Chapter 6 Physio Flashcards
Physiological Signals
- 2 kinds
- Electric signals- changes in a cells membrane potential
- Chemical signals - molecules secreted by cells into ECF
Local Communications
3 types
- GAP JUNCTION
- CONTACT DEPENDENT SIGNALS
- AUTOCRINE SIGNALS
GAP JUNCTION IS
Direct communication cytoplasmic connection between cells
Contact dependent signals require
Cell to cell contacts
AUTOCRINE SIGNALS are
Self , CHEMICALS diffuse through ECF to act on nearby cells
Long Distance Communication
Uses…….
Uses chemical ( endocrine) & Electrical (nervous) signals
Example is CENTRAL NERVOUS SYSTEM
And endocrine system
Cytokines uses what type of signals
And involved mainly in
BOTH local and long distance signals
Involved in stress and inflammation
2 kinds of signals inside cell
- Lipophilic - hydrophobic ( fat loving)
- Lipophobic - Hydrophilic
Can be found on the surface of the cell membrane
4 categories of membrane receptor - LIPOPHOBIC SIGNALS (hydrophilic)
- Receptor Channel
- G-protein coupled - GPCR
- Receptor Enzyme
- Intergrin receptor
1st messenger is
Receptor, signal outside cell
2nd Messanger is
Signal created inside the cell
Signal Transduction is
Process converting one signal to another
ONLY APPLIES TO LIPOPHOBIC SIGNALS
2 main purposes of Signal Transduction
- Cascade Reaction- cell to cell
- Amplification- one signal that creates more signals
2nd Messenger Pathways
- CAMP
- CGMP
- IP3
- DAG
- CA2+
- Nucleotide
cAMP
Name the following :
Enzyme
Linked to
Action
Effects
L: GPCR
A: PKA
E: PHOSPHORYLATES PROTEINS
ENZYME : ADENYLYL CYCLASE
g protein coupled receptor = GPCR**
- nucleotides
Cgmp
Name the following:
Enzyme
Linked to
Action
Effects
Enzyme : Guanylyl cyclase
L: Receptor Enzyme
A: PKG
E: Phosphorylates proteins
*Lipid Derived
IP3
Name the following :
Enzyme
Linked to
Action
Effects
E: Phospholipase C
L: GPCR
A: Releases CA2 (mostly found in SER )
Eff: CA2
*lipid derived
DAG
Name the following :
Enzyme
Linked to
Action
Effects
E: PLC
L: GPCR
A: activates protein kinase C
Eff: Phosphorylates Proteins
CA2+
Name the following :
Action
Effects
Action: Binds to calmodulin, contract smooth muscles
Binds to other proteins
Eff: Alters enzyme activity
Exocytosis , muscle contraction, cytoskeleton movement, channel opening
What are Receptor Channels-
Ligands binds to receptor (1st messenger)
And opens gate allows ions to move
- found in nerves and muscles, rapid signal
Gases are Ephemereal Signal which are ……
Short lived
Nitric Acid
cGMP
- Causes vasodilation
Cannon’s Postulate
(Reflex pathway)
Nervous
Tonic
Antagonistic
One chemical signal
ARACHIDONIC ACID CASCADE ( AA CASCADE)
Produce…..
Produce from membrane phospholipids
2 Enzymes of AA cascade
And what do they convert to
Lipoxygenase - converts to leukotrienes
Cyclooxygenase - coverts to 2 prostaglandins and Thromboxanes
Modulation of Signal pathways
- Specificity- shape
- Saturation - proteins working in max capacity
- Competition
Agonists
Same Effect
Antagonist
Opposite effect
Example: Insulin & Glucagon
True or false
One Ligand may have multiple receptors
True
Down Regulation
Decreases in receptor number
Up-Regulation
Inserts more receptor in the membrane
Process of converting one signal to another
Signal Transduction
Sympathetic Nerves
Increase heart rate
- Antagonistic
Parasympathetic Nerves
Decrease heart rate
- Antagonistic
What is IP3
Inositol Triphosphate
What does Kinase do?
Transfers 1 phosphate from ATP to another molecule
GPCR does
GPCR binds to Gprotein
Activates ADENYLYL CYCLASE
Converts ATP to cAMP
Activates PKA
cGMP stands for what
Cyclic GMP
Which category doesn’t have Gproteins?
Receptor enzyme
What enzyme activates your cAMP
AC
What receptors PLC is linked to?
IP3 AND DAG
Which receptor has a product of PKG
CGMP
AC stands for what?
Adenylyl Cyclase
What do you mean by Ephemeral
Short lived
What does Ephemeral cause?
Vasodilation
Receptor Enzyme does not have what?
Does NOT have Gprotein
Calcium needs to activate
Exocytosis
