Hula Hoop
Where do Arteries carry blood?
Where do Veins carry blood?
1. Arteries: carry blood away from the heart (doesn't matter which system we are talking about)
2. Veins: carry blood to the heart (doesn't matter which system we are talking about)
What is the shape of an Artery?
What is the shape of a Vein?
1. Artery: almost always circular
2. Vein: Usually partially collapsed
Do Arteries have valves?
Do Veins have valves?
1. Arteries: no valves other than the ones allowing it to leave the heart
2. Veins: have one way valves that run the length of the venous system
What are the factors that determine the return of venous blood to the heart? (3)
1. Slight difference in blood pressure in venus end of the capillaries and right atrium so there is enough difference there to push blood black to the heart, couple that with one way valves
2. The squeezing or pumping due to muscular contractions
3. Respiratory pump that is generated as you breathe that changes the pressure around your vena cava
How do veins act as a blood reservoir? (3)
1. They hold 60% of the blood
2. When you are excited or exercising your sympathetic branch of the nervous system causes contraction of the walls and that pushes more blood back into the heart
3. You can use blood that is normally held in your veins to push it back to the heart with that contraction of the walls
Define blood pressure
Force of blood against the walls of the vessel
What is a normal systolic/diastolic reading of pressure?
120/80
What is Mean Arteriole Pressure?
Reading of blood pressure throughout the cardiac cycle
Why is Mean Arteriole Pressure thought to be a better indicator?
It allows you to see the force of profusion through tissue throughout the cardiac cycle rather than just when the ventricles are contracting or relaxing
Define pulse
A measurable difference in systolic and diastolic pressure
In what vessels would you find a pulse? (3)
1. Disappears at arteriole level
2. Feel in large and small arteries
3. Feel your pulse in temporal artery, neck, wrist
What are the 2 major factors that affect blood pressure?
1. Blood volume
2. Radius of the vessels
How does heart rate affect blood volume?
If your heart rate goes up your volume goes up
What factors affect heart rate?
Sympathetic branch of ANS, hormones, etc.
What 3 hormones affect blood volume?
1. Antidiuretic hormone
2. Renin Angiotensin Aldosterone Pathway
3. Atrial Natriuretic hormone
Where does Antidiuretic Hormone come from?
Posterior pituitary
Why is Antidiuretic Hormone released?
When blood gets too salty
Causes the kidneys to save water into the blood
What is Antidiuretic Hormone's effect on blood volume/pressure?
Goes up
Where is Renin Angiotensin Aldosterone Pathway released from?
Adrenal cortex
Why is Renin Angiotensin Aldosterone Pathway released?
Renin (when blood pressure or salt levels get too low in the kidney - cells in the kidneys sense low blood pressure or low salt)
What is Renin Angiotensin Aldosterone Pathway's mechanism of action?
Aldosterone saves salt into blood and water follows
What is Renin Angiotensin Aldosterone Pathway's effect on blood pressure and volume?
Goes up
Where does Atrial Natriuretic Hormone come from?
Cells in the walls of the heart
Why is Atrial Natriuretic Hormone released?
When blood pressure in the heart gets too high