Flashcards in Coordination and Regulation, Nervous System Physiology Deck (33):
Between what must organ systems be coordinated?
Within an animal and with the environment.
What are the two major systems of coordination and regulation?
Nervous system [communication primarily through electricity] and endocrine system [hormones, chemical communication system]. Both systems act together.
What animal does not have a nervous system?
The sponges because all the cells in the sponge can survive independently and do not rely on communication to survive.
What are the three major roles of the nervous system?
1. Collecting information
2. Process and integrate information
3. Transmit information
What does "collecting information" mean?
From the internal or external environment, a network of nerves are constantly accessing what is going on and transmitting the information to the brain. Modified neurons (sensory receptors) are also used.
What does "process and integrate information" mean?
Evaluating information based on past experiences or genetics; occurs mostly in the CNS, in the brain.
What does "transmit information" mean?
The brain comes up with a response signal that is then transmitted to a response/effector organ.
What is a neuron?
A cell that generates bioelectric signals that are used to transmit information to other cells. When a neuron is fully grown/matured, it loses the capacity to divide. Glial cells support the development and functioning of neurons.
What are Sensory/Afferent Neurons?
Neurons that sense external or internal information and sends it to the brain.
What are Motor/Efferent Neurons?
Neurons that send response signals from the CNS and send it to the response organ.
What are Interneurons?
Neurons that form interconnections between other neurons in the CNS; primarily found in the brain, accepts information from afferent neurons.
Where are Afferent and Efferent Neurons located?
In the Peripheral Nervous System.
What are Glial Cells?
They play a supportive role, they protect the cell and provide structural support. They guide neurons through growth and provide nutrients for growth.
What are the types of vertebrate glial cells?
Schwann cells, oligodendrocytes, and astrocytes.
What are Schwann cells?
An insulating layer [myelinate PNS neurons] for the afferent/efferent neurons.
What are Oligodendrocytes?
They mylinate CNS neurons.
What are Astrocytes?
The blood-brain barrier, a very fine protective layer that keeps harmful substances out of the brain. Star-shaped.
What are dendrites?
They are the branching around the cell body that receive information from incoming stimulus.
What is the soma?
The cell body, contains the nucleus and most organelles.
What is the Axon Hillock?
Where the action potential is generated, between the soma and the axon.
What is the Axon?
Where the information is transmitted away from the cell body. Long, glial-cell layered, tail coming off of the soma.
What are the Terminal Branches?
Nerve terminals that transmit information to other neurons or effectors.
What do the Glial Cells do to the Axon?
A single glial cell wraps itself around an axon to form a segment of the myelin sheath, allowing signals to jump from one gap to another to speed up the velocity of the signals.
What is a Nerve?
A bundle of axons.
A nerve fiber.
What is a Synapse?
Connections between axon terminal and effector cells.
What are the basis of bioelectricity?
Membrane potentials, the difference between the charge inside and outside of the cell.
What is the Electrical Potential?
The difference in electrical charge between regions, measured in volts.
The flow of electrical charge between regions.
What is Membrane Potential?
Unequal charge distribution across a cell membrane.
All living cells are electrically polarized, which means:
1. They all have a Membrane Potential.
2. The inside of the membrane is negative relative to the exterior.
3. Size of membrane potential ranges from -10 to -70 mV.
4. Voltmeters can record the voltage difference.
5. Measure of MP is a function of time.
What are the three types of Membrane Potential?
1. Resting Membrane Potential
2. Action Potential (depolarization, very large and rapid)
3. Electron Potential (small)