Name: __________________________ Class: _____________________ Date: _____________________

Nervous System Study GuideLatin and Greek RootsGive an example of a word from this chapter that contains each prefix or suffix.

Vocabulary1. Myelin – A sheath of lipids that surrounds and insulates axons.

2. Stimulus – Something that initiates a nerve impulse, such as a smell, sound, or other sensation.

3. Synapse – The space in between the axon terminal of one neuron and dendrite of another.

4. Neurotransmitter – A chemical message released into a synapse by a neuron.

5. Reflex – An action that occurs in response to something that bypasses the brain.

6. Meninges – Protective coverings of the brain made of connective tissue.

7. Ventricles – Spaces inside the brain that contain cerebrospinal fluid.

8. Cranial Nerves – Twelve pairs of nerves that originate directly from the brain.

Short Answer1. Differentiate between these divisions of the nervous system:

afferent / efferent – Afferent neurons send signals towards the brain. Efferent send signals away from the brain.

somatic / autonomic – Somatic neurons innervate voluntary muscles. Autonomic innervates involuntary muscles.

sympathetic / parasympathetic – Sympathetic neurons stimulate the “fight or flight” responses. Parasympathetic neurons stimulate the “rest and digest” responses.

Latin/Greek Root

Meaning Example

af- to Afferent

Arachne spider Arachnoid mater

dura hard Dura mater

ef- from Efferent

-glia glue Neuroglia

Latin/Greek Root

Meaning Example

Inter- between Interneuron

pia delicate Pia mater

Syn- together Synapse

2. Label each of the parts of a neuron below. Include the axon, axon terminal, dendrite, cell body, myelin sheath, and nucleus.

3. What is demyelination? What are two disorders that are the result of demyelination?Demyelination is the loss of myelin sheaths from the axons of neurons. This interferes with the normal rate of conduction of nerve impulses, causing a loss of sensation and motor control. Two disorders include mercury poisoning and multiple sclerosis.

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4. Label the pons, occipital lobe, precentral gyrus, postcentral gyrus, cerebellum, parietal lobe, central sulcus, spinal cord, temporal lobe, lateral sulcus, and frontal lobe.

5. Which portion of the neuron receives incoming signals? Which part conducts signals away from the cell body?The dendrites receive, while the axon conducts signals away.

6. Compare the function of sensory neurons, motor neurons, and interneurons.Sensory neurons conduct information such as sight, hearing, touch, and smell towards the brain. Motor neurons conduct signals from the brain to muscles, causing them to contract. Interneurons conduct impulses between two other neurons.

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7. Label depolarization, hyperpolarization, peak action potential, resting potential, Na/K ATP pump.

8. These statements describe the process of a neuron transmitting a nerve signal and recovering. Fill in the blanks with the words sodium, potassium, negative, positive.

a. A resting neuron has more potassium ions inside the membrane and sodium ions

outside the membrane. The overall charge across the membrane is negative.

b. Depolarization causes a protein channel to open, allowing sodium ions to flood inside the

cell membrane. The overall charge across the membrane is positive.

c. Repolarization opens a second protein channel, allowing potassium ions to leave the cell.

The overall charge across the membrane is negative.

d. The sodium-potassium ATP pump moves potassium ions back into the cell and

sodium ions back out of the cell.

9. Which of the steps of nerve signal transmission requires ATP to complete? The last step, the sodium potassium ATP pump.

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10. Order these events from start (1) to finish (6) as an efferent signal is sent to perform a voluntary movement.

___1___ A nerve signal is initiated somewhere in the cerebrum.

____5___ The neurotransmitter is absorbed by the membrane of the target muscle.

____4___ A neurotransmitter is released into the synapse.

____3___ The nerve signal travels down the axon, towards the terminal.

____2____ The signal is received by the dendrite of a neuron in the brain and travels through the cell body.

____6___ The effector muscle contracts.

11. What is the difference between botulism and tetanus?Botulisum is caused by a bacterial toxin that blocks the release of the neurotransmitter acetylcholine. This prevents muscle contraction, causing paralysis. Tetanus is a bacterial toxin that inhibits the normal breakdown of acetylcholine, causing prolonged contractions.

12. How is a reflex arc different than a typical muscle action? Give an example.Reflex arcs bypass the brain. The circuit includes a sensory neuron, an interneuron (in the spinal cord), and a motor neuron. An example is touching something sharp or hot and immediately pulling your hand away.

13. Label the afferent neuron, efferent neuron, and interneuron in this diagram of a reflex arc.

14. What part of the brain accounts for most of its mass?The cerebrum.

15. Describe a specific function that occurs in each of these lobes of the cerebrum.

a. Frontal Lobe – Higher level thinking, spoken language, writing, reading.

b. Temporal Lobe – Hearing, taste, olfaction sensory areas.

c. Parietal Lobe – Integration of sensory information.

d. Occipital Lobe – Vision.

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16. What is grey matter made of? White matter? Which is found on the surface of the brain?Grey matter is made of neuron cell bodies, white matter is the axons. The surface of the brain contains grey matter.

17. The thalamus is often referred to as the “sensory switchboard”. Explain why.Sensory information enters the thalamus and is routed to the appropriate lobe for interpretation.

18. Give two examples of the hypothalamus controlling homeostasis, or the body’s internal balance. Water balance and body temperature.

19. Some people take melatonin supplements to help them sleep regularly or more deeply. Why? Where does this hormone come from?Melatonin is a hormone released by the pineal gland that helps to regulate circadian rhythms, or the day-night cycle.

20. Give a specific example of something the medulla controls, and something the pons controls.Medulla – Heart rate, blood pressure, swallowing, vomiting, breathing.Pons – Breathing.

21. What is the purpose of the cerebellum?The cerebellum coordinates motor movements, creating posture and balance.

22. Label each structures in this sagittal view of the brain, including the corpus callosum, pineal gland, pons, medulla oblongata, hypothalamus, thalamus, cerebellum, parietal lobe, frontal lobe, occipital lobe, lateral ventricle, and the pituitary gland.

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23. Complete this graphic organizer of the nervous system.

24. Which of the three meninges is the strongest and thickest? Which contains all the blood vessels?The dura mater is the strongest. The arachnoid mater contains the blood vessels.

25. Explain how cerebrospinal fluid and the blood-brain barrier protect the brain differently.Cerebrospinal fluid helps to cushion the brain from sudden movements. If the skull is hit or suddenly moved, the fluid will cushion the shock of that force. The blood brain barrier protects the brain from foreign substances present in blood. Since blood does not directly enter the cranial cavity and nutrients diffuse into the fluid instead, infection is much less likely.

26. Explain the similarities the spinal cord has with the brain.The spinal cord is made of nerve axons, similar to the white matter of the brain. It is also encased in layers of bone (vertebrae) and dura mater. It also has cerebrospinal fluid around it.

27. Which division of the autonomic nervous system is associated with “fight or flight” type responses, such as increased heart rate?Sympathetic.

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28. Which division of the autonomic nervous system is associated with “rest and digest” type responses, such as increased blood flow to the intestines?Parasympathetic.

29. For each of the central nervous disorders, explain what is affected and the exact cause.

Disorder Affected Region(s) Cause

Encephalitis Brain Virus

Meningitis Meninges Inflammation (bacterial or viral)

Alzheimer’s Cerebrum UnknownConcussion Varies Impact

Brain Tumors Varies Cell overgrowth.

Multiple Sclerosis Myelin sheaths of axons Demyelination.

Stroke Varies Loss of blood flow.

30. For each of the cranial nerves, list one function.

Cranial Nerve Function

Olfactory Smell

Optic Vision

Oculomotor Eye movement

Trochlear Eye movement

Trigeminal Facial senses, chewing muscles

Abducens Eye muscles

Facial Sense of taste, facial muscles

Vestibulocochlear Sense of hearing and balance

Glossopharyngeal Sense of taste, swallowing muscles

Vagus Various – Sweating, peristalsis, heart rate, Page 8

larynx

Accessory Neck and back muscles

Hypoglossal Tongue

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