Week 2 - Lesson 2 (Part 2) Flashcards
What is the respiratory pump useful for?
Assisting venous return to the heart
What happens to the thoracic pressure during inspiration?
It decreases
What happens to the abdominal pressure during inspiration?
It increases
What happens to the thoracic pressure during expiration?
It increases
What happens to the abdominal pressure during expiration?
It decreases
What is pressure in the thorax always lower than?
The atmospheric pressure
What happens if you apply a suctioning action?
It tends to pull the column of blood towards the chest
Diaphragm motion
Breathing in and out
Inspiration
Breathing in
Expiration
Breathing out
What does inspiration cause? (2)
- Reduced flow in the abdomen
2. Increased venous flow in the chest
When is the venous flow in the upper extremities opposite to that of the lower extremities?
During each phase of respiration
What role does gravity play in?
Venous return
How does gravity help venous return in the upper extremities?
Naturally moves down to the heart
How does gravity help venous return in the lower extremities?
It acts as a deterrent
- the force that gravity puts on the column of blood within the veins
Alveoli
Tiny air sacs
How thick are alveoli?
1 cell thick
Where are alveoli located?
In the lungs at the end of the smallest airways
What happens in the alveoli?
Exchange of oxygen and carbon dioxide
How many alveoli absorb oxygen from the air?
300 million
What are in close contact to alveoli? (2)
- Pulmonary arteries
2. Pulmonary veins
What kind of blood do pulmonary arteries carry?
Deoxygenated
Where are pulmonary arteries located?
Branches from the pulmonary trunk off the base of the right ventricle
- left and right branches extend to the corresponding lung
How many pulmonary arteries are there?
2
What kind of blood do pulmonary veins carry?
Oxygenated
How many pulmonary veins are there?
4
What kind of blood do arteries carry to the organs and tissues?
Oxygenated
How is flow maintained through diastole? (5)
- Ventricles contract throughout systole
- Blood is sent into the aorta
- Forces expansion of vessel wall
- potential energy is stored in the walls - Aortic valve closes in the heart and diastole occurs
- Wall recoils to release the stored potential energy
- this recoil forces blood to continue in a forward motion
