cardiovascular system. i. system anatomy heart pumps blood blood vessels deliver blood…
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II. System Physiology
Transports oxygen, nutrients, hormones, carbon dioxide, waste products and other substances
III. Heart
Size of your fist Weighs less than 1 pound Made of Cardiac Muscle Tissue Has 4 chambers
Right Atrium – receives blood from body Right Ventricle – pumps blood to lungs Left Atrium – receives blood from lungs Left Ventricle – pumps blood to body (most muscular part)
Superior Vena Cava
Right Pulmonary Artery
Right Atrium
Tricuspid Valve
Right Pulmonary Veins
Right Ventricle
Inferior Vena Cava
Aorta
Left Pulmonary Artery
Left Atrium
Bicuspid/Mitral Valve
Left Ventricle
Septum
Pulmonary Valve Aortic Valve
Left Pulmonary veins
Path of Blood
1. Superior and Inferior Vena Cava 2. Right Atrium 3. Tricuspid Valve 4. Right Ventricle 5. Pulmonary Valve 6. Right/Left Pulmonary Arteries 7. Lungs – get rid of Carbon Dioxide, Pick up Oxygen 8. Pulmonary Veins
Path of Blood (cont)
9. Left Atrium 10. Bicuspid/Mitral Valve 11. Left Ventricle 12. Aortic Valve 13. Aorta 14. Arteries 15. Capillaries – give oxygen to cells, pick up carbon
dioxide 16. Veins Again!!
IV. Heart Physiology
Heart pumps entire volume of blood 1000 times per day around the body
Double Pump System Right Side – Pulmonary Circuit – pumps blood to
lungs to pick up oxygen and get rid of carbon dioxide
Left Side – Systemic Circuit – pumps blood to body – brings oxygen to cells and picks up carbon dioxide
Heart Physiology (cont)
Valves Let blood flow in one direction only (prevent
backflow)1. AV valves – Tricuspid and Bicuspid – between atrium
and ventricle Make first sound of heart beat (lub)
2. Pulmonary and Aortic Valves Make second sound of heart beat (dup)
Heart Physiology (cont)
Cardiac muscle is involuntary Must have a control system to coordinate the heart beat Pacemaker – sets the pace for the heart and
coordinates the beatsAlso called the Sinoatrial node
Approximate average heart rate is 75 bpm (beats per minute)
Cardiac Cycle
DiastoleHeart relaxationPressure in heart is lowBicuspid/Tricuspid are openPulmonary and Aortic Valves are ClosedBlood flowing from atrium to ventricle
Cardiac Cycle (cont)
SystoleHeart Contraction (pumping)Pressure in heart is highBicuspid/Tricuspid valves are closedAortic and Pulmonary valves are openBlood is being pumped to lungs and body
Blood Vessels
Transport blood from heart throughout the body Can have up to three layers
Tunica intima – inner layer – made of squamous epithelial tissue
Tunica media – middle layer – made of smooth muscle tissue
Tunica externa – outer layer – made of fibrous connective tissue
Arteries
Carry blood AWAY from the heartHave Thick walls due to high pressure of
bloodHave all three layersExpand as blood is pumped You can feel a pulse in your arteries
Veins
Carry blood TOWARDS the heart Pressure is lower than in arteries Have thinner walls Have VALVES to prevent backflow of blood Usually blood tests are done with blood from
the veins
Capillaries
Very thinOne have inner layer (tunica intima)Come into contact with cellsLink between arteries and veinsSite of gas (oxygen and carbon dioxide)
and nutrient exchange with cells
Atrial Pulse
Expanding and recoil of arteries that occur with each beat of heart
Average 70 to 76 bpm Don’t use your thumb when taking pulse
measurements – you’re thumb has its own pulse
Blood Pressure
Pressure the blood exerts on inner walls of blood vessels
Keeps blood circulating in between heartbeats Arteries closest to heart have highest
pressure
Measuring Blood pressure
Systolic pressure Number when you first hear soundsVentricle is contracting
Diastolic pressureNumber when sounds stopWhen ventricles are relaxing
Measuring Blood Pressure
Put cuff with stethoscope over the brachial artery Close valve and inflate cuff to 160 mmHg – DO NOT
GO HIGHER THAN 160 (you are cutting off the circulation to the artery)
Slowly release air and listen for a sound like a heart beat
Record the number at the first soft tapping sound Sounds will get louder and then decrease Record the number when the sound stops (blood is
flowing freely)
Factors that Affect blood pressure
Normal range: Systolic 110 – 130mmHg; Diastolic 70-80mmHg Many factors affect blood pressure
Age Temperature
Cold – constricts blood vessels = increase in bpWarm – dilates blood vessels = decrease in bp
Diet Clogged arteries Physical Activity
Factors that Affect blood pressure
Chemicals Epinephrine (Adrenaline) increases blood
pressureNicotine increases due to constricting of
veinsAlcohol and histamine decrease due to
dilation of veins
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