3.1.2: Transport In Animals Flashcards
What is the smooth muscle layer like in capillaries?
No smooth muscular wall
Capillaries allow for the exchange of materials between blood and cells.
What is the wall thickness of arteries compared to veins?
Thicker than veins
This thickness allows constriction and dilation to control blood volume.
How do arterioles differ in wall thickness compared to arteries?
Thicker than in arteries
This thickness helps restrict blood flow into the capillaries.
What is the role of the collagen outer layer in blood vessels?
To provide structural support
Collagen helps maintain blood pressure in arteries.
What is the characteristic of the elastic layer in venules?
No elastic layer
This contributes to their thinner structure.
What distinguishes veins in terms of smooth muscle?
Relatively thin smooth muscle
This prevents them from controlling blood flow effectively.
What is the pressure condition in veins?
Much lower than in arteries
This results in thinner walls and lower risk of bursting.
Fill in the blank: The walls of blood vessels can stretch and ______ in response to the heart beat.
recoil
This property is essential for maintaining blood pressure.
What is the thickness of the walls in capillaries?
One cell thick
This allows for a short diffusion distance for exchanging materials.
True or False: Valves are present in venules.
No
This is due to the lower pressure in these vessels.
What happens to several venules?
They join to form a vein
This process helps facilitate blood flow back to the heart.
What is the collagen layer like in veins?
Thinner collagen layer
This is due to the lower pressure in veins.
