Describe the following types of cell signaling: Autocrine:

Juxtacrine:

Endocrine:

Paracrine:

Autocrine =  Autocrine signaling is a form of cell signaling in which a cell secretes a hormone or chemical messenger (called the autocrine agent) that binds to autocrine receptors on that same cell, leading to changes in the cell.This can be contrasted with paracrine signaling, intracrine signaling, or classical endocrine signaling.

Juxtacrine =  Juxtacrine signalling (or contact-dependent signalling) is a type of cell–cell or cell–extracellular matrix signalling in multicellular organisms that requires close contact.

Endocrine = Endocrine signaling occurs when endocrine cells release hormones that act on distant target cells in the body. Endocrine signaling can be distinguished from two other types of signaling: neural signaling and paracrine signaling. ... Neurons are connected to their target cells via synapses.

Paracrine = Paracrine signaling is a form of cell signaling or cell-to-cell communication in which a cell produces a signal to induce changes in nearby cells, altering the behaviour of those cells.

poor water quality affects most estuarine organisms, including commercially important fish and shellfish. the pollutants that have the greatest impact on the health of estuaries include toxic substances like chemicals and heavy metals, nutrient pollution (or eutrophication), and pathogens such as bacteria or viruses.