AP PSYCHOLOGY

Detailed explanation-1: -Peristalsis is a type of involuntary muscle movement that occurs in your digestive system. It begins in your throat when you swallow, and continues to propel food and fluids throughout your gastrointestinal tract.

Detailed explanation-2: -Smooth muscle, found in the walls of the hollow internal organs such as blood vessels, the gastrointestinal tract, bladder, and uterus, is under control of the autonomic nervous system. Smooth muscle cannot be controlled consciously and thus acts involuntarily.

Detailed explanation-3: -Stomach. After food enters your stomach, the stomach muscles mix the food and liquid with digestive juices. The stomach slowly empties its contents, called chyme, into your small intestine.

Detailed explanation-4: -Chemical digestion, through a process called hydrolysis, uses water and digestive enzymes to break down the complex molecules. Digestive enzymes speed up the hydrolysis process, which is otherwise very slow.

Detailed explanation-5: -Involuntary muscles of the heart, respiratory and digestive systems work automatically. These operations are triggered by nerves and the nerves are stimulated by complex chemical fluids (such as acetylcholine and norepinephrine) that surround them and other living cells.