Orientation: R and L are the perspective of the heart’s owner as it sits in their chest cavity. All mammals & birds have 4 chambered heart that don’t allow oxygenated and deoxygenated blood to mix. Ectotherms have 1, 2, or 3-chambered heart, don’t need the efficiency of a 4-chambered heart because they don’t need the extra energy for thermoregulation.
EXPERIMENT 14.1 - Your Own Cardiac Cycle Supplies : A watch with a second hand or (better yet) a stopwatch Introduction - Each person has his or her own cardiac cycle time depending on metabolic rate and other factors. In this experiment, you will determine your own cardiac cycle under different conditions. Procedure : You have probably been sitting down quietly (or at least reasonably quietly) reading this incredibly interesting course. Although you have, most likely, been excited about all of the wonderful things you have been learning, chances are good that you are close to your “resting” cardiac cycle. Thus, I want you to measure that now. To measure your cardiac cycle, place the index finger of your right hand at the inside of your left wrist on the thumb side. Lightly push around the area until you feel a constant beat. That&apos;s your pulse. Count the number of times your pulse beats in 30 seconds. When your heart pumps blood into your aorta, the increased pressure in your arteries causes them to expand. That expansion travels through the arteries. When you feel your pulse, you are touching an artery, and the beat that you feel is caused by the artery expanding and contracting in response to the heart pumping blood into the aorta. In the end, then, each beat you feel corresponds to a heartbeat. If you double the number of beats you felt in 30 seconds, that will tell you how many times your heart beats per minute. However, I want you to do something else. Divide 30 by the number of beats you counted. This will give you your cardiac cycle, which essentially tells you how long your heart takes to make one beat. The average person your age has a cardiac cycle of about 0.75, which corresponds to 80 beats per minute. Now, of course, the cardiac cycle you just measured corresponds to your resting cardiac cycle. If your body starts expending lots of energy, the blood must flow more quickly so that the cells in your body can get enough oxygen to make the energy they need. This changes your cardiac cycle. To measure this, do one full minute of vigorous jumping jacks right now. As soon as you are done with the jumping jacks, put your finger back on your wrist and count the beats you feel in your pulse for 30 seconds. Wait for one full minute, sitting quietly, and count your pulse beats again for a period of 30 seconds. Repeat step (F) at least 4 more times. Once you are done, go back and divide 30 by each of the number of pulse beats that you counted. This gives you your cardiac cycle during the time that you rested after completing the jumping jacks.
Supplies: laminated circulatory system labels, string/yarn, envelopes with oxygen & carbon dioxide cards. Optional: use balls (inflatable beach balls, stuffed soccer balls, big rubber playground balls, etc.) that students toss or hand off to each other as they stand at different body locations. Students in the lungs and capillaries have the job of removing/attaching O2 and CO2. Set labels on floor in order.
Blood vessels carrying deoxygenated blood appear to be blue, when in fact they are dark red. Even though this is a distortion of color caused by viewing the blood vessels through the skin, the blue color is still used as a means of representing deoxygenated blood. Arteries also have a smooth muscular layer that functions to regulate the flow of blood through the artery. Contraction of the smooth muscle decreases the internal diameter of the vessel in a process called vasoconstriction. Relaxation of the smooth muscle increases the internal diameter in a process called vasodilation. If you took a person&apos;s arteries (not including arterioles or capillaries) and laid them all out end to end, you&apos;d have about the same distance as Portland to LA...and back again (2,500 miles)
Human Body Systems
1. Name the building blocks (monomers) of proteins, carbs, fats, and nucleic
• Proteins: amino acids, Carbs: saccharides, Fats (lipids): fatty acids (& glycerol), and
Nucleic acids: nucleotides
1. What protein/hormone produced in the pancreas lowers blood sugar by
signaling body cells to take it in out of the bloodstream?
1. True or False? The liver and muscles store excess glucose as a long, branched
polysaccharide called glycogen.
• True (the pancreas produces glucagon to signal the breaking down of glycogen)
1. Why does your body need more carbohydrate than any other nutrient,
especially since most of the body is made of water, fat, and protein?
• All carbs are broken down into glucose, which provides energy (to make ATP) for all
anabolic chemical reactions and cellular processes.
1. What does %DV mean?
• Percent Daily Value (what part of the suggested amount of a nutrient
one serving provides - per day, for a 2,000 Calorie diet)
In your lab notebook, please answer as best you can:
Bonus: What is a Calorie?
- Heat energy that comes from food that your body can use or store up.
The Circulatory System
• Heart contracts about once/second
– Average adult heart = 65 beats/min.
• That's 100,000 times/day
– Blood has to reach every cell in the body
• If circulation stops, cells die
• Brain tissue dies within 5 - 7 min. without
• Pumps 4,000 gallons blood per day
– Enough blood to fill a tanker truck!
Blood flow animation
The Human Heart
• Muscular Pump
– Striated cardiac muscle
– Size of your fist (child)
• About 2 fists for adult
• 4 Chambers
– Open spaces for blood to
gather before being
• 4 One-Way Valves
– Prevent back-flow
– Allow pressure to build
Four Chambers of the Heart
• Red = oxygenated
• Blue = deoxygenated
• Septum: dividing wall
Which chambers have the thinnest
muscular walls? Thickest? Why?
The Heart - a double pump
• Left & Right Atria Contract
– blood forced into ventricles
– Pulmonary/Aortic valves close
– Pacemaker within right atrium
• “sinoatrial node”
• Left & Right Ventricles Contract
– Mitral/Tricuspid valves close
– blood forced out to lungs & body
Four Valves of the Heart
• Prevent backflow of blood during contractions
• Tricuspid & Mitral valves have fibrous "anchors"
• Clean ear buds with alcohol
• Listen for valves closing
– "lub" is Mitral & Tricuspid
– "dub" is Aortic & Pulmonary
Blood Flow in the Heart
out to body
• Pulmonary (lungs)
– CO2 dropped off
– O2 picked up
• Systemic (body)
– O2 & nutrients delivered
– CO2 & waste picked up
• Coronary (heart’s blood supply)
– O2 to heart
– CO2 taken away
• Find your way around
the circulatory system!
• The “PLAYER” is a red
• Pick up O2 and CO2
– drop them off at the right
• If you mess up, you're
OUT of the game!
Blood Vessels - Miles of Tubes
– carry blood AWAY from heart
• Take oxygen-rich blood (red) to extremities
• Take oxygen-depleted blood (blue) to the lungs
– thick, muscular
• withstand higher pressure than veins
• control blood flow
– carry blood TO the heart
• Brings deoxygenated blood (blue) back from extremities
• Brings oxygenated blood (red) back from the lungs
– thinner, with valves
• valves prevent back-flow
• skeletal muscles aid in return blood flow
– tiny network or "web" of vessels
– very thin - one cell thick!
• to allow exchange of molecules
– reaching every living cell in the body
• around air sacs in lungs
• all organ tissues
Blood - What's in it?
– liquid in which cells are suspended
• mostly H2O
• Macronutrients & micronutrients
• hormones, toxins, bacteria, glucose
& other nutrients, etc
• Red Blood Cells
– no nucleus, donut-shaped
– hemoglobin (iron)
• carries O2& CO2
• White Blood Cells
– help fight infection
– B cells produce antibodies
– neutrophils, basophils, monocytes,
– Clump together to form blood clots
that stop bleeding