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Lesson 4- Critical Thinking in Physiology: Valves

Lesson 4

Valves 

Simple Line drawings & constructing a study page

Week 3  recap: You have practiced drawing from a grid again looking at those sinewy papillary muscles etc. now you’re  continuing with  some exercises on controlling your pencil and shading, negative spaces

This week: Valves between the atria and ventricles and the rest of the heart to the outside

There are a few main structures: Aortic Valve, Pulmonary valve, mitral valve, tricuspid valve, fibrous ring

For each session you will be given tasks to improve three elements of your critical thinking;

 

  1. Accuracy
  2. Draughtsmanship
  3. Knowledge of cardiac anatomy

Accuracy and draughtmanship:

Positioning of the valves, their shapes and creating a shine to appreciate the smooth surfaces of the valves

ANTERIOR STRUCTURE- gross anatomy

1. Accuracy

Accuracy/draughtmanship

I have initially chosen to look at the fibrous framework of the heart. The heart is seen from the right and behind after removing both atria looking down onto the fibrous rings that surround the mitral and tricuspid orifices.

The nice thing about this image is you get a real sense of their positions and their shapes that you would not normally see with a normal dissection

Tracing an image that is initially the correct way round

Is this how you imagined they would look?

Most of the time if you’re really looking at dissection from above where you have removed the pulmonary trunk and descending aorta above those three cusps it can be quite difficult to appreciate these structures .

Play Video

Fibrous Structures

This is a cartoon of the valves- 

The mitral valve is also known as a bicuspid valve or left atrioventricular valve and lies between the left atrium and left ventricle.

You can appreciate the importance of the mitral valve in incidences where it doesn’t work so if it doesn’t close properly blood will leak backwards to the left atrium (regurgitation) or the valve may be narrowed (stenosis).

Drawing of a fibrous valves

  • Down load the  photo of the heart provided for you to trace.
  • You can take the picture here and  alter it if that makes it easier using your phone/computer setting to emphasise black and white, tone and contrast.
  • You can also fiddle with the settings to increase brightness or any other settings that make the picture more appealing to you.
  • I would suggest creating an outline to copy the shape of the heart- which contains the coronary blood vessels and the major blood vessels going into and out of the heart.
  • Make outlines of the major structures. As with all accurate drawings it is essential everything is in place.

 

Questions

How easy was it to identify as much of what you saw in front of you?

What was your first impression of the valves?

append these  your final drawing

  1. Pulmonary Valve
  2.  Aortic Valve
  3. Tricuspid valve
  4. Mitral valve

2. Knowledge of anatomy

  1. For additional sketching, go to the images below where the valves have not been de-cellularised
  2. Identify any structures that  that you did not get before
  3. What is the function of the fibrous ring?

The mitral valve is also known as a bicuspid valve or left atrioventricular valve and lies between the left atrium and left ventricle.

You can appreciate the importance of the mitral valve in incidences where it doesn’t work so if it doesn’t close properly blood will leak backwards to the left atrium (regurgitation) or the valve may be narrowed (stenosis).

 

On the right side of your heart there are two main valves.

The tricuspid valve has (funnily enough) three flaps allowing blood to flow from the right atrium to the right ventricle preventing blood from flowing backwards . Tricuspid regurgitation isn’t a good thing and you can’t live long if it doesn’t work. Good news however is that it can be repaired or replaced .

 

The other valve is aortic valve between the left ventricle and the aorta . It’s one of the two semi lunar valves of the heart (the other is the pulmonary valve ). You can hear aortic valve problems using a stethoscope where you have a heart murmur .

like all valves it prevents blood from flowing backwards during diastole .

 

 

The fibrous framework is made of collagen . The fibrous rings that encircle the basis of the heart valves and these dense bands are made of tough elastic tissue . it is sometimes referred to as a cardiac skeleton where these four rings of dense connective tissue which surround the mitral tricuspid valves and extend to the origins of the aorta and the pulmonary trunk. The aortic valve occupies the central position with the other valves rings attached to it.

The cardiac skeleton separates and partitions the Atria from the ventricles .

 

Hopefully after a bit of work you should have identified through observation alone those gross anatomical structures 

see next tab

  1. Aortic Valve
  2. Pulmonary Valve
  3. Right Atrium
  4. Superior Vena Cava
  5. Mitral Valve

3. Draughtmanship

 

  1. Use shading techniques- either stippling, hatching/crosshatching, or continuous shading to create a 3D effect.
  2. Highlight those major structures and draw straight lines using a ruler to identify them with legible annotation.
  3. Don’t forget :Date, title and legends

You should now have a complete page, tracings, and annotations with notes. Do remember to date it. When you have done so, upload a PDF or photo of your work into the forum AND email to me

Forums

Enter your work here

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More Updates

Critical Thinking in Physiology:Cardiac anatomy

For the next session on the anterior heart click here

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