AP Psychology Chapter 3 Test Prep

What is the nature and importance of the myelin sheath? Which disorder results from inadequate myelinization?

Myelin sheath: a fatty whitish insulation layer on the axon of some neurons that increases the speed of neural transmission. A tube like myelin sheath covers many axons that transmit info throughout the brain and spinal cord. Multiple sclerosis.

what is neural plasticity

Neural plasticity refers to the ability of neurons to change in structure and function.

What are the four lobes of the brain, and where are they located?

Neurologists have divided each hemisphere into four lobes: frontal (front), parietal (middle above), occipital (back), and temporal (middle underneath).

How does the endocrine system differ from the nervous system as a communications system?

Rather than using nerve impulses, the endocrine system conveys information in the form of hormones :)

cerebellum

The cerebellum is concerned primarily with muscular movement coordination, but it also plays an important role in certain types of learning and memory. Physical damage to the cerebellum results in severe motor disturbances characterized by jerky, uncoordinated movements, as well as an inability to perform habitual movements such as walking.

hypothalamus

The hypothalamus plays a major role in controlling many different basic biological drives, including sexual behaviour, temperature regulation, eating, drinking, aggression, and the expression of emotion.

Action potential

Unlike the graded potential which varies in proportion to the intensity of stimulation, the action potential obeys the all or none law; it either occurs with maximum intensity or not at all.

Wernicke's area and Broca's area

Wernicke's area in the temporal lobe is involved in language comprehension. Broca's area is in the frontal lobe is necessary for normal speech production.

Graded potential

a change in the electrical potential of a neuron that is proportional to the intensity of the incoming simulation, but not sufficient to produce an action potential

Peripheral nervous system

composed of all the neurons that connect the central nervous system with the muscles, glands, and sensory receptors

Central nervous system

consisting of all the neurons in the brain and spinal cord

Describe two methods by which neurotransmitter molecules are deactivated at the synapse.

deactivated by other chemicals located in the synaptic space that breaks them down into their chemical components. In other cases, the deactivation mechanism is reuptake (process where transmitter substances are taken back into the presynaptic neuron so that they do not continue to stimulate postsynaptic neurons)

Action potential (nerve impulses)

sudden reversal in the neuron's membrane voltage during which the membrane voltage moves from -70 millivolts to +40 millivolts. This negative to positive shift in voltage is called depolarization

pons functions

the pons lies just above the medulla, and it indeed serves as a bridge carrying nerve impulses between higher and lower levels of the nervous system. Like the medulla, the pons helps to control the vital functions, especially respiration, and damage to it can produce death.

What are three major types of neurons in the nervous system? What are their functions?

3 major types of neurons carry out the system's input, output, and integration functions. - Sensory neurons carry input messages from the sense organs to the spinal cord and brain - Motor neurons transmit output impulses from the brain and spinal cord to the body's muscles and organs - Interneurons, which far outnumber sensory and motor neurons, perform connective or associative functions within the nervous system. They link the input and output functions.

4. What causes the resting potential of neurons? Under what condition is a neuron said to be in a state of polarization?

A salty liquid environment surrounds neurons that carry a positive electrical charge (sodium ions). Although the inside of the neuron has some positively charged potassium ions, it contains many other ions that are charged negatively. The inside of neurons are electrically negative in relation to the outside producing an electrical resting potential of -70 millivolts across the membrane. When in resting state the neuron is said to be polarized

Name and describe the functions of the three main parts of the neuron

Cell body (soma): contains the biochemical structures needed to keep the neuron alive and its nucleus carries the genetic info that determines how the cell develops and functions. Dendrites (Greek word meaning tree): like antennas that collect messages from neighboring neurons and send them to the cell body. Axon: conducts the electrical impulses away from the cell body to other neurons, muscles or glands

3. How do glial cells differ from neurons? What three functions do they have in the nervous system?

Glial cells (Greek for glue) surround neurons and keep them in place. - Manufacture nutrient chemicals that neurons need - Form the myelin sheath around some axons - Absorbs toxins and waste materials that might damage neurons - Protects brain from toxins

medulla functions

medulla plays an important role in vital body functions such as heart rate and respiration. Because of the medulla, these functions automatically. Damage to the medulla usually results in death or, at best, the need to be maintained on life support systems