Unicellular organisms such as bacteria and protists utilize behavioral physiology for thermoregulation. 1. loose connective tissue - binds tissues to other tissues, such as skin to underlying tissues 2. Glial cells - support cells for the neurons Muscle Tissue Muscle fibers or cells are elongated and contract when they receive signals from neurons. The skin is an example. Organ Systems Organ systems are made up of organs.
Organs often consist of more than one cell or tissue type.
Endocrine system - processes information and helps control the physiology and behavior of the organism, but works more slowly than the nervous system and its effects tend to be more widespread. Secretions from endocrine organs reach their target cells via the blood because the endocrine organs are ductless glands. Some tissues that are not organs also secrete local or tissue hormones. Skin This is the largest organ of the body. Skin helps protect the organism from the external environment and water loss.