Common examples include seat belts in cars, helmets on motorcycles and bicycles, fire extinguishers on boats, buses and airplanes and life jackets on boats and commercial aircraft. Passenger aircraft carry a great deal of safety equipment including inflatable slides are rafts, oxygen masks, oxygen tanks, life jackets, satellite beacons and first aid kits. Some equipment such as life jackets has led to debate regarding their usefulness. In the case of Ethiopian Airlines Flight 961, the life jackets saved many people but also led to many deaths when passengers inflated their vests prematurely. Right-of-way
There are specific real-estate arrangements made to allow vehicles to travel from one place to another. The most common arrangements are public highways, where appropriately licensed vehicles can navigate without hindrance. These highways are on public land and are maintained by the government. Similarly, toll routes are open to the public after paying a toll. These routes and the land they rest on may be government or privately owned or a combination of both. Some routes are privately owned but grant access to the public. These routes often have a warning sign stating that the government does not maintain the way. An example of this are byways in England and Wales. In Scotland, land is open to un-motorised vehicles if the land meets certain criteria. Public land is sometimes open to use by off-road vehicles. On US public land, the Bureau of Land Management (BLM) decides where vehicles may be used. Railways often pass over land not owned by the railway company.
An arteriovenous fistula is an abnormal connection or passageway between an artery and a vein. It may be congenital, surgically created for hemodialysis treatments, or acquired due to pathologic process, such as trauma or erosion of an arterial aneurysm. Clinical features
Pathological
Hereditary hemorrhagic telangiectasia is a condition where there is direct connection between arterioles and venules without intervening capillary beds, at the mucocutaneous region and internal bodily organs. Those who are affected by this conditions usually do not experience any symptoms. Difficulty in breathing is the most common symptom for those who experience symptoms.Just like berry aneurysm, a cerebral arteriovenous malformation can rupture causing subarachnoid hemorrhage. Causes
The cause of this condition include
Congenital (developmental defect)
Rupture of arterial aneurysm into an adjacent vein
Penetrating injuries
Inflammatory necrosis of adjacent vessels
Complication of catheter insertion rarely causes arteriovenous fistula. It is usually caused by brachial artery puncture because brachial artery is located between two brachial veins.Surgically created Cimino fistula is used as a vascular access for hemodialysis. Blood must be aspirated from the body of the patient, and since arteries are not easy to reach compared to the veins, blood may be aspirated from veins. The problem is that the walls of the veins are thin compared to those of the arteries. The AV fistula is the solution for this problem because, after 4–6 weeks, the walls of the veins become thicker due to the high arterial pressure. Thus, this vein can now tolerate needles during hemodialysis sessions.