capillary function
what are the two mechanisms that alter blood flow in capillary beds?
1. vasoconstriction/vasodilation of the arteriole supplying a capillary bed
2. precapillary sphincters that can open and close
where do lymph vessels start? why do they begin here?
in capillary beds, which leak a lot of blood filtrate into the tissue. the lymphatic system starts here to mop up this excess fluid.
what filtrate substances make up the matrix of the blood?
which three components are necessary for blood to clot?
platelets, damaged cells, and blood plasma
what is the driving force behind O2 and CO2 diffusion during respiration?
partial pressure
what is vasoconstriction? will it increase or decrease blood pressure? explain your answer.
vasoconstriction is the tightening of blood vessels; it will increase blood pressure due to a smaller volume of filtrate to pass through
lymph, the fluid in lymph nodes and vessels, has a similar composition to what other bodily fluid?
interstitial fluid
what are leukocytes? what are their function?
these are white blood cells, which function in immune defense
Fibrinogen is converted to what protein? what purpose does this converted protein serve?
fibrinogen is converted to fibrin, which forms the structural framework of a clot
what is the name of the tiny air sacs in which diffusion occurs? what structure of the circulatory system are they closely related with?
alveoli - closely related to capillaries
what is vasodilation? will it decrease or increase blood pressure?
vasodilation is the stretching/expansion of blood vessels; it decreases blood pressure
what are lymph nodes and their main function?
they are little lymphatic organs that filter incoming filtrate
what is hemoglobin? why is it important?
an iron-containing protein in red blood cells - binds oxygen to RBCs
what type of feedback loop does blood clotting depend on?
positive feedback loop
what is countercurrent exchange?
a system used by fish - blood flows in the opposite direction of water across gills to maximize oxygen uptake
Are the walls of capillaries thick or thin? Explain how the thickness of capillaries is important in blood circulation.
caps have thin walls - allows for easier diffusion of red blood cells for gas exchange!
What is the important role of the lymphatic system as a whole?
immune response
where are red blood cells produced?
stem cells in red bone marrow
what is a thrombus? are they typically harmful or beneficial to the body
a type of blood clot that forms within a blood vessel and may block blood flow
what is ventilation?
the process of moving around to allow fresh water to comb over respiratory surfaces. if a marine animal does not move, it will suck up all the oxygen from the immediate space around it
Precapillary sphincters can constrict and decrease the amount of blood delivered to an area, thus allowing the majority of blood to be delivered and used in a different area of the body. Why is this an important adaptation of the circulatory system?
The body needs to be able to shunt blood to different parts of the body for different activities. In rest/digest, your digestive organs need the majority blood supply. In fight/flight, your skeletal muscles and heart will need the majority blood supply.
After lymph is collected and filtered in the lymph nodes, it is delivered to what major vein of the body?
what is sickle-cell disease? why is it dangerous?
a genetic disease that causes the hemoglobin in RBCs to fold into an abnormal shape; RBCs have a shorter lifespan and can't carry oxygen as well. contributes to anemia.
what is atherosclerosis?
what is the 'mucus escalator' found in the trachea?
a mechanism in the trachea and bronchi where mucus and cilia move particles out of the lungs and back up the throat