurons Flashcards
What are neurons?
Are cells which carry action potential around the body
What are neurons involved with?
Cell signalling and cell communication
Adaptation One of Neurons
Many dendrites/axon terminals to connect with many other neurons
Adaptation Two of Neurons
Many have a mylein sheath which protects and insulates the axon/dendron and speeds up transmission of the action potential
Adaptation Three of Neurons
Are long so action potential can be transmitted over long distances quickly
Adaptation Four of Neurons
Have many sodium-potassium pumps so neurons have many mitochondria for ATP
Adaptation Five of Neurons
Have many sodium, calcium and potassium channels
How do some neurons end up paralysed?
Many neurons are amitotic so if damaged, can’t do mitosis so end up paralysed
What are the 3 types of neuron?
-Sensory
-Relay
-Motor
Sensory Neuron
-Afferent Neuron
-From PNS to CNS
Relay Neuron
-In CNS (brain and spinal chord)
Motor Neuron
-Efferent Neuron
-From CNS to PNS
What can an effector be?
-Muscle
-Gland
Structure of Sensory Neuron
-Dendrites
-Long Dendron
-Schwan Cells
-Short Axon
-Axon Terminals
-Cell Body just outside of CNS
-Action Potential along from PNS to just outside CNS
Structure of Relay Neuron
-Many Dendrites
-Short/No Dendron
-No Schwan Cells
-Short Axon
-Axon Terminals
-Cell Body
-Action Potential from top of CNS/Spinal Chord working way down
Structure of Motor Neuron
-Dendrites connect straight to cell body
-No Dendron
-Schwan Cells
-Long Axon
-Axon Terminals leading to effector
-Cell Body in CNS
-Action Potential from CNS out into PNS
Draw a Sensory Neuron
See Notes
Draw a Relay Neuron
See Notes
Draw a Motor Neuron
See Notes
What does it mean if neurons are myelinated?
They have schwan cells that produce mylein
How many peripheral neurons (PNS) are myelinated?
1/3
What neurons are usually myleinated? And why?
-Neurons that are involved taking action potentials to/from CNS
-Have to transmit action potential quickly
What does a Schwan cell look like that produce mylein?
See Notes
Schwan cell look like that produce mylein properties
-Axon/Dendron
-Nuclues
-Schwan cell membrane which secretes mylein but don’t have any Na+ of K+ channels where Schwan Cells are
What does a Schwan cell look like that doesn’t produce mylein?
See Notes
Schwan cell look like that don’t produce mylein properties
-Nucleus
-Houses several axons/dendrons and provides some protection
-There’s a gap around axons/dendrons so NA+ and K+ channels are found along the whole length of axon/dendron
