Question 1

Steroid hormones are chemically described as

Accepted Answer

Steroid hormones are composed of a nucleus of four interconnected cyclic structures, which gives them their characteristic shape and chemical properties. They are derived from cholesterol and include hormones such as testosterone, estrogen, and cortisol.

Question 2

Nerves that use acetylcholine as their neurotransmitter are said to be

Accepted Answer

Nerves that use acetylcholine as their neurotransmitter are classified as cholinergic. This is because acetylcholine binds to cholinergic receptors on the postsynaptic membrane.

Question 3

A molecule that enters the body from an external source and alters its normal functions is a(an)

Accepted Answer

A drug is a substance that is introduced into the body to produce a physiological effect, whether it is for medical or recreational purposes. It can alter normal body functions and has the potential for therapeutic or harmful effects depending on the intended use and dosage. The other options (agonist, antagonist, hormone, and steroid) do not necessarily indicate that a molecule is foreign or introduced externally.

Question 4

Which descriptions are true of neurotransmitters?
I.produced by the endocrine system
II.transported in the bloodstream
III.interact with cells in their direct pathway
IV.act within 1 second or less after release
V.effects are of short duration

Accepted Answer

Neurotransmitters interact with cells in their direct pathway (III), act within 1 second or less after release (IV), and their effects are of short duration (V). They are not produced by the endocrine system or transported in the bloodstream.

Question 5

Birth control pills work by mimicking what type of hormones?

Accepted Answer

Birth control pills contain synthetic versions of both estrogen and progesterone hormones, which prevent ovulation and pregnancy.

Question 6

Which of the following is a steroid based hormone?

Accepted Answer

Testosterone is a steroid hormone. The other options - epinephrine, vasopressin, glucagon and thyroxine - are not steroid hormones.

Question 7

Which type of steroids is mimicked by anabolic steroids?

Accepted Answer

Anabolic steroids mimic the effects of testosterone, which is a male sex hormone. Estrogen and progesterone are female sex hormones, and norethindrone is a synthetic hormone that is used in birth control pills.

Question 8

Depression is known to be caused by a deficiency of

Accepted Answer

Depression is associated with deficiencies in serotonin, dopamine, and norepinephrine, all of which are neurotransmitters involved in mood regulation.

Question 9

The neurotransmitter that is associated with the perception of pleasure and pain in the brain is

Accepted Answer

Dopamine is the neurotransmitter associated with the perception of pleasure and pain. It is involved in the reward system of the brain, and is released in response to positive stimuli such as food, sex, and social interaction. It is also involved in the experience of pain, and can be released in response to negative stimuli.

Question 10

Which of the following hormones acts directly rather than through a secondary messenger?

Accepted Answer

Estradiol is a steroid hormone and can diffuse across the plasma membrane of target cells to bind to intracellular receptors in the cytoplasm or nucleus. It then directly affects gene expression and protein synthesis without the need for secondary messengers. The other hormones listed, including glucagon, thyroxine, epinephrine, and vasopressin, all use secondary messengers to carry out their actions.

Question 11

Chemical messengers that carry signals between neurons are

Accepted Answer

Chemical messengers that carry signals between neurons are called neurotransmitters.

Question 12

A neurotransmitter that controls the perception of pain in the brain is

Accepted Answer

Enkephalin is an endogenous opioid neuropeptide that functions as a neurotransmitter to control the perception of pain in the brain. It is involved in regulating mood, emotion, and motivation, and is also responsible for modulating pain signals in the central nervous system. GABA is an inhibitory neurotransmitter that is involved in regulating anxiety, sleep, and muscle tone. Taurine is an amino acid that plays an important role in the function of the nervous system and is involved in regulating mood and behavior, but it is not directly related to pain perception. Histamine is a neurotransmitter that is involved in regulating wakefulness, appetite, and gastric acid secretion, but it is not directly related to pain perception. Dopamine is a neurotransmitter that is involved in regulating reward and motivation, but it is not directly related to pain perception.

Question 13

Which of the following is not part of a nerve cell?

Accepted Answer

The synaptic cleft is the tiny gap between the sending neuron, or presynaptic neuron, and the receiving neuron, or postsynaptic neuron. The axon, dendrites, and vesicles are all parts of a nerve cell.

Question 14

When acetylcholine is adsorbed onto a cholinergic receptor of a neuron,

Accepted Answer

When acetylcholine is adsorbed onto a cholinergic receptor of a neuron, the ion gates are opened and ions freely flow across the membranes. This triggers a signal and leads to neurotransmission. The other options are not accurate descriptions of this process.

Question 15

Monoamine oxidase inhibitors are good antidepressants because they

Accepted Answer

Monoamine oxidase inhibitors (MAOIs) increase the concentration of monoamine neurotransmitters such as serotonin, dopamine, and norepinephrine in the brain by blocking the action of the monoamine oxidase enzyme responsible for their breakdown. This increased concentration of neurotransmitters is believed to be responsible for the antidepressant effects of MAOIs.

Question 16

If a neurotransmitter molecule is to be used again to carry messages,it is removed from the postsynaptic neuron by the process of

Accepted Answer

Neurotransmitter molecules are removed from the synaptic cleft through reuptake, in which they are taken back up by transporters on the presynaptic neuron. This allows for the recycling and reuse of neurotransmitter molecules in subsequent neurotransmission. Antagonism refers to a situation where one neurotransmitter opposes the effects of another, enzymatic destruction and hydrolysis refer to ways in which neurotransmitter molecules can be broken down or degraded, and impulse transmission refers to the actual transfer of electrical signals along neurons.

Question 17

The short,tentacle like appendages coming from the main body of a nerve cell are called

Accepted Answer

Dendrites are the short, tentacle-like appendages coming from the main body of a nerve cell that receive incoming signals from other neurons or sensory receptors. Axons, on the other hand, are longer projections that transmit signals away from the cell body. Synapses are the gaps between neurons where these signals are transmitted. Vesicles are small sacs that contain neurotransmitters for release at the synapse. Collaterals are branches along an axon.

Question 18

The three monoamine neurotransmitters most studied in relation to moods and emotions are

Accepted Answer

Serotonin, norepinephrine, and dopamine are the three monoamine neurotransmitters most studied in relation to moods and emotions. These neurotransmitters are involved in regulating mood, motivation, and emotional responses. Imbalances in these neurotransmitters have been linked to various mood disorders such as depression, anxiety, and bipolar disorder.

Question 19

Compare the nervous system and the endocrine system with respect to chemical messengers used,and the messenger molecules' means of transport,specificity,and time lapse between release and effect.

Accepted Answer

The answer of Compare the nervous system and the endocrine...

Question 20

Which hormone is an example of a steroid?

Accepted Answer

Cortisone is a steroid hormone that is produced by the adrenal cortex. It plays a role in regulating numerous physiological processes such as metabolism, immune response, and stress response.

Quiz 28: Chemical Messengers: Hormones, neurotransmitters, and Drugs