Nerves

Neurons are classified by their structure and function. Structurally, neurons can be categorized as sensory neurons, motor neurons, or interneurons. Functionally, neurons can be classified as excitatory or inhibitory based on the type of signals they transmit.

Neurons are covered by a myelin sheath, which consists of layers of fatty tissue that insulates the axon and reduces leakage of impulses. The myelin sheath is formed by specialized cells called oligodendrocytes in the central nervous system, and Schwann cells in the peripheral nervous system. This insulation allows for faster and more efficient transmission of electrical impulses along the axon.

The first step for nerve impulse generation is the depolarization of the cell membrane, which is triggered by a stimulus. This depolarization causes a change in the electrical charge of the cell membrane, leading to the opening of ion channels and the initiation of an action potential.

The olfactory receptor neurons in the nose are the only neurons in the body that routinely undergo mitosis to replace damaged or aging cells. Other neurons in the central nervous system typically do not undergo mitosis and have limited capacity for regeneration.

Afferent Neurons

The alveoli in the lungs do not pertain to neurons. Alveoli are small air sacs in the lungs where gas exchange occurs during breathing, while neurons are the cells that transmit electrical signals in the nervous system.

In neurons, short, tapering, diffusely branched processes from the cell body are known as the dendrites. If the dendrites are short/tapering and diffusely branched, then this is referring to the dendrites of motor neurons.

thalamus, which acts as a relay station for sensory information traveling to the cerebral cortex. It plays a crucial role in processing sensory inputs before they reach higher brain regions responsible for perception.

Neurons make up only about 10% of the cells in the nervous system but they play a crucial role in transmitting and processing information. Glial cells, which provide support and protection to neurons, make up the majority of cells in the nervous system.

The synapse. It's comprised of 3 parts: an end of the pre-synaptic neuron (called an axon terminal, or axon button), the beginning of the post-synaptic neuron (usually a dendrite, or often a dendritic spine), and the gap in between them (called the synaptic cleft).

The synapse is held in place by small molecules called synaptic adhesion molecules, which protrude from each of the axon terminal and the dendrite, and stick together along parts of their lengths, like the two end joints of two fingers, one from each hand, laying against one another and glued together there.

Neurons can be functionally classified based on the direction in which they transmit signals: sensory neurons carry signals from sensory organs to the brain and spinal cord, motor neurons transmit signals from the brain and spinal cord to muscles and glands, and interneurons act as connectors and process information within the central nervous system.

A dendrite (or often a small protrusion from it called a dendritic spine) is the structure of a neuron that is usually the input to the neuron. A synapse is what makes the input to a neuron, via chemical messengers called neurotransmitters. And inputs to a neuron cansometimes be made to the soma (body) of a neuron, or even to the axon. But the dendrites are the "normal" input structures.

The Axon Hillcock is the site where EPSPs AND IPSPs are integrated in the neuron.

Interneurons

Actually, association nerve cells, also known as interneurons, primarily function to form connections between sensory and motor nerve cells, helping to integrate and process information within the nervous system. They play a crucial role in determining how the body responds to sensory information and in coordinating complex behaviors.

The nucleus of a neuron is typically located in the cell body, also known as the soma. It is located towards the center of the neuron, where it functions to control the activities of the cell and contains the genetic material needed for cellular functioning.

Acetylcholine is NOT the only chemical transmitter released by nerve endings. There are literally dozens. Ach is only the first discovered. Others include: glutamate, aspartate, serine, gamma-aminobutyric acid, glycine,dopamine, norepinephrine, epinephrine (adrenaline), histamine, serotonin, melatonin, adenosine, anandamide,

True ACh was discovered first and is not the only neurotransmitter released, BUT Acetylcholine is basically the one of most important in producing an impulse.

Bundles of neuron processes are called tracts in the cns and nerves in the pns

The action potential occurs at the axon hillock, which is the initial segment of the axon where the cell body transitions into the axon. This is where the threshold potential is reached and an all-or-nothing electrical signal is generated and propagated down the axon.

All processing at the circuit level going up to the perceptual level ultimately occurs within the neural networks in the brain. At each synapse, which is the connection between neurons, information is passed on in the form of electrical and chemical signals, allowing for complex processing and integration of sensory inputs to generate perceptions and behaviors.

The threadlike extensions of a neuron are called axons and dendrites. Axons transmit electrical signals away from the cell body, while dendrites receive signals from other neurons and transmit them towards the cell body.

The optic nerve begins at the back of the eye at the optic disc, also known as the blind spot. This is where the ganglion cell axons converge to form the optic nerve, which carries visual information from the retina to the brain for processing.

Serotonin is not a neuron, it is a neurotransmitter. It relays information between neurons, with serotonin producing a calming, happy feeling. Lack of serotonin can cause depression, but an over abundance of serotonin can cause psychosis.

The sense of touch is used when handling something. It allows us to feel the texture, weight, temperature, and shape of objects.

The opening across which one neuron communicates with another neuron is called a synapse. At the synapse, chemical signals called neurotransmitters are released from the presynaptic neuron, which then bind to receptors on the postsynaptic neuron to transmit the signal.