Ianowski - theme 11 and 12

Question 1

Components of circulatory systems that are common to all animals:

Answer 1

Fluid, pump, vessels

Question 2

Different kinds of circulatory systems:

Answer 2

Gastrovascular cavity, open system, closed system

Question 3

Main difference between open and closed systems:

Answer 3

Capillaries!

Question 4

Gastrovascular cavity:

Answer 4

Simplest circulatory system. Found in cnidarians.
Fluid: water
Pump: body
Vessels: cavity

Question 5

Open system:

Answer 5

Found in many invertebrates.
Fluid: hemolymph
Pump: heart(s)
Vessels: hemocoel (blood vessels that open to the body cavity)

Question 6

Main disadvantage of open system:

Answer 6

Can’t direct blood to specific places.

Question 7

Insect open system:

Answer 7

Circulatory system doesn’t fuck wit O2, so metabolic rate can be very high.
Transports nutrients, hormones, waste, and immune molecules. Wound repair, heat transfer, and CO2 sink. Hydraulic skeleton in larvae.

Question 8

Closed system:

Answer 8

Found in vertebrates and cephalopods.
Fluid: blood
Pump: heart
Vessels: blood vessels and capillaries

Question 9

Different closed systems and which organisms use them:

Answer 9

Single circulation - fish
Parallel circulation - amphibians
Double circulation - mammals, birds, crocodilians

Question 10

Double circulation:

Answer 10

Pulmonary and systemic blood are separated.

Question 11

What supplies the heart with O2?

Answer 11

Coronary arteries, a part of the systemic circuit.

Question 12

How do the volumes of blood in pulmonary vs systemic compare?

Answer 12

Must be equal, or there would be buildup in one circuit.

Question 13

What is the main advantage of having separate circuits (with the same volume)?

Answer 13

Systemic circuit can have high pressure so flow can go fast

Pulmonary circuit can have low pressure and low resistance (so nothing blows up)

Question 14

Congestive cardiomyopathy:

Answer 14

70% normal fraction ejection - only 30% is ejected. Swelling in left ventricle.

Question 15

Parallel circulation, a beautiful story:

Answer 15

Body tissue circuit: ventricle pushes oxygenated blood to the tissues, and deoxygenated blood goes to the right atrium. Low pressure.
Lung circuit: ventricle pushes mixed blood (from right atrium) to the lungs, where it is oxygenated. It returns to the left atrium. Moderate pressure.
Cutaneous circuit: ventricle pushes mixed blood (from right atrium) to the skin, where it is oxygenated. It returns to the right atrium to mix with deoxy body blood. Low pressure.

Question 16

Pros and cons of parallel circulation:

Answer 16

Pros: systemic and pulmocutaneous systems are separate. Periodic ventilation (divert blood to or away from lungs).
Cons: can’t have very high pressure with only one ventricle.

Question 17

Single circulation:

Answer 17

One atrium and one ventricle. Ventricle pushes deoxy blood to gills. Oxy blood travels to body tissue. Deoxy blood travels to atrium. Low pressure the whole time.

Question 18

Classification of blood vessels:

Answer 18

Artery, arteriole, continuous capillary, fenestrated capillary, venule, vein

Question 19

Which vessels are: pressure reservoirs? blood reservoirs? sites of exchange with interstitial fluid?

Answer 19

Arteries are pressure reservoirs. Capillaries are exchange. Veins and venules are blood reservoirs.

Question 20

What is the function of arterioles?

Answer 20

Controls where blood flow goes by opening/closing access to capillaries.

Question 21

Let’s talk about how tiny capillaries are.

Answer 21

Consist of a single layer of endothelial cells. So smol that RBCs have to travel in single file.

Question 22

Muscles help return blood to the heart.

Answer 22

Muscles contract to push blood in veins. A venous valve closes to stop backflow and another venous valve opens to allow blood to be pushed towards the heart.

Question 23

Lymphatic system:

Answer 23

Collects excess interstitial fluid and returns it to the venous blood.

Question 24

Tissues and organs of the lymphatic system:

Answer 24

Lymph nodes, spleen, thymus, tonsils. They remove bad guys from lymph and blood.

Question 25

Where do white blood cells like to hang out?

Answer 25

Lymph nodes

Question 26

Where do the thymus and spleen guard?

Answer 26

Thymus - inhaled bad guys

Spleen - blood bad guys

Question 27

Neurogenic hearts vs myogenic hearts:

Answer 27

Neurogenic can’t contract spontaneously. Insects and crustaceans.
Myogenic have pacemaker cells.

Question 28

Pacemaker cells:

Answer 28

Membrane potential changes as Na and Ca come in more and K leaves less. AP is produced when L-type Ca2+ channels open at threshold.

Question 29

Are heart valves energy dependent?

Answer 29

NO! They open when blood flows the right way, and close against backflow PASSIVELY.

Question 30

Cardiac cycle:

Answer 30

Systole: contraction. max pressure.
Diastole: relaxation. min pressure.

Question 31

Vertebrate heart walls:

Answer 31

Myocardium between endo and epicardium.

Question 32

Myocardium:

Answer 32

Interlacing bundles of cardiac fibres arranged in spirals. Intercalated discs contain desmosomes and gap junctions.

Question 33

Functional syncytium:

Answer 33

All myocardial cells that are connected by gap junctions (so impulses spread to all of them).

Question 34

Electrical conduction system in heart:

Answer 34

Electrically non-conducive tissue band between atria and ventricles. SA node in right atrium propagates charge to both atria and to the AV node. AV node sends signals to the ventricles.

Question 35

Consequences of nodey electrical conduction:

Answer 35

Contractions happens from right to left, and the atria contract slightly before the ventricles.

Question 36

ECG interpretation:

Answer 36

P wave - atrial depolarization
QRS complex - ventricular depolarization
T wave - ventricular repolarization

PR segment - AV nodal delay
ST segment - plateau phase
TP interval - passive ventricular filling, total rest

Question 37

What cells relay charge from AV node to the bottom of the heart?

Answer 37

Purkinje cells