Endocrine System Overview Exam1 Flashcards
Types of Cellular Communication
- Synaptic Connection
- neurotransmitters (type of chemical messenger)
- Endocrine communication
- classical hormones
- neurohormones
- cytokines
- Paracrine communication
- Direct communication
- gap junction (electrical)
- juxtacrine communication - Pheromone communication (animals)
Pheromone Communication
A pheromone is released by one animal that travels through the air and binds a receptor on a target cell in another animal.
Characteristics of Classical Hormone action
- Glands secrete hormones into the blood stream
- Hormones travel through blood to target cell in target tissue
- They bind a receptor in or on the target cell.
- Receptor binding activates a cell signaling pathway that changes what is happening inside the target cell
Methods by which a endocrine cell can be stimulated to secrete hormones
3 Major methods
- Ions or nutrients- changes in concentrations of ions or organic nutrients in blood and interstitial fluid (humoral regulation)
- Neurotransmitters-Neurotransmitters released on endocrine cell (nervous regulation)
- Another Hormone or Neurohormone (endocrine regulation)
Tropic Hormone
A hormone that stimulates the release of another hormone.
Juxtacrine Communication
Type of Direct Cellular Communication
The binding of molecules on adjacent cells (literally cells touching each other)
Are Water Soluble and Lipid Soluble Hormones transported in the blood stream? Where are they found in the blood?
Yes
Water Soluble Hormones are found in the solution (directly in blood)
Lipid Soluble Hormones are bound to carrier proteins to facilitate their transport
Are water soluble hormones also bound to carrier proteins in some instances?
Yes, there are carrier proteins for many water soluble hormones
Carrier Proteins
They help to raise the concentration of the hormone in the bloodstream.
Location of receptors for water soluble hormones
In Cell Membrane
Location of receptors for lipid soluble hormones
- In Cell Nucleus
- Cytoplasm
! The main receptors are in the nucleus or cytoplasm and affect transcription of genes (i.e. turn on protein synthesis) !
*rarely on cell membrane
Will water soluble hormone receptors be found on the cell membrane
The receptors for water soluble hormones such as peptides/proteins and most amines will on the cell membrane just like receptors for neurotransmitters.
Signaling Pathway
Physical interactions that take place when a hormone binds with a receptor
Signaling Pathway for a Water soluble hormone
- Enzymatic reactions
- protein binding
- Second Messenger systems
What does a signaling pathway do?
A cell signaling pathway is turned on when a hormone or neurotransmitter binds its receptor.
These pathways “translate” the signal of receptor binding into the activity that needs to occur in the target cell.