3) Enzymes, Hormones, Nerves, Blood

Hormones are classified into two main types:

1. Peptide hormones (e.g. human growth hormone): These protein hormones are made up of amino acids and are water-soluble. They cannot pass through a cell membrane. They bind to receptors on the cell's surface...

Veins and arteries are major players in the circulatory system of all vertebrates . They work together to transport

Saliva and gastric acid contain enzymes that break the chyme down further with a process called chemical digestion, where our body further breaks everything we eat into small absorbable molecules.

The bolus keeps being pushed through the intestines and broken down ...