Cellular Physiology Flashcards
Disk-shaped structure for tight intercellular adhesion.
macula adherens / desmosomes
Ribbon-like patterns (structures) in cardiomyocytes which increase surface area for contact with adjacent cells.
fascia adherens
equivalent of zonula adherens
Identify the following tight junctions if leaky or tight:
a. proximal collecting tubule
b. jejunum
c. collecting duct
d. terminal colon
e. blood-brain barrier
leaky: PCT, jejunum
tight: CD, terminal colon, BBB
Recite the Fick’s law of diffusion.
J = PA (C1-C2)
Which of the following will decrease the permeability of a solute through a semi-permeable membrane?
a. decreased oil-water partition coefficient
b. decreased radius of solute
c. decreased membrane thickness
d. NOTA
e. AOTA
A. A decrease in partition coefficient will decrease the solubility of the solute in the lipid of the membrane.
Review Fick’s law of diffusion.
Doubling the area of the membrane and tripling the concentration gradient will
a. not affect the flux
b. double the flux
c. triple the flux
d. 6x the flux
e. 2/3 the flux
D. 6x the flux
J = P x A x (C1-C2) J' = P x 2A x 3(C1-C2) J' = 6J
Enumerate the three characteristics of carrier-mediated transport.
stereospecificity
saturation
competition
At high-solute concentration, facilitated diffusion will be _____ compared simple diffusion.
a. similar
b. slower
c. faster
d. NOTA
B. slower
At higher concentration, carrier proteins will be saturated hence facilitated diffusion will be slower.
The SERCA protein transfers calcium from the ____ to the ____.
from the cytosol to the sarcoplasmic reticulum
MOA of digoxin
inhibits Na-K-ATPase pump > inhibits Na-Ca pump > increase in intracellular calcium > greater cardiac contractility
The reflection coefficient of albumin is
a. >1
b. 1
c. <1
d. 0
e. undefined
B. 1
The reflection coefficient (RC) is a number between zero and one which describes the ease by which a particular solute permeates a membrane
1 = no penetration (all are reflected) 0 = complete penetration (none reflected)
The cell membrane resting potential is approximately
-70 mV
Conduction velocity of an action potential is most dependent on
nerve diameter
A nervous system tissue macrophage that act as scavenger cell which removes debris
microglia
Which of the following forms myelin in the peripheral nervous system?
a. Schwann cells
b. oligodendrocytes
c. astrocytes
d. fibrocytes
e. protoplasmic astrocytes
A. Schwann cells
oligodendrocytes - macroglia that forms myelin in CNS
astrocytes - macroglia acting as nurse cells
fibrocytes - astrocytes in the white matter
protoplasmic astrocytes - astrocytes in the gray matter
