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24 Cards in this Set
- Front
- Back
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What are the two main types of circulatory systems?
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Open circulatory system
blood leaves blood vessels filling hemocoel (sinuses) enters vein goes to heart Closed heart --> arteries -->arterioles --> capillaries --> venules --> veins --> heart |
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External pump
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Squeeze vessels and blood flows, valves will allow flow in one direction only.
eg- invertebrates eg- vertebrate leg skeletal muscle acts as pumps for veins to pump blood to heart. |
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Peristaltic Contraction
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wave of contraction by smooth muscles in blood vessel
Muscles acts as pumps |
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Contractile Chamber
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Muscle walls that contract,
unidirectional flow controlled by valves. Eg- vertebrates |
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How hearts pump over time?
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Irregular wave of contraction.
Rythmic Exercise- high frequency blood flow in leg muscle. Peristaltic contraction- regular waves of contraction |
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Overview of open circulatory systems in vertebrates?
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Fluid moves through cavities of animal.
Sponge, Flatworms- open circulation. Insects- through back of an insect, tube has peristaltic waves of contraction. Ostia- where blood gets sucked in from the sinuses. Insects have their own supply of oxygen through trachioles to all cells of the body. Blood is bringing not oxygen but all nutrients of the other cell. Not same type of blood flow. Wings- base has accessory pumping organ to generate contractile peristaltic waves for flight. |
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Heart is surrounded by ligaments
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Heart is in a sinus, with ostia. When the ligaments contract, they push open the heart chamber, the ostia open up, surrounded by blood (gets sucked in)
Heart contraction- ostia close, blood gets pumped to sides. |
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Systole/Diastole in insect circulation
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Ligaments open ostia, blood sucked in.
Diastole- ostia close, blood pumped to body tissues |
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Annelids/Polychaetes
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Annelids first ( Earth worm)- closed circulation
not polychaetes |
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single-circuit circulatory system/ double-circuit circulatory system
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Cycle: Heart pumps into gills --> tissues --> heart.
Humans: Heart --> respiratory surface --> heart --> body --> lungs --> body. |
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Neurogenic heart with pace maker cells
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1. Nerve tissue on top of heart (9) generate the beating. Separate them from muscle, muscle cannot contract. every other heart is myogenic vs. neurogenic, pacemaker (stimulation) inherent in one of the population of muscle cells itself. (separate heart from body, and will beat)
2. Isolated from muscle |
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Caudal heart of catfish
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Center of heart has cartilage (flexible)
with two extrinsic muscles moving to the right of the left (muscle contraction of the cartilage) turn to right, opening it. Turn left, opening it. (no turning- no pumping) |
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Spongy heart
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Space- no need capillary for heart muscle because many chambers for O2 to enter, heart can feed itself.
Human- myocardium (packed with cells, packed solid need their own capillary supply) |
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Fish- one chamber heart
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1. body blood enters sinus venosus.
2. Enter atrium 3. Ventricle- main contractile chamber 4. Bulbous areriosus All contract! |
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What did the Shark add?
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Non-contracticle (stiff) pericardium fill with fluid.
Sinus vinosus Atrium Ventricle Bulbous arterious Pericardium- put a lot or remove fluid, potential of modifying how solid you want the structure to be. When atria contracts, blood enters ventricle (largest), fluid cannot be distended, as this contracts, the pressure becomes subatmospheric, and atria balloons out. Contracting a section, and another stops. At ventricular contraction, helps in the feeding of the atria. Ventricle an bulbous contract, atria balloons out filling more with blood- how much depends on pressure of fluid in the chamber. or can balloon little, blood supply coming in is less. Amoutn of blood in ventricle is not constant, can change. Force of contraction of the ventricle muscle directly propotinal to blood volume it has inside, more stronger contraction, more blood outside. less blood, less contraction, less blood gets uout. PUMP adapts to contents in chamber. heart changes output to meet the body's demand. |
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Holes in ventricles and left atrium.
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Oxygenated and deoxygenated blood in ventricle- blood mix but not true.
Blood doesn't mix. because the way it is distributed, the holes keep the deoxygnated and oxygenated blood separated. 2 atria and 2 ventricle, slowly dividing circulation, not yet a double-circuit. |
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Two totally separated ventricles occur where?
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Reptiles on.
Added nice touch? Dive underwater- crocodiles. Two chambers: R/L atria, R/L Ventricles. Extra vessel leaving the right ventricle also goes to the body, and hole- foramen of panizzae (not valve) blood body -> right ventricle --> left ventricle thicker than the right. normal in all four chamber hearts. left pumps to body with a stronger force. RIght- weaker force. Blood comes in at a very high pressure, wcompared to right. High pressure left ventricle closes the right side, Shape of valve allows in one direction only. Nothing from the right. Animal divides- sensory cells in nose of animal send message from cardiovascular centers (only do: constrict the smooth muscle surrounding the pulmonary artery) No smooth muscle, reflex, closes, shrinks the pulmonary artery- shrink, less going to lungs, less coming from lungs, pressure is less than before. Constricting this, as blood continues from body, right atria pushes blood through constricted vessel, pressure increases, while pressure is lower in other chamber, valve finally opens, the right atria pushes blood to body with little going into lungs- adaptation, reduce diameter of cardiac artery, increase pressure in right ventricle exceeds left ventricle (went down b/c less blood flow), goes favors the right ventricle. get out of water, changes. |
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Mammalian heart has 2 circulations
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From body- systemic circuit -- right atria - right ventricle -- pulmonary circuit is short b/c heart is in middle of longs) pulmonary veins left atria left ventricle to body via systemic circulation.
THIs has a long way to travel- left side is always stronger than the right. Systemic circulation is always greater than pulmonary. |
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Pacemaker cells
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Comprise 1% of entire population of heart cells 99% cardiac cells. Pacemaker- generate heart rythm embedded in muscle mass, cannot contract b/c cannot contract, not nerve cells, have wierd time of membrane channels, hybrids between muscle/nerve but neither. If you isolate heart muscle, isolate cell type, heart keeps on beating outside body- myogenic?!
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Heart grand central station
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Inferior (below)
Superior (above) meet in the junction- where lymphatic system empties into the circulatory system (chylomicrons get to blood at junction of the sup/inf vena cava) right atria, right ventricle, pulmonary artery, lungs, capillaries, alveoli, veins, pulmonary veins, left ventricle, pulmonary circulation above- systemic circulation goes below Gigantic aorta- main vessel in heart producing main 3 arteries to upper, and main gigantic for lower portion. |
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Cardiac muscle
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1 .Similar in size to smooth muscle cells.
2. One nucleus per cell, similar. 3. Striations- contraticle muscle organized. 4. Largest concentration of mitochondria than any tissue in body. Pumping requires ATP, best supply. 5. Between cells- intercollated discs- mixture of gap junctions (ions flow) and spot weld (desmosome) proteins on one side, and linked to another inseparable. LEAKY spot Weld! Communication btw cells but strong connections! |
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Pacemaker
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Four populations:
1. Base where vena cava enters atria, sinoatrial node. 2. Atrioventricular node- middle 3. Bunlde of His close to AV node 4. Pukinje fibers connected togehter via cardiac cells, with gap junctions, currents spread systemicly, each can do spotnaenous activity driving th eheart on their own. |
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ECHTOPIC pacemaker.
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When these four cells drive heart on own- one that is fastest, commands al the others. Fastest is the sinoatrial node- main one driving the heart. SA node slows down, AV node takes over, heart now follows different pacemaker.
Happens with caffeinated people. Atria contract independent of ventricles due to purkinje fibers. if not in unison, pump doesn't work well. |
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Cardiac action potnetial
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Different from the regular action potenail due to the different actors:
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