Chapter 1 of Physiological Psychology

1.              List the major structures of animal cells discussed in the text and give the main function for each.

1.     Membrane: the surface of a cell that separates the inside from the outside.

2.     Nucleus: structure that contains the chromosomes.

3.     Mitochondrion: a structure that performs metabolic activities by providing energy.

4.     Ribosomes: the sites within a cell that synthesize new protein molecules.

5.     Endoplasmic reticulum: a network of thin tubes that transport newly synthesized proteins to other locations.

2.              Copy and paste in a picture of a typical neuron.  Label the major structures discussed in the text.

3.              Give the main function for each major structure of a typical neuron.

a. Dendrite: receives information from other neurons via neurotransmitters.

b. Cell body/Soma: the major powerhouse of the cell containing the nucleus, ribosomes, and mitochondria, and is responsible for the metabolic work of the neuron.

c. Axons: a thin fiber that transports information from the dendrites to the presynaptic terminals.

d. Myelin sheath: an insulating material that covers the axon and increases the speed that information goes.

e. Nodes of ranvier: interruptions in the myelin sheath.

f. Presynaptic terminal: terminals at the end of axons that release information to neighboring cells.

4.              List the 4 main types of glial cells discussed in the text and give the main function for each.

a.     Astrocytes: synchronize the activity of surrounding axons by taking ions and transmitters, enabling axons to send messages in waves. Additionally, it dilates blood vessels to bring more nutrients into brain areas that have heightened activity.

b.     Oligodendrocytes and Schwann cells: build the myelin sheath.

c.     Radial glia: guide the migration of neurons and their axons and dendrites during embryonic development.

d.     Microglia: acts as part of the immune system by removing viruses and fungi from the brain.

5.              What is the function of the blood-brain barrier?  Why don’t we have a similar barrier around other body organs?

The blood-brain barrier surrounds the brain and keeps select chemicals outside of the brain. Neurons generally do not regenerate, unlike other cells, so that is why there is that extra layer of protection.

6.              What is the role of the active transport system?  What 4 types of chemicals are transported this way?

The active transport system expends energy to pump chemicals from the blood into the brain that includes glucose, certain hormones, amino acids, and a few vitamins.

7.              What is the function of the sodium-potassium pump?  How many of each ions are pumped in and out of the neuron in order to maintain the resting potential?

The sodium-potassium pump maintains the electrical gradient. 3 sodium ions are pumped out and 2 potassium ions are pumped in to maintain resting potential.

8.              Copy and paste a graph of how the electric potential of a neuron changes during an action potential.  Label the resting potential, threshold of excitation, and at which points the sodium and potassium channels open and close.

9.              What are the 2 types of refractory periods?  What are the conditions that lead to each?

a.     The absolute refractory period: the membrane cannot produce another action potential because it so recently produced an action potential.

b.     The relative refractory period: a stronger than usual stimulus is required to initiate an action potential because the cell is still resting after producing an action potential.

10.           Explain how the action potential travels down the axon by way of saltatory conduction.

As the signal travels down the axon, it lessens in strength, but the signal can trigger gates at the nodes of Ranvier to increase the current. At each node of Ranvier, the signal increases enough to reach the next node, effectively jumping from node to node