Transport In Animals Flashcards
What are 3 reasons why animals need transport systems?
They are large
High metabolic rate
Low surface area to volume ratio
What kind of circulatory system do insects have?
Open, single - haemolymph is their transport medium which carries food, nitrogeneous waste and immune cells. tracheal system deals with gas exchange
What kind of circulatory system do fish have?
Closed, single
Why kind of circulatory system do mammals have?
Closed, double
Describe the structure of an artery?
Tunica intima
- endothelium 1 cell think
- connective tissue and elastic fibres
Tunica media
- lots of smooth muscle
- elastic tissue
Tunica adventitia
Collagen
What is the purpose of elastic tissue in blood vessels?
To maintain pressure and even out surges of blood
What is the function of smooth muscle in blood vessels?
To provide strength and to control the flow of blood
What is the function of collage in blood vessels?
To prevent overstretching and damage to them
Compared to artery’s what is the composition of arterioles?
The have more smooth muscle and less elastin
3 adaptions of capillaries as an exchange surface?
Small lumen -RBC single file to slow them down
Large cross sectional area slows blood down and increases area for diffusion
Walls are 1 cell thick
What is the composition of venules?
Thin walls
Very little smooth muscle
Structure of veins?
Valves to prevent back flow as pressure is low and no pulse
Between muscles which contract and squeeze up blood
Ventilation movement squeeze up
How is tissue fluid formed?
Hydrostatic pressure at arteriole end is higher than oncotic so plasma moves out into surround tissue forming tissue fluid
Oncotic pressure at venule end is higher so water moves back in
What’s in blood that isn’t in tissue fluid?
Plasma proteins
Red blood cells
Platelets
What does lymph contain?
Dissolved solutes
White blood cells
Proteins