Neuron Quest
The electrical charge of a neuron when it is in the resting potential state is about _____
-70 millivolts
There are roughly _____ neurons in the human brain
100 billion
What do the brain and spinal cord make up?
Central Nervous System (CNS)
What three parts do most neurons contain?
Dendrites; cell body (soma); axon
True or False: In the most sophisticated areas of the brain, glial cells send and receive information in almost exactly the same way that neurons do.
False; glial cells perform four major tasks: waste removal, myelin sheath creation in the brain and the rest of the body, and neuron nutrition
What is a function of cerebrospinal fluid?
It protects the central nervous system from being jarred
What is the function of acetylcholine?
Muscle contractions and memory
Paul was awakened by a thumping noise in the middle of the night. Frightened, he jumped out of bed to investigate. Hearing a muffled meow, Paul realized that his cat was locked in the closet and was pushing against the door. Breathing a sigh of relief, Paul let the cat out of the closet and went back to bed. Which subdivision of the nervous system helped calm down and restore Paul's body functioning back to normal?
Parasympathetic
What symptoms are too little dopamine in the brain associated with?
Parkinson's disease
What represents the sequence of ion movements that causes an action potential?
Sodium ions move into the axon and then potassium ions move out of the axon
True or False: Axons often have branches near their tips for communicating with more than one target
True, these branches are called synaptic/axon terminals
What is the action potential best described as?
a brief electrical impulse that transmits information along the axon of a neuron
What best defines a neurotransmitter?
a chemical messenger that crosses the synaptic gap between neurons
Professor Romero discovered that the overhead projector in her classroom had a short in the wiring system. When she touched the metal edge of the projector, she got an electric shock and instantly jerked her hand back. What is this instantaneous reaction is an example of?
a spinal reflex
What neurotransmitter is implicated in Alzheimer's disease?
acetylcholine (ACh)
_____ is another word for epinephrine
adrenaline
In general, the sympathetic nervous system _____, while the parasympathetic nervous system _____.
arouses and mobilizes; maintains and conserves
Where are the sodium ion channels concentrated in myelinated axons?
at each of the nodes of Ranvier
While taking this test, you have probably paid little attention to ongoing body functions, such as breathing, heartbeat, and digestion. What are such involuntary bodily functions governed by?
autonomic nervous system
What is the branch of psychology that is focused on understanding the internal physical events and processes that correspond with our experiences and behavior called?
biological psychology
The two main divisions of the nervous system are the _____ and the _____.
central nervous system; peripheral nervous system
The analogy used in the book referred to the axon membrane as a "gatekeeper." What does this mean?
controls the balance of positive and negative ions in the interior and the exterior of the axon
What does the all-or-none law refer to?
either the neuron is sufficiently stimulated and an action potential occurs or it is not sufficiently stimulated and the action potential does not occur
What are neurons?
highly specialized cells that receive and transmit information from one area of the body to another
The endocrine system involves communication by chemical messengers called _____, which circulate through the _____.
hormones; bloodstream
Prolactin and oxytocin are examples of _____ produced by the _____.
hormones; pituitary gland
What is the main link between the nervous system and the endocrine system?
hypothalamus
What happens to the neurotransmitters that fail to attach to a receptor site?
in a process called reuptake, they are reabsorbed by the sending neuron (presynaptic neuron) and recycled
How do antianxiety medications like valium and Xanax work in the brain?
increasing GABA activity
What is the primary purpose of the myelin sheath?
insulate the axon and increase the speed at which neurons convey their message
Presynaptic neuron is to postsynaptic neuron as _____ is to _____.
message-sending neuron; message-receiving neuron
What does the stimulus threshold of the neuron refer to?
minimum level of stimulation required to activate a particular neuron
What signals muscle to relax or contract?
motor neurons
Like a key in a lock, the shape of the _____ must fit the _____ to affect the postsynaptic neuron
neurotransmitter; receptor site
What do synaptic vesicles contain?
neurotransmitters
What drug mimics acetylcholine?
nicotine
In the _____, information is communicated along nerves.
peripheral nervous system (PNS)
Which gland directly regulates the production of hormones in other endocrine glands?
pituitary gland
What does the cell body of a neuron do?
provides the energy needed for the neuron to function
What is are the specialized calls that carry information from the sense organs to the brain called?
sensory neurons
What are the three basic types of neurons?
sensory neurons, motor neurons, and interneurons
As you are taking a test, you inadvertently drop your pencil, reach down, pick it up, and put it back on the desk. This voluntary action involved motor signals that were communicated out to your muscles via the _____ nervous system.
somatic
The two main subdivisions of the peripheral nervous system are the _____ nervous system and the _____ nervous system.
somatic; autonomic
The autonomic nervous system is composed of two different branches called the _____ and _____ nervous systems
sympathetic; parasympathetic
What is the point of communication between neurons called?
synapse
The presynaptic neuron and the postsynaptic neuron are separated by a tiny, fluid-filled space called the _____
synaptic gap
Generally, how does communication flow in the neuron?
the dendrites to the cell body to the axon (DCBA)
What does it mean when the neuron is in the resting potential state?
the fluid within the axon has a larger concentration of potassium ions than the fluid surrounding the axon (more negative inside with positive outside)
Which gland produces melatonin, a hormone that helps to regulate our sleep-wake cycle?
the pineal gland
The word dendrite comes from a Greek word meaning "_____."
tree