Chapter 16.1- The Endocrine System is one of the body's two major control systems

endocrine system

-Controls body functions using chemical signals (hormones)

Endocrine chemical signals

-Signal is released into the blood to regulate the metabolic properties of other cells -travel long distances in the bloodstream (usually more than one type of target cell) eg. endocrine glands

The endocrine glands

-are made of epithelial tissue -Synthesize hormones and release them into the bloodstream -highly vascularized -can be multi or unicellular

Forms of chemical signaling include

-autocrine -signaling across gap junctions -paracrine -endocrine

nervous system

-controls body functions using electrical signals (action potentials)

Multicellular Endocrine Glands

-ductless glands that secrete hormones into the blood

Unicellular Endocrine Glands

-hormone-producing cells located in non-endocrine organs (adipose) Leptin Signaling cell: Adipose Target cell: Neuron (CNS) Effects: Triggers satiety

In the endocrine system, hormones travel through the

-more slowly through the blood. -Target cells respond for longer durations. (seconds to days) -response lasts much longer

In the nervous system, electrical signals travel

-quickly. -target cells respond for a short period of time (milliseconds) -response is short-lived

Paracrine chemical signals

-signal between two different cells in the same location -only act locally eg. neuromuscular junction

All chemical signals use some basic terminology...

-signaling cell -signaling molecule -target cell -receptor

Signaling across gap junction signals

-signaling cell and target cell are linked together by gap junctions -very special type of signaling eg. heart, intestines

Signaling molecule

-the small chemical that travels between cells -aka ligand

Autocrine chemical signals

-used by a cell to signal itself -(signaling molecule and receptor are on the same cell) eg. immune cells

Signaling across gap junctions

A cell targets a cell connected by gap junctions eg. heart, intestines

Endocrine signaling

A cell targets a distant cell through the bloodstream (long-distance signaling, chemical signals travel through blood) eg. endocrine glands

paracrine signaling

A cell targets a nearby cell eg. neuromuscular junction

autocrine signaling

A cell that targets itself eg. immune cells

The upper chambers of the heart contain individual cells that release a chemical signal that regulates blood pressure by altering kidney function. What type of signaling is this?

Endocrine signaling

Generally, endocrine signals travel faster than nervous system signals? T/F

False

Chemical signals are classified based on

How far the signaling molecule must travel

In autocrine signaling, where is the receptor for the chemical signal located?

In the same cell

Target Cell

cell that recognizes the sent chemical signal

Signaling Cell

makes and releases chemical signal

Receptor

protein on or (inside) the target cell that binds signaling molecule