dendrites

Examples of dendrites in the following topics:

• Dendritic Cells

  • Dendritic cells are immune cells that function to process antigens and present them to T cells.
  • All dendritic cells are thought to arise from bone marrow precursors.
  • Immature dendritic cells (e.g.
  • Dendritic cells are constantly in communication with other cells in the body.
  • For example, stimulating dendritic cells in vivo with microbial extracts causes the dendritic cells to rapidly begin producing interleukin 12 (IL-12).

• Neurons

  • While some neurons have no dendrites, other types of neurons have multiple dendrites.
  • Dendrites can have small protrusions called dendritic spines, which further increase surface area for possible synaptic connections .
  • A bipolar neuron has one axon and one dendrite extending from the soma.
  • Each multipolar neuron contains one axon and multiple dendrites.
  • They also have more specialized structures, including dendrites and axons.

• Introducing the Neuron

  • Although some neurons do not have any dendrites, other types of neurons have multiple dendrites.
  • Dendrites can have small protrusions called dendritic spines, which further increase surface area for possible connections with other neurons.
  • The synapse is the chemical junction between the axon terminals of one neuron and the dendrites of the next.
  • One neuron's axon will connect chemically to another neuron's dendrite at the synapse between them.
  • Electrically charged chemicals flow from the first neuron's axon to the second neuron's dendrite, and that signal will then flow from the second neuron's dendrite, down its axon, across a synapse,  into a third neuron's dendrites, and so on.

• Structural Diversity of Neurons

  • A typical neuron consists of a cell body and neuronal processes such as dendrites and axon.
  • The dendrites are short, tapering extensions that are the receptive regions and help in conveying incoming messages towards the cell body.
  • Bipolar neurons have two processes, an axon and a dendrite, that extend from opposite ends of the soma.
  • Multipolar neurons, the most common type, have one axon and two or more dendrites.
  • A signal propagating down an axon to the cell body and dendrites of the next cell

• Phagocytes

  • The main types of phagocytes monocytes, macrophages, neutrophils, tissue dendritic cells, and mast cells.
  • Most monocytes leave the blood stream after 20–40 hours to travel to tissues and organs; in doing so differentiate into macrophages or dendritic cells depending on the signals they receive.
  • Dendritic cells are specialized antigen-presenting cells that have long outgrowths called dendrites, which help to engulf microbes and other invaders.
  • Dendritic cells are present in the tissues that are in contact with the external environment, mainly the skin, the inner lining of the nose, the lungs, the stomach, and the intestines.
  • Monocytes differentiate into dendritic cells and macrophages, while mast cells and neutrophils are in a separate group of PMN granuolcytes as well.

• Electric Potential in Human

  • Neurons receive an impulse at the dendrites.
  • When the signal reaches the end of the axon, neurotransmitters are released, which then are received by the dendrites of the next neuron.
  • Neurons receive an impulse at the dendrites.

• Characteristics of Nervous Tissue

  • A typical neuron consists of dendrites, the cell body, and an axon.
  • Dendrites are responsible for responding to stimuli; they receive incoming signals towards the cell body.
  • The dendrites receive incoming signals while axons propagate signals away from the neuron cell body.

• The Synapse

  • Synapses between axon endings of one neuron and a dendrite is called axodendritic synapse.
  • Synapses between 2 axons is called axoaxonal and between 2 dendrites is called dendrodendritic and between dendrites and cell body is somatodendritic.
  • Release of neurotransmitters usually follows arrival of an action potential at the synapse, but may also follow graded electrical potentials found in dendrites.

• Types of Nervous Tissue

  • The two types of neuron processes are called dendrites and axons.
  • Dendrites are motor neurons that are short and have a large surface area for receiving signals from other neurons.
  • Dendrites convey incoming messages towards the cell body and are therefore called the receptive input region.

• Lymph Nodes

  • Lymph nodes are repositories of B cells, T cells, and other immune system cells, such as dendritic cells and macrophages.
  • The cortex is mainly composed of clusters of B cells in the outer layers and T cells in the inner layers, and may contain antigen presenting dendritic cells as well.
  • Then, antigen presenting cells called dendritic cells present the antigen molecule to naive B and T lymphocytes, that then undergo cell cycle proliferation into lymphocytes that are able to specifically detect and eliminate pathogens associated with that antigen, through a variety of ways, such as cytotoxic action (T cells) and antibody production (B cells).
  • The lymph node is also arranged in such a way that the chance of B and T lymphocytes encountering dendritic cells is quite high, in order to facilitate antigen presentation.