exocrine
Epithelial tissue from epithelium. Below this is dermis, thicker and with blood vessels. Two specialized epithelia: pseudostratified transitional Pseudostratified epithelia lines the trachea where it is ciliated and the male urethra where it is non ciliated , looks stratified but not. Transitional epithelia found only in bladder and urinary system. As it stretches it appears to go from 6 to 3 cell layers deep. Glandular epithelia gland: group of cells that excretes something. mostly derived from epithelium. Glands are classified into endocrine and exocrine by where they excrete. Endocrine glands secrete hormones into the blood without use of ducts. Exocrine glands secrete onto the body surface or into a cavity, thru a duct. Exocrine substances include sweat, mucous, oil, and saliva. An exocrine gland is the liver, which secretes bile.