Circulatory System Quiz

Question 1

Do all organisms require a circulatory system?

Answer 1

No, single celled organisms, sponges and yeast are examples as they don’t need to transport oxygen or nutrients (they can just absorb them as they are directly exposed to environment)

Question 2

What are the functions of a circulatory system? (6)

Answer 2

1. Delivers O2 from respiratory system
2. Delivers nutrients from digestive system
3. Delivers hormones from endocrine system
4. Delivers chemicals or cells from immune system
5. Delivers metabolic wastes from cells to kidneys and liver
6. In warm-blooded animals, it plays a role in distributing thermal energy throughout body to maintain body temp

Question 3

What are the 3 main features of circulatory systems?

Answer 3

1. A fluid that circulates materials through the body
2. A network of tubes in which the fluid circulates
3. A pump that pushes the fluid through the tubes

Question 4

What are open circulatory systems? (5)

Answer 4

Found in most invertebrates (snails, insects, crustaceans)

Circulatory fluid (hemolymph - mixture of blood and tissue fluid) pumped into interconnected system of body cavities (sinuses) where it bathes the cells directly

Contractions of one or more hearts forces hemolymph out circulatory tubes through sinuses

When the heart relaxes, hemolymph is drawn back to heart through open ended pores (pump and bucket)

Body movement can help circulation

Question 5

What is a closed circulatory system? (3)

Answer 5

All vertebrates and some invertebrates have them (earthworms, squid, octopus)

Fluid (often blood) is contained w/in a network of tubes or blood vessels which separates the blood and the tissue

Tissue fluid surrounds the cells and provides a medium for diffusion of substances from the bloodstream to the cells (open-blood and tissue mix in tissues)

Question 6

What is a two-circuit circular system?

Answer 6

Mammals, birds and crocodilians have it

Circulation to the lungs is separate from circulation to the body

2 parts - pulmonary circuit: delivers blood to lungs; systemic circuit: delivers blood around the body

Question 7

How many liters of blood die the human body contain?

Answer 7

4-5L

Question 8

What is the circulatory system made of?

Answer 8

Cellular component and intercellular component (plasma)

Question 9

What is plasma?

Answer 9

Protein-rich liquid in which blood and platelets are suspended

Made mostly of water but also contains albumins, globulins and fibrinogen

Question 10

What are albumins?

Answer 10

Determine how much water enters or leaves bloodstream

Question 11

What are globulins?

Answer 11

Transport lipids, cholesterol, some fat-soluble vitamins and some minerals (immunoglobulins/antibodies- fight infectious diseases)

Question 12

What are fibrinogens?

Answer 12

Plays a critical role in blood clotting

Question 13

What does the cellular component consist of?

Answer 13

Red blood cells, white blood cells and platelets

Question 14

What are red blood cells? What is the main function? How do they form? Is there a nucleus? How many days does it spend in circulation?

Answer 14

Aka erythrocytes

Shaped in Biconcave disks

Main function: carry O2 from lungs to body and carry CO2 from body to lungs

Formed from stem cells in marrow of vertebrae, ribs, breastbone, skull and bones of arms and legs

Has a nucleus when developing but it dissolves after

Spend about 120 days in circulation

Question 15

What are white blood cells? Where are they formed? What are the 2 categories?

Answer 15

Aka leukocytes

Formed in bone marrow as well

2 categories are granular and agranular

Question 16

What are granular leukocytes? What are the three kinds?

Answer 16

Have granules in their cytoplasm

Neutrophils: play role in immune system; first to travel to infection site; ingest microorganisms

Eosinophils: play role in immune system; releases enzymes during infection, allergic reaction and asthma

Basophils: play role in immune system; releases enzymes during allergic reaction and asthma

Question 17

What are agranular leukocytes?

Answer 17

Specialized for engulfing bacteria and other microorganisms

Use phagocytosis to destroy bacteria/harmful substances (engulfs it and then releases enzymes to break it and the WBC down - pieces left behind as pus)

Two kinds- lymphocytes and monocytes

Question 18

What are lymphocytes?

Answer 18

Produce antibodies that attack microorganisms or their toxins

Question 19

What are monocytes?

Answer 19

Enlarge to become macrophages

Clean up bacteria, dead cells and other debris in bloodstream and tissue

Question 20

What are platelets?

Answer 20

Small cell fragments produced from stem cells in the bone marrow

Essential in blood clotting, or coagulation

Question 21

What are the three types of blood vessels?

Answer 21

Arteries, veins and capillaries

Question 22

What are arteries?

Answer 22

Blood vessels that carry blood away from the heart toward body tissues

Question 23

What is the aorta?

Answer 23

The single large artery that leaves the heart

It branches into other major arteries that carry blood through the body

Question 24

What happens when the heart pumps blood?

Answer 24

Arteries expand in diameter to accommodate the increased pressure

When the heart relaxes, they return to normal size pushing blood further down the vessel (like a water balloon)

Question 25

Where can we feel the movement of blood?

Answer 25

Pulse points, like inner wrist, throat, inside of elbow, etc

Question 26

What are arterioles?

Answer 26

The smallest arteries that have smooth muscles in its wall that allow it to be controlled by the nervous system

Question 27

How does the nervous system control arterioles?

Answer 27

Nervous system will constrict or dilate arterioles in response to external stimuli - both a cooling and heat retention strategy

Question 28

What is vasodilation?

Answer 28

When body is overheated, nerve impulses send a message to relax muscles in arterioles in the skin which causes them to increases in diameter A cooling strategy as warm blood close to the surface of the skin will lose thermal energy to surrounding environment Cooled blood will circulate to the rest of the body to cool it

Question 29

What is vasoconstriction?

Answer 29

Nerve impulses cause smooth muscles in the arterioles to contract Diameter of vessels narrow in response to cold temperatures which makes less blood flow near the surface of skin, reducing amount of heat lost to the environment Construction directs blood flow to places it is most needed

Question 30

What does construction do when resting?

Answer 30

Divert blood from muscles to organs like stomach and intestines as they are what needs it

Question 31

What does construction do when resting?

Answer 31

Reduces blood flow to organs and diverts it to muscles which are more in use

Question 32

What are capillaries?

Answer 32

The smallest vessels at the end of arterioles Role is to supply oxygen and nutrients to the cells of the body

Question 33

How extensive is the network of capillaries? How thick are the walls?

Answer 33

No body cells or father than two cells away from a capillary 1 cell thick to make diffusion in and out easier

Question 34

How are capillaries controlled?

Answer 34

Don’t have smooth muscles so they can’t be controlled by nervous system Instead pre-capillary sphincters serve the same function

Question 35

What are venules? What are veins?

Answer 35

Venules are the smallest veins that are attached to opposite end of the capillaries Venules merge to form veins

Question 36

What do veins do?

Answer 36

Carry deoxygenated blood, carbon dioxide and waste away from tissues Takes blood from capillaries back to heart

Question 37

What are varicose veins?

Answer 37

Veins become less elastic and have damage to valves as people age Damage to valves can cause bulges where the blood pools called varicose veins

Question 38

What are the two numbers on blood pressure readings?

Answer 38

Systole/Systolic pressure: period in cardiac cycle where ventricles contract causing blood to be ejected from the ventricles; 1st number Diastole/Diastolic pressure: when ventricles are relaxed (ventricles full with blood); 2nd number

Question 39

What are the two major roles of the Lymphatic System?

Answer 39

Helps ensure blood volume is maintained in circulatory system Filters bacteria and other components from blood in immune system

Question 40

What is the purpose of the lymphatic system? What is it composed of? (4)

Answer 40

As blood circulates, some proteins leak out of the capillaries Excess fluid is collected in lymph vessels and is returned to the blood in the veins Composed of lymph vessels, lymph nodes, spleen and thymus

Question 41

What are lymph nodes?

Answer 41

Nodes in the lymph vessels Acts as a filter to remove bacteria and foreign particles

Question 42

What is the spleen?

Answer 42

Large organ of lymphatic system Acts as filter and reservoir of erythrocytes and leukocytes

Question 43

What is a thymus?

Answer 43

Glandular organ Secretes hormones to promote maturity of lymphocytes

Question 44

What are the two circuits of the heart?

Answer 44

Pulmonary circuit- the part that delivers blood to the lungs Systemic circuit- the part that delivers blood around the body

Question 45

Where is the heart located? What is it’s structure? What is it mostly composed of?

Answer 45

In the middle of the chest under the breastbone between the lungs Hear is enclosed in a sac (pericardium) which is a two layer wall. Between the walls is a lubricating fluid that allows the walls to slide over one another as the heart beats without friction from other organs Heart is mostly composed of cardiac muscle (type that is exclusive to heart and has ability to contract and relax quickly)

Question 46

How man chambers does the heart have?

Answer 46

4; left atrium, right atrium, left ventricle and right ventricle

Question 47

Where are the atria? Which side does what? What does the cardiac muscle in the atria do?

Answer 47

At the top of the heart, 1st to receive blood from around body and from lungs Right atrium receives blood from body Left atrium receives blood from lungs Lines the walls and is very thin because atria are responsible for pumping blood into ventricle (a short distance)

Question 48

What are ventricles? How are the muscles arranged? What happens when they contract?

Answer 48

Bottom part of the heart with thick walls that are more powerful than atria. They pump blood throughout the body (left to body tissues, right to lungs; making left side stronger as it pumps to more places) Muscles arranged in spiral around the heart; when they contract it produces a slight twisting motion that rings the blood out of the heart

Question 49

What separates the left and right side of the heart? How do the sides pump in relation to each other? Which ways do blood flow?

Answer 49

The septum Sides pump in sync, so they happen at the same time Blood flows one way, always the same direction, with help from valves to stop blood from flowing backwards

Question 50

What are the two types of valves?

Answer 50

Atrioventricular: separate atria and ventricles (bicuspid on left, tricuspid on right) Semilunar: separate ventricles and arteries (pulmonary valve of right, aortic valve on left)

Question 51

What is a cardiac cycle?

Answer 51

A single heart beat, where there is actually 2 contractions as one pump brings blood in right side and out and the other brings blood in left side and out Makes a lub-dub sounds

Question 52

What are the chordae tendinae?

Answer 52

Tendons in the ventricles that prevent AV valves from opening backwards (heartstrings)

Question 53

What is the sinoatrial , or SA, node?

Answer 53

A specific region in the right atrium that sends an electrical signal to both atria, causing them both to contract. This causes blood to be pushed out of the atria and fill ventricles

Question 54

What is the atrioventricular, or AV, mode? Where is the impulse sent?

Answer 54

A specific region in the right atrium that receives a signal from SA node when it sends its impulse, triggering the AV node to send out its electrical signal. The impulse send to Purkinje fibers which are special conducting fibers that run down the septum This causes both ventricles to simultaneously contract, sending blood to lungs and body tissues

Question 55

What are the lub and dub sounds you hear when using a stethoscope?

Answer 55

The lub sound is made by the closing of the atrioventricular valves (ventricular systole) The dub sounds is made by the closing of the semilunar valves (ventricular diastole)

Question 56

How is the heart controlled?

Answer 56

The heart mainly controls itself but brain and hormones can influence the frequency During times of increased body activity, heart rate increases to releases more O2 from body cells. The brain sends a signal to adjust the frequency. Hormones like adrenaline can also affect frequency

Question 57

How can you analyze a heartbeat?

Answer 57

Cardiac cycle can be monitored using electrocardiograph which measures electric signals and produces an electrocardiogram

Question 58

Explain the flow of blood.

Answer 58

Deoxygenated blood from the body travels through the superior and inferior vena cava into the right atrium. Then blood flows through the atrioventricular valve, or the tricuspid valve, into the right ventricle. Blood then flows through the semilunar valve, or pulmonary valve, into the pulmonary artery and goes to the lungs (blood from left pulmonary artery goes to the left lung, blood from right pulmonary artery goes to the right lung; both pick up O2 and release CO2). The now oxygenated blood returns to the heart through the left and right pulmonary vein. The blood flows from the pulmonary veins into the left atrium then through the atrioventricular valve, or bicuspid valve, into the left ventricle. Blood then flows through the semilunar valve, or aortic valve, into the aorta. Finally blood flows from the aorta to all parts of the body before the cycle repeats.