Answer:
Activation of the sympathetic branch of the autonomic nervous system results in Fight or flight response
Explanation:
The sympathetic nervous system originates in the spinal cord and its main function is to activate the physiological changes that occur during the fight-or-flight response. This component of the autonomic nervous system utilizes and activates the release of norepinephrine in the reaction. Sympathetic nervous system stimulation causes vasoconstriction of most blood vessels, including many of those in the skin, the digestive tract, and the kidneys. This occurs as a result of activation of alpha-1 adrenergic receptors by norepinephrine released by post-ganglionic sympathetic neurons.
The sympathetic nervous system activates what is often termed the fight or flight response. In response to this stimulus, postganglionic neurons principally release noradrenaline (norepinephrine). Prolonged activation can elicit the release of adrenaline from the adrenal medulla.
So in response to a stressor, the sympathetic nervous system orchestrates the fight-or-flight response. It increases muscle blood flow and tension, accelerates heart rate and respiration, and increases perspiration (sweating) and arterial blood pressure, widen bronchial passages, decrease motility of the large intestine, constrict blood vessels, increase peristalsis in the esophagus, cause pupillary dilation, piloerection (goose bumps) and raise blood pressure.
Answer: mechanical weathering
Explanation:
Weathering is the breaking down of rocks into small fragments or pieces by agent such as animals,water, wind. Erosion helps in the transport of this materials from its region to another.
Mechanical weathering is also known as physical weathering, it causes rocks to crumble as a results of disaggregation of rocks which could results from cracks, freeze thawing.
Water is an important agent of mechanical weathering, in either liquid or solid form.
Liquid water can seep into cracks and crevices in rock as in the case of Lurray Caverns in Virginia,and rock fragments will be eroded this materials accumulation of this leads to a new formation of calcite. If temperatures drop low enough, the water will freeze creating an expansion in the rock that could results in a crack or fragments of rocks falling off.