WASHINGTON (AP) — Campers in national parks are to pull up stakes and leave, some veterans waiting to have disability benefits approved will have to cool their heels even longer, many routine food inspections will be suspended and panda-cams will go dark at the shuttered National Zoo.

Those are among the immediate effects when parts of the government shut Tuesday because of the budget impasse in Congress.

In this time of argument and political gridlock, a blueprint to manage federal dysfunction is one function that appears to have gone smoothly. Throughout government, plans are ready to roll out to keep essential services running and numb the impact for the public. The longer a shutdown goes on, the more it will be felt in day-to-day lives and in the economy as a whole.

A look at what is bound to happen, and what probably won't:

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THIS: Washington's paralysis will be felt early on in distant lands as well as in the capital; namely, at national parks. All park services will close. Campers have 48 hours to leave their sites. Many parks, such as Yellowstone, will close to traffic, and some will become completely inaccessible. Smithsonian museums in Washington will close and so will the zoo, where panda cams record every twitch and cuddle of the panda cub born Aug. 23 but are to be turned off in the first day of a shutdown.

The Statue of Liberty in New York, the loop road at Acadia National Park in Maine, Skyline Drive in Virginia, and Philadelphia's Independence National Historical Park, home of Independence Hall and the Liberty Bell, will be off limits. At Grand Canyon National Park, people will be turned back from entrance gates and overlooks will be cordoned off along a state road inside the park that will remain open.

"People who waited a year to get a reservation to go to the bottom of the Grand Canyon all of a sudden will find themselves without an opportunity to take that trip," said Mike Litterst, a spokesman for the National Park Service.

BUT NOT THIS: At some parks, where access is not controlled by gates or entrance stations, people can continue to drive, bike and hike. People won't be shooed off the Appalachian Trail, for example, and parks with highways running through them, like the Great Smokies, also are likely to be accessible. Officials won't scour the entire 1.2 million-acre Grand Canyon park looking for people; those already hiking or camping in the backcountry and on rafting trips on the Colorado River will be able to complete their trips. The care and feeding of the National Zoo's animals will all go on as usual.

The shutdown won't affect Ellis Island or the Washington Monument because they are already closed for repairs.

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THIS: The Board of Veterans Appeals will stop issuing rulings, meaning decisions about some disability claims by veterans will wait even longer than usual. Interments at national cemeteries will slow. If a shutdown drags on for weeks, disability and pension payments may be interrupted.

BUT NOT THIS: Most Department of Veterans Affairs services will continue; 95 percent of staff are either exempted from a shutdown or have the budget to keep paying them already in place. The department's health programs get their money a year in advance, so veterans can still see their doctor, get prescriptions filled and visit fully operational VA hospitals and outpatient clinics. Claims workers can process benefit payments until late in October, when that money starts to run out.

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THIS: New patients won't be accepted into clinical research at the National Institutes of Health, including 255 trials for cancer patients; care will continue for current patients. Federal medical research will be curtailed and the government's ability to detect and investigate disease outbreaks will be harmed. Grant applications will be accepted but not dealt with.

BUT NOT THIS: The show goes on for President Barack Obama's health care law. Tuesday heralds the debut of health insurance markets across the country, which begin accepting customers for coverage that begins in January. Core elements of the law are an entitlement, like Social Security, so their flow of money does not depend on congressional appropriations. That's why Republicans have been trying explicitly to starve the law of money. An impasse in approving a federal budget has little effect on Obamacare. As for NIH operations, reduced hospital staff at the NIH Clinical Center will care for current patients, and research animals will get their usual care.

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THIS: Most routine food inspections by the Food and Drug Administration will be suspended.

BUT NOT THIS: Meat inspection, done by the Agriculture Department, continues. The FDA will still handle high-risk recalls.

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THIS: Complaints from airline passengers to the government will fall on deaf ears. The government won't be able to do new car safety testing and ratings or handle automobile recall information. Internal Transportation Department investigations of waste and fraud will be put on ice, and progress will be slowed on replacing the country's radar-based air traffic system with GPS-based navigation. Most accident investigators who respond to air crashes, train collisions, pipeline explosions and other accidents will be furloughed but could be called back if needed.

Kristie Greco, speaking for the Federal Aviation Administration, said nearly 2,500 safety office personnel will be furloughed but may be called back incrementally over the next two weeks. The union representing aviation safety inspectors said it was told by FAA Administrator Michael Huerta that nearly 3,000 inspectors will be off work. Greco did not confirm that.

BUT NOT THIS: Air traffic controllers and many of the technicians who keep air traffic equipment working will remain on the job. Amtrak says it can continue normal operations for a while, relying on ticket revenue, but will suffer without federal subsidies over the longer term. FAA employees who make grants to airports, most Federal Highway Administration workers and federal bus and truck safety inspectors will also stay on the job because they are paid with user fees. Railroad and pipeline safety inspectors will also remain at work.

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THIS: About half the Defense Department's civilian employees will be furloughed.

BUT NOT THIS: The 1.4 million active-duty military personnel stay on duty and under a last-minute bill, they should keep getting paychecks on time. Most Homeland Security agents and border officers, as well as other law enforcement agents and officers, keep working.

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THIS: The Special Supplemental Nutrition Program for Women, Infants and Children, known as WIC, could shut down. It provides supplemental food, health care referrals and nutrition education for pregnant women, mothers and their children.

BUT NOT THIS: School lunches and breakfasts will continue to be served, and food stamps, known as the Supplemental Nutrition Assistance Program, or SNAP, will still be distributed.

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THIS: A shutdown that lasts two weeks or more would probably start to slow an already sluggish economy, analysts say. Closures of national parks would hurt hotels, restaurants and other tourism-related businesses. And federal workers who lost pay would spend less, thereby curbing economic growth. A three-week shutdown would slow the economy's annual growth rate in the October-December quarter by up to 0.9 of a percentage point, Goldman Sachs has estimated. If so, that could mean a growth rate of 1.6 percent, compared with the 2.5 percent that many economists now forecast.

BUT NOT THIS: Little impact on the economy if the shutdown only lasts a few days.

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THIS: Economic data will be interrupted as the Bureau of Labor Statistics ceases almost all operations. This will leave the stock market without some of the benchmark economic indicators that drive the market up or down. The key September jobs report, due Friday, could still be released on time if the White House authorizes that, but that's not been determined. Statistical gathering also is being interrupted at the Commerce Department and Census Bureau. This means the government won't come out on time with its monthly report on construction spending Tuesday or a factory orders report Thursday.

BUT NOT THIS: The weekly report on applications for unemployment benefits is still expected Thursday. The Treasury Department's daily report on government finances will be released normally and government debt auctions are to proceed as scheduled. And at Commerce, these functions continue, among others: weather and climate observation, fisheries law enforcement and patent and trademark application processing.

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THIS: Some passport services located in federal buildings might be disrupted — only if those buildings are forced to close because of a disruption in building support services.

BUT NOT THIS: Except in those instances, passport and visas will be handled as usual, both at home and abroad. These activities of the Bureau of Consular Affairs are fully supported by user fees instead of appropriated money, so are not affected. As well, the government will keep handling green card applications.

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THIS: The Federal Housing Administration, which insures about 15 percent of new loans for home purchases, will approve fewer loans for its client base — borrowers with low to moderate income — because of reduced staff. Only 67 of 349 employees will keep working. The agency will focus on single-family homes during a shutdown, setting aside loan applications for multi-family dwellings. The Housing and Urban Development Department won't make additional payments to the nation's 3,300 public housing authorities, but the agency estimates that most of them have enough money to keep giving people rental assistance until the end of October.

BUT NOT THIS: It will be business as usual for borrowers seeking loans guaranteed by Fannie Mae and Freddie Mac, which together own or guarantee nearly half of all U.S. mortgages and 90 percent of new ones.

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THIS: Possible delays in processing new disability applications.

BUT NOT THIS: Social Security and Medicare benefits still keep coming.

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Associated Press writers Sam Hananel, Matthew Daly, Joan Lowy, Kevin Freking, Hope Yen, Lauran Neergaard, Andrew Miga, Deb Riechmann, Ricardo Alonso-Zaldivar, Lolita C. Baldor, Jesse Holland, Mary Clare Jalonick and Alicia Caldwell in Washington; and Felicia Fonseca at Grand Canyon National Park, contributed to this report.