Transcript Cardiovascular System

Cardiovascular
System
Chapter 12
The big idea
• Why is the cardiovascular system important?
• The cardiovascular system pumps blood
which carries oxygen and removes CO2 from
the tissues of the body.
Parts of the System
• Heart
• Blood Vessels
• Blood
Anatomy of the Heart
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Located in the Thoracic Cavity
The heart is a muscle (cardiac muscle)
Main Function: Pump Blood
The Human heart has four chambers
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Left Atrium
Right Atrium
Left Ventricle
Right Ventricle
Anatomy of the Heart
• Atria – receiving chambers of the heart
• Left receives blood from the lungs
• Right receives from the body
• Ventricles – sending chambers of the heart
• Left sends blood to the body
• Right sends blood to the lungs
• Interventricular septum separates the two
Anatomy of the Heart
• Operation of Blood Valves
• Atrioventricular (AV) valves – between the
Atrium and ventricle
• Tricuspid valve – right side
• Bicuspid valve – left side
• always open until the ventricles contract
• Contraction pressure forces them to shut
Anatomy of the Heart
• Semilunar valves – valve leading out of ventricles
• Normally closed until ventricle contraction opens it
• https://www.youtube.com/watch?v=JA0Wb3gc4mE
Anatomy of the Heart
Major Blood Vessels of the Heart :
• Vena Cava – carry deoxygenated blood from body
to heart
• enters right atrium
• Aorta – delivers oxygenated blood from heart to
body
• exits left ventricle
Anatomy of the Heart
• Pulmonary Veins – delivers oxygenated blood
from lungs to heart
• Enters left atrium
• Pulmonary Arteries – carries deoxygenated blood
from heart to lungs
• Exits right ventricle
Physiology of the Heart
• Heart beats 115,200 times a day
• How does the heart contract (pump)?
• Bundles of nerve fibers stimulate the muscle to
contract
• The main bundle is the SA node (this is our
natural pacemaker)
• Electrocardiogram (ECG) – measure the
electrical activity of heart beats
• Ineffective valves can cause a heart murmur.
Anatomy of the Blood Vessels
• Function: transport blood & contents
• Types of Blood Vessels:
1. Arteries – transport blood away from heart
2. Veins – transport blood to the heart
3. Capillaries – microscopic vessels where gas
exchange occurs
Anatomy of the Blood Vessels
• Size of vessels (large to small)
• Arteries  arterioles  capillaries
• Veins  venules  capillaries
• Major arteries: Aorta, Pulmonary Artery
• Major Vein: Vena Cava, Pulmonary Vein
Anatomy of the Blood Vessels
Anatomy of the Blood Vessels
Physiology of the Blood Vessels
• It only takes one minute for a drop of blood to go
from the heart to the foot and back to the heart!
• Blood moves from areas of high pressure to areas
of low pressure
• Blood pressure – is the force of blood against a
blood vessel wall
Physiology of the Blood Vessels
• Factors that affect blood pressure: (pg 236)
1. Amount of blood leaving the heart
2. Peripheral resistance – friction
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Size of vessels
Length of vessels
Obese individuals are prone to high bp
For one extra pound of fat, 200 miles of blood
vessels develop
Evaluating Circulation
• Heart Beat
• Stethoscope
• Pulse
• Pulse points: pg. 238
• Blood Pressure
• sphygmomanometer
Anatomy of the Blood
• Composed of 2 basic components
1. Cells (red, white, platelets) = 45%
2. Plasma (water, amino acids, vitamins,
hormones, electrolytes, cellular waste) = 55%
Anatomy of the Blood
• Erythrocytes (red blood cells) – transport
oxygen and carbon dioxide
• Hemoglobin – protein that binds with gases
• Iron is an important part
• Oxyhemoglobin – full of O2 (bright red)
• Deoxyhemoglobin – not carrying O2 (dark red)
• Shape: concave discs
Anatomy of the Blood
• About 5 million per cubic
millimeter
• No nucleus…they must be
made in the bone marrow
• Erythropoetin (EPO) – is a
hormone that increases RBC
production
• Anemia – condition where
there are too few blood cells
Anatomy of the Blood
• Blood Facts
• http://www.bloodcenters.org/blooddonation/facts-about-blood-donation/
• Heart Labeling Practice
• http://sciencelearn.org.nz/Contexts/See-throughBody/Sci-Media/Animation/Label-the-heart
Chapter Review
• Pg. 252
• Study Q’s - # 1, 3, 8, 9, 11
• Objective Q’s - # 1-4, 9, 12
Sheep Heart Dissection
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Part 1 – External anatomy of heart
https://www.youtube.com/watch?v=iYKhrjfkMwA
Part 2 – Internal anatomy of heart
https://www.youtube.com/watch?v=HNxSC244Bpo