Endocrine Regulation Flashcards
Rb
Hypophospholyrated Rb is growth suppresive (cell cycle halted)
Paracrine systems
Employ hormones that DIFFUSE short distances to affect neighboring cell.
Also circulated throughout body at lower concentrations
Autocrine systems
Employ hormone to influence its own behavior
SAME CELL
Neuroendocrine and synaptic systems
release a chemical messenger that diffuses only a very short distance to neighbor
Justacrine signaling
cell to cell contact
through membranes or connexin molecules
Cytokines - def. , #
chemical messengers that coordinate the responses of the immune system. Can behave anyhow.
12
The body will try to keep glucose related variables _______
Constant
How does one get a higher response?
More receptors
Higher concentration of ligands
Messenger molecules, types, function
CM1 (membrane), CM2 (inside)
must bind to an appropriate receptor
Ultimate effect of messengers
Bind to the receptor to change enzyme activity in cell
How does one terminate messenger activity?
- Destroy ligand
- Desensitize receptor, internalize receptor ligand complex
- Internalize receptor ligand complex and destroy complex or just ligand/recycle receptor
Trophic effects
Promotes another glands health and growth w/o necessarily stimulating release of that hormone
Permissive effect
Presence of one hormone in a concentration greater than some threshold is required for second hormone to express its effect
Water and Lipid Solubility
Proteins
Steroids
Ameines
Proteins - No Solubility - LIPIDS Proteins - High Solubility - WATER Steriods - High Solubility - LIPIDS Steroids - No Solubility - WATER Amines - No Solubility - LIPIDS Amines - Low Solubility - WATER
Effects of Solubity
Can cross cell membrane - binds to Mobile Receptor - alter gene expression
Cannot cross cell membrane - binds to Membrane Receptor - triggers cascade to alter enxyme activity
Diuranal
Hormones level variation throughout day
Peaks early morning, lowest level @ 12am-4am
Kinds of stimuli that cause release of hormones
Other hormones
Solutes
Physical stimuli
Neural actiity
Hormonal Concentrations v electrolyte concentration
nanamolar, millimolar
Neurons - use, act on …, speed, concentrations
Neurotransmitters,
Other neurons, muscle cells and some gland cells
Fast
Locally high but little reach the rest of body
How does cytokine differ from hormone?
Produced by wide variety of cells all over the body while hormones are typically produced by a specific set of cells found in an endocrine organ
Present in concentrations three order of magnitude smaller than hormones
