Summary of Effects of Adrenaline

Target Organ Effects of adrenaline Purpose & resultsLiver 1) Increases rate of

conversion of: Glycogen Glucose2) Arterioles dilate (become wider)

1) To increase blood sugar level so that more glucose is available for energy production (esp in muscles)2) Person feels active

Heart 1) Rate & Force of heartbeat increases2) Arterioles dilate

1) Send more blood containing oxygen and glucose to skeletal & heart muscles2) Heart thumps rapidly

Breathing center of brain and gaseous exchange organs

1) Breathing rate increases2) Arterioles in lungs dilate

1) To breathe in more air and increase blood flow to lungs so that more oxygen is absorbed into blood & more carbon dioxide is got rid of from it2) Person breathes rapidly (panting)

Muscles (skeletal)

1) Become tense2) Arterioles dilate

1) To prepare them for immediate action and increase blood flow to them2) Person trembles and feels tense

Blood vessels of kidney, skin & gut

Constrict (diameter becomes smaller)

1) Send less blood to these regions so more blood can flow to the muscles, liver and lungs2) Person looks pale, mouth becomes dry

Eye: radial muscles of iris

Contract Pupils (opening) become bigger

1) To allow more light to enter eye to form brighter images helps to detect visual dangers in surroundings2) Pupils dilate