Related by context. Frequent words. (Click for all words.) 71 blood vessels 60 pores 60 vasculature 59 membranes 59 cell membrane 59 bloodstream 59 nerve fibers 58 membrane 57 cell membranes 57 circulatory system 57 capillary 57 urethra 57 dermis 56 lymphatic system 56 intestines 56 artery walls 56 muscle fibers 56 digestive tract 56 secretions 56 molecules 55 hair follicles 55 nerve cells 55 muscle tissue 54 axons 54 nasal passages 54 arteries 54 mucous membranes 54 aorta 54 tissues 54 intestine 54 epidermis 53 nerve endings 53 droplets 53 vesicles 53 lungs 53 filaments 53 epithelial cells 52 particles 52 sacs 52 mucus 52 artery 52 GI tract 52 droplet 52 glands 51 connective tissue 51 clot 51 ventricles 51 optic nerve 51 internal organs 51 carotid arteries 51 soft tissues 51 chest cavity 51 abdominal cavity 51 lymph 51 gastrointestinal tract 51 endothelium 50 intestinal tract 50 cilia 50 retina 50 salivary glands 50 mucous 50 secretion 50 sweat glands 50 cerebrospinal fluid 50 diseased cells 50 fatty tissue 50 fibroblasts 50 nuclei 50 vortices 50 neurons 50 left ventricle 50 proteins 50 immune cells 50 trachea 49 cells 49 microtubules 49 tissue 49 atria 49 arterial 49 fatty deposits 49 lipids 49 collagen 49 lobes 49 outer layer 48 axon 48 uterus 48 molecule 48 bile duct 48 tumor cells 48 veins 48 follicle 48 fibrous 48 outer layers 48 endothelial cells 48 small intestine 48 oxidize 48 clots 48 neutrophils 48 mitochondria 48 coronary arteries 48 esophagus