Cardiovascular System

Question 1

Is a cardiovascular system required for the existence of a multicellular organism?

Answer 1

No, many multicellular organisms do not have a dedicated cardiovascular system.

Question 2

What is the major function of the cardiovascular system?

Answer 2

Maintain cellular metabolism.

Question 3

Do all triploblastic organisms have a cardiovascular system?

Answer 3

No, e.g. mollusk, flat worm

Question 4

List the three major components of blood.

Answer 4

Plasma, buffy coat (platelets and white blood cells), erythrocytes.

Question 5

What is plasma?

Answer 5

The liquid extracellular matrix of blood.

Question 6

How much of the blood’s volume does plasma make up?

Answer 6

50%

Question 7

Which of the components of blood is least dense?

Answer 7

Plasma

Question 8

What makes up the buffy coat?

Answer 8

Platelets and white blood cells.

Question 9

What is the lifespan of blood?

Answer 9

120 days

Question 10

In what bones are RBCs made?

Answer 10

Flat bones, e.g. femur.

Question 11

What are tunics?

Answer 11

Layers of blood vessels.

Question 12

Describe the three tunics of blood vessels.

Answer 12

1. Tunica externa (fibrous)
2. Tunica media (smooth muscular layer- constriction/relaxation).
3. Tunica intima (single cell endothelial layer).

Question 13

What is an anastomosis?

Answer 13

Connection between blood vessels, such as the capillary bed or connections between arteries.

Question 14

What are the two function of the pulmonary loop?

Answer 14

Oxygenation and decarboxylation.

Question 15

Within which circuit is the hepatic loop located?

Answer 15

Systemic

Question 16

Provide an evolutionary explanation for the fact the the base of the heart contains all of the blood vessels, the apex of the heart does not contain any and that the heart is comprised of four chambers.

Answer 16

The formation of two chambers in a primitive blood vessel and its folding.

Question 17

Where is the heart located?

Answer 17

Central mediastinum.

Question 18

What are the two types of pericardium?

Answer 18

Fibrous and serious pericardium.

Question 19

What does the fibrous pericardium attach to?

Answer 19

The great vessels and diaphragm.

Question 20

What is the function of the fibrous pericardium?

Answer 20

Protection of the heart and prevention of overfilling.

Question 21

What is the function of the serious endothelium?

Answer 21

Secrete lubricating fluid to ensure the heart does not get caught on anything.

Question 22

In which chamber is the sino-atrial node located?

Answer 22

Right atrium

Question 23

What are subendocardial branches?

Answer 23

Purkinje fibres

Question 24

Do vagal (parasympathetic) nerves increase or decrease heart rate?

Answer 24

Decrease

Question 25

What is the function hepatic portal?

Answer 25

To metabolise, process and filter deoxygenated, nutrient-rich blood coming from the GI tract before it returns to the rest of the body.

Question 26

List the organs blood passes when in the hepatic portal?

Answer 26

Heart, aorta, GI tract, veins, liver, inferior vena cava.

Question 27

Does the vein draining the GI tract enter the liver inferiorly or superiorly?

Answer 27

Inferiorly.

Question 28

Is the inferior Vena Cava inferior or superior of the liver?

Answer 28

Superior.

Question 29

What is the functional unit of the CVS?

Answer 29

Capillary beds.

Question 30

Why is it advantageous for veins to be located close to large skeletal muscle?

Answer 30

Contraction of skeletal muscle applies pressure to the veins to return blood to the heart.

Question 31

How can lack of movement result in thrombosis?

Answer 31

Muscles are not pumping blood up to the heart, causing RBCs to collect at valves and form a thrombosis.

Question 32

What is the function of valves?

Answer 32

Prevention of back flow of blood.

Question 33

What is the purpose of the lymphatic system?

Answer 33

Drain interstitial fluid for it to become lymph for immunity and prevent fluid accumulation.

Question 34

Why does the size of the thymus decrease after puberty?

Answer 34

The body has been exposed to many of the potential pathogens and the thymus is metabolically expensive.

Question 35

What is the function of the spleen?

Answer 35

Storage of white and red blood cells.

Question 36

What is the white pulp of the spleen?

Answer 36

Storage of white blood cells.

Question 37

What is the red pulp of the spleen?

Answer 37

Storage of red blood cells.

Question 38

What parts of the body drain into the thoracic duct?

Answer 38

Left side of the body and the lower half of the right side.

Question 39

What parts of the body drain into the right lymphatic duct?

Answer 39

Top right half.