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3 Types of Transport
Gastrovascular Cavity, Open Circulatory System, and Closed Circulatory System.
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Gastrovascular Cavity
The circulatory system most invertebrates use for internal transport.
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Open Circulatory System
What insects, mollusks, and most arthropods use as a circulatory system. It bathes organs in blood directly.
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Hemolymph
The mixture of blood and interstitial fluid which flows in open circulatory systems.
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Closed Circulatory System
The type of circulatory system earthworms, squid, octopuses, and vertebrates use. Blood is confined to vessels.
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Fish Circulatory System
The heart is 2-chambered. Blood goes from ventricles to gills, disposes of CO2, and crosses capillary walls. Capillaries join into one vessel that carries O2-rich blood to different capillary beds. Blood then goes back to the heart. The right side contains O2-poor blood and the left side contains O2-rich blood.
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Amphibian Circulatory System
The heart is 3-chambered (2 artia and 1 ventricle). The ventricle pumps blood into a forked artery. One side of the fork feeds the pulmocutaneous system and the other feeds the systemic system.
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Bird/Mammalian Circulatory System
The heart is 4-chambered. The left side holds O2-rich blood and the right side holds O2-poor blood.
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Cardiac Cycle
The pumping and filling of the heart ONCE.
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Systole
Contraction phase of the heart.
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Dystole
The relaxation phase of the heart.
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Atrial and Ventricular Dystole
(.4 seconds) The atrioventricular valves open and the semilunar valves shut. First step in the cardiac cycle.
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Atrial Systole, Ventricular Dystole
(.1 second) Blood goes towards the semilunar valves, but they stay shut. 2nd step in the cardiac cycle.
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Ventricular Systole, Atrial Dystole
(.3 seconds) Semilunar valves open and atrioventricular valve close. 3rd step of cardiac cycle.
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Arteries
The outside is composed of connective tissue with elastic fibers. The middle is composed of smooth muscle and elastic fibers. The inside is composed of endothelium. Carries O2-poor blood. Has thicker connective tissue and smooth muscle.
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Veins
The outside is composed of connective tissue with elastic fibers. The middle is composed of smooth muscle with elastic fibers. The inside is composed of endothelium. Have valves to prevent blood from flowing in the wrong direction. The connective tissue and smooth muscle is thinner. Blood flows as a result of skeletal muscle contractions.
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Capillaries
The outside is composed of basement membrane. The inside is composed of endothelium. Where transfer occurs.
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As the blood flow in capillaries reaches its cross-section...
Area increases, velocity decreases, and pressure decreases.
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Where does the exchange of substances occur?
At the endothelial walls of capillaries.
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How much fluid returns to the arteries after the exchange of substances? If not 100% comes back, where does the rest go?
85% returns to the capillaries (and then goes to the arteries) after the exchange of substances. The other 15% enters the lymph system.
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Lymph Capillaries
Where fluid from the blood diffuses to. Intermingled with capillaries of the cardiovascular system.
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The thinner-walled veins convey blood back to the heart at...
Low velocity and low pressure.
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What does the elasticity of arteries do?
It helps maintain blood pressure, even as the heart relaxes.
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At any given time, only about _______ to _______ percent of the body's capillaries have blood flowing through them.
5-10%
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Lymph
Fluid which has leaked into the lymphatic system from the circulatory system. Its composition is similar to interstitial fluid.
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What does lymph flow in?
Vessels.
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The lymphatic system drains into the circulatory system near the junction of the ____________________ with the __________________.
The venae cavae with the right atrium.
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What is in blood?
Plasma (55%) and Cellular Elements (45%).
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What is in plasma?
Water, ions, plasma proteins, and substances transported by blood.
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What is in the cellular elements of blood?
Erythrocytes, leukocytes, and platelets.
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What is the purpose of water in plasma?
Water acts as a solvent to carry other substances.
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What is the purpose of ions in plasma?
Osmotic balance, pH buffering, and regulation of membrane permeability.
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What is the purpose of plasma proteins?
Osmotic balance, pH buffering, clotting, and defense.
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What do erythrocytes do? How many erythrocytes are in each mm3 of blood?
Erythrocytes transport O2 and help transport CO2. 5-6 million are in each mm3 of blood.
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What do leukocytes do? How many leukocytes are in each mm3 of blood?
Leukocytes provide defense and immunity. There are 5,000-10,000 leukocytes in each mm3 of blood.
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What do platelets do? How many platelets are in each mm3 of blood?
Platelets are responsible for blood clotting. There are 250,000-400,000 in each mm3 of blood.
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What does oxygen transport depend on and what type of cell carries it out?
Oxygen transport depends on the rapid diffusion of oxygen across the cell's plasma membrane. Erythrocytes carry out oxygen transport.
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How long do erythrocytes circulate in the body? What happens to them after they're done circulating?
Erythrocytes circulate for 3-4 months. After circulation, they are destroyed by phagocytic cells in the liver and spleen.
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What do pluripotent stem cells do? Where are they located?
Pluripotent stem cells creat erythrocytes, leukocytes, and platelets. They are located in the red marrow of bones.
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Describe the process of blood clotting:
A hole in connective tissue is created (like a cut or scrape). Platelets stick to this hole and release chemicals to make nearby platelets sticky. Prothrombin turns into thrombin. The platelets create a platelet plug, and fibrinogen turns into fibrin. A seal is put into place by the fibrin.
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What does clotting factor from?
Platelets, damaged cells, and plasma.
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Give two examples of types of clots which are dangerous
A clot in a heart artery causes a heart attack. A clot in a brain artery causes a stroke.
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Gas Exchange
The uptake of molecular oxygen (O2) from the environment and the discharge (CO2) to the environment.
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What is the percentage of O2 present in air?
21%
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Which has a higher concentration of O2, air or water?
Air.
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Gills
Outfoldings of the body surface that are suspended in water.
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Advantages of using water as a respiratory medium:
It is easy to keep cells moist.
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Disadvantages of using water as a respiratory medium:
O2 concentrations in water is lower than O2 concentrations in air. Ventilation becomes necessary.
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Ventilation
An increase in the flow of the respiratory medium over the respiratory surface.
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Describe the path of water flow through fish:
Water enters the fish through its mouth. It then passes through slits in the pharynx, flows over gills, and exits the body.
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Gas exchange at teh gill surface is enhanced by the _______________________________ of water and blood at the gills.
Opposing flows
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What are the advantages of using air as a respiratory medium?
The O2 concentration is higher than that of water. Because O2 and CO2 diffuse faster as gases, ventilation does not have to be as thorough. Less energy is required during ventilation because air is lighter and easier to pump.
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What are the disadvantages of using air as a respiratory medium?
Because gas exchanges is better over fluids and air is dry, water is constantly lost to the environment. This problem is greatly reduced by having a respiratory system which is folded into the body.
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The epithelium lining the major branches of the respiratory tree is covered by __________________________________. What purpose does this serve?
By cilia and a thin film of mucus. The mucus traps dust, pollen, etc. The cilia sweep these things upwards. Eventually you cough or sneeze it out.
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Exactly where does gas exchange occur?
In the alveoli.
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Alveoli
A cluster of air sacs located at the end of the smallest bronchioles. Gas exchange occurs here. The total surface area of alveoli in humans is approximately 100m2.
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How does gas exchange occur?
Oxygen diffuses across the epithelium of alveoli into a web of capillaries which surrounds the alveoli. CO2 goes in the opposite direction (from capillaries to alveoli).
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Tidal Volume
The amount of air an animal inhales and exhales. (approximately 500mL).
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What is the maximum tidal volume during forced breathing for humans?
3.4L for females and 4.8L for males.
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Does all air leave the lungs with each exhalation? If not, what is happening to the rest of the air?
No, the rest of the air is residual air, which is held in the lungs because alveoli do not completely collapse.
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Is residual air kept separate from the rest of the air in alveoli?
No, it is mixed in with fresher air.
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Whose lungs are more efficient: Mammals or Birds?
Birds. Their air flows in a circular path and does not have dead ends like mammalian lungs.
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A gas will always move from a region of __________ partial presser to a region of ___________ partial pressure.
Higher to lower.
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Is there more O2 or CO2 in air that is exhaled? Why?
There is more O2 in air that is exhaled because the air exhaled mixes with the air that's being inhaled.
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Most animals transport most of their O2 bound to proteins called _____________________. Why?
Respiratory pigments because the blood can carry more O2 this way.
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Which protein carries O2?
Hemoglobin
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What color are respiratory pigments? Why are they that color?
Respiratory pigments are red because of the iron they contain. This is why O2-rich blood is red.
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What does hemoglobin do?
Hemoglobin transports O2, transports CO2, and buffers blood pH.
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Which of the following has the most direct impact upon the ability to move blood through veins? A dystole phase of cardiac muscle, B systole phase of cardiac muscle, C skeletal muscle constrictions and one-way valves, D negative pressure from the filling heart?
C. skeletal muscle constrictions and one-way valves
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Which location has the red blood cells that contain the most O2 gas bound inside of them? A Pulmonary Veins, B Pulmonary Arteries, C Venae Cavae, D Right Atrium, E Right Ventricle?
A. Pulmonary Veins
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Where is the lowest concentration of CO2? A In the air we breathe, B In the pulmonary arteries, C In the alveolar spces of lungs, D In veins, or E in Capillaries?
A. In the air we breathe.
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Most of the liquid that leaks out through capillary walls into the interstitial fluid is returned to the same capillary bed. What happens to the remainder of the liquid?
A it stays in the tissue it leaked out of
B it is returned to the circulatory system through the kidney
C it is returned to the circulatory system through the lymph system
D it is returned to the circulatory system through the liver
E it is removed from the body through the gastro-intestinal tract
C. It is returned to the circulatory system through the lymph system
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