The Circulatory System Flashcards
Do single celled organisms need a circulatory system?
nope, they just use diffusion in order to get the materials they need
What do multicellular organisms need need the circulatory system to transport?
nutrients and O2
What does the circulatory system regulate?
hormones and body temp
What does the circulatory system protect from?
wounds and pathogens
What is the most common element of blood?
erythrocytes
What are erythrocytes?
red blood cells
What are leukocytes?
white blood cells (immune cells)
What are platelets?
cell fragments
What is the function of platelets?
help with blood clotting
How much of your blood is made up of plasma?
55% (mostly water)
How much of your blood is made up of erythrocytes?
45%
How much of your blood is made up of leukocytes?
less than 1%
How much of your blood is made up of platelets?
less than 1%
What is different about erythrocytes when compared to regular cells?
they don’t have organelles
What is hematopoiesis?
the synthesis of erythrocytes
Where does hematopoiesis occur?
in the bone marrow
Are red blood cells aerobic or anaerobic?
anaerobic (ONLY do glycolysis)
How many days do red blood cells live for?
120 days
What is the main function of red blood cells?
bind and transport O2 with their hemoglobin
What happens when blood O2 levels drop (in terms of hormones)?
- kidney activates the production of EPO
- EPO stimulates stem cells to produce more red blood cells in the bone marrow
Why is injecting EPO harmful?
this increases production of red blood cells and this leads to thicker blood, which then leads to clotting problems
How many chambers of the heart do fish have?
2
What are the two chambers that fish have?
1 ventricle and 1 atria
What is a pulmonary circuit?
path of blood circulation between heart and lungs
How does a fish breathe?
- the deoxygenated blood leaves the heart and travels to the gills where it picks up O2
- then, the blood travels throughout the body and it is brought back to the heart
Do fish have a pulmonary circuit?
nope, they breathe through gills
How many chambers do amphibians have?
3 chambered hearts
Why did amphibians need 3 chambered hearts compared to fish?
amphibians needed to live on land where O2 is harder to get compared to the water where fish live
What are the 3 chambers in amphibian hearts?
1 ventricle and 2 atria
What is the drawback with 3 chambered hearts?
since there’s only one ventricle, there’s a mixing of oxygen and deoxygenated blood
Do amphibians have lungs?
yes !
How do amphibians breathe?
- deoxygenated blood travels to the heart and then to the lung to get O2
- the blood then comes back to the heart and then goes to the rest of the body
What is unique about reptiles and their hearts?
they have a complete or incomplete septum separating the ventricles
How many chambers does the mammalian heart have?
4 chambers
Do birds have 4 chambered hearts?
yes
What are the 4 chambers?
left and right ventricle and atria
What problem did we fix by having 4 chambers?
mixing of blood
What is the reason we’re warm blooded?
because we have 4 chambers and need lots of O2 to stay warm
Do dinosaurs have 4 chambered hearts?
yes, some do and they are theorized to be warm blooded!
What do arteries do?
carry blood away from the heart to the rest of your body (typically O2 rich)
What do veins do?
carry blood to the heart from the rest of your body (typically O2 poor)
What do capillaries do?
small blood vessels where O2 is delivered to organs and CO2 is picked up
What chambers of the heart does deoxygenated blood go to?
right atrium and ventricle
What chambers of the heart does oxygenated blood go to?
left atrium and ventricle
Be able to trace blood flow through the heart and know parts of the heart relevant to this pathway!
got it!
What are arterioles?
connectors between arteries and capillaries
What are capillaries?
small blood vessels that are thin and leaky so they allow for O2 and nutrient drop off from the blood to the tissues
How narrow are capillaries?
1 red blood cell wide
What are capillaries also used in?
vasoconstriction for body temperature regulation
What do plasma proteins do for capillaries?
protein stays in the capillaries (while fluid leaks out) and the proteins in the blood lead to osmotic pressure where water is then drawn back in by the proteins into the capillaries, so that the blood doesn’t lose the water it needs with the fluids
What are interstitial fluids?
fluids around cells (outside of capillaries)
Why do arteries need to be thick?
they basically control blood pressure and so it needs to be thick and elastic for when heart pumps blood
What are venules?
small veins that connect the veins to the capillaries
Why are veins thinner and less elastic?
blood pressure doesn’t really affect veins so they are able to be more rigid
What is lymph?
excess plasma that leaks out of capillaries
How does lymph travel?
it travels from lymphatic capillaries to lymphatic vessels to lymph nodes
What is the venous pathway?
the pathways where lymph nodes dump fluids back to the heart
Why do lymph nodes dump fluids back to the heart?
this helps maintain stable blood pressure and volume and it also helps against unnecessary blood clots
What is the endothelium?
inner lining of blood vessels
How do capillaries regulate blood temperature?
capillaries dilate, causing your body to feel warm to the touch (lots of blood flow), but constrict which decreases your body temperature
Where is the sinoatrial node located?
the right atrium
What does the sinoatrial node do?
this signals when the atria should constrict (or pump), this helps pump blood throughout the heart and helps with maintaining blood pressure
What is systolic blood pressure?
pressure inside arteries when your heart is pumping
What is diastolic blood pressure?
pressure inside arteries when heart is at rest
What is an open circulatory system?
system that has no vessels to conduct blood flow
What is the sinoatrial node?
the pace maker, it creates electrical impulses throughout the heart to regulate heartbeat and pumping of blood
What happens when there’s no oxygen?
hypoxia
What is the pressure called when the heart is beating?
systolic
What is the pressure called when the heart is at rest?
diastolic
What layer is thicker in arteries?
tunica media (helps with changing vessel diameter)
