d) longitudinal muscle layer
e) submucosa
4) which of the following statements about the action potential is false?
a) the rapid depolarization phase is caused by the entry of potassium ions.
b) during the repolarization phase, sodium channels close and potassium channels open.
c) during the depolarization phase, membrane potential becomes positive.
d) in the after-hyperpolarization phase, membrane potential approaches the potassium
equilibrium potential.
e) repolarization occurs as potassium ions leave the axon.
5) aldosterone
a) is secreted in response to decreased levels of potassium in the blood.
b) promotes sodium retention in the kidneys.
c) helps decrease blood volume and lower blood pressure.
d) regulates blood calcium levels.
e) regulates water reabsorption in the kidneys.
6) the junction type that lets neighboring cells exchange small molecules is the
a) desmosome
b) hemidesmosome
c) gap junction
d) tight junction
e) zonula adherens
7) the atomic number represents the number of
a) electrons in an atom.
b) protons in an atom.
c) neutrons in an atom.
d) protons and neutrons in an atom.
e) chemical bonds the atom may form.