Psych- Chapter 3: Biological Process

antagonists

they block the action of neurotransmitters; e.g. curare

depolarization

when ion channels open and sodium ions flow into the cell; moves the electrical potential of the cell from negative toward zero

normally, ions will distribute themselves evenly in an environment through a process called ____

diffusion

agonists

drugs that enhance or mimic the action of neurotransmitters; e.g. nicotine

ions

electrically charged atoms and molecules that are distributed unevenly between the inside and the outside of the cell

messages travel _____ from one point to another within a neuron, but the message is transmitted _____ between neurons.

electrically, chemically

inhibitory messages

the cell membrane either pushes more positive ions out of the cell or allows negative ions to move in.

dopamine

a neurotransmitter that has been linked to reward and pleasure systems in the brain; decreased levels have been linked to Parkinson disease and increased levels have been linked to schizophrenia

serotonin

a neurotransmitter that has been linked to sleep, dreaming, and general arousal and may also be involved in some psychological disorders such as depression and schizophrenia

gamma- amino- butyric acid (GABA)

a neurotransmitter that may play a role in the regulation of anxiety; it generally produces inhibitory effects

acetylcholine

a neurotransmitter that plays multiple roles in the central and peripheral nervous systems, including the excitation of muscle contractions

the all-or-none electrical signal that travels to the end of the axon, causing the release of chemical messengers ____

action potential

myelin sheath

an insulating material that protects the axon and helps to speed up neural transmission

neuroscience

an interdisciplinary field of study directed at understanding the brain and its relation to behavior

the long tail- like part of a neuron that serves as the cell's main transmitter device ___

axon

pattern of activation

behaviors, thoughts, feelings, ideas do not arise from the activation of single neurons- they are produced by groups of neurons operating together that produces conscious experience and complex behaviors

sensory neurons

cells that carry environmental messages toward the spinal cord and brain

motor neurons

cells that carry information away from the central nervous system to the muscles and glands that directly produce behavior

glial cells

cells that fill space between neurons, remove waste, or help neurons to communicate efficiently

interneurons

cells that transfer information from one neuron to another; interneurons make no direct contact with the outside world

neurotransmitters

chemical messengers that relay information from one neuron to the next

the branchlike fibers that extend outward from a neuron and receive information from other neurons _____

dendrites

4 main parts of neurons

dendrites, soma, axon, terminal buttons

the thicker the axon, the ____ the message will travel

faster

nodes of ranvier

gaps in the insulation

reflexes

largely automatic body reactions- such as the knee jerk- that are controlled primarily by spinal cord pathways

endorphins

morphinelike chemicals that act as the brain's natural painkillers

the myelin sheath speeds up transmission and protects the message from interference from other neuronal signals. Some diseases such as, ________, damage the myelin sheath which results in the slowing of nerve impulses

multiple sclerosis

the inside of the cell is more ___ than the outside of the cell due to large protein molecules

negative

acetylcholine, serotonin, GABA, and dopamine are all examples of ______

neurotransmitters

soma

the cell body of a neuron; the cell's metabolic center and where the genetic material is stored

Three types of neurons

sensory neurons, interneurons, motor neurons

When the neuron is resting, the ____ and ___ are concentrated outside the cell and the _____ ions are largely contained inside

sodium, chloride, potassium

the main ions in neural transmission are positively charged ___ and ___ ions and negatively charged ____ ions.

sodium, potassium, chloride

the main body of the cell, where excitatory and inhibitory messages combine ____

soma

hyperpolarization

the cell membrane either pushes more positive ions out of the cell or allows negative ions to move in; the electrical potential of the cell becomes more negative

excitatory messages

the cell membrane- ion channels open- and sodium ions flow into the cell.

neurons

the cells in the nervous system that receive and transmit information

action potential

the electrical signal that the neuron transmits if sufficient electrical signal is present; the all- or- none electrical signal that travels down a neuron's axon

dendrites

the fibers that extend outward from a neuron and receive information from other neurons

Simple reflex pathway

the information that flame has touched flesh travels through a sensory neuron to the spinal cord, which directs it to an interneuron, which sends it on to a motor neuron. The motor neuron then alerts the finger muscles, which quickly withdraw from the heat. The original information is also passed upward to the brain, which registers pain.

axon

the long tail- like part of a neuron that serves as the cell's transmitter

glutamate

the most common neurotransmitter in the brain; usually an excitatory neurotransmitters, involved in many aspects of brain functioning including memory

refractory period

the period of time following an action potential when more action potentials cannot be generated

synpase

the small gap between the terminal buttons of a neuron and the dendrite or cell body of another neuron

resting potential

the tiny electrical charge in place between the inside and the outside of the resting neuron

terminal buttons

the tiny swellings at the end of the axon that contain chemicals important to neuron transmission

saltatory conduction

when the action potential jumps down the axon rather than traveling point to point