Question 1

All of the following would occur if a neurotransmitter remained in the synaptic cleft except

Accepted Answer

If a neurotransmitter remained in the synaptic cleft, the rate of information processing would decrease as there would be less neurotransmitters available to bind to postsynaptic receptors. Therefore, choice C is the only option that is not a possible effect of a neurotransmitter remaining in the synaptic cleft.

Question 2

Evolutionarily, as animals increased in behavioral complexity, the pairs of ganglia in the anterior ends of their bodies fused to form

Accepted Answer

The fusion of ganglia in the anterior end of animals' bodies led to the formation of brains, which allowed for increased behavioral complexity. This occurred through the evolution of different groups of animals, such as invertebrates and vertebrates. Therefore, the correct option is (C) brains.

Question 3

As part of the peripheral nervous system, efferent neurons transmit information to

Accepted Answer

Efferent neurons are responsible for transmitting information from the central nervous system to effectors such as muscles and glands. They are part of the peripheral nervous system, which controls voluntary and involuntary movements of the body.

Question 4

Limb movement is controlled by sets of antagonistic muscles called flexors and extensors that work against one another.A sensory input to the motor neurons of these muscles will cause opposite effects.Why is this?

Accepted Answer

When a muscle is stimulated to contract, an interneuron applies an inhibitory stimulus to the antagonistic muscle. This allows for the coordinated movement of limbs by preventing both flexor and extensor muscles from contracting at the same time, providing a smooth and efficient movement.

Question 5

Infections of the brain are quite rare, thanks to the protective role of the _______, to which astrocytes contribute.

Accepted Answer

The answer of Infections of the brain are quite rare,...

Question 6

If you step on a sharp tack, sensory receptors in your foot will stimulate action potentials to be sent via sensory neurons into the spinal cord.The sensory neurons will synapse with several different interneurons there to

Accepted Answer

The stimulation of sensory receptors in the foot will trigger the withdrawal reflex, causing the foot to be pulled away from the sharp object. This reflex is mediated by interneurons in the spinal cord, which synapse with both sensory and motor neurons to produce a rapid and automatic response. The sensation of pain is also produced by the sensory neurons, which transmit the information to the brain for further processing. Therefore, option B is the best choice as it accurately describes the immediate response to stepping on a sharp tack.

Question 7

In the spinal cord, the gray matter contains the _______, and the white matter contains the _______.

Accepted Answer

Gray matter in the spinal cord primarily contains the cell bodies of neurons, while white matter consists of myelinated axons that facilitate the transmission of nerve signals.

Question 8

Morphine reduces pain because it is an _______ that potentiates the effects of _______.

Accepted Answer

Morphine is an agonist that binds to and activates opioid receptors in the brain and spinal cord. These receptors are normally activated by endorphins, which are the body's natural painkillers. By binding to these receptors, morphine potentiates the effects of endorphins and reduces the sensation of pain.

Question 9

In vertebrate nervous systems, most synapses between neurons are _______ whereas those between astrocytes are electrical.

Accepted Answer

The answer of In vertebrate nervous systems, most synapses between...

Question 10

Choose the correct order in which information moves through the vertebrate nervous system.

Accepted Answer

The correct order is: Specialized sensory cells detect a stimulus and send the information to sensory neurons, which relay the information to the central nervous system (CNS). The CNS processes the information and sends a response via motor neurons to effector cells (muscles or glands) to carry out a response.

Question 11

Earthworms and squid have clusters of neurons called

Accepted Answer

Earthworms and squid both have ganglia, which are clusters of neurons that serve as their primary control centers for sensory and motor functions. This is different from more complex animals like mammals, which have a centralized brain as their primary control center. The nerve net, peripheral nervous system, spinal cord, and central nervous system are all terms that can be used to describe various parts of the nervous system in different animals, but ganglia are the specific clusters of neurons that are characteristic of earthworms and squid.

Question 12

Neural networks contain functional categories of neurons involved with input, output, and integration.The types of neurons that carry information that has been transduced by specialized sensory cells to the central nervous system are

Accepted Answer

Afferent neurons carry sensory information from the sensory organs to the central nervous system, where it can be processed and integrated by interneurons and eventually lead to the activation of motor neurons or efferent neurons to produce a response. Transducing neurons are not a commonly recognized category of neurons, so B is not a correct answer. Interneurons, motor neurons, and efferent neurons are involved in processing and generating movements or responses, but not in carrying sensory information to the CNS, so A, D, and E are not correct answers.

Question 13

Damage to which brain structure would affect basic physiological functions?

Accepted Answer

The brainstem controls basic physiological functions such as breathing, heart rate, and blood pressure. Damage to this area can lead to serious complications and even death.

Question 14

One way to prevent a sensory stimulus, such as pressure, from being received by the nervous system is to chemically block

Accepted Answer

Afferent neurons transmit sensory information from the sensory cells to the nervous system. Blocking these neurons would prevent the physical stimulus from being detected by the nervous system. Choices A, B, C, and E do not directly relate to the detection of physical stimuli.

Question 15

A drug that blocks the GABA receptor

Accepted Answer

Blocking the GABA receptor can lead to increased neuronal excitability, which in some studies has been shown to improve cognitive functions, such as learning ability, in certain models like the mouse model of Down syndrome.

Question 16

Refer to the figure showing brains of various sizes and complexities.Keep in mind that the species shown can have similar body masses as adults.  Which statement is false?

Accepted Answer

The statement that brain size is a better indicator of behavioral complexity than brain size controlled for body size is false. Brain size alone cannot determine behavioral complexity as it must be scaled according to body size.

Question 17

The ventral horn of the spinal cord contains the

Accepted Answer

The ventral horn of the spinal cord contains the cell bodies of motor neurons, which are responsible for sending signals to muscles to initiate movement.

Question 18

The knee-jerk reflex is an example of

Accepted Answer

The knee-jerk reflex is an example of a monosynaptic reflex arc that involves a direct communication between a sensory neuron and a motor neuron within the spinal cord, allowing for a quick reflex action without the need for brain involvement.

Question 19

In vertebrates, most cells of the nervous system are found in the

Accepted Answer

The central nervous system (CNS) is where the majority of nervous system cells are found in vertebrates. The CNS includes the brain and spinal cord, which are responsible for processing and coordinating information from the body. The peripheral nervous system (PNS) consists of nerves that extend from the CNS to organs, muscles, and other parts of the body. The spinal reflex system and nerve net are both components of the PNS, but they do not make up the majority of nervous system cells in vertebrates. The spinal column is a part of the skeletal system and provides support and protection for the spinal cord, but it is not involved in processing or transmitting nerve impulses.

Question 20

Ganglia frequently come in pairs

Accepted Answer

Ganglia frequently come in pairs in animals that show bilateral symmetry, meaning they have a left and right side that are mirror images of each other. This allows for coordinated movement and sensory input on both sides of the body.

Quiz 44: Neurons, Glia, and Nervous Systems