Neural Homeostatic Control Pathways Flashcards
What makes up the nervous system?
Central nervous system (CNS) and the peripheral nervous system (PNS)
What are neurons?
Neurons are the nerve cell and they send rapid messages from one neuron to another through nerve impulses.
What are the 3 types of neurons and their pathways?
- Sensory (Receptor → CNS)
- Relay (CNS → CNS)
- Motor (CNS → Effector)
Label the Structure of a typical nerve cell (motor neuron)
- Dendrites
- Cell body (soma)
- Axon- myelin sheath
- axon terminal
What are the structural differences between a sensory and motor neuron?
- The sensory neuron is unipolar, has a short axon, consists of a receptor,
- The motor neuron is multipolar, has a long axon, does not consist of a receptor,
(Unipolar means only 1 extension of dendrites from the cell body while multi means multiple dendrites extending from the cell body)
What are the 4 stages of the action potential?
- During the resting potential the membrane potential is -70mV and there is no stimulus
- In depolarisation a stimulus has occurred causing Na+ channel to open and Sodium ions flow into the cell making it more positive and it reaches 40mV
- In repolarisation K+ channels open and Potassium ions flow out of the cell setting the polarisations back to their original state, however K ions overshoot making it more negative
- Over time K+ channels close and the neuron returns to its resting state
What is the purpose of the action potential?
It is the electrical pulses through the neuron that are used to transmit information from one place to another.
Label the Diagram Below with Processes 1 through to 8
- Action potential arrives at axon terminal
- Voltage-gated Ca2+ channels open
- Ca2+ enters the presynaptic neuron
- Ca2+ signals to neurotransmitter vesicles
- Vesicles move to the membrane and dock
- Neurotransmitters released via exocytosis
- Neurotransmitters bind to receptors
- Signal initiated in post synaptic cell
