Circulatory System Flashcards
What are the parts of the circulatory system?
Lungs Heart Mouth Blood Blood vessels
Why is the body’s transport system called the circulatory system?
It transports gases around the body.
What 2 gases are transported around the body?
Carbon dioxide and oxygen
What type of blood does the left side of the heart carry?
Oxygen-rich blood
Wha type of blood does the right side of the heart carry?
Oxygen-poor blood
What gas is picked up by the blood from the body’s cells?
Carbon dioxide
Where is the oxygen-poor blood sent?
To the lungs
How does blood circulate around the body? Start with the left side of the heart.
The blood flows from the left side of the heart to the body’s cells.
From the body’s cells the blood is transported into the right side of the heart.
From the right side of the heart, the blood is transported to the lungs.
From the lungs the blood is transported back into the left side of the heart and the cycle starts again.
What are the 4 sections of the heart?
Left ventricle
Right ventricle
Left atrium
Right atrium
What is the atria (atrium) job?
Collects blood into the heart
What is the ventricle’s job?
Pump blood out of the heart
What are the 2 jobs of the heart?
Take oxygen-rich blood to the body’s cells for respiration
Transport carbon dioxide out of the body via exhaling
Name the four valves of the heart.
Left semilunar valve
Right semilunar valve
Tricuspid valve
Mitral valve
Which vein/artery transports oxygenated blood to the body’s cells?
Aorta
Which vein/artery transports carbon dioxide-rich blood from the body’s cells to the heart?
Right Pulmonary Vein
Which vein/artery transports carbon dioxide-rich blood from the heart to the lungs?
Right Pulmonary Artery
Which vein/artery transports oxygenated blood from the lungs to the heart?
Left Pulmonary vein
Describe a heartbeat.
A heartbeat begins with all muscles contracted and the valves closed.
Blood flows into the 2 atria and both sides fill up with blood.
The atria contract and the blood is squeezed which causes the valves leading to the ventricles to open.
Blood then flows from the atria into the ventricles.
The valves between the atria and ventricles close to prevent any backflow.
Almost immediately, the ventricles contract and the blood is squeezed again, this time forcing the valves leading out of the heart to open.
Blood is pumped out of the heart.
Once the ventricles are empty, the atria refill with blood and the heartbeat sequence starts again.
What is the job of an artery?
Carries oxygenated blood away from the heart.
What is the job of a vein?
Carries deoxygenated blood to the heart.
What are the jobs of a capillary?
Carries blood to and from the body’s cells and exchanges substances between the blood and the surrounding body cells by the process of diffusion.
At what pressure (high/low) is the blood pumped in an artery?
High
At what pressure (high/low) is the blood pumped in a vein?
Low
Describe the cross-section of an artery.
Thick outer wall
Thick inner layer of muscle and elastic fibres
Narrow central tube
Describe the cross-section of a vein.
Thin outer wall
Thin inner layer of muscle and elastic fibres
Wide central tube
What is in the veins that helps prevent backflow?
Valves.
Why do veins have valves?
To prevent the possible backflow of blood
What else does a vein have that helps squeeze blood back to the heart, besides valves?
The veins are surrounded by muscles that when one moves, the muscles contract and force the blood to the heart.
Describe the cross-section of a capillary.
Very thin wall made of a single layer of cells
Narrow central tube
What percentage of blood is plasma?
55%
What percentage of blood is blood cells?
45%
What are the 4 components of blood?
Plasma
Red blood cells
White blood cells
Platelets
Define plasma
Blood fluid that surrounds body cells and carries them along as it flows through blood vessels. Mostly made of water. Contains waste substances as well as useful products.
What do red blood cells do?
They transport oxygen from the lungs to the body’s cells.
Give 5 facts about the red blood cell and describe each.
Large surface area compared to volume: o2 is kept close to the surface and can be released quickly.
Disc-shaped and flexible: Cell can travel easily through narrow blood vessels.
No nucleus: More room for haemoglobin and so more o2 can be carried.
Larger diameter than capillaries: Cell is forced to slow down, therefore gas exchange will definitely happen.
Contains haemoglobin: Carries o2 picked up in the lungs and released to the body’s cells.
What does a white blood cell do?
Protect the body from disease by fighting invading microbes that cause infections.
Name 2 ways that white blood cells fight off diseases.
Some fight against infection by surrounding invading microbes and then digesting them.
Others produce antibodies or antitoxins to fight against infection.
What are platelets for?
They help with blood clots. They are cell fragments that have broken off of larger cells.
