3 Mixed seromucous salivary glands, structure of glandular acini The three large glands have a different composition in the type of secretory units is concerned: - The parotid glands (which represent 25% of the production of saliva) are formed by serous production units and they are compound acinar type.
How Anti-Lock Brakes Work. An anti-lock brake system (ABS) is a braking system that is made to allow a vehicle to maintain traction with the road when braking. Braking is controlled by driver input via the brake pedal, and older braking systems response to a driver braking suddenly or with intense pressure was sometimes to lock up or skid.
3/1/99 - All hydraulically braked trucks and busses. 3/1/01 - All ABS trailer systems require a malfunction signal circuit to connect to the towing vehicle. Note: Electric, Hydraulic & Vacuum/Hydraulics trailer systems are not required to implement ABS. Anti-lock brakes are not new. In March 1975 FMVSS-121 mandated ABS on heavy duty air brake systems. These rules created havoc because of the lack of technology available to implement compliance.