Question 1

Based on your understanding of homeostatsis in humans,you would expect a shutdown of the central nervous system of a cat to affect homeostasis.

Accepted Answer

The central nervous system plays a crucial role in regulating and maintaining homeostasis in humans and other animals. It controls and coordinates various physiological processes such as temperature regulation, heart rate, breathing, blood pressure, and fluid balance. A shutdown of the central nervous system, including the brain and spinal cord, would disrupt these vital functions and lead to a breakdown of homeostasis. Therefore, if a cat's central nervous system were to be shut down, it would also affect its ability to maintain homeostasis.

Question 2

During an action potential,

Accepted Answer

During an action potential, sodium ions rush into the cell, causing the potential to rapidly switch from its resting state of around -70 mV to a peak of around +35 mV. This depolarization phase is followed by repolarization, during which potassium ions rush out of the cell, causing the potential to return to its resting state. Therefore, option C is the correct choice because it describes the initial depolarization phase of the action potential.

Question 3

In myelinated axons,_____ ions can diffuse _____ the axon only at nodes of Ranvier.

Accepted Answer

Sodium ions can diffuse into the axon only at nodes of Ranvier in myelinated axons, as these nodes are the sites where the axonal membrane is exposed and ion channels are concentrated, allowing for the rapid exchange of ions necessary for the propagation of action potentials.

Question 4

The nervous tissue that consists of myelinated axons transmitting information throughout the central nervous system is the

Accepted Answer

The nervous tissue that consists of myelinated axons transmitting information throughout the central nervous system is known as white matter.

Question 5

The nervous system of a cat is more similar to the nervous system of a human than to the nervous system of a crayfish.

Accepted Answer

Cats and humans are both members of the animal kingdom and have a similar level of nervous system complexity, consisting of a brain and spinal cord connected to sensory and motor nerves throughout the body. In contrast, crayfish have a much simpler nervous system, with a series of ganglia or clusters of neurons that form a decentralized nervous system.

Question 6

A nerve impulse travels about __________ times faster when it leaps between nodes of Ranvier than when it travels along an unmyelinated axon.

Accepted Answer

A nerve impulse can travel up to 100 times faster when it leaps between the nodes of Ranvier compared to when it travels along an unmyelinated axon. This is due to the insulation provided by the myelin sheath, which allows the nerve impulse to jump from node to node instead of propagating along the entire length of the axon.

Question 7

Even though a hydra only has a nerve net,not a central nervous system,it still has

Accepted Answer

Hydra have synapses, which are the connections between nerve cells that allow for communication and transmission of signals. While they do not have a central nervous system like humans, they still have the ability to coordinate basic behaviors and responses through their nerve net and synapses.

Question 8

Usually nerve impulses travel from one neuron to another by

Accepted Answer

Nerve impulses travel between neurons by the release of neurotransmitters, which are chemicals that transmit signals across a synapse (the gap between two neurons).

B, C, D, and E all relate to the generation and propagation of action potentials within a single neuron, but do not explain how nerve impulses travel between neurons.

Question 9

The nervous tissue of the central nervous system that consists of neuron cell bodies and synapses is the

Accepted Answer

Gray matter consists of neuron cell bodies and synapses in the central nervous system.

Question 10

If you administered an acetylcholine-destroying drug directly into the brain of a rat,this might lead to a mimicking of

Accepted Answer

Acetylcholine is a neurotransmitter that is important for learning and memory. The destruction of acetylcholine in the brain is a hallmark of Alzheimer's disease, a neurodegenerative disorder characterized by cognitive decline and memory loss. Therefore, administering an acetylcholine-destroying drug directly into the brain of a rat would mimic Alzheimer's disease-like symptoms.

Question 11

The part of the brain that is responsible for homeostatic control of most organs is the

Accepted Answer

The hypothalamus plays a crucial role in regulating and maintaining homeostatic balance in the body, including controlling temperature, hunger and thirst, and the release of hormones from the pituitary gland.

Question 12

You are examining a primitive vertebrate and want to determine whether the same part of its brain coordinates muscular movement as in the human brain,so you would do a surgical experiment to disconnect the rest of the brain from the

Accepted Answer

The cerebellum is the part of the brain that is primarily responsible for coordinating muscular movement in both humans and other animals. By disconnecting the rest of the brain from the cerebellum in the primitive vertebrate, it can be determined whether the same region of the brain is involved in this function, as seen in the human brain. Therefore, the surgical experiment would involve disconnecting the rest of the brain from the cerebellum.

Question 13

You are asked to design a chemical to mimic another chemical critical for transmitting nerve signals from one neuron to another.Therefore,you know that you need to design an inhibitor chemical to counteract a(n)

Accepted Answer

Nerve signals are transmitted from one neuron to another through the release of neurotransmitters. Therefore, to mimic a critical neurotransmitter, an inhibitor chemical must be designed to counteract its effects.

Question 14

A condition that develops when serotonin levels in the brain are deficient is

Accepted Answer

Insomnia is a sleep disorder that can be caused by low serotonin levels in the brain. Serotonin helps regulate the sleep-wake cycle, so a deficiency can lead to difficulty falling asleep and staying asleep.

Question 15

You hear that a friend has had a traumatic injury to a part of the nervous system,resulting in a large loss in the ability to transmit nerve impulses.You guess that this means damage to the

Accepted Answer

The spinal cord is crucial for transmitting nerve impulses between the brain and the rest of the body. Damage to it can significantly impair the ability to transmit these impulses, affecting both sensory and motor functions.

Question 16

In nerve impulse transmission,the neuron sending the message across a synapse is called the

Accepted Answer

The neuron sending the message across a synapse is called the presynaptic cell. This is because it is located before (pre) the synapse and is responsible for sending the signal to the postsynaptic cell.

Question 17

If you read about a drug designed to lead to more release of dopamine from the synaptic terminals of certain brain neurons,you would know that the drug was designed to fix synaptic function and thus cure

Accepted Answer

Parkinson's disease is characterized by a loss of dopamine-producing neurons in the brain, leading to movement difficulties. A drug designed to increase dopamine release from synaptic terminals would help to restore normal synaptic function in Parkinson's disease patients.

Question 18

Nodes of Ranvier are intervals between Schwann cells that _____ the conduction of nerve impulses.

Accepted Answer

Nodes of Ranvier speed up the conduction of nerve impulses by allowing the impulses to jump from one node to the next along the axon, a process known as saltatory conduction.

Question 19

The division of the peripheral nervous system that carries signals to voluntary muscles is the _____ system.

Accepted Answer

The somatic nervous system is responsible for carrying signals to the voluntary muscles. The autonomic nervous system controls involuntary actions such as heart rate and digestion. The sympathetic and parasympathetic divisions are part of the autonomic nervous system and control responses to stress and relaxation respectively. Therefore, choices B, C, and D are incorrect.

Question 20

A condition that develops when GABA levels in the brain are deficient is

Accepted Answer

The answer of A condition that develops when GABA levels...

Quiz 26: The Nervous System