Planarians have an incomplete digestive tract, one entrance surving as the mouth and anus.
Types of connective tissue would include all of these except blood. This is not a type of connective tissue like bone and muscle.
connective tissue
That is lactic acid.
This is what produces a "burning" feeling.
stabilizes, raises, retracts, and rotates scapula; adducts scapula and elevates /depresses scapula stabilizes, raises, retracts, and rotates scapula; adducts scapula and elevates /depresses scapula
chemicals
oxygen-rich blood
ganglion
endoskeleton
osteocytes
vertebrates
exoskeleton
salt-former ;)