Mass transport in animals Flashcards
What is plasma?
The liquid component of blood
What are the 4 components of blood?
- White blood cells
- Red blood cells
- Plasma
- platelets
Define mass transport
The bulk movement of liquids or gases in one direction, usually through a system of tubes or vessels
When centrifuged what is closest to the bottom?
Red blood cells are at the bottom with white blood cells above them and then plasma at the top. Plasma is about 55% white blood cells and platelets are less than 1% and red blood cells are around 45%
What does plasma do?
Plasma allows blood to flow and therefore has to be a large proportion of blood. This means the heart has to work less hard
The heart is a double pump, where does it pump blood to?
The left half of the heart pumps to the tissues while the right pump to the lungs
Where do veins flow?
Veins move blood towards the heart
Where do arteries flow?
Arteries (away) move blood away from the heart.
Properties of arteries:
- thick flexible walls to withstand pressure
- 3 layer walls - the middle is elastic - outside is strong
- the endothelium is smooth to reduce friction
Why are the elastic walls in arteries important?
The elastic walls can expand and contract to allow better maintenance of pressure, to make it easier for the heart to pump. It means blood flow can be kept constant.
Properties of veins:
- much thinner walls than arteries as blood pressure is lower and blood moves slower
- less elastic than arteries
- there are valves in veins to stop the backwards flow
Epic fact
The capillaries are around 100km long when stretched out
Properties of capillaries:
- expansive networks for surface area
- very thin walls for rapid diffusion
What is in capillaries?
- Lumen
- nucleus
- endothelial cell
- junction between cells
- capillary wall
What is an epithelium?
(OUTSIDE) the thin tissue forming the outer layer of a body’s surface and lining the alimentary canal and other hollow structures.
What is an endothelium?
(INSIDE) The tissue which forms a single layer of cells lining various organs and cavities of the body, especially the blood vessels, heart, and lymphatic vessels. It is formed from the embryonic mesoderm.