What is the function of the heart valves quizlet?
What is the function of the heart valves quizlet?
The job of the heart valves is to prevent backflow of blood. The vena cava is a large artery that carries blood from the right ventricle to the lungs. The three main coronary arteries are the aorta, the left main, and the chordae tendonae.
What is the function of the four valves?
The heart has four valves – one for each chamber of the heart. The valves keep blood moving through the heart in the right direction. The mitral valve and tricuspid valve are located between the atria (upper heart chambers) and the ventricles (lower heart chambers).
How does the valve work?
A valve is a mechanical device that blocks a pipe either partially or completely to change the amount of fluid that passes through it. When you turn on a faucet (tap) to brush your teeth, you’re opening a valve that allows pressurized water to escape from a pipe. Valves regulate gases as well as liquids.
How do I know if my water valve is on or off?
In order to tell if the valve is open or closed, the general rule is, if the handle is switched 90deg to the flow, it is off. As you can see from the diagram above, if the handle is in line with the flow path, it is on. Simple.
How do you know if a valve is open or closed?
When the handle of a ball valve is parallel to the valve or pipe, it’s open. When it’s perpendicular, it’s closed.
Which way opens a valve?
The proper way to open a gate valve is to gently turn the handle counter-clockwise (to the left) without applying excessive force – do not ‘jerk’ the handle. A typical 1″ main control valve for a water line will take about six full turns to fully open. Stop turning as soon as there is any resistance.
Should main water valve be open all the way?
Similar to gate valves, ball valves should be all the way open to allow the full flow of water or all the way closed to restrict all water from flowing. The valve is controlled by moving it between 0 and 90 degrees. If the lever is aligned with the pipe, water will flow.
Which shutoff valve is open and closed?
If you’re only pulling one trailer, the shut off valves should always be closed or else the air will simply escape out the back of the trailer. If you’re pulling more than one trailer, all valves should be open except the very last trailer, which should have all valves in the closed position.
How do you test air is flowing through all trailers?
Check That Air Flows to All Trailers. Use the trailer handbrake to provide air to the service line. Go to the rear of the rig. Open the emergency line shut-off valve at the rear of the last trailer. You should hear air escaping, showing the entire system is charged.
What method can be used to test that air flows to all trailers?
Check air flow to all trailers: Use the tractor parking brake and or chock the wheels to hold the vehicle. Wait for air pressure to reach normal, then push in the red “trailer air supply” knob. This will supply air to the emergency (supply) lines.
Why must air tanks be drained?
Why must air tanks be drained? Water and compressor oil can get inside of the tank and can freeze in cold weather and cause brake failure. When the air pressure is removed the springs put on the brakes. A parking brake control in the cab allows the driver to let the air out of the brakes.
What is the emergency air line for?
Emergency air line: The emergency line (also called the supply line) has two purposes: (1) To supply air to the trailer air tanks, and (2) to control the emergency brakes on combination vehicles. Loss of air pressure in the emergency line causes the trailer emergency brakes to come on.
What 3 methods can you use to secure a second trailer before coupling?
What three methods can you use to secure a second trailer before coupling? Release dolly brake by opening the air tank petcock or if the dolly has spring brake, use the dolly parking brake control. Wheel the dolly into position by hand so it is in line with the kingpin.
What two things are important to prevent rollovers?
The following two things will help you prevent rollover–keep the cargo as close to the ground as possible, and drive slowly around turns. Keeping cargo low is even more important in combination vehicles than in straight trucks. Also, keep the load centered on your rig.
How can you be sure you supplied air to a second trailer?
How can you be sure you supplied air to a second trailer? You should check the height of the trailer before connecting a converter dolly to a second or third trailer. The trailer height is right when: The trailer will be raised slightly when the converter dolly is backed under it.
What is a dolly converter?
A converter dolly is a piece of equipment designed to allow commercial trucks, such as semi-trucks, to pull a trailer. The converter dolly is an auxiliary axle with a coupling device. Its fifth wheel makes it easier for the truck to pull a trailer. http://www.life123.com/
Is a converter dolly?
Terms in this set (10) What is a converter dolly? It is a coupling device of one or two axles and a fifth wheel by which a semitrailer can be coupled to the rear of a tractortrailer combination forming a double bottom rig.
What does a Dolly do?
A camera dolly is a wheeled cart or similar device used in filmmaking and television production to create smooth horizontal camera movements. The camera is mounted to the dolly and the camera operator and focus puller or camera assistant usually ride on the dolly to push the dolly back and forth.
What is doing it for Dolly?
Do It For Dolly Day is about bringing the community together to celebrate kindness and unite in taking a stand against bullying . #
How did do it for Dolly died?
Amy Jayne “Dolly” Everett (1 May 2003 – 3 January 2018) was an Australian teenager who died by suicide after becoming the victim of cyberbullying.
How old was Dolly when she died?
14
What is Dollys Dream?
The aim of Dolly’s Dream is raising awareness to prevent bullying. Dolly’s Dream is proudly brought to you by the Alannah & Madeline Foundation, a charity set up to care for children who have experienced or witnessed serious violence, bullying, cyberbullying or other safety and well-being risks.
Why did Dolly die?
Death. On 14 February 2003, Dolly was euthanised because she had a progressive lung disease and severe arthritis. A post-mortem examination showed she had a form of lung cancer called ovine pulmonary adenocarcinoma, also known as Jaagsiekte, which is a fairly common disease of sheep and is caused by the retrovirus JSRV …
Why is dolly shot used?
Frequently, dolly shots are used to focus in on a character when they’re thinking, or when they come to a realization about something important.
What is the effect of a long shot?
Long shots (also commonly called Wide shots) show the subject from a distance, emphasizing place and location, while Close shots reveal details of the subject and highlight emotions of a character.