10

Question 1

Fish heart anatomy?

Answer 1

They have a single circuit circulatory system with linear flow. They have a thin-walled atrium that contracts weakly, and a thick-walled ventricle that contracts strongly. The blood enters the atrium first.

Question 2

Mammal heart basic steps?

Answer 2

Blood goes from the right atrium to the right ventricle, and then gets pumped to the lungs. Then, blood goes from the lungs to the left atrium, then to the left ventricle, and then gets pumped throughout the circulatory system.

Question 3

Complex steps of a mammalian heart.

Answer 3

Blood is coming from the superior vena cava or inferior vena cava, which then goes into the right atrium, passes the atrioventricular valve and goes into the right ventricle, and gets pumped out into the lungs by passing through the semilunar valve and into the pulmonary artery. Blood returns to the heart by the pulmonary vein and into the left atrium. Blood then enters through the atrioventricular valve into the left ventricle, and then through the semilunar valve into the aorta.

Question 4

Pressure mechanism in a mammalian heart at the left side?

Answer 4

Blood flows from left atrium to left ventricle from the pressure being higher in the atrium than in the ventricle, negative pressure. Then during a contraction of the ventricle, all valves are closed and the pressure increases with the volume starting the same, and once the valve from the ventricle open, blood flows to the aorta, positive pressure.

Question 5

Is blood moving from the atrium to the ventricle passive or pumped?

Answer 5

Passive since the pressure of the ventricle is lower than the atrium.

Question 6

At the beginning of the ventricular systole, the pressure inside of the ventricle when the valves are closed increases/decreases since volume increases/decreases/stays the same?

Answer 6

Increases, stays the same since liquids are non-compressible in a sealed chamber.

Question 7

Why do valves open?

Answer 7

Due to the differences in pressure, passively.

Question 8

Why are valves inside the heart one way?

Answer 8

There are tendons that attach to the valves of the heart that prevent it from opening in the other direction.

Question 9

Why does the valve close from the atria to the ventricle in the left side of the heart?

Answer 9

So pressure can build inside the ventricle and to ensure that blood does not flow back.

Question 10

The valve between the ventricle and the aorta opens when?

Answer 10

The pressure inside the ventricle should be higher than the aorta for positive pressure.

Question 11

!!!!!The two special words for contraction in no change of volume?

Question 12

Does the right side of the heart pump blood through the same differences in pressure?

Answer 12

Yes, but less force.

Question 13

Why is the right side of the heart pump with less force?

Answer 13

Since blood only needs to be pumped into the blood to ensure that the lungs do not have high pressure that can damage the lungs.

Question 14

Which side of the heart is less muscular?

Answer 14

The right side of the heart.

Question 15

The cardiac cycle of the heart is similar to all vertebrate hearts, but what differs?

Answer 15

Pressure

Question 16

How are cardiac cells connected?

Answer 16

Cardiac cells are connected by gap junctions at a structure called the intercalated disk. It allows electrical signals to travel from cell to cell.

Question 17

EKG Signal?

Answer 17

Contraction occurs in the atrium first, then in the ventricle. This occurs due to electrical signals. sinoatrical node, that generates an electrical signal that travels from cell to cell or through specialized conducting pathways (internodal pathways) that are modified heart cells that do not contract, and they travel more rapidly. The signal travels to the AV node, and at the same time, it spreads slowly throughout the atria from cell to cell to contract the atria. The signal then pauses. The signal is then passed through the ventricular conducting system to the apex of the heart by the AV bundle and spreads up the heart throughout the ventricle by Purkinje fibers.

Question 18

Ventricular defibrillation?

Answer 18

The conducting system has failed, and instead of getting a signal from the SA node, every heart cell is contracting when it feels like. Often, the fastest cell in the ventricular contracts more.

Question 19

Pressure, velocity, and total area differences between the entire circulatory system?

Answer 19

Increase to decrease, and fast to slow to fast (so it provides time for substances to be exchanged in the capillaries), low to high to low (since there are many capillaries, even through it is very slow).

Question 20

!!!!!!Why does the pressure fluctuate but not near 0 pressure in the aorta?

Answer 20

Since the aorta is elastic and so

Question 21

Why does pressure decrease in the arterioles?

Answer 21

Since the radius decreases, so resistance increases.

Question 22

How does blood gets back to the heart if veins is in low pressure?

Answer 22

Skeletal muscle squeeze the veins, and the valves prevent the blood from going back.

Question 23

The body can use the sympathetic and the parasympathetic nervous system to regulate blood flow. How?

Answer 23

When the low reaches a branch point, it will divide among different vessels. Fluids take the path of least resistance. Since the resistance is equal, flow is distributed equally. Flow should be equally distributed. Thus, flow is regulated if by changing the radius of vessels.

Question 24

Vasoconstriction and vasodilation of arterioles do what?

Answer 24

Regulates flow by changing the radius of vessels to increase or decrease resistance.

Question 25

How does blood get collected if it leaks out of a capillary?

Answer 25

Through the lymphatic system which is a series of blindended tubes that carry fluid from the body back to the heart. This is needed because blood pressure forces fluid out of the circulatory system into the tissues.

Question 26

Edema?

Answer 26

The rate of fluid that leaves the capillaries is greater than can be handled by the lymphatic system. Results in an accumulation of fluid in the tissues.

Question 27

!!!!!!3• What factors affect fluid movement?

Answer 27

Blood pressure forces fluid out of the capillary through osmotic pressure. It can occur in three ways:

•Filtration +10 mmHg (fluid exits capillary since capillary hydrostatic pressure is greater than blood colloidal osmotic pressure)
•No net movement 0 mmHg (no net movement of fluid since capillary hydrostatic pressure = blood colloidal osmotic pressure)
•Reabsorption -7 mmHg (fluid re-enters capillary since capillary hydrostatic pressure is less than blood colloidal osmotic pressure).

Question 28

Flow of lymph?

Answer 28

It has to flow from periphery back to heart. Since mammals do not have hearts in the lymphatic system (frogs do), mammals have to use skeletal muscle contraction to move lymph.

Question 29

Ventricle and atrium pressure differences in a fish heart?

Answer 29

Ventricle contracts to increase pressure, and push blood out of the heart via positive pressure. The ventricle thus increase in size after, decreasing in pressure, and pulling blood from the atrium in via negative pressure.

Question 30

The cardiac cycle has two phase. What are the phases?

Answer 30

•Systole: contraction and pressure increase
•Diastole: relaxation and pressure decreases

Question 31

Apex of heart?

Answer 31

The muscle of the bottom of the heart.