Cardiovascular System Chapter 42 IB Biology. Biological Function of Cardiovascular System T R A N S...
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Transcript of Cardiovascular System Chapter 42 IB Biology. Biological Function of Cardiovascular System T R A N S...
Cardiovascular System
Chapter 42
IB Biology
Biological Function of Cardiovascular System
• T R A N S P O R T !– Maintains constant flow of :
• Nutrients
• Hormones
• Respiratory Gases
• Wastes
• Enzymes
to /from tissue cells!
3 Major Componentsof CV System
1. Blood
2. Blood Vessels1. Arteries / Arterioles
2. Veins / Venules
3. Capillaries
3. Heart
Heart Anatomy
250-300 grams--size of fist
Located in mediastinum
Rests on diaphragm2/3 left of midlineShifts toward right shoulderApex points to left hip
Protective Features of the HeartP E R I C A R D I U M
• Layered membrane surrounding heart
• Fibrous pericardium– Tough, superficial layer
• Serous pericardium– Thin, deep layer subdivided into:
• Parietal layer: lines underside of fibrous pericardium
• Epicardium: lines external surface of heart
• Pericardial cavity: btwn parietal layer and epicardium
filled with fluid!
Pericarditis
• Inflammation of pericardium
• Pericardial fluid increases pressure on heart
• Cardiac tamponade
Heart Anatomy
3 Layers of Heart Wall
1. Epicardium: Superficial Layer
Composed of CT
2. Myocardium: Intermediate Layer
Composed of Muscle
3. Endocardium: Deep Layer
Composed of Endothelium
Internal Heart Anatomy
FOUR CHAMBERS
2 ATRIA(Right Atrium, Left Atrium)
Entry Chambers
2 VENTRICLES(Right Ventricle, Left Ventricle)
Exit Chambers
Right atrium
Left atrium
Right ventricle
Left ventricle
So what’s the big deal about a four chambered heart?
E F F I C I E N C Y
What leads to the heart’s efficiency?
A T R I O V E N T R I C U L A R
S E P T U M
wall that creates a physical separation between right and left sides of heart
(Interatrial septum + Interventricular septum = Atrioventricular Septum)
A V
SEPTUM
How does the AV septum lead to efficiency?
Creates two hearts in one!
Maintains separation between oxygenated blood (high O2 / low CO2 ) and deoxygenated blood (low O2 / high CO2 )
Oxygenated blood always on left side!
Deoxygenated blood always on right side!
Mixing of Blood Occurs!
Mixing of Blood Prevented!
FOUR MAJOR BLOOD VESSELS ATTACHED TO HEART
1. VENA CAVA major vein of body
2. AORTAmajor artery of body
3. PULMONARY ARTERY
4. PULMONARY VEIN
superior vena cava
inferior vena cava
pulmonary artery
aorta
pulmonary veins
pulmonary veins
Coronary Artery
• Provides blood to the myocardium of the heart!
Arteries vs. Veins
ARTERY
Always conducts blood AWAY from the heart!
Usually carries oxygenated blood
VEIN
Always conducts blood TOWARD the heart!
Usually carries deoxygenated blood
Heart Valves
• Flaps that open/close passageways for blood through the heart
2 Major Types of Valves:
1. Atrioventricular (AV) ValvesFound between atria and ventricles
Right AV Valve = Tricuspid Valve
Left AV Valve = Bicuspid Valve / Mitral Valve
Chordae tendinae / papillary muscles
• Open/close AV valves
• Prevent valves from opening backwards
Valves prevent backflow
incompetent valve
heart murmur
2. Semilunar Valves
found between ventricles and blood vessels leading out of the heart
Right Valve = Pulmonary Semilunar Valve
Left Valve = Aortic Semilunar Valve
31
Right AV (tricuspid)
Left AV (bicuspid)
Pulmonary semilunar
Aortic semilunar
Circulatory Pathways
Systemic Circulation:
blood flows to/from body tissues
Pulmonary Circulation:
blood flows to/from lungs
Coronary Circulation:
blood flows to/from heart muscle
The Heart’s Assignment…
…maintaining blood flow through ALL circulatory pathways of the body!
Right side receives blood from tissues and
pumps to lungs(pulmonary circulation)
Left side receives blood from lungs and
pumps to tissues(systemic circulation)
Pathway of Blood Through the Heart
Heart acts as double pump (Rt side/left side)
Both pumps act in unison
Deoxygenated blood returns to heart through vena cava
Right side pumps blood to lungs
Oxygenated blood returns to heart through pulmonary veins
Left side pumps blood to body
Blood through
the heart
Capillaries of lungs for oxygenation
Inferior & superior vena cavae
Right atriumTricuspid valve
Right ventricle
Pulmonary semi- lunar valve
Pulmonary trunk (arteries)
Arteries of body
Capillaries of tissues--exchange gasesVeins of body
Pulmonary veins
Left atrium
Bicuspid valve
Left ventricle
Aortic semi- lunar valveAorta