1) What is a neuron? Draw one, and identify the major parts. Don’t peak at the answers until you try it. And don’t complain about drawing, I’m definitely not an artist, but I drew one for the answer sheet!
2) What are the functions of the different parts of the neuron? P.S. If you didn’t label the above neuron with all of the parts below, maybe you should go back and do that now…
1. Dendrites
a. Receive incoming “messages” (aka electrical current, or nerve impulses) from other neurons
2. Soma
a. The cell’s body, it contains the nucleolus
3. Axon hillock
a. Collects all the “messages,” and fires an electrical current if there is enough electrical current to make it
4. Axon
a. Carries the electrical message out to the Synaptic buttons
b. The Synaptic buttons release neurotransmitters into the synapse (synapse: the space between 2 neurons)
c. The neurotransmitters bind to dendrites on another neuron, thus continuing the electrical current
5. Myelin sheaths
a. Helps to strengthen and speed up the electrical current as it travels down the axon. If they weren’t there (such as in the case of a demyelination disease like Multiple Sclerosis), then the neurons would be able to communicate very little or not at all.
3) What are the 4 lobes of the brain, where are they located, and what function are they most known for?
1. Frontal lobe
a. Located at front of brain
b. Higher cognitive function, voluntary movement
2. Temporal lobe
a. On the lower sides, by your temples and your ears
b. Hearing (remember – ears)
3. Parietal lobe
a. Above the temporal lob on the upper sides (‘Parietal’ sounds like ‘parent,’ so I remember this by thinking that the parietal lobe is above the temporal lobe, just as a parent is above a child)
b. Sensory information
4. Occipital lobe
a. Back of head
b. Vision
4) How is the nervous system divided up?
1. Central Nervous System (CNS)
a. Brain
i. For most people, it thinks
b. Spinal cord
i. Bundle of nerves contained by vertebrae, is the information highway to the brain
2. Peripheral Nervous System (PNS)
a. Cranial Nerves
i. They’re fun to know, but I don’t think they really come up all that often
b. Spinal Nerves
i. Motor-sensory nerves coming in and out of the spine
c. Autonomic Nervous System (ANS): Mostly involuntary
i. Sympathetic Nervous System (SNS)
1. Tends to get you ready for “fight or flight” (i.e. dilates airway, increase cardiac output)
ii. Parasympathetic Nervous System (PNS)
1. Tends to ‘calm’ the body (i.e. constricts airway, decreases cardiac output)
5) What are some other major structures in the brain, and what do they do? Name as many as you can, your list may not be exactly the same as mine.
1. Corpus callosum
a. Connects the right and left sides of the brain so that they can communicate with each other
2. Hippocampus
a. Processes and stores memories
3. Amygdala
a. A major part of the Limbic System, deals with emotions
4. Thalamus
a. Major relay center for information going to the brain
5. Cerebellum
a. Movement and balance
6. Ventricles
a. Not the kind you find in the heart. These are like canals through the brain, and they are filled with cerebro-spinal fluid (CSF).
b. Cerebro-Spinal Fluid (CSF)
i. Clear, odorless fluid that contains glucose, protein, and O2, among other things.
ii. Cushions and protects the brain in a similar way that amniotic fluid helps protect a fetus! It flows around the brain through the sub-arachnoid space (one of the layers between the skull and brain), ventricles, and spinal column.
6) Describe what the blood-brain barrier is, and summarize its function.
The blood-brain barrier is a tightly packed wall of specialized cell (they’re endothelial cells to be exact, but you don’t have to memorize that). These cells line the walls of the capillary blood vessels in the brain so that nothing can accidentally get through from the blood to the brain.
But! The brain does need some things in order to survive (two important ones are O2 and glucose), so the blood-brain barrier will let these needed things into the brain (through active transport through the cell, if you care how).