Human Structure and Function 1  Study Guide for Exam 4

Nervous System I:
First, don’t forget what you learned about the structure of a neuron and about the glial cells of the central and peripheral nervous system!
What is found in gray matter? Where is gray matter found?
Why is white matter white? What is myelin? What functions does the myelin sheath perform for the axon? What is missing from the plasma membrane of myelinating cells? Are unmyelinated axons without any covering?  What would happen if myelin was lost (as it is in Multiple Scerlosis)?
If I gave you a picture, could you identify a multipolar, bipolar and unipolar nerve cell? Why is the single process of the unipolar cell considered to be virtually all axon?
Which of the above neurons would be sensory neurons? Which would be interneurons?
What is meant by afferent and efferent neurons ? What type of information would each carry?
How do nerve fibers in the peripheral nervous system repair themselves? Why does this not happen (typically) in the CNS?
What is a resting membrane potential? What ions ( +and -) are found in higher concentrations inside the cell? Outside the cell? How do these ions get separated?
What is a leakage channel? A gated channel? What are the different kinds of gated channels?
What makes current in a cell?
Know the difference between graded potentials and action potentials. (Remember the chart on the PowerPoint?)
What do we mean when we say that a neuron is polarized?
What is a threshold?
What is depolarization? Hyperpolarization? How would they affect the ability of a neuron to achieve a threshold?
Why do graded potentials die out so quickly? (What is happening here?)
Know how an action potential is generated: what happens with the Na+ and K+ voltage-gated channels, how a cell depolarizes and repolarizes.  Be able to talk about Na+ activation and inactivation gates!
How is an absolute refractory period different from a relative refractory period?  What is happening that accounts for this difference?
Why does the propagation of an impulse travel in only one direction?
How does saltatory conduction differ from continuous conduction? Why are the gaps (nodes of Ranvier ) needed? Why is salutatory conduction more efficient than continuous conduction?
What two factors affect the speed of impulse propagation ?
How do anesthetics like novacaine and lidocaine work?
When the action potential reaches the synaptic end bulb, in addition to the Na+ and K+ channels, what other ion comes into the cell through voltage-gated channels and causes the release of the neurotransmitter?
Since axons have an all-or-none response, how does the central nervous system perceive a stimulus as being weak or strong?
What is an excitatory postsynaptic potential? What is an inhibitory postsynaptic potential?
What is happening to the neuron when a neurotransmitter is inhibitory?
What is summation? What are two types of summation?
What are electrical synapses? Are they common? What is the more common type of synapse?
In terms of neurotransmitters, what is a quantum? What is meant by “quantum content”?
Can a certain neurotransmitter be both excitatory and inhibitory?
What is a neuromodulator?
What are the classes of neurotransmitters?
Where is acetylcholine used as a neurotransmitter?  How is it broken down?
What effect do the amino acids glutamic acid and aspartic acid have in the CNS? What effect do GABA and glycine have?
Biogenic amines are modified amino acids. What are the catecholeamines?  How do they function? What are the indolamines?
What are neuropeptides, and how do they work? Which ones are the body’s natural pain killers?
How do purines act as neurotransmitters?
Which neurotransmitters are made only when needed, and why are they made this way? How do they affect the postsynaptic neuron?
Don't worry about all the problems associated with neurotransmitters listed in table - know Parkinson's disease and Alzheimer's disease.
How are neurotransmitters removed from the synaptic cleft?
What is meant when we say that a drug is an agontist or antagonist to a particular neurotransmitter?
What is a neuronal pool? A simple circuit? a diverging circuit? a converging circuit? What is a reverberating circuit good for? A parallel after-discharge circuit?

Nervous System II:
What are the three meninges that surround the brain and spinal cord ? Which is closest to the spinal cord? Which is outermost? What is each layer like? What are the falx cerebri, the falx cerebelli and the tentorium cerebelli?  What else protects the brain and spinal cord?
What does cerebrospinal fluid do for the brain? Where would you find cerebrospinal fluid? Where is cerebrospinal fluid formed? How? Where are the four ventricles in the brain? Where does the CSF flow, and where does it return to the vascular system?  What are dural sinuses?
What nerves come from and go to the cervical enlargement? The lumbar enlargement?
What is the filum terminale? The denticulate ligaments?  The conus medullaris?  The cauda equina? Where are spinal taps done? (i.e.,what level of the spinal column? )
Which type of nerves (motor or sensory) enter or leave the spinal cord by the posterior or dorsal root? By the anterior or ventral root?
What cell bodies are found in the anterior gray horn? In the lateral gray horn?
Would a single tract in the spinal cord carry both motor and sensory fibers? How else do tracts differ from peripheral nerves?
Where is the central canal? What flows through it?
Don't spend time memorizing all the tracts, but understand how the name indicates where it starts, where it ends, and what it carries.
Know that direct or pyramidal pathways conduct impulses for precise, voluntary movements of skeletal muscle, and that the indirect or extrapyramidal pathways convey impulses that deal with automatic movements, sweat glands, and maintain skeletal muscle tone and posture.
What are association neurons (interneurons) and what do they do? Where are they found?
What is a nerve pathway?
What is a reflex? What is the difference between a somatic and an autonomic reflex?
What are the components of a reflex arc?
Know how the stretch, flexor and crossed extensor reflexes work. Know which are monosynaptic and which are polysynaptic. What is reciprocal innervation?
Which of the reflexes are ipsilateral and which are contralateral?
Which are intersegmental?  (what does this mean?)
Read over brain development, but don't spend a lot of time here. What neural tube defects can be prevented if a pregnant woman gets enough of what vitamin?
What are the four principal parts of the brain?
The cerebrum:
What is a gyrus? A sulcus?
Where is the longitudinal fissure? The lateral fissure? The central sulcus? The transverse fissure?
What does the corpus callosum do? What are the three main paths for white matter fibers in the cerebrum?
What are the four lobes of the brain? Where is the central sulcus?  What and where are the primary motor cortex and primary somatosensory cortex? Remember that the lower motor neurons receive both excitatory and inhibitory input from both the direct and indirect pathways, and so lower motor neurons are called the final common pathway.  What type of paralysis will result if the upper motor neurons are damaged? What type of paralysis will result if the lower motor neurons are damaged?
What are Brodmann areas? (Know in general, don’t memorize all 52!)
What is an association area, and what does it do?
In a right handed person, what skills tend to be localized on which side of the brain? Which side of the brain controls which side of the body?
What is short term memory? Long term memory? What kinds of changes are associated with long term memory?
What is memory consolidation?
What and where are the basal ganglia? What neurotransmitter do they use? What happens when they degenerate?
Where is cerebrospinal fluid formed? How is it formed? Where does it go?
What happens if too much is formed, or not enough drains?
The diencephalon:
What makes up the diencephalon? What hormones does the pineal gland make?  What does this hormone do?
What does the infundibulum make?
The mamillary bodies are associated with what sense?
What does the thalamus do?
What does the hypothalamus control?
What part of the brain is called the "emotional brain"? Why? The cerebellum: What is the arbor vitae? The folia? The vermis? 
What is the main function of the cerebellum?
What are "intention tremors"?
Peripheral nerves: What are the connective tissue layers of a peripheral nerve?
How many spinal nerves are there? How many are cranial? Thoracic? Lumbar? Sacral? Coccygeal?
What type of fibers travel through the ventral or anterior root? Through the dorsal root?
What is a dermatome?
What is the autonomic nervous system? What are the two divisions of the autonomic nervous system? How are they the same? How are they different? What are cholinergic fibers? Where are they found? What types of receptors react to acetylcholine?
What are adrenergic fibers? Where are they found? What types of receptors react to norepinephrine and epinephrine? How would this be helpful to someone with asthma?
What part of the endocrine system is sometimes considered to be part of the sympathetic nervous system?
Which neurotransmitter would have a longer lasting effect, acetylcholine or norepinephrine? Why?
We reviewed the autonomic nervous system - very important stuff. Be sure you get it straight!!
Cranial nerves: Know the names and numbers of all 12 cranial nerves and their functions.
Know what the circle of Willis is, and what it does.

Text:
Chapter 3: Neurotransmitters bind with receptors on the postsynaptic neuron. These receptors can be one of two types. How do these two types of receptors function? (pg47)
Which are more likely to bring an axon to threshold: axodendritic synapses or axosomatic synapses?  Why? (Pg 49)
What is the most common method of removal of a neurotransmitter from the synaptic cleft? How does this method work? What are some others? (pg 49)
See page 52 for an explanation of why a certain neurotransmitter can be excitatory in one location and inhibitory in another.  (M1 and M2 receptors for Ach)
Understand in general the common pathway for  the formation of dopamine, norepinephrine and epinephrine, but you do not have to know all the enzymes. What two enzymes are involved in breaking down the catecholamines? (pg 53)
Why do peptide neurotransmitters have a longer effect than other neurotransmitters? (pg 57)
Why are they more readily depleted?

How does the “central pattern generator” of the spinal cord help to explain the “dance with madame guillotine” we spoke of in class? Pg 97
Do NOT get bogged down in detail here, but compare what your book is saying in a general sense with what was talked about in class.
What are ataxia, action (intension) tremors and hypotonia? Pg 106

Chapter 7: You DO NOT have to memorize the nuclei of the hypothalamus, but be aware of what the hypothalamus does.
What is leptin? Pg 121
What are circadian rhythms? What body responses follow this pattern? Pg 122
What are the alpha, beta, theta and delta waves of an EEG? What happens to brain waves during sleep?  What happens to body muscles during sleep? (pg 123 -125)
Note:  Sylvian fissure = lateral fissure. You will also hear the central sulcus called the fissure of Rolando.
Be sure to read about association areas on page 126.
What can happen if the limbic system malfunctions? (pg 126)
What are MAOI’s used for, and how do they work? (pg 128)
Where is the site of “working memory”? What happens to the information after it has been processed? (131)
What are declarative and procedural memory? (Pg 131)

Chapter 6:
What are the functions of the autonomic nervous system? (pg 108)
What is the difference in the way the somatic nervous system innervates a target structure and the way the autonomic nervous system innervates a target structure? (pg 109)
Why is the adrenal medulla sometimes considered to be part of the sympathetic nervous system? (pg 113)
You DO NOT have to worry about all the nuclei of the parasympathetic nervous system! (although some of the information here does give insight into the functions of the cranial nerves)
Table 6.1 You should know the action of the sympathetic and parasympathetic nervous systems on these organs, but will NOT be required to memorize the type of receptors.