Term | Definition |
circulatory systems | transport necessary materials to all the cels of an animal's body and transport waste products away from the cells so they can be released into the environment |
simple circulatory system | organisms with gastrovascular cavity. surrounding water acts as a circulatory system |
gastrovascular cavity | body cavity with a single opening to the outside that functions as both mouth and anus |
true circulatory systems contain | blood/hemolymph, vessels and heart |
open circulatory system | one or more hearts that pump fluid through vessels that open into the animal's body cavity called the hemocoel |
in open circulatory system nutrients and waste are exchanged by | diffusion between the hemolymph and body cells and hemolymph eventually returns to the heart |
hemolymph | mixed fluid. part of open circulatory system |
closed circulatory system | blood and interstitial fluid are separated and differ in their components and chemical composition |
Blood | watery solution containing solutes to be transported throughout the body. Pumped by heart |
single circulation | blood pumped from heart to lungs to tissues back to heart |
double circulation | blood pumped from heart to the lungs back to heart and the pumped to tissues then back to the heart |
Single circulation heart has | one atrium and one ventricle |
double circulation heart has | two atria and two ventricles |
arteries carry blood | away from the heart |
veins carry blood | towards the heart |
intermediate circulation on land | blood pumped from heart to lungs and less skin |
intermediate circulation on water | blood pumped from heart to skin. Skips lungs |
pulmonary circulation | delivers oxygenated blood from the lungs to the left atrium then to left ventricle |
systemic circulation | delivers deoxygenated blood from the tissues to the right atrium then right ventricle |
4 components of blood | plasma, leukocytes, erythrocytes and thrombocytes/platelets |
plasma | water and dissolved organic and inorganic nutrients. base. transports, keeps body's pH, maintains fluid balance |
leukocytes | white blood cells |
erythrocytes | red blood cells |
hematocrit | volumes of blood that is composed of red blood cells |
hemoglobin | in cytosol of red blood cells. |
each hemoglobin carries ___ oxygens | 4 |
anemia | lower than normal amounts of hemoglobin |
platelets | cell fragments that lack a nucleus |
thrombocytes | intact cells |
platelets and thrombocytes | play crucial role in the formation of blood clots |
first step of blood clotting | injury |
second step of blood clotting | platelets secrete substance that causes them to lump together and bind to collagen fibers in the surrounding connective tissue at wound site. Forms a plug |
third step of blood clotting | fibrin forms a meshwork that traps red blood cells and platelets forming a clot that seals the wound |
system veins | return blood from the body |
pulmonary veins | return blood from lungs |
AV valves | between atria and ventricles. Controls movement of blood between them |
each ventricle empties into the | aorta |
pulmonary trunk | divides into the pulmonary arteries that lead to left and right lungs |
semilunar valves | between each ventricle and the artery. One way valves |
neurogenic heart | will not beat unless it receives regular electrical impulses from nervous system |
myogenic heart | signaling mechanism that initiates contraction resides within cardiac muscle itself |
myocyte | has membrane extensions that form interlocking networks with other myocytes |
intercalated disks | within networks of myocytes. Gap junctions |
SA node | collection of modified cardiac cells that have an inherently unstable resting membrane potential |
atrial contraction pumps blood | through the AV valves into the ventricles |
ventricular | action potentials in SA node reach Av node |
AV node | located near junction of the atria and ventricles and conducts electrical signals from the atria to the ventricles |
cardiac cycle | contraction and relaxation events that produce a single heartbeat |
diastole | first phase. Ventricles are relaxed and fill with blood coming from the aorta through open AV valves. Atria contract and more blood fills ventricle |
systole | second phase. ventricles contract and eject the blood through the open semilunar valves |
blood pressure | force exerted by blood on the walls of blood vessels. |
Blood pressure is highest in the arteries during | systole |
blood pressure is lowest in the arteries during | diastole |
EKG | medical test used to investigate the function of the heart |
Order of blood flow- arteris | heart, large arteries, small arteries, arterioles, capillaries, venules, small veins, large veins, heart. |
artery walls are | thick |
arteries distribute blood leaving heart to all of the | organs and tissues of an animal's body |
Resistance | the tendency of blood vessels to slow down the flow of blood through their lumens |
Resistance depends on | vessel radius, length and blood viscosity |
vasodilation | increase in blood vessel radius |
vasoconstriction | decrease in blood vessel radius |
cardiac output | amount of blood the heart pumps per unit of time, usually expressed in units of liters per minute |
cardiac output depends on | size of heart, how often it beats per minute, and how much blood it ejects with each beat |
stroke volume | amount of blood ejected with each beat |
binding of epinephrine to receptors on heart | increases heart rate. |
epinephrine released during | exercise |
cardiovascular disease | disease of heart and blood vessels |
hypertension | high blood pressure |
coronary artery disease | when plaque forms in the coronary vessels. Symptom- angina pectoris (chest pain) |
Myocardial infarction | heart attack |
Baroreceptors | stretch receptors |
Oder of blood flow | body, superior/inferior vena cava, right atrium AV valves right ventricle, SV valve, pulmonary arteries, lungs, left atrium, AV valve, left ventricle, aorta, body. |