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
