Answer:
Sympathetic nervous system activation constricts arteries found within the salivary glands
Explanation:
The ANS controls the involuntary contraction of the heart cardiac muscles, glands, intestine,the peripheral resistance of vascular systems, and the rate of pumping of the blood by the heart.
Thus, the ANS system during stressful conditions increases the blood pressure,heart rate, constrict blood vessels in glands and intestine and dilate the pupils, in anticipation for fight or flight.
<span>Fifty percent of the gases that make up the atmosphere are found below 5.6 kilometers in the atmosphere. As height increases the density of gasses is lowered until you finally exit the atmosphere and enter a vacuumous space.</span>
Answer:
B) cAMP
Explanation:
Phosphodiesterase is an enzyme that breaks a phosphodiester bond, for example in molecules such as cAMP and cGMP. So, phosphodiestarases are are regulators of signal transduction: regulate the duration of signaling pathway.
Caffeine is central-nervous-system stimulant and the mechanisms of its action usually are: mobilization of intracellular calcium or inhibition of specific phosphodiesterases.
1. Action potential reaches the axon terminal and depolarizes it.
2. Depolarization opens voltage-gated calcium channels, enabling influx of Ca into the neuron.
3. Calcium binds to specialized proteins on vesicles (containing pre-made acetylcholine) and triggers them to fuse with the neuron membrane at the synapse.
4. Exocytosis of acetylcholine into the synaptic cleft occurs.
5. Acetylcholine diffuses across the synapse and binds to nicotinic receptors on the end plate of the myocyte.
6. Activated nicotinic receptors, themselves ion channels, cause cation influx into the myocyte and generate an end plate potential. This eventually gives rise to the full depolarization within the myocyte that enables contraction.
This is a scientific question because you could conduct an experiment to test the theory.
