B3.2 Transport in animals Flashcards
What’s the name of the fluid that comes out of capillaries?
tissue fluid
What are fenestrated capillaries and what is their function?
capillaries with gaps in endothelial cells, which allow for rapid exchange of fluids
Describe the structue of the artery (wall, lumen, shape, pressure)
- wall: thick, stretchy, muscular
- lumen: narrow
- shape: circular
- pressure: high
What provides elasticity in arteries and what is it for?
elastin, allows arteries to stretch and return to normal state after contraction
What muscle layer is in arteries and what are they for?
smooth muscle, it is responsible for controlling the lumen (vasoconstriction and vasodilation)
What are the three main layers of wall of artery?
- tunica intima - endothelium layer
- tunica media - smooth muscle and elastin
- tunica externa - collagen
Describe the structue of the veins (wall, lumen, shape, pressure)
- wall: thin, flexible
- lumen: wide
- shape: flattened
- pressure: low
How blood in veins is pushed along if it’s less muscular?
veins are compressed, when skeletal muscles contract and they contain valves that prevent the backflow of blood
What’s the function of narrow lumen in arteries?
maintaining high pressure
What’s the function of thick walls with collagen?
they allow for artery to contract and expand without bursting
What’s the function of elastic fibers in arteries?
provide recoil to push blood through, stretch and come back to original state after contraction
What’s the function of muscular walls?
contract to push blood through
What’s the function of wide lumen in vein?
low pressure, easier for muscles to squeeze the vein
What’s the function of thin wall in veins?
easier for muscles to squeeze
What’s the function of valves?
prevent the backflow
What is occlusion of blood vessel?
blockage of blood vessel by plaque
What is plaque?
is a collection of cholesterol and other lipids in the coronary arteries and block the blood flow to the heart
What are the risk factors for coronary heart disease?
- smoking
- obesity
- lack of exercise
- genetics
- high blood pressure
- diet rich in saturated fats
- age
Due to what factor the tissue fluid is forced out of arteries and then into veins?
high pressure in arteries and low pressure in veins
What percentage of tissue fluid moves into lymphatic capillaries?
10-15%
What is lymph and what’s it function?
fluid containing tissue fluid, white blood cells, proteins, it helps support immune cells and remove toxins from the body
What is pulmonary circulation?
blood pumped from the heart -> to the lungs -> to the heart
What is systematic circulation?
blood pumped from the heart -> to the body -> to the heart
What is an advantage of double circulatory system?
- more efficient removal of CO2 and higher rate of oxygen delivery
- can meet high metabolic demands of mammals
