Understanding Neurons

What are the main parts of a neuron?

• Cell membrane, synapse, neurotransmitter

• Nucleus, ribosome, mitochondria

• Glial cells, axon terminals, myelin sheath

• Cell body, dendrites, axon

Answer explanation

The main parts of a neuron are the cell body, dendrites, and axon. The cell body contains the nucleus, dendrites receive signals, and the axon transmits impulses, making this choice the correct answer.

Describe the structure and function of dendrites.

• Dendrites are the main part of the neuron that sends signals to other cells.

• Dendrites are responsible for producing neurotransmitters in the neuron.

• Dendrites are unbranched structures that only transmit signals away from the neuron.

• Dendrites are branched structures of neurons that receive and integrate signals from other neurons.

Answer explanation

Dendrites are branched structures of neurons that play a crucial role in receiving and integrating signals from other neurons, making them essential for communication within the nervous system.

What role does the axon play in neuron communication?

• The axon receives signals from other neurons.

• The axon stores neurotransmitters for later use.

• The axon transmits electrical impulses and communicates signals to other cells.

• The axon protects the neuron from damage.

Answer explanation

The axon is crucial for neuron communication as it transmits electrical impulses away from the cell body, allowing signals to be communicated to other cells, making it essential for the functioning of the nervous system.

Differentiate between sensory, motor, and interneurons.

• Interneurons are the primary sensory receptors, motor neurons are involved in reflex actions, and sensory neurons control voluntary movements.

• Sensory neurons receive input from sensory organs, motor neurons send output to muscles, and interneurons connect the two within the central nervous system.

• Sensory neurons send signals to muscles, motor neurons receive input from sensory organs, and interneurons are found only in the peripheral nervous system.

• Motor neurons are responsible for processing sensory information, sensory neurons connect muscles to the brain, and interneurons transmit signals to the heart.

Answer explanation

The correct choice accurately describes the roles of sensory neurons (input from sensory organs), motor neurons (output to muscles), and interneurons (connecting the two in the central nervous system).

How do neurons transmit signals?

• Neurons transmit signals through electrical impulses only.

• Neurons send signals using only hormones.

• Neurons transmit signals via action potentials and neurotransmitter release.

• Neurons communicate solely by direct contact with each other.

Answer explanation

Neurons transmit signals via action potentials, which are electrical impulses, and neurotransmitter release at synapses. This combination allows for effective communication between neurons, making the correct choice the third option.

What is the function of the myelin sheath?

• To store neurotransmitters for later use.

• To protect neurons from damage.

• To insulate axons and increase the speed of electrical impulses.

• To connect different parts of the brain.

Answer explanation

The myelin sheath insulates axons, allowing electrical impulses to travel faster along the nerve cells. This is crucial for efficient communication within the nervous system, making it the correct function of the myelin sheath.

Explain the process of synaptic transmission.

• Synaptic transmission occurs only in the spinal cord and not in the brain.

• Synaptic transmission involves the direct electrical connection between neurons.

• Synaptic transmission is the process by which signaling molecules are released by a neuron and bind to receptors on another neuron, facilitating communication between them.

• Synaptic transmission is the process of muscle contraction in response to nerve signals.

Answer explanation

Synaptic transmission is the process by which signaling molecules, called neurotransmitters, are released from one neuron and bind to receptors on another neuron, enabling communication and signal propagation in the nervous system.

What is the significance of the cell body in a neuron?

• The cell body is significant because it processes information and maintains the neuron's health.

• The cell body stores neurotransmitters for later use.

• The cell body is responsible for the formation of myelin sheath.

• The cell body transmits signals to other neurons.

Answer explanation

The cell body is crucial as it processes incoming signals and maintains the neuron's overall health, ensuring proper functioning. This distinguishes it from other options that do not accurately describe its primary role.

How do neurotransmitters affect neuron function?

• Neurotransmitters have no impact on the communication between neurons.

• Neurotransmitters only affect muscle cells, not neurons.

• Neurotransmitters affect neuron function by transmitting signals between neurons, influencing excitatory or inhibitory responses.

• Neurotransmitters are solely responsible for the growth of neurons.

Answer explanation

Neurotransmitters play a crucial role in neuron function by transmitting signals between neurons. They can influence whether a neuron becomes excited or inhibited, thus affecting overall communication in the nervous system.

This refers to the process by which neurons are generated from neural stem cells and progenitor cells.