Quiz 3. Neurons/Nervous System

Explanation
Neurons, also known as "nerve cells," are responsible for forming a communication network within the body. They coordinate and enable the functioning of all the systems in the body. Neurons transmit electrical and chemical signals, allowing for the exchange of information between different parts of the body.

Explanation
Dendrites are the receiving part of the neuron. They are branch-like structures that extend from the cell body of a neuron and receive signals from other neurons. These signals, in the form of electrical impulses, travel through the dendrites and are then transmitted to the cell body and eventually to other parts of the neuron. Dendrites play a crucial role in the communication between neurons, as they receive and integrate incoming signals, allowing for the transmission of information throughout the nervous system.

Explanation
Myelin sheaths are layers of fat cells that insulate the axon. They are formed by specialized cells called oligodendrocytes in the central nervous system and Schwann cells in the peripheral nervous system. The myelin sheath acts as an electrical insulator, allowing for faster and more efficient transmission of nerve impulses along the axon. It also provides structural support and protection to the axon.

Explanation
A sensory neuron is a type of neuron that transmits information from the sensory organs (such as the eyes, ears, nose, and skin) to the brain or spinal cord. These neurons are responsible for detecting and conveying sensory stimuli, allowing us to perceive and interpret our environment. They play a crucial role in our ability to sense and respond to various stimuli, such as touch, temperature, pain, and sound.

Explanation
A motor neuron is a type of neuron that transmits signals from the brain or spinal cord to the muscles or glands, allowing for the initiation of movement or secretion. This type of neuron is responsible for controlling voluntary muscle movements and plays a crucial role in the overall functioning of the nervous system.

Explanation
A synapse refers to the tiny gaps between neurons and dendrites of another neuron. It is a crucial junction where information is transmitted from one neuron to another. This communication occurs through the release and reception of chemical neurotransmitters. The synapse plays a vital role in the functioning of the nervous system, allowing for the transmission of electrical signals and the coordination of various neural processes.

Explanation
The statement "It consists of the brain and spinal cord" accurately describes the central nervous system. The central nervous system is responsible for processing and coordinating information throughout the body. It receives sensory input from the peripheral nervous system and sends motor commands back to the muscles and organs. The brain, located in the skull, is the control center of the central nervous system and is responsible for higher cognitive functions. The spinal cord, protected by the vertebrae, acts as a pathway for signals between the brain and the rest of the body.

Explanation
The peripheral nervous system is responsible for connecting the central nervous system (which includes the brain and spinal cord) to the rest of the body. It consists of nerves and ganglia located outside of the brain and spinal cord, and it helps transmit sensory information from the body to the central nervous system and motor commands from the central nervous system to the muscles and organs. This allows for communication and coordination between the brain and the body, enabling various bodily functions and responses to occur.

Explanation
The autonomic nervous system is responsible for regulating the body's internal organs and processes, such as breathing, heart rate, and digestion. It controls these functions automatically, without conscious effort.

Explanation
The sympathetic nervous system is responsible for activating the fight or flight response in the body. When faced with an emergency or stressful situation, this system prepares the body to either confront the threat or escape from it. It increases heart rate, dilates blood vessels, and releases stress hormones like adrenaline, all of which help to mobilize the body's resources for immediate action. This response is crucial for survival in dangerous situations.

Explanation
The spinal cord is a complex cable of nerves that connects the brain to most of the rest of the body. It is made up of bundles of long nerve fibers.

Explanation
Axon terminals, also known as terminal buttons, are the small structures located at the ends of axons in neurons. These terminals are responsible for transmitting signals to other neurons or target cells. They contain synaptic vesicles that store neurotransmitters, which are released into the synapse when an action potential reaches the terminal. This allows for communication between neurons and is essential for the transmission of signals in the nervous system.

Explanation
The cell body of a neuron contains the nucleus, which is responsible for directing the production of substances needed for the neuron's growth and maintenance. This includes the synthesis of proteins and other molecules necessary for the neuron's functioning. The cell body also houses various organelles that support the neuron's metabolic processes. Therefore, the cell body plays a crucial role in ensuring the overall health and functioning of the neuron.

Explanation
An interneuron is a type of neuron that carries messages from one neuron to another within the central nervous system. It acts as a mediator between sensory input and motor neurons, allowing for the transmission of information and coordination of responses. Interneurons play a crucial role in processing and integrating signals within the nervous system, allowing for complex functions such as perception, decision-making, and movement.

Explanation
The nervous system is responsible for coordinating and organizing the activity of all living organisms. It is composed of the brain, spinal cord, and nerves, and it controls and regulates bodily functions such as movement, sensation, and cognition. Through its complex network of neurons, the nervous system receives and processes information from the environment and sends signals to different parts of the body, allowing for communication and coordination between different organ systems. Therefore, the nervous system is the correct answer for the system that coordinates and organizes the activity of all living organisms.