1) Endocrine
e.g: adrenal gland releases adrenaline throughout the body, causing an overall body reaction.
This is the most common form of cell signaling, and this type of signaling involves secreting hormones to other parts of the body.
Organs that release hormones (pituitary gland,
adrenal gland, etc.) are referred to as endocrine glands.
Organs that release hormones (pituitary gland,
adrenal gland, etc.) are referred to as endocrine glands.
2) Paracrine
A form of signaling in which a chemical secreted by a single cell travels through the interstitial fluid and affects nearby cells.
e.g: immune system and inflammation processes
e.g: immune system and inflammation processes
3) Neuronal
An extremely specific form of cell signaling, this type is utilized by neurons of the nervous system to invoke a response. Uses an electrical impulse traveling from one neuron to another neuron, releasing neurotransmitters from the synapses, at the terminal ends of the neuron.
e.g: Serotonin and neurotransmitters to convey emotion
e.g: Serotonin and neurotransmitters to convey emotion
4) Juxtacrine
This type of signaling does not involve the release of chemicals like the other three types, it only involves cells making physical contact with one another. Extremely important during cell specification of an embryo.
e.g: Gap junctions and plasmodesmata
e.g: Gap junctions and plasmodesmata