A gateway substance is something that may be menial but could lead to something bigger, an example is weed in the drugs world, weed is not hard to get and is usually a gateway drug to stronger types of drugs and potentially more dangerous
Indeed, It is a progestin
Answer:
Produced by the choroid plexus -T.This is the major secretion site.It is also produced in smaller quantities in the interstitial compartment.
Blocks blood toxins from brain tissue-F, that is the job of the blood brain barrier(BBB).
Supplies oxygen to the brain tissue-T.This gas is dissolved in the CSF together with CO2 for distribution among nervous tissues by the CSF
Maintains the concentration of glycine surrounding the brain-T
Found in the ventricles of the heart and brain-False,it does not reach the heart ventricles.This are occupied by blood.
Prevents concussions-T
Produces antibodies in response to antigen exposure in the brain tissue-False.These are produced by the B-cells, not by in the CSF,based on the specif antigen stimulation.
Effectively decreases the brain's weight-T It reduces the weight of the brain.This is done by the buoyancy it provided for the brain.
Compared to levels in the blood plasma, the CSF is higher in glucose-F.This is wrong, the glucose of the blood plasma is higher.But equal sodium ion,more chloride in CSF, and less protein.It s levels is a relefection of blood glucose.Although it may lag 2-4hrs in the CSF.
It prevents concussion,(T)and and the contraction of cardiac muscles propels its movement(T).
Explanation:
Circulatory system:
--The circulatory system is also known as the cardiovascular system.
-- It is composed of the heart, blood, blood vessels and also includes the lungs.
The primary function of the circulatory system to distribute oxygen, nutrients, hormones and other gases to cells of the other body systems. It delivers all the necessary components needed for all the cell activities. Without the circulatory system, we would not be alive.
It is our blood that carries these necessary nutrients, hormones, and oxygen. All these components trigger certain processes that keep other organs functioning. It also plays a role in eliminating waste by carrying them to the necessary organs that will filter them out. Without a way to dispose of waste, the body will eventually die.
