chapter 8 Flashcards
Transport systems in multicellular animals
what are elastic fibres
stretch and recoil and allows for flexibility
what is collagen
structural support
what is smooth muscle
changes size of lumen
contracts and relaxes
arteries
oxygenated blood away from heart
apart from heart to lungs pulmonary artery
contains smooth muscle, elastic fibres and collagen
the endothelium lining is smooth so blood can flow easily
lumen endothelium elastic muscle collagen
veins
away from the cells into the heart
de oxygenated blood
apart from the lungs to the heart (Pulmonary vein)
don’t have a pulse
low pressure
valves
muscles contract to squeeze the blood out
breathing acts as a pump which moves blood through veins to heart
wide lumen with smooth endothelium
elastic fibres, muscle and collagen
venules link capillaries to veins
capillaries
lumen is small so single file red blood cells
capillary walls made of endothelial cells
blood from areoles is oxygenated
blood going to he venules is has less oxygen and more CO2
single endothelial cell thick for diffusion
large surface area
rate of blood flow is low which means more time for diffusion
why do we need a specialised transport system
high metabolic demands (need O2 food and need to get rid of waste products like CO2)
SA:V ratio gets smaller as the animal gets bigger so diffusion and absorption wont transport enough
hormones needed to be transported from places round body
open circulatory system
few vessels
pumped straight from heart to body cavity (haemocoel)
low pressure
direct contact to tissues and cells for exchange
returns to the heart through open ended vessels
blood is called haemolymph
doesn’t transport O2 or CO2 as that’s spiracles
transports food and nitrogenous waste products (urea)
closed circulatory system
enclosed in blood vessels
no direct contact with cells
diffuses through vessel walls
blood pigment carries gas
single closed circulatory system
blood only travels once through the heart
heart - gills - body - heart
capillaries at body and gills allows for diffusion
low pressure so more time for diffusion
takes long time to get back to the heart
double closed circulatory system
animals with high metabolic needs
most efficient system
2 separate systems:
-heart to lungs picks up O2 and
releases CO2 then back to heart
-from heart round body then back to
heart
only passes through one set of capillaries so high pressure and fast flow of blood
what are the functions of blood
O2 and CO2 from and to cells
digested food from intestine
nitrogenous waste gone
chemical messages
platelets to damaged areas
cells and antibodies
food molecules from storage compounds
what is lymph
it’s made up of the tissue fluid that does not return to he blood
transported through lymph cappilleries
squeezing of body muscles move lymph which
returns to veins
lymph nodes produce lymphocytes
they also detect bacteria and debris
enlarged lyph nodes means the body is fighting against pathogens.
diastole
heart relaxes
pressure is building as blood enters either atium or venticles
arteries has low pressure
systole
atrium and venricles contracts
pressure is very high in heart
at end of systole pressure is low in heart and blood pressure in arteries are high pressure
the heart sound
“lub-dub”
“lub” is the bi and tricuspid valves as blood is forced aginst it as ventricle squeezes (contracts)
“dub” is the backflow of blood on the semilunar valves in he aorta and pulmonary valves
tachychardia
fast heart beat 100+
excersise, fever or frightened
brachycardia
slow heart beat 60-
fit and healthy
ectopic heartbeat
extra beats out of rythem
happens once a day on average
atrial fibrilation
abnormal rythem
atria contract very fast 400 per minute
not fully contracted
not effective
Plasma
The main component in blood. A yellow fluid containing many dissolved substances and carrying the blood cells.
platelets
Components of large cells (megakaryocytes), found in bone marrow, involved in clotting mechanisms.
What substance in plasma cant pass through the capillary walls?
large plasma proteins
Why does water move into the blood in the capillaries from the surrounding fluids
Blood has large plasma proteins that cannot leave through the capillaries, this gives the blood a high solute potential and low water potential which means water moves in by osmosis.