Chapter 42: Circulation and Gas Exchange

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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• Transport nutrients O2 to all cells
• Transport metabolic waste to kidneys CO2 to
  lungs
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Gastrovascular cavity
• digestion distribution of nutrients
• 2 cell layered thick organisms Cnidarians

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Figure 42.2 Internal transport in the cnidarian
Aurelia
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• Transport nutrients O2 to all cells
• Transport metabolic waste to kidneys CO2 to
  lungs
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Gastrovascular cavity
• digestion distribution of nutrients
• 2 cell layered thick organisms Cnidarians
• Animals with more than 2 cell layers need more

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Figure 42.3 Open and closed circulatory systems

• Heart pump hemolymph into large cavity
• VERY inefficient due to mixing of good bad
  substances

• Heart pump blood through vessels in a complete
  circuit
• More efficient consistent

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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• Transport nutrients O2 to all cells
• Transport metabolic waste to kidneys CO2 to
  lungs
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Gastrovascular cavity
• digestion distribution of nutrients
• 2 cell layered thick organisms Cnidarians
• Animals with more than 2 cell layers need more
• 3. Lets compare some vertebrate hearts

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Figure 42.4 Vertebrate Circulatory Systems
FISH

• 1atrium 1 ventricle
• single circuit
• blood flows from gills directly to rest of the
  body

• BP is LOW after gill capillaries
• Swimming helps blood complete the circuit

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Figure 42.4 Vertebrate Circulatory Systems
AMPHIBIANS

• 2 atria 1 ventricle
• Double circulation
• blood flows from ventricle to pulmocutaneous
  circuit, back to the heart
• then from the same ventricle to the systemic
  capillaries

- Mixing of blood in ventricle is INEFFICIENT
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Figure 42.4 Vertebrate Circulatory Systems
REPTILES

• 2 atria 1 ventricle
• pulmonary circuit since skin is dry
• 90 ridge between right left ventricles
• ridge is complete in crocodilians

- Mixing of blood in ventricle is less
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Figure 42.4 Vertebrate Circulatory Systems
MAMMALS

• 2 atria 2 ventricles
• no mixing of O2-rich O2 poor blood
• 2 complete circuits pulmonary systemic

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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• Transport nutrients O2 to all cells
• Transport metabolic waste to kidneys CO2 to
  lungs
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Gastrovascular cavity
• digestion distribution of nutrients
• 2 cell layered thick organisms Cnidarians
• Animals with more than 2 cell layers need more
• Lets compare some vertebrate hearts
• What is the route of blood flow through our
  circulatory system?

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Figure 42.5 The mammalian cardiovascular system
an overview
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• Right ventricle
• Pulmonary artery
• Pulmonary capillaries
• Left atrium
• Left ventricle
• Aorta
• Capillaries above heart head arms
• Capillaries below heart abdominal organs legs
• Anterior vena cava from above heart
• Posterior vena cava from below heart
• Right atrium
• How does structure fit function of the heart?

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Figure 42.6 The mammalian heart a closer look
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• Atria have thin walls only pump to ventricles
  below
• Ventricles have THICK walls left is thickest
• Valves prevent back flow
• Atrioventricular valves between atria
  ventricles
• Semilunar valves - between ventricles exit
  vessels
• 6. How is the heart beat controlled?

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Figure 42.8 The control of heart rhythm
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• Atria have thin walls only pump to ventricles
  below
• Ventricles have THICK walls left is thickest
• Valves prevent back flow
• Atrioventricular valves between atria
  ventricles
• Semilunar valves - between ventricles exit
  vessels
• How is the heart beat controlled?
• How does blood flow through our vessels?

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Figure 42.9 The structure of blood vessels
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Figure 42.10 Blood flow in veins
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• How is the heart beat controlled?
• How does blood flow through our vessels?
• What is the relationship between vessel size, BP
  velocity?

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Figure 42.11 The interrelationship of blood flow
velocity, cross-sectional area of blood vessels,
and blood pressure

• Capillaries increase surface area
• Cells flow through single file
• Slow flow means better ability for exchange

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Figure 42.14 Fluid exchange between capillaries
and the interstitial fluid
Tissue cell
INTERSTITIAL FLUID
Net fluid movement out
Net fluid movement in
Capillary
Capillary
Red blood cell
15 ?m
At the venule end of a capillary, blood pressure
is less than osmotic pressure, and fluid flows
from the interstitial fluid into the capillary.
At the arterial end of a capillary, blood
pressure is greater than osmotic pressure, and
fluid flows out of the capillary into the
interstitial fluid.
Direction of blood flow
Blood pressure
Osmotic pressure
Inward flow
Pressure
Outward flow
Venule end
Arterial end of capillary
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• How is the heart beat controlled?
• How does blood flow through our vessels?
• What is the relationship between vessel size, BP
  velocity?
• What is blood made of?

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Figure 42.15 The composition of mammalian blood
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• Atria have thin walls only pump to ventricles
  below
• Ventricles have THICK walls left is thickest
• Valves prevent back flow
• Atrioventricular valves between atria
  ventricles
• Semilunar valves - between ventricles exit
  vessels
• How is the heart beat controlled?
• How does blood flow through our vessels?
• What is the relationship between vessel size, BP
  velocity?
• What is blood made of?
• Where do blood cells originate?

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Figure 42.16 Differentiation of blood cells
Ch 43
Erythropoeitin (EPO) kidney hormone released in
response to low O2 to stimulate production of
erythrocytes
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• How is the heart beat controlled?
• How does blood flow through our vessels?
• What is the relationship between vessel size, BP
  velocity?
• What is blood made of?
• Where do blood cells originate?
• How does blood clot?

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Figure 42.17 Blood clotting
3
This seal is reinforced by a clot of fibrin when
vessel damage is severe. Fibrin is formed via
amultistep process Clotting factors released
fromthe clumped platelets or damaged cells mix
withclotting factors in the plasma, forming an
activation cascade that converts a plasma
proteincalled prothrombin to its active form,
thrombin.Thrombin itself is an enzyme that
catalyzes the final step of the clotting
process, the conversion of fibrinogen to fibrin.
The threads of fibrin become interwoven into a
patch (see colorized SEM).
The platelets form a plug that
provides emergency protection against blood loss.
The clotting process begins when the endothelium
of a vessel is damaged, exposing connective
tissue in the vessel wall to blood.
Platelets adhere to collagen fibers in the
connective tissue and release a substance
that makes nearby platelets sticky.
Collagen fibers
Red blood cell
Fibrin clot
Plateletplug
Platelet releases chemicalsthat make nearby
platelets sticky
Clotting factors from Platelets Damaged
cells Plasma (factors include calcium, vitamin K)
Thrombin
Prothrombin
Fibrinogen
Fibrin
5 µm
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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• How is the heart beat controlled?
• How does blood flow through our vessels?
• What is the relationship between vessel size, BP
  velocity?
• What is blood made of?
• Where do blood cells originate?
• How does blood clot?
• What are some CV diseases?
• gt50 of deaths due to CV disease
• LDLs low-density lipoproteins - bad cholesterol
• Associated with arterial plaques
• HDLs high-density lipoproteins good
  cholesterol
• Reduce deposition of cholesterol

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Figure 42.18 Atherosclerosis

• Atherosclerosis cholesterol plaques in
  arteries slows blood flow
• Arteriosclerosis hardening of the arteries due
  to Ca2 added to plaques

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Chapter 42 Circulation and Gas Exchange

• What is the function of the circulatory system?
• What is the difference between a gastrovascular
  cavity and an open
• closed circulatory system?
• Lets compare some vertebrate hearts
• What is the route of blood flow through our CV
  system?
• How does structure fit function of the heart?
• How is the heart beat controlled?
• How does blood flow through our vessels?
• What is the relationship between vessel size, BP
  velocity?
• What is blood made of?
• Where do blood cells originate?
• How does blood clot?
• What are some CV diseases?
• LDLs low-density lipoproteins - bad cholesterol
• HDLs high-density lipoproteins good
  cholesterol
• Hypertension high BP
• Heart attack death of heart muscle due to
  blocked coronary arteries
• Stroke death of nervous tissue in brain due to
  blocked brain arteries

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