Download - Lab 11: Cardiovascular System
Lab 11: Cardiovascular System
Cardiovascular system
Circulates blood throughout the body.
• Blood carries oxygen and nutrients to cells
• Also transports waste (CO2) away from cells
Consists of:
• Heart
• Blood vessels
Blood vessels
• Arteries and arterioles – carry (generally oxygenated) blood away from the heart.
• Veins and venules – carry (generally deoxygenated) blood towards the heart.
• Capillaries – where nutrient and gas exchange takes place; single layer of cells.
Heart The human heart has 4 chambers total.
Atrium – where blood enters the heart
Heart
Ventricle – where blood leaves the heart
Heart: Blood Flow
Fetal Pig: External Heart Anatomy
Major Veins: Venae Cavae
Attached to the right atrium are major veins:
• superior vena cava: anterior (near head)
• inferior vena cava: posterior (near tail end)
They return de-O2 blood from head/body to heart
Heart valves: controlling blood flow Heart valves control blood flow within the heart and prevent backflow.
Atrioventricular valves occur between the atria and ventricles:
• bicuspid valve on the left
• tricuspid valve on the right
Both valves are reinforced by chordae tendinae attached to muscular projections within the ventricles.
Heart valves: controlling blood flow
Additional valves within the heart:
• Pulmonary semilunar valve – between the right ventrical and pulmonary trunk
Heart valves: controlling blood flow
• Aortic semilunar valve – between the left ventrical and the aorta
Major Arteries
• Pulmonary arteries: Along with umbilical arteries, only arteries to carry de-O2 blood.
Major Arteries
• Aorta: largest artery in the body, carries blood to the body.
Blood pressure
• Blood pressure = force that carries blood to all parts of the body.
• A blood pressure reading is the pressure that blood puts on the walls of arteries.
Blood pressure
There are 2 parts to a blood pressure:
• Systolic = the peak blood pressure when the heart is beating or squeezing out blood
• Diastolic = the pressure when your heart is filling with blood or resting between beats.
How to measure blood pressure
• Grab a stethescope and sphygmomanometer.
• Clean earpieces with alcohol and kimwipe before you use it.
• Wrap cuff about an inch above the elbow, it should fit snug.
How to measure blood pressure
• Using your middle and index fingers, gently feel for the pulse in the elbow. This is the brachial artery, put the stethoscope here.
• Do not use your thumb to feel for the pulse because your thumb has a pulse of its own.
How to measure blood pressure
• Make sure valve on the pump is closed and then start pumping air into the cuff.
• Meanwhile listen for sounds. When you hear it, make a note. This will be your systolic.
How to measure blood pressure
• Keep pumping until around 160 or just about 10mm past when you last heard the thumping sound.
• Then VERY SLOWLY release the pressure in the cuff with the valve on the pump, letting the gauge fall about 5 points a second.
How to measure blood pressure
• Record the pressure at which you stop hearing the thumping sounds. This is your diastolic.
• Record your results: systolic/diastolic
Finishing Up
• Save your pig! We are going to use it again. Put it back in bag with wet paper towels and label.
• Clean your workstation with disinfectant spray. Rinse utensils.
Reminders
Quiz 4 is next week!
On Tues. Nov 22nd (our last class )
Questions on mammalian anatomy and cardiovascular system.
No class on Thurs. Nov 24th & Dec. 1st
2nd Practical Exam on Thurs. Dec 8th