The average menstrual cycle is 28 days long. However, a normal cycle can be shorter or longer than this. It may be anywhere from 21 to 35 days long. Most periods last 3 to 5 days, but anywhere from 2 to 7 days is normal.Menstrual cycles may happen around the same date every month or they may be irregular.A menstrual period is considered late if it hasnât started 5 or more days after the day you expected it to start.A period is considered missed if you have had no menstrual flow for 6 or more weeks after the start of your last period.enstrual cycles may happen around the same date every month or they may be irregular. A menstrual period is considered late if it hasnât started 5 or more days after the day you expected it to start. A period is considered missed if you have had no menstrual flow for 6 or more weeks after the start of your last period.
Transcript of Theory of Dorothy Johnson. Theory of Dorothy Johnson. The Behavioral System Model. Johnsonâs Behavioral System Model is a model of nursing care that advocates the fostering of efficient and effective behavioral functioning in the patient to prevent illness.
IMPORTANCE OF NURSING THEORIES. 1  Nursing theory aims to describe, predict and explain the phenomenon of nursing (Chinn and Jacobs1978). 2  It should provide the foundations of nursing practice, help to generate further knowledge and indicate in which direction nursing should develop in the future (Brown 1964).