Chapter 1 ( Cell Physiology ) Flashcards
Na+
136-145 mEq/L
K+
3.5-5 mEq/L
Cl-
100-106 mEq/L
HCO3-
22-26 mEq/L
BUN
8-25 mg/dl
Creatinine
0.8-1.2 mg/dl
ECF osmolality equation ?
ECF estimated osmolality =
2(Na)mEq/L + Glucose mg% / 18 + Urea mg% / 28
Factors stimulating aldosterone release ?
1- plasma angiotensin ll
2- plasma K
Regulators of ADH secretion ?
1- plasma osmolality ( directly related )
2- blood pressure ( inversely related )
3- angiotensin ll
4- CRH
Regulators of renin secretion ?
1- perfusion pressure to the kidney ( inversely related )
2- sympathetic stimulation by Beta-1 receptors
3- Na delivery to macula densa ( inversely related )
Circulating agents that increase capillary permeability ?
TNF-alpha
Bradykinin
Histamine
Cytokines
ECF measurement tracers ?
Inulin
Mannitol
Sodium
Sucrose
Total body water measurement tracer ?
Titrated water
Urea
Formula to convert plasma volume to blood volume ?
Blood volume =
Plasma volume / 1 - hematocrit
Diffusion equation ?
J = PA(C1-C2)
Characteristics of carrier mediated transporters ?
Stereospecificity
Saturation
Competition
Specific inhibitors of Na,K ATPase ?
Ouabain
Digitalis
Location of Na-Glucose cotransport ?
The luminal membrane of intestinal mucosal cells
Renal proximal tubule cells
Examples of cotransports ?
Na-glucose cotransport
Na-K-2Cl cotransport
Examples for countertransport ?
Na-Ca countertransport
Na-H countertransport
Effective osmotic pressure equation ?
Effective osmotic pressure =
Number of particles in solution osm/mol x concentration mol/L x gas content x absolute temperature x the reflection coefficient
Mechanism of nicotinic receptor ?
Its a ligand gated ion channel that opens when ACh binds to it , when open its permeable for Na and K causing the motor end plate to depolarize
Nernst equation ?
Equation to calculate equilibrium potential E = ( 60/z ) x log10(c1/c2) z : charge on the ion c1 : intracellular concentration c2 : extracellular concentration
Properties of action potential ?
Has stereotypical size and shape
Propagating
All or none
Mechanism of Tetrodoxin and lidocaine ?
Blockage of the voltage sensitive Na channels and abolish action potentials
Tetraethylammonium mechanism ?
Blockage of the voltage gated K channels
Why the myelinated nerves exhibit saltatory conduction ?
Because action potentials can be generated only at nodes of Ranvier where there are gaps in the myelin sheath
Toxins that block inactivation of the voltage gated Na channels
Ciguatoxin (fish)
Batrachotoxin (frogs)
Botulinus toxin mechanism ?
Blocks release of ACh from presynaptic vesicles leads to total blockade of neuromuscular transmission
Curare mechanism ?
Competes with ACh for receptors on motor end plate , leads to decreased size of EPP , maximum doses of which cause respiratory muscles paralysis and death
Neostigmine mechanism ?
Inhibits acetylcholinesterase leading to prolongation and enhancing of ACh action at MEP
Hemicholinium mechanism ?
Blocks reuptake of choline into presynaptic terminal leading to depletion of ACh stores from presynaptic terminal
Excitatory neurotransmitters ?
Acetylcholine Norepinephrine Epinephrine Dopamine Serotonin Glutamate
Inhibitory neurotransmitters ?
GABA
Glycine
Enzymes that metabolize norepinephrine ?
Monoamine oxidase (MAO) Catechol-O-methyltransferase (COMT)
Parkinson disease mechanism ?
Degeneration of dopaminergic neurons that use the D2 receptors
Schizophrenia mechanism ?
Increased levels of D2 receptors
Subtypes of glutamate receptors
Inotropic receptors ( ligand gated ion channels ) Metabotropic receptor ( coupled to ion channels via heterotrimeric G protein
Types of GABA receptors ?
1- GABA a receptor : increases Cl conductance , site of action of Benzodiazepines and barbiturates
2- GABA b receptor : increases K conductance
Glycine receptor mechanism ?
Increases Cl conductance
Myosin structure ?
6 polypeptide chains , one pair of heavy chain and two pairs of light chain
Troponin structure ?
Complex of three globular proteins :
Troponin T
Troponin I
Troponin C
Receptor of the T tubules ?
Dihydropyridine receptor , voltage sensitive protein
Calcium release channel in the SR ?
Ryanodine channel
Types of smooth muscles ?
1- Multiunit : iris , ciliary muscle , vas deferens
2- Unitary : uterus , git , ureter , bladder
3- vascular smooth muscles