Card Set Information
circulation and gas exchange
What is the function of a circulatory system?
to provide the body with oxygen, nutrients, remove wastes and CO2
Why do we have a circulatory system?
all cells in the body need access to oxygen, etc
What is an open circulatory system?
heart beats, fluid moves into some large vessels, and from there into the body ex)insects, many arthropods
what is an closed circulatory system?
blood is always confined to blood vessels ex) earthworms, vertebrates
What does the atrium do?
receives blood from the body, then moves blood to ventricle
What does the ventricle?
pumps blood out of the heart
What does the arteries do?
carry the blood to other parts of the body
What does the arterioles?
small vessles that give rise to capillaries
What do capillaries do?
infiltrate every organ and tissue in the body
What are venules?
coverge into larger veins
return blood to heart
What is the flow of blood through the adult mammal?
right ventricle----lungs---left atrium---left ventricle---body---right atrium---right ventricle
What is the cardiac cycle?
what happens from one heart contracton to the next
What is heart rate
number of times heart beats in one minute
What is stroke volume?
amount of blood pumped by left ventricle with one beat
What is cardiac output?
amount of blood pumped by left ventricle
What is systole?
What is diastole?
What causes the heart sounds?
the heart valves closing
What coordinates cardiac muscle cells?
What does the SA node do?
will release the signal to beat
What is the AV node?
dpecialized muscle fibers transmit signal to ventricles which then contract
What is the EKG or ECG
What can a EKG show?
data about heart health
What do intercalated disks do?
allow rapid dissemination of electrical stimulus and so the atria contract
Why can a defibulator be useful?
when blood is not pumped and heart needs to be "reset"
What influences heart rate?
hormones, body temperature, stimuli from nerves reaching the heart, condition
epinephrine causes an increase in heart rate
fever increases the heart rate
if one is in excellent condition, heart rate is often much lower
What is blood pressure?
the force that blood exerts against the walls of your blood vessels
What is systolic pressure?
maximum pressure when ventricles contract
What is diastolic pressure?
minimum pressure when ventricles are relaxed
How do we measure blood pressure?
in the artery of the arm
What units are used to measure blood pressure?
Why do we have minimum blood pressure?
elasticity of artery walls; peripheral resistance; go through sphygmomanometer; and as one moves away from the heart, blod pressure drops
What hapens to blood pressure as we move inthe capillaries?
blood pressure drops and smooths out
What structure do veins have to help move blood back to the heart?
valves, skeletal musces contracting, and some contraction by muslces in veins
How can capillary beds be turned on and off?
by muscles that control access to capillaries
What is the advantage of capillary beds turning on and off?
when exercising( diverts blood from digestive system); when hot ( shunts blood to skin); when suffering from blood loss ( shunts blood to vital systems)
What is the danger from anaphylactic shock?
many capillary beds may open at once causing a drastic fall in blood pressure
What is the lymphatic system?
involved in both innate and adaptive immunity
What does the lympathic system do?
returns fluid to the circulatory system
What can happen if lymph vessels get blocked?
can be painful and cause serious deformities
What % of blood is living?
What % of blood is non-living?
What are components of blood?
water, solvents, ions, proteins, nutrients
How many molecules of hemoglobin in a red blood cell?
250 million molecules
What are stem cells?
cells in bone marrow
What can happen if the stem cells do not work correctly?
overproduction of certain types
What triggers blood clotting?
if platelets encounter a rough surface, it becomes sticky and releases a substance that causes nearby platelets to become sticky as well
What are the steps of blood clotting?
if damage is more sever, this causes the release of substance that changes protherombin into thrombin, which will then change fibrinogen into fibrin which interweaves itself into the clot
What are the risks for heart disease?
diet, exercise, smoking, aging, family history, males
Are these risk factors the same for hypertension?
has many of the same risk factors, but the exact connections between some of these factors and hypertension are not understood very well
Which factors can you control?
diet/lack of exercise
Which factors can you not control?
aging/family history(& disease)/being male
What effects do these factors have?
can lead directly to heart attack, stroke, or kidney disease
What are the different kinds of heart disease discussed in class?
congenital, arrythmias, heart valve, heart failure, heart attack
What is a heart attack (what are coronary arteries)?
offten caused by blockage of the coronary arteries; coronart arteries supply the heart muslce
What is a stroke?
blockages in the blood vessels to the brain