Cardio II Flashcards
What is the process by which oxygen enters the body?
Air that you inhale ends up in the alveoli by bulk flow or convective flow. You create negative pressure difference in the lungs and this allows the air to be sucked in.
What is the process by which the air in the alveolus ends up in the RBC to be transported? Name the 6 steps it must go through.
It moves via diffusion (1) from the interior of the alveolus, (2) across the alveolar membrane and (3) the interstitial space. Then it must (4) cross the wall of the capillary, then it ends up (5) inside of the blood plasma. Then it must (6) cross the membrane of the red blood cell. The O2 molecule will then bind to the Hb to form OxyHb. Blood must cross through 6 barriers via diffusion, all driven by the O2 concentration gradient.
Blood transports RBC to other places in the body via the process of […]
convective flow
Describe the process by which oxygen reaches the organs once it has travelled into the capillaries.
It is in the capillary, so the oxygen must unbind from the Hb, diffuse out from the Hb molecules, go through the cellular membrane of the blood cell, into the plasma, cross the capillary, go into the ISF, cross the cell membrane of the destination, go into the cytoplasm of that cell, and cross the inner and outer membrane fo the mitochondria. The oxygen molecule cross many different barriers by diffusion. It can do that because the concentration of O2 in the RBC is must larger than in the destination, so there is a concentration gradient over a short distance.
CO2 is transported from the organ of origin to the alveoli via the process of […]
convective flow
The transport of oxygen and CO2 each consist of steps either consisting of […] or […].
diffusion or convection.
Describe the anatomy of insect circulation
Two components: a vessel called the dorsal aorta (runs along back of animal), and the structure towards the back with 5 chambers, which is the heart. Insects are extremely diverse.
The anterior end of the vessel is open. The blood flows towards it, and the blood simply squirts out of the open tube and seeps around the organs. It re-enters through the holes (each hold is an ostium) in each chamber (each chamber has 2).
The fluid circulating in the insect circulation is […]
haemolymph
Do insects have open or closed circulation? Explain why.
This is open circulation. The blood leaves the cardiovascular system and comes back in through the ostia. This is as opposed to closed circulation, where the blood is always in the heart or in a vessel.
Is the amphibian and most reptilian circulation open or closed?
Closed
Is the piscine circulation open or closed? Explain why.
Closed. The blood doesn’t leave the circulatory system.
Describe piscine circulation in terms of:
a) Number of atria and ventricles
b) Total chambers
c) Where gas exchange occurs
d) Number of loops
a) One atrium and one ventricle
b) 2 chambers
c) Deoxygenated blood flows from ventricle to gills, where it is oxygenated. Oxygenated blood flows to the systemic capillaries, where it becomes deoxygenated. This deoxygenated blood flows into the atrium.
(All blood in the heart is deoxygenated!)
d) Single loop
How do insects obtain oxygen?
Diffusion. They don’t have red blood cells.
Describe amphibian and most reptilian circulation in terms of:
a) Number of atria and ventricles
b) Total chambers
c) Where gas exchange occurs and how it returns to the heart
d) Number of loops
a) 2 atria, 1 ventricle
b) 3 chambers
c) Deoxygenated blood leaves the ventricle and goes to the pulmonary and skin capillaries (pulmocutaneous circuit), where it gets oxygenated. They can breathe through skin and lungs. This blood comes back into the left atrium.
Oxygenated blood leaves the ventricles and goes to the systemic capillaries, where it becomes deoxygenated. This blood comes back into the right atrium.
d) Double loop
Do amphibians and most reptiles have a septum separating the atria and the ventricles?
Atria - yes
Ventricle - no because there’s only one.
How does the concentration of blood O2 vary in amphibians and most reptiles compared to mammals?
They have a lower concentration of O2 in their blood compared to us due to the mixing that does occur. They are cold blooded, because they need less oxygen and lower temperatures.
Describe the avian heart in terms of:
a) Number of atria and ventricles
b) Total chambers
c) Where gas exchange occurs and how it returns to the heart
d) Number of loops
a) 2 atria and 2 ventricles
b) 4 chambers
c) Deoxygenated blood goes to the pulmonary capillaries, where it gets oxygenated. It returns to the left heart.
Oxygenated blood goes to the systemic capillaries, where it gets deoxygenated. It returns to the right heart.
d) Double loop
Is the avian circulation open or closed?
closed
Do birds have a septum separating the atria and the ventricles?
Yes for both There’s no mixing of oxygenated and deoxygenated blood.
Describe the circulatory system of alligators and crocodiles.
It is similar to that of mammals and avians - 4 chambered heart.
The right heart is dedicated to […] circulation, while the left heart is dedicated to […] circulation.
pulmonary (lungs), systemic (rest of organs)
What is the typical total blood volume in an individual?
5 L
Note that in reality, it is proportional to weight
What is the typical amount of blood per kg in an individual?
75 mL/kg
How much is 1 unit of blood? What is a unit of blood?
1 unit of blood = 450 mL
About 9% of blood volume
Describe the breakdown of where blood is found throughout the circulatory system.
61% in veins and venules
12% in pulmonary circulation
9% in the heart
11% in artieries
7% in arterioles and capillaries
What is stroke volume? What is its value?
It is the amount of blood expelled per pump. It is equal to 70 mL
The arterial system is characterized by […], while the venous system is characterized by […]
resistance, capacitance
What is cardiac output?
5,000 ml/min (5L/min). This is how much blood is pumped out of the left ventricle every time.
What is the nominal resting heart rate? How do we know?
If the cardiac output is 5,000 ml/min and the stroke volume is 70 mL, you get a heart rate of 70 bpm. This is the nominal resting heart rate in a human being.
What elements of the circulatory system are in series vs in parallel?
The organs in the systemic circulation are all in parallel with one another. The systemic circulation as a whole + the right heart + the pulmonary circulation + the left heart are in series with one another.
What is venous return?
The flow returning the blood to the right heart is called venous return. This is the flow coming from the veins that is returning the blood to the heart to be circulated again. This flow equals the cardiac output.
Why must CO = VR?
If they are not equal, blood will accumulate in the organs.
What is the formula for flow?
Flow = V/T
