Ch 5 - Cardiovascular System: Heart and Blood Vessels

Question 1

Where does blood remove waste products from our system?

Answer 1

It removes waste products in the capillaries by exchanging its oxygen and nutrients for carbon dioxide and other waste products.

Question 2

Where is blood purified of waste products?

Answer 2

In the kidneys, but water and salt are retained as needed. Also in the liver.

Question 3

What is the difference between detoxification in the kidneys vs. in the liver?

Answer 3

Although both organs purify our blood by removing potential toxins, they work differently. The kidney filters the blood to remove water-soluble molecules, while the liver focuses on removing molecules that are not soluble in water and thus can’t be filtered

Question 4

What role do lymphatic vessels play?

Answer 4

Collects excess tissue fluid and returns it to the cardiovascular system

Question 5

Which direction do arteries and veins flow?

Answer 5

Arteries flow away from the heart. Veins flow toward the heart

Question 6

What controls blood pressure?

Answer 6

Precapillary sphincters in the arterioles. When arterioles dilate, blood pressure decreases. When sphincters constrict, capillary beds close.

Question 7

What is the arteriovenous shunt?

Answer 7

A pathway where blood moves from arteriole to venule

Question 8

What are venules?

Answer 8

Small veins that drain blood from the capillaries and then join to form a vein

Question 9

Why are valves needed in veins but not in arteries?

Answer 9

Valves are found in veins that carry blood agains the force of gravity, particularly in the lower extremities like the toes.

Question 10

What is the myocardium? What does it have to do with heart attacks?

Answer 10

Its the interior wall of tissue that makes up the heart. There are 3 layers of tissue that make up the heart, and the myocardium is the middle layer. When a portion of the myocardium muscle dies due to lack of oxygen, this results in a myocardial infarction (MI), or heart attack. There is a lack of oxygen to the myocardium if the coronary artery is partially or completely blocked.

Question 11

What are intercalated discs?

Answer 11

“Cardiac muscle consists of individual heart muscle cells (cardiomyocytes) connected by intercalated discs to work as a single functional organ.” Intercalated discs are connected via gap junctions and desmosomes, or protein fibers that hold on tightly to membranes of adjacent cells.

Question 12

Why are gap junctions important for the heart?

Answer 12

“The gap junctions, which are protein-lined tunnels, allow direct transmission of the depolarizing current from cell to cell, across the chambers of the heart, so that the cells contract in unison.”

Question 13

What is the pericardium?

Answer 13

A thick, membranous sac outside of the heart that supports and protects the heart. The inner part of the pericardium secretes a fluid that lubricates the outside of the heart so that it can slide smoothly as it beats.

Question 14

What is the wall that separates the heart into a right and left side?

Answer 14

The septum

Question 15

What are the upper heart chambers called? What do these chambers do?

Answer 15

Atrium/atria. These chambers receive blood into the heart.

Question 16

What are the two lower heart chambers called? What do these chambers do?

Answer 16

Ventricles. These chambers push blood away from the heart.

Question 17

What are the valves called that are located between the atria and ventricles?

Answer 17

AV, or atrioventricular valves.

Question 18

What valves push blood out of the heart?

Answer 18

The semilunar valves

Question 19

Which arteries/veins service the heart?

Answer 19

Coronary arteries/veins

Question 20

Which arteries/veins go to the lungs?

Answer 20

Pulmonary arteries/veins.

Question 21

Where do all veins drain into?

Answer 21

The INFERIOR and SUPERIOR vena cava.

Question 22

Why is the heart referred to as a “double pump?”

Answer 22

Because the right ventricle of the heart pumps blood through the lungs, and the left ventricle pumps blood throughout the body

Question 23

Which of the four chambers has the thickest walls and why?

Answer 23

The left ventricle because it needs to pump blood out with enough pressure/force to send blood all throughout the body.

Question 24

Where is blood pressure greatest?

Answer 24

Blood pressure is greatest in the aorta

Question 25

What does each heartbeat represent? What is the “lub-dub” sound from?

Answer 25

A cardiac cycle. The lub is when the AV close. The dub is when the semilunar valves close.

Question 26

Which part of the heart controls the rhythmic contraction of the atria and ventricles?

Answer 26

The SA node, or sinoatrial node, and the AV node, or atrioventricular node. The SA node initiates the heartbeat and sends out an excitation signal, causing the atria to contract. The signal reaches the AV node, causing the ventricles to contract.

Question 27

What’s another name for the SA node?

Answer 27

The pacemaker

Question 28

What part of our brain helps manage the heartbeat and how?

Answer 28

The medulla oblongata, which regulates beat by way of the sympathetic and parasympathetic nervous system. Parasympathetic division decreases SA and AV nodal activity.

The hormones epinephrine and norepinephrine released by the adrenal medulla also stimulate the heart. During exercise, heart rate increases as a result of releasing those hormones & sympathetic stimulation.

Question 29

What is an ECG, and how does it work?

Answer 29

It’s a recording of the electrical changes that occur in the myocardium during a cardiac cycle. Body fluids contain ions that conduct electrical currents, and thus we can use an ECG to detect electrical changes in the heart.

Question 30

What is ventricular fibrillation and how can we normalize it?

Answer 30

Uncoordinated, irregular electrical activity in the ventricles. We use a defibrillator to discharge electricity from heart cells so that the SA node can reestablish a coordinated beat.

Question 31

What is a pulse?

Answer 31

The rhythmic expansion and recoiling of an arterial wall can be felt as a pulse in any artery that runs close to the body’s surface.

Question 32

What is systolic pressure?

Answer 32

The highest arterial pressure, during ejection of blood from the heart.

Question 33

What is diasystolic pressure?

Answer 33

The lowest arterial pressure, when heart ventricles relax. Normal range is 120/80

Question 34

What are high and low blood pressure called?

Answer 34

Hypertension and hypotension, respectively.

Question 35

What does blood move slowly through the capillaries?

Answer 35

Because there are thousands of tiny capillaries for blood to move through. This allows time for nutrient-waste exchange

Question 36

Since blood pressure plays only a small role in returning blood to the heart, what are the other 3 factors that help blood move through veins?

Answer 36

1. Skeletal muscle contraction
2. Respiratory pump (when we inhale, the thoracic cavity loses pressure, and thus blood in the abdominal cavity [where there is high pressure] moves to the lower-pressure thoracic cavity)
3. Valves in veins

Question 37

How many miles of blood vessels do we have?

Answer 37

About 60,000 miles

Question 38

Which areas of the body filter blood into the superior vena cava?

Answer 38

The head, chest and arms

Question 39

What is the hepatic portal vein? Why is it depleted of oxygen?

Answer 39

It’s the vein between two different capillary beds, that of the intestines and the liver. It lacks oxygen because the O2 is used up by the intestines.

Question 40

What is the path of blood?

Answer 40

Aorta > Arteries > Arterioles > Capillaries > Venules > Veins > Vena Cava

Question 41

Where is blood pressure highest and osmotic pressure lowest? What happens as a result?

Answer 41

In the arteriole & beginning of the capillary. Causes water to travel from the capillary to tissue fluid.

Question 42

Where is blood pressure lowest and osmotic pressure highest? What happens as a result?

Answer 42

In the venule & end of the capillary. Causes water to travel back into the capillary.

Question 43

Where is blood pressure and osmotic pressure equal? What happens as a result?

Answer 43

In the center of the capillary. This is when diffusion takes place.

Question 44

What creates osmotic pressure?

Answer 44

The presence of solutes dissolved in plasma, but especially the presence of plasma proteins, which are manufactured by the liver. Plasma proteins cannot pass the membranes of capillaries because they’re too big.

Question 45

What’s an aneurysm?

Answer 45

A bursted blood vessel

Question 46

What is atherosclerosis?

Answer 46

Caused by the formation of atherosclerotic plaques on the inside of blood vessels. The plaques narrow the blood vessels, choking off blood and oxygen supply to tissues.

Question 47

What is a thromboembolism?

Answer 47

A thrombus is a stationary clot of plaque. If that thrombus dislodges, it’s called an embolus. A thromboembolism is a clot that gets carried in the bloodstream and then lodges itself in a small blood vessel.

Question 48

What is a stroke?

Answer 48

A cerebrovascular accident (CVA). Results when a small cranial arteriole bursts or is blocked by an embolus. A lack of oxygen causes a portion of the brain to die.

Question 49

What is angina pectoris?

Answer 49

When a coronary artery becomes partially blocked, pressure, squeezing or pain in the chest occur. It’s not a complete heart attack, however.

Question 50

What is a bypass surgery?

Answer 50

Taking a blood vessel like a vein from the leg and stitching one end to the aorta and the other end to a coronary artery so that the blood can still flow.

Question 51

What is angioplasty?

Answer 51

When a plastic tube is inserted into an artery until the blockage is located. Then a balloon inflates and opens the artery. A stent with an inner balloon is pushed into the blocked area to hold it open.

Question 52

What is heart failure?

Answer 52

When the heart no longer pumps as it should. It’s damaged, saggy and swollen. Usually happens after a heart attack if the person doesn’t die.