Chapter 8- Transport in Animals Flashcards
Describe a closed circulatory system.
Blood is always kept within blood vessels
Describe a open circulatory system.
Blood is always kept within the body, but not in vessels.
Describe a single circulatory system.
Blood is pumped from the heart to gills and then round the body. Blood travels only once through the heart for each complete circuit of the body.
Describe a double circulatory system.
Blood is pumped from the heart to the lungs, then back to the heart, and then round the body. Blood travels twice through the heart for each complete circuit of the body.
What is blood called in insects?
Haemolymph
What do arterioles do?
Link the arteries and the capillaries
Compare and Contrast arteries and arterioles
Different types of blood vessels vary slightly in their structures, but they share the same general features. Arteries and arterioles have thicker walls than veins and venules because they are closer to the heart and receive blood that is surging at a far greater pressure Arteries have smaller lumens than veins, a characteristic that helps to maintain the pressure of blood moving through the system. Together, their thicker walls and smaller diameters give arterial lumens a more rounded appearance in cross section than the lumens of veins.
What does Collagen provide?
Structural Support to maintain the shape and volume of the vessel
How many RBC can fit through the lumen of a capillary
1
How far must Oxygen diffuse to go from the capillary into the alveoli?
Through 2 1 cell thin walls, so thorough 2 cells
Give three ways capillaries are adapted to their function
Very large Surface Area of diffusion into and out of the cell
Cross Sectional area of capillaries is always smaller than the arterioles supplying them so rate of blood flow falls. This slow rate allows more time of the exchange of materials.
The walls are one cell think, minimising distance for diffusion.
Which is present most in veins? Elastin, smooth muscle or collagen?
Collagen
What are venules made of?
Collagen
How is the low pressure blood in the veins moved upwards against the force of gravity?
One way valves inside veins
Some of the larger veins run between large muscles. When they contract, it squeezes the vein, forcing the blood upwards.
Breathing movements of the chest act as a pump. The pressure changes and squeezing actions move blood towards the heart.
Give 6 things that are transported in the blood.
Oxygen to, and Carbon Dioxide from, living cells
Digested food from the small intestine
Nitrogenous waste products from the cells to the excretory organs.
Hormones
Food molecules from storage compounds to the cells that need them
platelets to damaged areas
Cells and antibodies involved in the immune response
Give 3 roles of the blood.
Transportation of items
Maintain internal temperature
Buffer, minimising pH changes
How is tissue fluid formed?
Osmotic potential inside capillary at arteriole end is greater than outside, so fluid flows out to capillary to form tissue fluid. At the venule end, this is reversed as what ever is lost must be gained again.
What is lymph and how does it form?
10% of the fluid that leaves the blood vessels drains into a system of blind ended tubes and returns to the heart through the lymphatic system, instead of through the cardiovascular system. It has less oxygen and less nutrients than tissue fluid.
