Basic Tissue Types. All of the various tissues of the human body can be categorized into four basic tissue types. All organs are built of these four tissues, which have consistent characteristics and arrangements from organ to organ. Thus an appreciation of the major features of these four basic tissue types can greatly simplify your understanding of the cellular composition of the many organ systems. 1  OVERVIEW.
Definition of session for English Language Learners : a period of time that is used to do a particular activity : a formal meeting or series of meetings of a group of people (such as a court of law or legislature)
2. trimester-one of three divisions of an academic year. academic year, school year-the period of time each year when the school is open and people are studying. academic session, academic term, school term, session-the time during which a school holds classes; they had to shorten the school term. Translations.