Chapter 2 - Nerves
- Created by: stef17
- Created on: 20-04-16 10:35
View mindmap
- Chapter 2 - Nerves
- Types of Neurones
- Intermediate (Relay) Neurones
- Carry impulses from and to numerous other neurones
- Sensory neurones
- Carry impulse via a dendron (a feature unique to sensory neurons) from the sense organs to the CNS
- Can be myelinated
- Transmit impulses from the CNS to effectors
- Can be myelinated
- Carry impulse via a dendron (a feature unique to sensory neurons) from the sense organs to the CNS
- Motor neurones
- Transmit impulses from the CNS to effectors
- Intermediate (Relay) Neurones
- Nerves
- Sensory nerves only contain sensory neurons
- Mixed nerves contain both sensory and motor neurones
- Motor nerves only contain motor neurons
- Uses reflex arcs
- Transmission of nerve impulses
- Action potentials
- 1. When a stimulus is detected, Na voltage-gated channels open, Na+ ions come in down their electrochemical gradient
- 2. Axon membrane is depolarised
- 3. Na+ channels close while K+ channels opren
- 4. K+ ions overshoot, membrane becomes hyperpolarised
- 5. Membrane becomes repolarised
- 'All-or-nothing' law
- Refractory period
- Resting potential
- -70mV
- Sodium-potassium pump, 3 Na+ out, 2 K+ in
- Action potentials
- Speed of conduction
- Depends on whether its myelinated or not
- Width of axon
- Saltatory or normal conduction
- Synapses
- Transmitter substances
- Cholinergic synapses
- Ca2+ ions
- Inhibitory and excitatory
- Types of Neurones
Similar Biology resources:
Teacher recommended
Comments
No comments have yet been made