Answer any pplease What is true during an action potential?
Group of answer choices
All choices are true.
C) Na+ channels close at a membrane potential of +100
B) Both Na+ and K+ channels open when depolarized.
None of the choices are true.
A) Only K+ is moving across the membrane during depolarization

Your patient is suffering from symptoms of excess cortisol. In order to diagnose the problem, you test his plasma levels of CRH, ACTH, and Cortisol.  His level of CRH is decreased but his levels of ACTH and Cortisol are both elevated. What is your diagnosis?

Group of answer choices
He has primary hypercortisolism due to a hypothalamus problem
He has primary hypercortisolism due to an adrenal cortex problem
He has secondary hypercortisolism due to an anterior pituitary problem
He has primary hypercortisolism due to an anterior pituitary problem
He has tertiary hypercortisolism due to a hypothalamus problem
 

The presence of myelin allows an axon to
Group of answer choices
conduct action potentials more rapidly.
produce action potentials of longer duration.
produce action potentials of larger amplitude.
produce more frequent action potentials.

A positive feedback loop is initiated in the conduction of an action potential when
Group of answer choices
the depolarized membrane closes the Na+ inactivation gate.
the depolarized membrane opens the Na+ activation gate.
the depolarized membrane opens the K+ inactivation gate.
the depolarized membrane opens the Na+ inactivation gate.
the repolarized membrane opens the Na+ inactivation gate.

Glycine is a neurotransmitter that opens Cl- channels in the membrane of a resting neuron. What will happen to the neuron after glycine binding?

Group of answer choices
Cl- ions will leave the cell and the cell will become hyperpolarized.
Cl- ions will enter the cell and the cell will become hyperpolarized.
Cl- ions will leave the cell and the cell will become depolarized.
Cl- ions will enter the cell and the cell will become depolarized.
 

Which of the following is NOT a way that hormone activity is terminated?
Group of answer choices
All choices are possible
Hormones may be converted into a new type of hormone
Hormones may be degraded by enzymes inside the target cell
Hormones may be degraded by enzymes in plasma

Graded potentials may
Group of answer choices
depolarize the membrane.
hyperpolarize the membrane.
all of the statements are true.
be initiated at dendrites and the cell body.
initiate an action potential.

A cell is separated from the ECF by a semi-permeable membrane. This membrane is permeable to X but not permeable to Y. The ICF has 4 osmoles/L of X and 2 osmoles/L of Y. The ECF has 3 osmoles/L of X and 3 osmoles/L of Y. Which of the following statements are true?
Group of answer choices
the cell will shrink
the cell will swell
the ECF is isotonic to the cell but the cell is hyperosmotic to the ECF
the cell and the ECF are both isosmotic and isotonic to each other
the ECF is isotonic to the cell but the cell is hyposmotic to the ECF

A few key areas of the brain lack the blood brain barrier (BBB) in order to do their job. Which structure below would lack the BBB?
Group of answer choices
cerebrum
cerebellum
hypothalamus
thalamus
midbrain