Thus, without blood to act as the intermediary and the heart and blood vessels to act as the hardware to pump the blood around the body, all the efforts of the respiratory system would be useless. In turn, angiotensin converting enzyme on lung capillary endothelium plays an important role in blood pressure regulation.
When do school speed limits apply? This depends on the kind of zone youâre travelling in. There are several types of school speed zones, including: permanent 40km/h zones ; time-based zones (where reduced speed limits apply between 8â9.30am and 2.30â4pm on school days â see below for dates)
The school day in elementary schools is usually from  8.30am to 3pm or 3.30pm, with an hour for lunch. In high schools, hours are usually from 7.30am to 2pm or 2.30pm. This is divided into six one-hour classes or four 90-minute classes (with a five-minute break between classes) and a 30-minute lunch break. Extra-curricular activities and sports are scheduled after school hours.