What are the four primary tissues in adult organ?

Epithelial Tissue- this tissue covers any bodily surface including organs, body cavities, and glands. There are subcategories of Epithelial Tissue, which are Squamous (pavement) , Simple Columnar, Simple Cuboidal, Glandular, Stratified, and Ciliated Columnar. The main functions of epithelial tissue are sensation, absorption, protection, cleaning, reduction of friction, excretion, diffusion, and secretion.

Connective Tissue- this tissue forms blood, cartilage, and bone. It is classified into dense connective, loose connective, reticular, elastic, and adipose.

Muscle- contractile tissue that causes movement in an organism as well as internal functions. The three types of muscle tissue are skeletal, smooth, and cardiac.

Nervous Tissue- this tissue is responsible for sending and receiving messages from muscle tissue to the brain. Nervous tissue is composed of neurons.