Chapter 50: Circulatory Systemsbio.classes.ucsc.edu/bio20b/Chapter50 Circulation Notes.pdf ·...
Transcript of Chapter 50: Circulatory Systemsbio.classes.ucsc.edu/bio20b/Chapter50 Circulation Notes.pdf ·...
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Chapter 50: Circulatory Systems
• Evolution of Vertebrate Circulatory Systems• Mammalian Heart (The Pump)• Circulatory System (The Plumbing)• Regulation of the Circulatory System• Blood
The Oxygen Pathway: Circulatory SystemCirculatory system :
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Cardiovascular System consists of: 1.2.3.
Some Organisms do NOT need Circulatory Systems
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Purpose:
2 Types of Circulatory Systems
Larger Organisms NEED Circulatory Systems
Figure 50.1 Circulatory Systems (A and B)
Open circulatory system:
CONS:
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Figure 50.1 Circulatory Systems (C)
Closed circulatory system:
PROS:
Closed vascular system contains:• Arteries :
• Arterioles :
• Capillaries :
• Venules :
• Veins :
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Fish Heart (p 1048)
2 circulatory circuits evolved:Pulmonary circuit :
Systemic circuit :
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Lungfish Heart (p 1049)
Amphibian Heart (p 1049)
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Reptilian Heart (p 1050)
Crocodilian Heart (p 1050)
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Bird and Mammalian Heart (p 1050)
Figure 50.2 The Human Heart and Circulation (Part 2)
Low O2 blood from body into right atrium via large veins-Superior vena cava:-Inferior vena cava:
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Figure 50.2 The Human Heart and Circulation (Part 2)
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Figure 50.2 The Human Heart and Circulation (Part 2)
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Pulmonary Pattern of Blood Flow
Heart Note the thickness changes
Venous Return
De-oxygenated Blood
Oxygenated Blood
Out To Lungs
Systemic Pattern of Blood Flow
Heart Note the thickness changes
Venous Return
De-oxygenated Blood
Oxygenated Blood
Out To Body
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Valves Prevent Back Flow
Valves enable:
Pulmonary & Aortic Valve (Semilunar Valves) :
Atrioventricular Valves :
Cardiac Cycle
Fig. 50.3
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ECG (Electrocardiogram)
Myocardium
Highly Specialized
Three areas of muscle:1.
2.
3.
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Cardiac muscle
Figure 50.7 The Action Potential of Ventricular Mu scle Fibers
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Specialized electrical conducting areas of the Heart (fig 50.6)1.
2.
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4.
Gap Junctions:
Carotid arteries & aorta have:
Cardiovascular control center has:
Fig. 49.18 CONTROL OF HEART RATE
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Nervous system adjusts HR:• Norepinephrine (sympathetic) increases:
• Acetylcholine (parasympathetic) increases:
Figure 50.11 Anatomy of Blood Vessels
Arteries/arterioles
Veins/venule
Neuronal & hormonal mechanisms:
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Figure 50.12 A Narrow Lane
Capillaries:
Why don’t capillaries get blown out by high pressureflow?
2.
1.
Fig. 50.16
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Figure 50.11 Anatomy of Blood Vessels (Part 2)
Blood pressure:
Resistance (R):1.
2.
*Blood pressure low in capillaries because of:
Figure 50.14 One-Way Flow
Blood Flow in Veins
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How Is Circulatory System Controlled and Regulated?
1. Autoregulatory mechanisms:
-Ex. Hyperemia : Low O2 & high CO2 levels
How Is Circulatory System Controlled and Regulated?
2. Endocrine & Nervous systems respond by changing:
Local changes affect central blood pressure & composition
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Cardiovascular control center in medulla also controls vessel constriction
• Epinephrine:
• Angiotensin:
Hormonal Influences
Sympathetic division acts on arteries/ arterioles:-norepinephrine:-acetylcholine (Ach):
Neurotransmitter Influences
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Blood Pressure (Flow)Blood Pressure (BP) = CO X R
Where CO is cardiac output and R is total resistanc e
Cardiac Output (CO )
Stroke Volume (SV)
CO = SV X HRWhere HR is heart rate
Frank–Starling law :
Ex: Exercise
How is Cardiac Output (CO) Adjusted?
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Circulatory HomeostasisBaroreceptors detect falling blood pressure1
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3RESULT:
Increased baroreceptor activity signals rising blood pressure:1.
2.
3.RESULT:
Master of Circulatory Control
Dive Response:1.
2.
3.
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Blood PressureSystolic Pressure –
Diastolic Pressure –
Hypertension -
5 MAIN EFFECTS OF TRAINING
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The Effects Of Exercise On The Cardiovascular System