Lesson 19 (Part 2) Flashcards
What do valves do?
They prevent the back flow of blood
Where are valves located? (2)
- Heart
2. Veins
Stenotic valves
Dont open enough
Insufficiency/regurgitation
Dont close the valves enough
Regurgitation
Having the valves not close properly and resulting in some back flow
What is hydrostatic pressure equivalent to?
The weight of a column of blood
What does hydrostatic pressure increase with?
Distance below the heart
What is the hydrostatic pressure in a patient that is supine?
0 mmHg
What is the hydrostatic pressure in a patient that is standing?
The pressure in veins is much higher
- 100mmHg
What happens to the diaphragm during inspiration?
It moves down
What happens to the thoracic volume during inspiration?
It increases
What happens to the thoracic pressure during inspiration?
It decreases
What does inspiration allow?
Air into the lungs
What happens to the abdominal volume during inspiration?
It decreases
What happens to the abdominal pressure during inspiration?
It increases
What does inspiration stop?
Venous return from the lungs
- the valves shut
What are examples of venous hemodynamic factors?
- Hydrostatic pressure
- Inspiration
- Valsalva
- Expiration
Valsalva
Patient can be asked hold their breath and ‘bear down
What happens to the abdominal pressure during valsalva?
It increases
What does valsalva stop?
Venous return from the legs
What happens to the diaphragm during expiration?
It moves up
What happens to the thoracic volume during expiration?
It decreases
What happens to the thoracic pressure during expiration?
It increases
What happens to the abdominal volume during expiration?
It increases
What happens to the abdominal pressure during expiration?
it decreases
What does expiration allow?
Venous blood return from the legs
- valves open
When are the valves closed?
During inspiration and valsalva
When are the valves open?
During expiration
