Cellular physiology II

The RMP of a muscle fiber is close to:
a. 0 mV
b. -90 mV
c. +50 mV
d. The K+ equilibrium potential

The RMP is mainly determined by:
a. The K+ gradient
b. The Na+ gradient
c. The Ca2+ gradient

Use the Nernst equation to calculate E for the following distribution of ions in mammalian SKM (values in mmol/L) (RT/F=26.7mV at 37°C)

Using the data from the previous question calculate the electrochemical gradients for Na+, K+, Ca2+, Cl-, and HCO3- when Vm is -90mV, -30mV, +50mV, and +100mV.

If Vm=-90mV at rest and +30mV at peak of AP what changes in relative P of Na+ and K+ take place? Hint: Use the Goldman equation ignoring the term for Cl- as it's passively distributed according to the prevailing K+ gradient (you could do the experiment in a Cl-free medium)

T/F? Hormones:
a. Are chemical signals secreted into blood
b. Can influence the behavior of many different cell types
c. Act only on neighboring cells
d. Are secreted by specialized glands

T/F? The following are released by 1 type of cell specifically to regulate activity of others:
a. NO
b. Prostaglandins
c. Insulin
d. Epinephrine
e. Ca2+
f. Glucose
g. cAMP

T/F? Receptors:
a. Are always proteins
b. Are always located in the cell membrane
c. May be membrane-bound enzymes
d. Can activate 2nd-messenger cascades via GP

T/F? Prostaglandins:
a. Are secreted by exocytosis
b. Are synthesized from phospholipids
c. Are hormones
d. Act on GPCRs

T/F? Steroid hormones:
a. Are lipid soluble
b. Directly activate ICH
c. Can alter gene transcription
d. Are secreted as they are synthesized

T/F?
a. Only excitable cells have Vm
b. RMP can be positive or negative
c. Vm generally between -40mV to -90mV
d. In excitable cells Vm is a physiological variable
e. RMP is an equilibrium potential

Which factors contribute to the RMP?

Why is RMP different from E(k+)?

Cells communicate in 3 ways:

Cells use chemical signals in 3 ways:

What is the difference between paracrine, autocrine and endocrine signals?

What are the advantages of synaptic compared to endocrine signaling?

Signaling molecules are very diverse in structure. What are the main 10 chemical classes they can be divided into?

What is the difference between agonist and antagonist?

What are the 4 basic ways cells respond to signals (depending on ligand and R)?

Certain GP subunits activate INC enzymes that synthesize INC signaling molecules (2nd messengers) which act on
specific INC targets. Give 3 examples of 2nd messengers and their activity.

	Criado por Francisco Sacadura quase 10 anos atrás

Physiology FlashCards sobre Cellular physiology II, criado por Francisco Sacadura em 15-01-2017.