Nervous System Flashcards
What are the 2 main divisions of the Nervous System
The Central Nervous System and the Peripheral Nervous System
What 3 functions do Glial Cells have? Give an example of a specific type
- Insulate and protect the neuron
- Supply neurons with oxygen and nutrients
- Facilitate the transmission of nerve impulses
Ex. Schwann cells
Describe the structure of a neuron
Has an enlarged cell body with dendrites (carrying message towards the cell body, an axon (long extension leaving the cell body)
What are the 3 divisions of neurons?
Sensory (afferent) neurons
Interneurons
Motor (efferent) neurons
What are the 5 components that make up a basic reflex arc?
Sensor, afferent neuron, interneuron, efferent neuron,effector
How is the Resting potential established along a neuron?
Through Na+/K+ pumps. 3 Na+ ions are pumped out of the membrane while only 2 K+ are pumped inside. This results in an overall negative charge inside the neuron (-70mV)
What is meant by the “All or Nothing” response?
The Action potential is only transmitted if the resting potential can be elevated above the threshold level. Anything below that (-55mV) will not transmit an impulse.
What happens during depolarization?
Na+ channels are opened and a rush of Na+ enters the neuron creating an action potential (+40mV)
What is the refactory period? Why is it important?
The time between the Action potential and reestablishing the resting potential. It ensures that the signal continues in one direction (1 -2 ms)
What are the 2 types of synapses? Advantages of each?
Electrical Synapses are directed connected, ensures an instantaneous connection
Chemical Synapses release a neurotransmitter which can connect thousands of other neurons.
Describe the role of Schwann cells in maximizing nerve transmissions
Schwann cells provide a myelin sheath which acts as an insulator and speeds up transmission. Between Schwann cells are Nodes of Ranvier which allows sodium to reenter the neuron and “boost” the signal.
What are the 2 divisions of the autonomic nervous system?
Sympathetic and parasympathetic
Describe the function of the sympathetic nervous system, and give examples of the body’s response.
The SNS prepares your body for action (fight or flight). Increase heart rate, blood pressure, releases epi/norepi, inhibits digestion, stimulates breakdown of glycogen
Describe the function of the parasympathetic nervous system
The PSNS restores balance after stress has been induced. Ex. decreases heart rate
What are the 2 main hormones released during chronic stress?
Oxytocin and Cortisol
