Unit 3- Cardiovascular Flashcards
1
Q
Why do we need a circulatory system + give 2 features.
A
- we have a small s.a.:vol
- ∴ diffusion x sufficient
1. exchange surfaces- 🫁
2. transport system- 🫀
2
Q
Why do we need a circulatory system + give 2 features.
A
- we have a small s.a.:vol
- ∴ diffusion x sufficient
1. exchange surfaces- 🫁
2. transport system- 🫀
3
Q
Features of an effective transport system
A
- suitable medium- eg. blood is water-based
- closed transport network of tubular vessels (capillaries, veins, arteries)
-
mechanism for moving medium within vessels
- 🐾- muscular heart
- 🌿- transpiration stream
4
Q
State the 2 main parts to the mammalian double pump
A
- pulmonary system: deoxygenated blood to the lungs
- systemic system: oxygenated blood depressurised + sent around the body
5
Q
Where is the heart located?
A
- enclosed by pericardium (between 2 lungs)
- pericardial fluid secreted–> aid movement
- protects ❤️ from overexpansion
6
Q
What are the walls of the ❤️ made up of?
A
Cardiac muscle- myocardium
- never tires unless lack of O2
7
Q
Suggest why it is important to prevent mixing of the blood in the 2 sides of the heart.
A
- only partially oxygenated blood–> tissues + lungs
- ↓ O2 supply
- ↓ diffusion gradient in lungs
- ↓ rate of O2 uptake
8
Q
Explain why blood pressure fluctuates up and down between the aorta and small arteries.
A
- contraction of left ventricle–> distension of aorta
- elastic layer- recoil –> series of pulses of ↑ Pa ∵ ventricular contraction
9
Q
Explain why the rate of blod flow decreases between the aorta and capillaries.
A
- ↑ area of blood vessel wall
- ↑ frictional resistance
