What gland produces a secretion that causes fight-or-flight responses in effectors? a) adrenal medullab) salivatory glandc) reproductive glandd) thymus

Adrenal medulla

Explanation:

Fight-or-flight or acute stress response is marked by physical changes, including nervous and endocrine changes, that prepare human or an animal to react or retreat. This response was first discovered by an American Physiologist, Walter Bradford Cannon.

In response to an acute stress, an area of the brain called AMYGDALA sends an emergency signal to the HYPOTHALAMUS, which acts like a command center and activates the body's sympathetic nervous system by releasing hormones. The sympathetic nervous system stimulate the adrenal medulla gland, triggering the release of CATECHOLAMINES (Epinephrine/adrenaline and Norepinephrine/noradrenaline) into the bloodstream.

This release induces several physiological changes in the body; The heart beats faster than normal; pushing blood to the muscles, heart and the vital organs, increased in blood pressure, blood sugar (glucose) are released into the bloodstream to give us the extra energy we need.

answer: - few nutrients

high pressure

low temperatures

explanation: 1. few nutrients:   open-ocean zone is located way far from the land, which is the main source of the essential nutrients.2. high pressure: pressure increases by 1 atmosphere for every 10 meters increase in depth.3. ample sunlight: a large fraction of the sunlight is reflected back to the atmosphere from the sea surface. 4. varying salinity: below the thermocline, the water is isolated from the atmosphere so the salinity remains stable over the year.5. low temperatures:   the temperature of open-ocean zone ranges from a low of -2°c to an average of 17°c