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Ch. 11 Fundamentals of the Nervous System and Nervous Tissue
Marieb - Human Anatomy & Physiology 7th Edition
Marieb, Hoehn7th EditionHuman Anatomy & PhysiologyISBN: 9780805359091Not the one you use?Change textbook
All textbooksMarieb, Hoehn 7th EditionCh. 11 Fundamentals of the Nervous System and Nervous TissueProblem 6
Chapter 11, Problem 6

Neuropeptides that act as natural opiates include
a. Substance P
b. Somatostatin and cholecystokinin
c. Tachykinins
d. Enkephalins

Verified step by step guidance
1
Step 1: Understand the term 'neuropeptides' — these are small protein-like molecules used by neurons to communicate with each other. They often modulate pain and other physiological functions.
Step 2: Recognize that 'natural opiates' refer to endogenous substances in the body that bind to opioid receptors and produce effects similar to opiate drugs, such as pain relief.
Step 3: Review the options given: Substance P, Somatostatin and cholecystokinin, Tachykinins, and Enkephalins, and recall their primary functions in the nervous system.
Step 4: Identify which neuropeptides are known to act as natural opiates by binding to opioid receptors and modulating pain — these are typically enkephalins and related peptides.
Step 5: Conclude that among the options, enkephalins are the neuropeptides that act as natural opiates.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Neuropeptides

Neuropeptides are small protein-like molecules used by neurons to communicate. They modulate brain activity and influence various physiological functions such as pain, mood, and appetite. Unlike classical neurotransmitters, neuropeptides often act over longer distances and times.

Natural Opiates (Endogenous Opioids)

Natural opiates, or endogenous opioids, are neuropeptides produced by the body that bind to opioid receptors to reduce pain and induce feelings of euphoria. Examples include enkephalins, endorphins, and dynorphins, which mimic the effects of opiate drugs like morphine.
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Natural Killer Cells

Enkephalins

Enkephalins are a type of endogenous opioid neuropeptide that bind to opioid receptors in the nervous system to inhibit pain signals. They act as natural painkillers and are involved in regulating nociception and stress responses.
Related Practice
Textbook Question

Match the names of the supporting cells found in column B with the appropriate descriptions in column A.

Column A 

_______ (1) myelinates nerve fibers in the CNS 

_______ (2) lines brain cavities 

_______ (3) myelinates nerve fibers in the PNS 

_______ (4) CNS phagocyte

________(5) helps regulate the ionic composition of CNS extracellular fluid

Column B

a. Astrocyte

b. Ependymal cell

c. Microglial cell

d. Oligodendrocyte

e. Satellite cell

f. Schwann cell

Textbook Question

Assume that an EPSP is being generated on the dendritic membrane. Which will occur?

a. Specific Na⁺ channels will open.

b. Specific K⁺ channels will open.

c. A single type of channel will open, permitting simultaneous flow of Na⁺ and K⁺.

d. Na⁺ channels will open first and then close as K⁺ channels open.

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Textbook Question

Biogenic amine neurotransmitters include all but

a. Norepinephrine

b. Acetylcholine

c. Dopamine

d. Serotonin

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Textbook Question

An IPSP is inhibitory because

a. It hyperpolarizes the postsynaptic membrane.

b. It reduces the amount of neurotransmitter released by the presynaptic terminal.

c. It prevents calcium ion entry into the presynaptic terminal.

d. It changes the threshold of the neuron.

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Textbook Question

Inhibition of acetylcholinesterase by poisoning blocks neurotransmission at the neuromuscular junction because

a. ACh is no longer released by the presynaptic terminal.

b. ACh synthesis in the presynaptic terminal is blocked.

c. ACh is not degraded, so prolonged depolarization is enforced on the postsynaptic cell.

d. ACh is blocked from attaching to the postsynaptic ACh receptors.

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Textbook Question

The anatomical region of a multipolar neuron where the AP is initiated is the

a. Soma

b. Dendrites

c. Axon's initial segment

d. Axon terminals

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