HBS 4.3

What do you think would happen in the body if blood flow to the right femoral artery was blocked? How would this change impact movement of blood and movement of the body?

If a major artery is blocked the limb may be lost due to lack of oxygen and glucose. Smaller arterioles will supply the leg for a while, but ultimately the leg will not function and tissue death is likely.

How can damage to the conduction system of the heart impact stroke volume?

If the SA Node fails to fire, or fires at a much slower rate, the AV node may take over as pacemaker at a rate of 40 - 60 BPM. If the AV Node fails or fires at a much slower rate, the Purkinje fibers may act as pacemaker at a rate of 20 - 40 BPM. Lower heart rate could mean lower cardiac output unless stroke volume increases to compensate.

What happens when your body can no longer compensate for heart failure?

If your body can no longer compensate for heart failure, you will begin to have symptoms, which consist of two major types: Congestive symptoms, which are caused by the backup of blood into the lungs and the other organs of the body. These symptoms include shortness of breath and swelling in the ankles and abdomen. Low-output symptoms, which are caused by the inability of the heart to generate enough cardiac output, leading to reduced blood flow to the brain and other vital organs. These symptoms may include lightheadedness, fatigue, and low urine output. If the cardiac output is very low, this can damage organs, particularly the kidneys.

Where do you think are the two most common places to detect pulse and count the heart rate? Why?

Inside of the wrist (ulnar artery) and carotid artery. They are the most superficial arteries and are easier to find and feel.

Where does the pulmonary vein lead to?

The lungs

Can the body grow new blood vessels?

Yes

What is a normal blood pressure?

120/80 (systolic/diastolic)

The tunica media is larger in the _______ (fill in the blank)

Artery

What is severe obstruction for ABI?

0-0.4

What is a moderate obstruction for ABI?

0.4-0.7

What is a mild obstruction for ABI?

0.71-0.9

What is a normal range for ABI?

0.9-1

What happens when plaque builds up in the arteries?

1. Plaque can't stretch, so it ruptures 2. Body thinks vessel wall is ruptured 3. Sends platelets 4. Platelets make clot 5. Vessel is 100% obstructed 6. Clots can break off and travel to other areas such as the brain, heart, lungs, causing an aneurysm, stroke, pulmonary embolism (respectively)

What is the average stroke volume?

75

What is the average blood flow?

5.25 L/min

What prevents backflow to the LV?

Aortic valve

What feeds the body part it goes to?

Arteries

What factors put people at more risk of developing varicose veins?

Age, obesity, gender

What is the difference between arteriolosclerosis and atherosclerosis?

Atherosclerosis is caused by plaque build up in the blood vessels, which can lead to PAD (peripheral artery disease)

How does the heart compensate for heart failure?

Beat faster (increase your heart rate). Pump more blood with each beat (increase your stroke volume).

Why do arteries need thick walls?

Because they are subjected to pressure

What prevents backflow to the LA?

Bicuspid valve

What are varicose veins?

Big, twisty veins near the skin's surface that are caused by weakened valves and appear as pink or purple in color.

What does ABI measure?

Blood pressure in the upper and lower limbs (higher of the ankle pressure/higher arm pressure)

What can scuff up arteries?

Chemicals, sugar, bacteria

What is plaque?

Cholesterol that builds up in arteries, which the arteries then build walls over. This narrows the arteries.

What characteristics do arteries have that veins don't?

Circular, even, thick walls Internal/external elastic lamina Under pressure

What do capillaries do?

Connect arteries and veins

What does systole mean?

Contraction of the heart

Superficial veins do what?

Cool down the body

Dehydration reduces blood volume. How would this affect cardiac output? Explain.

Dehydration causes low blood pressure and poor circulation so the body must constrict the vessels and increase heart rate to try to circulate the fluid faster to deliver oxygen and nutrients that are needed.

What does diastole mean?

Dilation (relaxation) of the heart

Why do you think arteries, veins and nerves always travel together?

Every area needs a nerve to tell it what to do, an artery to supply nutrients, and a vein to remove wastes therefore they have the same destinations. These structures are important and need to be protected. Therefore they travel together and travel deep in the body.

What are some factors that can increase the heart rate and the beat you feel at each pulse point?

Exercise Stress Dehydration Stimulants (caffeine, nicotine) Extreme hot or cold temperatures Poor sleep Poor nutrition

What causes varicose veins?

Extra blood that pools, faulty valves, gravity

What sticks to scuffing in the arteries?

Fat

What characteristics do veins have that arteries don't?

Floppy, thin, flexible walls Valves Not under pressure

Why are capillaries only one cell thick?

For faster gas exchange

Why are capillaries in networks?

For faster gas exchange in one place

How can you lose a leg from PAD?

Gangrene can occur. Blood flow to the leg will stop and infection will occur if a cut is made on the leg, causing necrosis. Necrosis may spread because of bacteria living in dead tissues.

How does the heart increase its stroke volume?

Get more blood into your heart and pump harder.

What is the equation for cardiac output?

Heartbeat x stroke volume

What is cholesterol used for in the body?

Hormones, myelin, cell membranes

Deep veins do what?

Keep the blood warm

What is the main role of arteries?

Moving oxygenated blood from the heart to the rest of the body

Why do varicose veins occur?

One way valves become deformed and blood pools in the superficial veins, pushing against the skin and forming bulging sacs. This occurs because there is no muscle around superficial veins.

Why don't we see arteries "pop out"?

One, arteries are not used to cool the body, two, they are under pressure and need to be protected so they don't get damaged, therefore they travel deeper where you cannot see them.

Suggest a reason why the veins of a bodybuilder "pop out" more than a person who does not lift weights.

Superficial veins dilate when heat is generated like when working out. Also large muscles can push the superficial veins a bit out of the skin.

How does the heart know to beat faster during heart failure?

Our brain signals your heart to beat faster by sending messages to your heart's electrical system, which controls the timing of your heartbeat. When your cardiac output is low, your adrenal glands also release more norepinephrine (adrenaline), which travels in the bloodstream and stimulates your heart to beat faster. Although beating faster helps to maintain cardiac output as the stroke volume falls, a faster heart rate can be counterproductive because it allows less time for the ventricle to fill with blood after each heartbeat. Also, a very fast heart rate can itself weaken the heart muscle over time.

What does PAD stand for?

Peripheral artery disease

What prevents backflow to the RV?

Pulmonary valve

Tricuspid valve is on which side?

Right

What are some factors that can decrease the heart rate and the beat you feel at each pulse point?

Sitting, relaxing Meditation Athlete post exercise Weight loss Avoiding stimulants Hydrating Proper nutrition

What is the tunica media made of?

Smooth muscle and elastic fibers

What happens during dehydration?

Stroke volume decreases and heart rate increases

Athletes often have a very low resting heart rate. What does this tell you about the health of their heart? Explain.

Stroke volume is larger because the heart muscle is stronger from exercise and waits longer between beats, so the chamber fills more and squeezes/contracts harder, meaning the heart is more efficient.

What can inflammation in the arteries be affected by?

Sugar, salt, infection

Where does the vena cava lead to?

The RA

Where does the pulmonary artery lead to?

The RV

What makes it easier to find veins?

The absence of subcutaneous fat.

What makes up the walls of arteries and veins?

The adventitia and media

How does the body know to grow new blood vessels?

The affected area will become hypoxic, which signals to the body that it needs better blood vessels to transport oxygen better.

Where does the aorta lead?

The body

How can a blockage in one of the coronary arteries impact stroke volume?

The heart muscle cannot generate ATP (no oxygen/glucose delivered) and muscle can die thus too weak to squeeze/contract which lowers cardiac output.

What is the main role of veins?

To drain deoxygenated blood from the body back to the heart to be reoxygenated

Where do arteries move blood to and from?

To the body, from the heart

Where do veins move blood to and from?

To the heart, from the body

The atrium dumps blood where?

To the ventricle

What prevents backflow to the RA?

Tricuspid valve

What drains the body part it goes to?

Veins

How can you get rid of varicose veins?

Wearing compression socks, catheterizing the vein (running electricity through the vein)

What are the consequences of having a low cardiac output? How will other body systems be affected?

When a person has a damaged heart and it cannot squeeze/contract hard enough to produce normal stroke volume, blood will begin to back up. If the left ventricle is weak blood will back up to the lungs and may fill the lungs with fluid. If the right ventricle is weak blood will back up in the body causing edema (swelling) in the legs. Body systems affected: delivery of oxygen and nutrients will be low to all body systems. Weakness and fatigue in the muscular system will be very noticeable. Also the brain lacking oxygen and nutrients will cause lightheadedness and even some confusion/slow thinking.