Chapter 50: Circulatory Systems Flashcards
cardiovascular system
heart, blood, and vessels
hearts
muscular chambers that move extracellular fluids around the body
extracellular fluid
fluid in the circulatory system and the fluid outside it
open circulatory system
heart helps move hemolymph through vessels leading to different regions of the body
inefficient
closed circulatory system
a system of vessels keeps circulating blood separate from the interstitial fluid
advantage of closed circulatory system vs open circulatory system
fluid can flow more rapidly, and therefore transport waste and nutrients faster
can control the flow of blood to tissues by the diameter of the vessels
pulmonary circuit
blood is pumped from the heart to the lungs and back to the heart
systemic circuit
blood pumped from the heart to the body, and then back to the heart
arteries
blood vessels that carry the blood away from the heart
arterioles
small arteries that feed blood into capillary beds
capillaries
tiny, thin walled vessels where materials are changed by tissue fluid and blood
venules
small vessels that drain capillary beds
veins
deliver the blood back towards the heart
sinus venosus (fish)
blood returning from all parts of the body collect here
bulbus arteriousus (fish)
highly elastic chamber, last part of fishes heart
aorta
large dorsal artery
atrioventricular valve
one-way valve between the atria and ventricles
prevent blood flow of blood into the atria when the ventricles contract
pulmonary valve
separates the right ventricle and pulmonary circuit, preventing blood flow
aortic valve
separates the left ventricle and systemic circuit, prevents blood flow
cardiac cycle
contraction of two atria, then contraction of two ventricles, and then relaxation
systole
when the ventricles contract
diastole
ventricles relax
pacemaker cells
can initiate action potentials without stimulation from the nervous system
sinoatrial node
primary pacemaker
modified cardiac muscle cells
located at the junction of superior vena cava and right atrium
atrioventricular node
stimulated by the depolarization of the atria
located between the atria and ventricles
with slight delay, generates AP which are conducted to the ventricles via the bundle of His
slight delay ensures that the atria contract before ventricles do
bundle of His
modified cardiac fibers that do not contract but conduct APs
Purkinje fibers
conducting fibers ensure cardiac potential spreads rapidly and evenly throughout the ventricular muscle mass
electrocardiogram
measured electrical events in the cardiac muscle during the cardiac cycle by placing electrodes on skin
plasma
fluid matrix of the blood
erythropoietin
hormone that controls the production of RBC
released by cells in the kidney
hypoxia
insufficient oxygen
spleen
recycles old RBC, they get ruptured b/c flexibility is lost
platelets
tiny fragment of cell without any organelles, but packed with enzymes and chemicals necessary for sealing leaks in blood vessels and initiating blood clotting
steps of blood clotting
- prothrombin converted to thrombin
- thrombin cleaves fibrinogen
- forms insoluble threads of fibrin
- fibrin forms the meshwork for clotting
Starling’s forces
- blood pressure squeezes water and small solutes out of the capillaries
- osmotic pressure pulls water back into the capillaries
edema
tissue swelling
histamine
mediator of inflammation released by certain WBC
increases capillary permeability and relaxes the smooth muscles of arterioles, raising blood pressure of the capillaries and leading to fluid into tissues
fenestrations
holes in the capillary walls
Frank-Starling law
if the cardiac muscle cells are stretched, they contract more forecefully
lymphatic system
returns interstitial fluid to the blood
lymph
interstitial fluid once it has returned to lymphatic system
thoracid duct
empty into large veins at the base of the neck
plaque
deposits formed at sites of endothelial damage
thrombus
intravascular blood clot
formed when blood platelets stick to the plaque
coronary arteries
pathway of blood supply to the heart muscle
myocardial infarction
heart attack
embolus
piece of a thrombus that breaks loose
stroke
embolism in an artery in the brain causes the cels fed by that artery to die
