What are the functions of the circulatory system?

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Cardiovascular System
What are the functions of the circulatory
system? Transport -- nutrients, proteins,
cells Protection Pathogens -- immunity
Damage -- clotting Homeostasis Heat control
Reservoir
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Cardiovascular System
What is blood?
Comprised of 2 major categoriesfluid 55
(Plasma) formed elements 45 Plasma is mostly
H2O with some suspended proteins and other
solutes Formed elements consist of RBC, WBC and TC
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Cardiovascular System
Where does blood come from?
Fluid obtained via diet and then osmosis into
blood stream. Formed elements result from the
process of making new blood cells Hemopoiesis
or Hematopoiesis from precursors (stem cells)
that reside multiply in red bone marrow.
Before birth yolk sac, liver, thymus, spleen
red marrowPostpartum red marrow
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Cardiovascular System
Where do erythrocytes come from?
Vascularization of the yolk sac involves the
formation of endothelial cells near the yolk sac
membrane. These surround islands of cells that
become blood islands These cells
(hemocytoblasts) are the stem cells that give
rise to all other hemopoietic stem cells
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Figure 12.07
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Cardiovascular System
Where does blood come from?
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Cardiovascular System
Whats important about Erythrocytes?
Structure Biconcave cells w/ no nucleus cant
conduct cell repair Purpose Carry gasesO2 (98
w/ hemoglobin)CO2 (23 w/ hemoglobin,
70 HCO3-) Life Span 120 days Contents
Hemoglobin, lipids, ATP and enzymes
7.5 µm
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Cardiovascular System
Whats important about Erythrocytes?
Hemoglobin 1/3 of RBC content is hemoglobin.
Each hemoglobin has 4 hemes and 4 globins. 1 O2
binds with 1 heme
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Cardiovascular System
What are the similarities between vessels?
3 Main layers (or tunics) 1) Tunica
adventitiaconnective tissue
2) Tunica mediasmooth muscle and elastic fibers
3) Tunica intimaconnective tissue, basement
membrane and endothelium
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Cardiovascular System
What are the similarities between vessels?
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Cardiovascular System
Whats unique about capillaries?

• The 3 tunics not present
• Endothelial cells continuous with endocardium
• Basement membrane
• Pericapillary cells

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Cardiovascular System
How is capillary flow regulated?
What function(s) do these sphincters accomplish?
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Figure 12.26
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Figure 12.27
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Figure 12.29
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Figure 12.36
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Figure 12.37
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Cardiovascular System
What is the external anatomy of the heart?
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Cardiovascular System
What is the external anatomy of the heart?
Vessels associated with sulci Coronary arteries
(Right and Left)
Interventricular arteries (anterior and
posterior)
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Cardiovascular System
What is the external anatomy of the heart?
Vessels associated with sulci Great small
cardiac veins return blood to heart via
?
Coronary sinus
To what chamber?
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Cardiovascular System
What is the internal anatomy of the heart?
Right atrium -3 entrances vena cavas
coronary sinus
Tricuspid valve
Right ventricle -Chordae tendineae
-Papillary muscles -Exit semilunar valves...to
pulmonary trunk

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Cardiovascular System
What controls the timing and sequence of a heart
beat?
SA node fires
Impulse reaches AV node, 0.1 sec delay
Impulse travels to AV bundle (Bundle of His)
Impulse travels down R and L bundle branches
Finally back up Purkinje fibers
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Cardiovascular System
How is homeostasis of the heart achieved?
Receptors monitor conditions including 1)
Changes in pressure (baroreceptors) in major
arteries work with medulla oblongata
2) Changes in chemistry (chemoreceptors) in
medulla oblongata (CO2) and major arteries (O2)
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Figure 12.52
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Figure 12.19
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Figure 12.03
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What are the key events during the fetal period?
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Figure 12.41
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What are the key events during the fetal period?
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What are the key events during the fetal period?
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Figure 12.43
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Figure 12.44
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Figure 12.45
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Figure 12.46
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