4.3 Heart Anatomy and Physiology + Floppy Valves

Last updated over 3 years ago

13 questions

Activity 1: Answer the following questions 1-9 as we go through lecture on the heart anatomy.

What do the blue blood vessels contain in comparison to the red blood vessels?

What chamber in the heart does the deoxygenated blood end up?

In addition to the four chambers in the heart, what does the heart also contain?

Compare the function of veins v. arteries.

Why is there a right and a left pulmonary artery?

What are the names of the four chambers of the heart?

What is the name of the largest artery of the body that allows blood to leave the heart and move into the rest of the body?

Based on the structure of the valves of the heart, conclude what you might think the function(s) of valves in the heart?

We will now rewatch the video and pay closer attention to the blood flow to try to sort the steps for how blood circulates through the heart starting from the sup. vena cava and inf. vena cava.

sup. vena cava recieve blood from head neck and upper limbs of chest and inf. vena cava recieves blood from trunk and lower limbs to the right atrium of the heart
the aorta distributes blood to the rest of the body
the blood will now flow from the right ventricle through the pulmonary valve and through the pulmonary artery
the blood will now flow through the right and left pulmonary artery to each of thier respective lungs
blood is then pumped into the left ventricle through the mitral valve
at the lungs CO2 is exchanged for O2 to reoxygenate the blood
the blood is now pumped from the left ventricle through the aortic semilunar valve to the aortic arch
blood will now come back to the lungs through the pulmonary viens to the left atrium
the blood from the right atrium will flow throught he tricuspid valve into the right ventricle of the heart

Activity 2: Our Case Study - Aging Heart Valves

Tina, 65, who has been a non-smoker and relatively healthy throughout her life, has recently noticed that she is becoming increasingly short of breath as she does simple things, such as climbing the steps in her house. She has also noticed that her heart rate increases when she does mild exercise, such as walking to the mailbox or going upstairs. What could be causing this? Is it just due to her getting older? Is there reason to be concerned? What can be done to help her?

Remember, the human heart is vital in sustaining homeostasis—the stability or equilibrium in a biological system. In fact, the heart has a specific anatomy that aids in this function. The way the heart is designed determines the path that blood must take through it in order to be pumped around the body.

For questions 10-12 develop as many ideas as you can, there are no wrong answers!

What do you already know about this problem?

What do you need to know to better understand this problem?

Where might you look to find answers to the questions you develop?

Below is an expert interview which will give us more ideas about how heart valves might contribute to health problems. 

 I’d like to introduce Denise Hutcheson, a doctoral candidate at Vanderbilt University who works in Mechanobiology. 
Interviewer: What is important to know about the heart and how it works in relation to disease?
 Ms. Hutcheson: When looking at a biological system, we spend a great deal of time looking at it on the cellular level. We are looking for the intersection between cell biology and engineering/ physical science. Understanding the stresses put on cells helps us understand what is happening to an organ.
 Interviewer: How does the structure of the heart relate to the stresses it incurs?
 Ms. Hutcheson: Heart valves are designed to move with blood flow, and consequently experience a lot of stress over time. Biomechanics plays an important role in the function of these valves. 
Interviewer: Can this stress lead to problems with the valves/heart over time?
 Ms. Hutcheson: Stress can cause the valve to become stiffer over time. 25% of people over 65 years of age tend to show signs of valve disease. 

For additional information on heart valves, we will watch the following video: http://www.youtube.com/watch?v=hmnzhuYRjz8

A note on different types of disease:

A congenital heart defect is a condition that approximately 9 of every 1,000 people are born with and affects the structure of the heart and the large blood vessels that directly move blood to and from the heart (aorta, pulmonary arteries, superior and inferior vena cava). These defects can block blood flow or cause blood to flow in irregular patterns through the heart. In some cases, no action needs to be taken, but in other cases, medication or surgery is necessary.

While a congenital heart defect is a condition that some people are born with, many other heart diseases and defects develop through people's lives. These conditions, referred to as cardiovascular or heart disease, affect the heart's valves, muscles and blood vessels, including arteries, capillaries and veins. These diseases include coronary heart disease (which affects the coronary artery that supplies blood to the heart muscles, and can lead to heart attack)s, cardiomyophathy (a disease of the muscles in the heart), hypertensive heart disease (includes complications to the heart due to high blood pressure), valvular heart disease (diseases such as inflammation or stiffness to the heart valves that affects the movement of blood through the heart), and many others.

Exit Ticket: Based off information about Tina, do you think that she has a congenital heart defect or cardiovascular disease? Take into consideration of her age and when she developed symptoms.