1. Normally a neural impulse must travel to the brain for processing before any action concerning the impulse is taken. However, during a(n) _____ the muscles may receive information about what action to take without any communication with the brain.

action potential
resting potential
reflex
axonal conduction

Correct Answer = reflex

Explanation = in most cases, a neural impulse must travel from sensory neurons to the interneurons inside the spinal cord, to the motor neurons so the brain can process the information and determine the proper course of action. However, there are times when an immediate response is necessary that does not require any processing from the brain; these times are called reflexes. For example, when a doctor taps your knee and your leg kicks, there is no need for the information about having the knee tapped to go to the brain in order for you to know what to do. It is an automatic response. In this case, the information travels from the sensory neurons in your knee to the interneurons in your spinal cord and then right back to the leg on the motor neurons telling the leg to kick. You don't think about it or have any voluntary awareness because the information never gets to the brain for processing.

2. After angering the local bully, Bobby Brady realized he was about to get "socked" in the mouth. Once confronted with this situation, his sympathetic nervous system kicked in and, among other things, increased production of adrenaline, increasing blood flow to his muscles and away from his stomach. This response is known as the:

about to get my butt kicked response
fight-or-flight response
parietal response
parasympathetic response

Correct Answer = fight-or-flight response

Explanation = anytime we are confronted with danger or an exciting situation, our body goes though a series of changes that prepares us to either fight or to flee. The fight-or-flight is a safety measure that prepares the body to respond to the situation. There are two nervous systems involved in this response, the sympathetic nervous system is responsible for speeding the body up (increasing heart rate and respiration, bringing blood to the muscles so you can run or fight, etc.), and the parasympathetic nervous system which is responsible for slowing the body down and returning it to its normal state (homeostasis).

3. The neural impulse travels from beginning to end on neurons in the following order:

motor neuron; impulse neuron; interneuron
sensory neuron; motor neuron; interneuron
interneuron; motor neuron; sensory neuron
sensory neuron; interneuron; motor neuron

Correct Answer = sensory neuron; interneuron; motor neuron

Explanation = there is not much to say here beyond what has been said earlier. In order for the brain to process information about external stimuli and determine the appropriate response or course of action, information must travel into the body and to the central nervous system on the sensory neurons, then to the brain on the interneurons, and then back to the muscles for a reaction on the motor neurons.

4. Myelin is a fatty substance which covers the axon of a neuron to allow for faster transport of neural impulses and as protection for that neuron. However, there are gaps in the myelin (spaces on the axon where no myelin covering exists) at sights along the axon called:

Nodes of Ranvier
myelin
dendrites
synaptic cleft

Correct Answer = Nodes of Ranvier

Explanation = the neural impulse travels along the axon of a neuron via the action potential, which works by opening and closing the membrane of the neuron. One action potential causes another to occur right next to it, and so until action potential have occurred all the way across the axon. Myelin makes it so these action potentials do not have to happen so often. Instead an action potential only occurs where there is no myelin, at the Nodes of Ranvier. In this case, for information to travel all the way across an axon it may require 10 action potentials (this is a hypothetical number) as opposed to 100 that are needed without any myelin (also a hypothetical number).

5. The period in which a neuron is not presently carrying a neural impulse, but is ready and able to do so is called the:

absolute refractory period
action potential
resting potential
what's a neuron?

Correct Answer = resting potential

Explanation = before an action potential occurs (or after it has occurred), a neuron is in a state of readiness. What this means is that the electrical charge of the neuron is such that is at its "normal", inactive, but ready range so that at any time it is needed, it can fire immediately. The ions on the outside of the neuron and those on the inside of the neuron are balanced - there is a negative charge on the inside, and a positive charge on the outside, just like the neuron wants it. Once the action potential begins, the neuron opens and the positive ions come rushing in and the negative ions go rushing out, thus the action potential begins. But for that to happen, the neuron must be electrically balanced and in this state of readiness.

6. The biological system of communication that uses glands and hormones is the?

autonomic nervous system
peripheral nervous system
limbic system
endocrine system

Correct Answer = endocrine system

Explanation = information can travel throughout the body via the nervous systems which are fast acting and use both electrical impulses and chemicals. On the other hand, information can travel on the endocrine system which uses hormones and glands. The endocrine system is much slower, but is still very important and effective. In addition, the endocrine system secretes hormones into the blood stream as opposed to sending information on neurons. For example, sex hormones that determine whether you become a male or female travel on the endocrine system. This type of information can be more long lasting and happen more regularly than information that travels on the nervous systems.

7. The human brain is divided into two hemispheres that can communicate with each other because they are linked by the:

thalamus
hypothalamus
duodenum
corpus callosum

Correct Answer = corpus callosum

Explanation = the other answers are all brain parts that send information to other parts of the brain and/or body to make us think and act. However, the corpus callosum does not do this. Instead, the corpus callosum really works like a bridge, allowing information to pass from one side of the brain (hemisphere) to the other, but it does not send dictate or produce commands itself.

8. When neurotransmitters are released through the axon of the presynaptic neuron it enters the _____ on the way to the receptor sites in the dendrites of the postsynaptic neuron.

synapse
synaptic cleft
cytoplasmic region
Nodes of Ranvier

Correct Answer = synaptic cleft

Explanation = one thing that people often confuse is the difference between the synapse and synaptic cleft. The synapse is an area that includes many parts, such as the terminal buttons of the presynaptic neuron, the dendrites of the postsynaptic neuron, and the space between the two. However, the synaptic cleft IS the space between the two neurons. This is the gap that either must be small enough for the neural impulse to jump or, if not, requires the neuron to get neurotransmitters to travel across the gap and stimulate the dendrites on the other side to keep the information traveling throughout the body.

9. Often called the "Master Gland", this small brain structure is part of the endocrine system and is responsible for releasing numerous hormones throughout the body.

pituitary gland
gonadotropin
hypothalamus
corpus callosum

Correct Answer = pituitary gland

Explanation = this small gland is responsible for and influential in many different bodily functions. For example, it releases at least 7 different hormones that do such things as help the kidneys work, help retain memories, helps women lactate for breast feeding, stimulates growth, and much more.

10. A neural impulse carries information along neurons. These impulses move through the neurons riding on a "wave" called a(n) _____, which may be defined as a brief change in a neuron's electrical charge.

synaptic cleft
action potential
reticular activating system
resting potential

Correct Answer = action potential

Explanation = the action potential was discussed a couple of times earlier on this page, so I won't go into much detail here. Essentially, the action potential involves the opening of the neuron's membrane, to allow negative ions to rush out, and positive ions in. When this happens, it creates a change in the electrical charge of the neuron, and stimulates the area of the neuron next to it to also open up. This event (the opening and closing of the neuron's membrane) occurs repeatedly all the way across the axon, allowing the information to ride this wave of openings and closing until it can be passed onto the next neuron.

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