Related by context. Frequent words. (Click for all words.) 76 gastrointestinal tract 76 intestines 74 intestine 72 digestive 68 small intestine 64 esophagus 64 intestinal 62 blood vessels 61 respiratory tract 61 bloodstream 61 urinary tract 59 colon 58 gastric 58 digestion 57 bowel 57 stomach 56 bladder 56 muscle tissue 55 pancreas 55 uterus 55 internal organs 55 gastrointestinal 54 rectum 54 lungs 54 liver 53 tissues 53 cell membrane 53 cell membranes 53 placenta 53 mucus 52 retina 52 sinuses 52 anus 51 circulatory 51 aorta 51 excreted 50 inflammation 50 connective tissue 50 metabolism 49 gland 49 thyroid gland 49 optic nerve 49 lung tissue 48 glands 48 spinal column 48 gallbladder 48 secretion 47 nerve cells 47 abdomen 47 bacteria 47 protein 47 collagen 46 brain 46 vital organs 46 cervix 46 tummy 46 enzymes 46 arteries 46 inner ear 46 fibrous 46 proteins 46 pores 46 lipids 46 immune cells 45 windpipe 45 lung 45 skin 45 fluids 45 mitochondria 45 stomachs 45 airway 45 enzyme 45 clot 45 vagina 45 scar tissue 45 micro organisms 45 chronic inflammation 45 tissue 45 spinal cord 45 calcium 45 parasite 45 ovary 44 diaphragm 44 tumor cells 44 cysts 44 lymph nodes 44 electrolyte 44 microorganisms 44 amino acid 44 metabolic 44 membranes 44 bacterium 44 lesions 44 coronary arteries 44 molecule 43 parasites 43 urinary 43 soft tissue 43 cancerous cells 43 membrane 43 acid reflux