Circulation and Immunity

Question 1

Units of life, smallest to biggest

Answer 1

Cell, Tissue (group of cell) , Organ (group of tissue), system (group of organs), organism (group of systems)

Question 2

What are the systems of the human body?

Answer 2

The systems of the body are the skeletal, muscular, nervous, endocrine (hormonal), cardiovascular, lymphatic (immune system and body fluid), respiratory, digestive, urinary and reproductive systems.

Question 3

What is homeostasis?

Answer 3

The ability of an organism to maintain a stable internal state (like temperature). This often involves reacting to outside stimuli.

Question 4

What is a sensor in the body?

Answer 4

A structure that detects changes in the internal or external environment of an organism, then signals these changes to the bodies control center to maintain homeostasis. Skin cells, eyes, and ears, for example.

Question 5

What is an effector in the body?

Answer 5

An organ or cell that produces a specific function in response to a stimulus, like a muscle contracting to move an arm, or cells in the immune system. For example, the thyroid gland, heart, or sweat glands.

Question 6

What is a control center?

Answer 6

It receives information from the sensors, and initiates a feedback response to maintain homeostasis. An example would be the brain, tropic glands, spinal cord.

Question 7

What is a negative feedback loop?

Answer 7

They are self correcting reactions that counteract changes in the body. They respond to a change by doing the opposite of whatever it is.
For example, if you’re too cold, it initiates shivering, a negative feedback loop that continues until you’re not cold. Shivering makes you warm, the opposite of cold.

Question 8

What is a positive feedback loop?

Answer 8

This is when the output of a reaction increases that output, creating a self reinforcing cycle. Negative feedback loops aim to stabilise a system, but this aims to amplify the change. Clotting is an example of this, as platelets gather into a clot, more and more gather into the clot to cover the wound.

Question 9

Directions used for things in the body

Answer 9

Superior - Head area, upper body

Inferior- Below head, lower body

Proximal - Close to center of the body, or an object’s point of attachment to the body

Distal - Far from center of the body, or an object’s point of attachment to the body

Question 10

What are veins?

Answer 10

They are blood vessels that always carry blood towards the heart. They normally bring oxygen-poor blood to your heart. The only exception is the pulmonary veins, which bring the oxygen-rich blood from your lungs to your heart. They all come into the vena cava. They receive the oxygen-poor blood from the capillaries passing through the tissues. There are valves in them that make the blood move in only one direction, and surrounding skeletal muscles aid movement.

Question 11

What are arteries?

Answer 11

They are blood vessels that always carry blood away from the heart. They normally carry oxygen-rich blood away from your heart into the body. The only exception is the pulmonary arteries, which carry the oxygen-poor blood from your heart to your lungs. They are elastic and can stretch and contract. They have thick walls and can withstand the pressure of the blood being pumped out by the heart. The inner layer of them is very smooth. They branch off the aorta, bringing blood to the capillary beds. They can vasoconstrict and vasodilate.

Question 12

What are capillaries?

Answer 12

The smallest blood vessels in the body that carry blood, nutrients and oxygen throughout the body, as well as removing CO2 from the blood. They also connect the veins and arteries, exchanging the aforementioned things. They have very thin walls.

Question 13

What are the atria?

Answer 13

These are the upper two chambers of the heart, which pump blood into the lower ventricles and receive the blood that returns from the body. There is a left and a right one.

Question 14

What are the ventricles?

Answer 14

These are the muscular chambers that pump blood out of the heart and into the circulatory system. The right side deals with pumping oxygen-poor blood into the lungs, and the left side deals with receiving oxygen-rich blood to pump into the body.

Question 15

What is the vena cava?

Answer 15

There are superior and inferior vena cavae. They are the large veins that bring deoxygenated blood back to the heart to be oxygenated. They attach to the right side of the heart.

Question 16

What is the systemic pathway?

Answer 16

This is also called the systemic circuit. It carries oxygenated blood from the left ventricle through the arteries, into the capillaries, and into the tissues of the body. When the blood becomes deoxygenated, it is brought into the veins by the capillaries, then it returns to the right atrium of the heart through a system of veins.

Question 17

What is the aorta?

Answer 17

The largest artery in the body that transports blood into the systemic circuit.

Question 18

What is the Coronary pathway?

Answer 18

All the arteries which supply blood to the heart muscle.

Question 19

What are the AV valves?

Answer 19

Atrioventricular valves are what connect the atrium to the ventricles. The left one is the mitral valve, and the right is the tricuspid.

Question 20

What are the semilunar valves?

Answer 20

There are two of them, one is located between the left ventricle and the aorta. The other is located between the right ventricle and the pulmonary artery. They connect the pulmonary blood vessels and the ventricles.

Question 21

What is the SA node?

Answer 21

This is the sinoatrial node, and it is the pacemaker of the heart. It is near the superior vena cava, near the right atrium. It generates electrical impulses that set the heart’s rhythm and rate. It makes the upper chambers of the heart contract.

Question 22

What is the AV node?

Answer 22

The atrioventricular node is a small structure in the heart on the right side, near the septum. It connects the electrical systems of the atria and ventricles, and controls the heart’s beats per minute. It makes the lower chambers of the heart contract.

Question 23

What are the Purkinje fibres?

Answer 23

These are specialized nerve cells that send electric signals to the right and left ventricles.

Question 24

What is an ECG?

Answer 24

An electrocardiogram records the electrical signals in the heart.

Question 25

What is a pulse?

Answer 25

The pulse is the rhythmic dilation of an artery generated by the opening and closing of the AV valves.

Question 26

What is Lub-Dub?

Answer 26

The sound the heartbeat makes. The first lub is the AV valves closing, and the second dub is the SL valves closing.

Question 27

What is vasoconstriction?

Answer 27

The narrowing or constriction of the blood vessels by small muscles in the walls of the vessel. When these vessels constrict, blood flow is slowed or blocked. This can result from a medical issue or an attempt by the body to heat up. It causes higher blood pressure.

Question 28

What is vasodilation?

Answer 28

The widening of blood vessels due to the relaxation of the muscular walls of the vessels. This decreases blood pressure and helps the body cool down. It also lets blood flow more easily, allowing blood to flow to areas of the body lacking oxygen or nutrients.

Question 29

What is blood pressure?

Answer 29

The measurement of the pressure or force of blood pushing against blood vessel walls. This reading has two numbers. The top is the systolic blood pressure, and the bottom number is the diastolic blood pressure. The more open the lumens are, the lower the blood pressure is. More room to flow.

Question 30

What does systolic mean?

Answer 30

The force of your blood flow when blood is pumped out of the heart. Blood flows out of the heart.

Question 31

What does diastolic mean?

Answer 31

The relaxation/recoil of the arteries. On a blood pressure test, it is the bottom number, It represents the pressure of the arteries when the heart rests between beats. This is the time when the heart fills with blood and gets oxygen. When the heart fills with blood.

Question 32

What are the tunics?

Answer 32

The Tunica Intima is the innermost tunic; it is adjacent to the lumen, and it is very elastic and slick, helping blood move without friction. The Tunica Media is the middle tunic, it is made of smooth muscle cells and sheets of elastin protein, which the other tunica also has. It is very elastic and can contract to cause vasoconstriction, which heightens blood pressure, or relax, causing vasodilation, lowering blood pressure. The tunica externa is the outside tunic, which protects and reinforces the vessel, and is made of collagen.

Question 33

What is bone marrow?

Answer 33

This is a spongy material in the bones, which makes red and white blood cells, as well as platelets.

Question 34

What are red blood cells?

Answer 34

Also called erythrocytes, they contain a lot of hemoglobin and carry oxygen through the body.

Question 35

What are white blood cells?

Answer 35

Also called leukocytes, these cells are part of the body's immune system. They help fight infection and other diseases. Some types of white blood cells are macrophages and lymphocytes. They are a nonspecific defense.

Question 36

What are platelets?

Answer 36

Also called thrombocytes, these are small, colourless cell fragments that form clots to stop bleeding.

Question 37

What is hemoglobin?

Answer 37

A special protein that carries oxygen. It is made of heme, which binds oxygen.

Question 38

What is the lymph system?

Answer 38

This system includes the lymph nodes, lymph vessels, bone marrow, spleen, thymus, tonsils, adenoids, and lymph tissue in the small intestine. It's a part of the immune system. There are also lymph capillaries, which are blind-ended and cover the vessels between cells. They're larger than capillaries. Like veins, the lymph fluid in the lymph system moves around when it is pushed by skeletal muscles. They also have valves.

Question 39

What are the interstitial fluids?

Answer 39

This is a fluid that surrounds the cells, leaking out of the capillaries. It helps bring oxygen and nutrients into the cells and removes the waste products from them.

Question 40

What is plasma?

Answer 40

The liquid component of blood which makes up 55% of the blood volume.

Question 41

What is prothrombin?

Answer 41

This is a protein made by the liver. It helps with clotting.

Question 42

What are fibrinogens?

Answer 42

These help with clotting by forming fibrin, which is one of the main proteins that help make clots by holding the platelets together, like a net. Thrombin is an enzyme that converts fibrinogen into fibrin, which helps form clots.

Question 43

What is a pathogen?

Answer 43

Any organism that causes disease. Viruses, bacteria, fungi and parasites are all pathogens.

Question 44

What are bacteria?

Answer 44

Single-celled microorganisms that lack a nuclear membrane, are metabolically active, and divide by binary fission. They cause disease. They only have one cell. They are prokaryotic cells. No nucleus, no membrane-bound organelles.

Question 45

What are viruses?

Answer 45

These are microscopic organisms that can infect hosts. They are not made of cells, do not grow, and cannot keep themselves in a stable state or make their own energy, and are unable to reproduce without a host. They are bits of nucleic acid covered by a protein coat. They inject DNA or RNA into cells, infecting them and making you sick.

Question 46

What are macrophages?

Answer 46

These are a type of white blood cell that remove dead cells, kill microorganisms, and can stimulate other cells involved in immune function, as they present antigens to T-cells. They initiate inflammation. They consume harmful bacteria and dead cells using phagocytosis. They are a non-specific defence.

Question 47

What are lymphocytes?

Answer 47

They are specialized immune cells made in the bone marrow and found in the blood and lymph tissue. There are B lymphocytes and T lymphocytes. B lymphocytes make antibodies, and T lymphocytes kill tumour cells and help control immune responses. Lymphocytes can turn into memory cells after encountering a pathogen. They will remember that pathogen, and if it comes back into the body, the body will be more effective against it. These are specific defences.

Question 48

What is immunity?

Answer 48

This is what keeps the body safe from all outside invaders. It consists of the immune system, which is made of organs, cells and proteins that work together to keep the body safe.

Question 49

What is acquired immunity?

Answer 49

Acquired immunity is when the body adapts to protect itself from specific germs after long-term exposure to them. Memory cells help with immunity, as they remember certain pathogens, and can tell that they do not belong in your body, so they are attacked sooner.

Question 50

What are antigens?

Answer 50

These are recognition proteins which are on the outside of our cells. They can mark any substance that the body may have a harmful reaction to, such as bacteria and viruses. Certain antigens will trigger an immune response. B cells will test antigens to see if they belong or not.

Question 51

What are antibodies?

Answer 51

Antibodies are recognition proteins which are produced by the body to combat antigens. They bind to antigens to eliminate them from your system, as when antibodies bind to antigens, the rest of the immune system will attack them.

Question 52

What are B-cells?

Answer 52

These are the cells that look for antigens and produce antibodies to respond to them. They can remember antigens. When they encounter a new antigen, they can become memory cells. Memory cells will remember antigens and will be able to attack them faster if they enter the body again.

Question 53

What are T-cells?

Answer 53

They kill harmful cells directly, especially cancerous or infected cells. Helper cells are a special type of T cell that detects infection and activates other immune cells to fight infection. They also help B cells secrete antibodies and activate other T cells to kill infected cells.

Question 54

What are NK cells?

Answer 54

These are natural killer cells. They are white blood cells that kill and destroy infected or diseased cells. They are a type of lymphocyte, like B and T cells. They help fight cancer and virus cells.

Question 55

What are suppressor cells?

Answer 55

A type of immune cell that blocks the actions of some other types of immune cells to stop the immune system from becoming overactive.

Question 56

What are memory cells?

Answer 56

Cells that remember certain antigens and can identify them in the future.

Question 57

What is the ABO blood system?

Answer 57

These are the antigens and antibodies produced by your blood cells. Each blood type produces antigens that match its type, and antibodies that are opposite its type. Blood type A carries A antigens and releases B antibodies, which means it is not compatible with any blood type carrying B antigens. Type O has no antigens, and triggers no attacks. Type AB positive has all types of antigens, but no antibodies, and can receive any other blood type.

Question 58

What is agglutination?

Answer 58

The clumping of particles together. This is what happens when antigens and antibodies of the same type meet. For example, type A blood antigens mix with type A blood antibodies from someone with type B blood.

Question 59

What is the RH factor?

Answer 59

An inherited protein that can be found on the surface of red blood cells. Positive blood types mean you have the Rh protein. Negative blood type means you do not have the Rh protein. An Rh factor problem happens when an Rh-negative person gives birth to an Rh-positive baby. The opposite Rh factors mean that antibodies from the Rh-negative mother could get into the Rh-positive baby's bloodstream, where the body will start attacking it, damaging the baby's red blood cells.