Circulatory system As Flashcards
properties of arteries
carry blood away from heart, towards tissues thickest elastic layer quite thick muscle layer thin endothelium no valves
properties of veins
carry blood to heart from tissues
thin muscle layer
thin elastic layer
valves
properties of arterioles
carry blood under lower pressure to tissues quite thick elastic layer thickest muscle layer (proportionally) thin endothelium no valves
properties of capillaries
exchange metabolic materials with cells numerous and branched no valves narrow lumen walls consist mainly of the lining layer narrow diameter
what is muscle layer for
changing the blood flow/pressure
muscles contract which reduces the diameter of the lumen (vasoconstriction)
can relax and increase the diameter of the lumen (vasodilation)
what is purpose of elastic tissue
allows stretching/recoiling smooths flow of blood maintains pressure when ventricles contract elastic tissue is stretched recoils back when ventricle relaxes
what is the purpose of the endothelium
can reduce friction since it is smooth
what is blood plasma
fluid that bathes blood cells in capillaries. same as tissue fluid but with large proteins
what is tissue fluid
fluid which has left capillaries and bathes cells
contains glucose, amino acids, and fatty acids
how materials are exchanged with cells
how does tissue fluid leave capillaries and return
the ventricles contract and this produces high hydrostatic pressure. this forces water out of blood capillaries
large proteins are left in capillary
low water potential in capillary
water moves into capillary through osmosis
other substances move through diffusion
where does the remainder of the tissue fluid which doesn’t return to the capillaries go
the lymphatic system
why do large organisms need circulatory system to do mass transport
because they have a too small surface area/volume ratio
define tissue
several types of cells working together
define organ
different tissues working together
define organ system
different organs working together
