Terms - Circulatory system Flashcards
Heart
the heart powers the circulatory system
- allows blood to transport oxygen nutrients, waste, heat, hormones, and immune cells to the tissue
- pressure pumps through the body
What are the layers of the heart?
Fibrous pericardium (outter layer)
serous pericardium ( inner layer): Parietal Layer, visceral layer (space), and pericardial cavity
pericardium
is a fluid-filled sac that surrounds the heart in order to protect and lubricate it from proper function
How many chambers does a heart have? and how is it divided?
4 chambers
- Left and right sides are divided by the septum
Atria
the upper chamber of the wall (1 and 3 chambers)
ventricles
Lower chambers of the heart wall. (2 and 4 chambers)
What type of blood does the right atrium and ventricle?
deoxygenated blood
- most of the oxygen in the blood is removed from the muscle
What function do the Right atrium and ventricle have when they contain deoxygenated blood?
After the oxygen is removed from the muscle, it is located on the right side of the wall. It tries to get that blood to the lungs so it can be reoxygenated.
What type of blood does the left atrium and ventricle?
Oxygenated after it was reoxygenated from the lungs
Which chambers (Artia/Ventricle) are under low pressure when pumping/sending blood
The Artia is under low pressure because it is sent to the ventricles. (which isn’t far)
Which chambers (Artia/Ventricle) are under high pressure when pumping/sending blood
The ventricle is under high pressure because it is sending blood to the lung or systemic circulation
- as thicker walls
Heart valves function
The valves work to prevent backflow of blood
- open under pressure, then close to prevent backflow
Pulmonary Valve
between the right ventricle and pulmonary parties
tricuspid valve
- between the right atrium and right ventricle
mitral (bicuspid) valve
between the left atrium and left ventricle
Aortic valve
between the left ventricle and aorta
Aorta
Thick, muscular structure that distributes blood directly from the heart to the arteries of the body
How many heart chambers do fish have
They only have two heart chambers (one atria and one ventricle)
How many heart chambers do amphibians and reptiles have
They have three heart chambers (two atria and one ventricle)
How many heart chambers do birds and mammals have
They have 4 heart chambers (2 atria and 2 ventricles)
- crocodiles and alligators are the exceptions of having 4 heart chambers
How does the heart pump the blood through the body and to the tissue, then bring it back?
Arteries and veins connect the heart to the rest of the circulation system.
Arteries
Carry blood away from the heart.
- oxygen-rich (red color)
- under high pressure
- Thick walls
- elastic and muscular
Have three layers: Endothelial lining (inner), smooth muscle and elastic tissue (middle), and Connective tissue (outer)
veins
carry blood back to the heart
-deoxygenated and has been taken up by the tissue
- under lower pressure
- rely on skeletal muscle contraction to increase pressure (prevents backflow)
pulmonary circuit
the blood pathway from the right side of the heart to the lungs, and eventually to the left side of the heart
systemic circuit
the circulation pathway
through the body between left and right sides of the heart
What are the pulmonary circulation steps
- Blood is pumped from the right ventricle to the pulmonary arteries (contains blood with low concentration blood, used up by the tissue)
- Blood gets reoxygenated at the capillaries of the lungs (picks up O2 and expels CO2)
- Blood travels back to the heart via pulmonary veins to the left atrium (moving down the pressure gradient and contains blood with the highest O2 concentration)
Which part of the body contains the lowest part of oxygenated concentrated blood
the pulmonary arteries
Which part of the body contains the highest part of oxygen-concentrated blood
pulmonary veins
What are the systemic circulation steps?
- Left atria contracts and pushes blood to the left ventricle (contract due to an increase in pressure
- The left ventricle contracts and blood travels to the aorta (the mitral valve closes and prevents backflow. Blood travels through the aortic valve)
- In blood from the aorta travels to the entire body
- Blood reaches the capillaries ( at the capillary level O2 and nutrients are delivered. Co2 and water are picked up)
- Veins carry the blood back to the superior and inferior vena cava, which empty into the right atrium (reenters the heart)
- Blood from the right atrium goes to the right ventricle (through the tricuspid valve)
What does the tissue do when Oxygenated blood reaches the tissue?
- The tissue of the body ‘suck out’ the O2 from the blood. At the capillaries, the blood becomes deoxygenated
- The capillaries also deliver nutrients, and waste and CO2 are transported back
Systole
When the heart contracts to pump blood out
Diastole
When the heart relaxes after a contraction
- mnemonic: Di = double, so in the relax stage, it db the size
Pacemaker cells
cells of the heart in the sinoatrial (SA) node capable of generating their own electricity
- keeps the heart beating to the correct rhythm
- located in upper wall of the right atrium, the SA node is a group of specialized cardiac muscle cells that
initiate by contracting both atria and sending an impulse that stimulates the
AV node.
Electrical transmission
cells separated by intercalated disc
- contains gap junction
gap junction
allow ions to travel from one cell to another
Left atrium
after traveling though the lungs, oxygenated blood enters the left atrium via the pulmonary veins
Cardiac output equation?
cardiac output (CO) = Stroke volume (SV) x Heart rate (HR)
- CO: Volume of blood discharged from both ventricles each minute
- SV: volume of blood discharged from the ventricles with each contraction
- HR: number of heart contractions per minute
What is the conduction pathway within the heart?
- SA node (contracts both atria)
- Av node (signal delays slightly to allow atria to completely empty)
- Bundle of His: ( located between both ventricles
- Purkinje fiber: ( innervate the ventricle from bottom up. Both ventricles contract simultaneously)
What is the Stroke volume formula?
SV = End Diastolic volume (EDV) - End systolic volume (ESV)
- EDV: Volume of blood in the ventricle just before contraction
- ESV: Volume of blood in the ventricle at the end of contraction
blood pressure formula
blood pressure (BP) = Cardiac output (CO) x Systemic Vascular REsistane (SVR)
- BP: pressure of circulating blood against the vessels
- SVR: resistance to the flow of blood
blood vessels
Carry blood throughout the circulatory system
- Deliver oxygen and nutrients
- Transport waste products
What is the blood circulation?
- From the heart to the arteries
- Artiers to the arterioles
- Arterioles to the capillaries
- capillaries to venules
- venules to the veins which reach back to the heart
arterioles
smaller vessels branched off of arteries
- wrapped in smooth muscle
- a major influence on blood pressure (have the great resistance to flow)
- Constrict and dilate to regulate
capillaries
smallest diameter vessels branching from the arterioles
- but have the greatest total surface area and cross-sectional area
- a single layer of endothelial cells
- allows for the exchange of nutrients and wastes via diffusion
capillary exchange
occurs in capillary beds
- location of nutrient exchange
- role in controlling thermoregulation
- role in regulating blood pressure
hydrostatic pressure
the pressure of the fluid against vessel walls
- in capillaries cause fluid to flow of vessel
oncotic pressure
the pressure of blood proteins pulling fluid toward themselves
- in capillaries causes fluid to flow into the vessel
precapillary sphincter
Rings of muscle that control blood flow
- contracting and relaxing
- Allows selective blood flow
ex: can restrict blood flow when the weather is cold
Venules
- smallest vein component
- very thin and porous
- drain blood from the capillary
Adult Circulation
Goal: get blood to the lung (pick up O2, remove Co2), then to the tissue
- Right Atrium/ventricle to lungs
- lungs to left atrium/ventricle
- left atrium/ventricle to body
- body to Right Atrium/ventricle
fetal circulation
Goal: is to get blood to the placenta instead of the lung (pick up o2, remove CO2 and waste) and then to the tissue
- Lungs and liver are undeveloped, so are a lower priority to receive oxygenated blood
Placenta (fetal and maternal blood exchange) –> umbilical vein –> split into (30% ductus venosus) and (70% liver) –> right atrium/ventricle –> both bypass the lung and split into ( Ductus arteriosus and doramen ovale) –> aorta –> fetus body and the cycle restarts itself
What happens to the circulation of the fetus as it develops into an adult circulation
as fetal circulation develops into adult circulation certain structures disappear
foramen ovale
a hole in the septum between the two atria that allows blood to flow from the right to left atrium
- bypasses the lungs and right ventricle so it can go to the body tissues faster
- lungs are not fully functional yet
ductus venosus
connects the umbilical vein to the inferior vena cava
- a shunt that exits for oxygenated blood to bypass the liver in fetuses
- bypass it because its not yet fully developed
Ductus arteriosus
not all blood goes through the foramen ovale
- for the blood that does enter the pulmonary artery, that blood can bypass the lungs using the ductus arterioles
- like the foramen ovale, allows blood to bypass the lungs and heart
Blood pressure
generated by the heart pumping in a closed circulatory system
- if it falls above or below equilibrium, blood vessels will dilate or constrict
effects of high blood pressure
Can damage blood vessels and organs and negatively affect health
- the body will expand the blood vessels to allow more blood flow, which drops the BP
effects of low blood pressure
can lead to fainting inadequate blood to the organs, and fatigue
- to deal with low BP we constrict the blood vessels
Vasoconstriction
- the compression of blood vessels and increases pressure
- The smaller the diameter, the greater the resistance to blood flow
vasodilation
- the widening of blood vessels and decreases pressure
- The larger the diameter, the less resistance to blood flow
How does the kidney affect the BP
they monitor the BP and can adjust it by raising or lowering the amount of water the body urinates
- the more water that urinated out, the lower our blood volume
What is Blood?
- connective tissue
- 55% liquid called plasma: a mixture of nutrients, salts gases, wastes, hormones, and proteins (lowest density)
- 45% cellular components: red blood cells (hematocrit) and WBC (buffy coat: WBC and platelets)
erythrocytes (RBC)
Cells that carry oxygen and carbon dioxide
- most abundant cell type i blood
- Biconcave shape (give larger SA)
- lack nucleus and organelles
- Carry O2 and come CO2 throughout the body
- Transport oxygen on hemoglobin
Leukocytes (WBCs)
Immune cells that protect against pathogens
- larger then RBC and phagocytize foreign matter and organisms
- has organelles but no hemoglobin
thrombocytes (platelets)
cell fragments involved in blood clotting
- lacks nuclei and tick to damaged epithelium in order to attract more platelets
- converts fibrinogen to fibrin
hematocrit
The portion of the blood that contains WBC, and when you centrifuge blood, the layer with the red blood cells)
antibodies
recognize and bind foreign components
- located in the plasma of blood
antigens
- a substance that can produce an immune response
- if recognized as antibodies bind to antigens
- the glycoproteins on RBCs are antigens
- determines your blood type
What are the types of antigens groups?
type a
Type B
Type AB
Type O
Type A
only A antigens = Blood type A
Type B
Only B antigens
Type AB blood
both A and B antigens
Type O
no A or B antigens
agglutination
-the reaction that causes particles in a liquid to clump together
- occurs if an antigen gets surrounded by many antibodies
- For ex: if you give someone blood of the wrong type, agglutination occurs (antibodies will react with blood cells and cause them to clump together)
Rh factor
another antigen on red blood cells
- If present, a person is Rh-positive
- If absent, a person is Rh negative
True universal donor
Grou O/ Rh factor negative
True universal recipient
Group AB/ Rh factor positive
what is oxygen transportation
the concentration of oxygen changes throughout the circulatory system
- arteries carry oxygen and nutrients to the tissue
- veins carry waste and CO2 away from the tissue
hemoglobin
the molecule responsible for binding and releasing O2 where needed
- contains 4 heme groups (each contains an iron atom)
- each iron atom binds to an Oxygen molecule
- Dangerous binding: CO binds to hemoglobin at 200x higher affinity than oxygen
myoglobin
A protein found in muscle to bind oxygen
bicarbonate
- found in the plasma
- the body needs to keep pH in a specific range
- the chemistry allows for the blood to adjust to variable conditions
- EX: when there is too much Acid in the blood, acid combines with bicarbonate to form carbonic acid
-For ex, when there is too much base carbonic acid dissociates to neutralize it, forming bicarbonate - most CO2 is transported in the form of bicarbonate
Blood-brain barrier
If we consume something that is bad for us and is toxic, the BBB prevents the harmful toxin from reaching the brain.
- tight junctions act as the first barrier to prevent most substances from crossing out of the blood to the extracellular space of the bain
- the astrocytes further support this barrier by surrounding the capillary cells
- A few things can pass through: water, certain gases, small lipid-soluble molecules
blood clotting
Blood clotting is triggered by damage to blood vessel
- is a chain of events to seal the injury to stop blood loss an prevent infections
clotting cascade
- begins when an injury exposes a voken blood vessel wall to blood constituents
- exposed proteins attract platelets to the site of injury, which act as an immediate stopgap
What is the clotting cascade process?
- clotting factors cause an enzymatic cascade to convert prothrombin to thrombin
- thrombin is involved in a positive feedback loop, which results in the conversion of more prothrombin to thrombin
- fibrin reinforces that initial platelet plug by forming interwoven fibrin strands
thrombin
It is an enzyme that catalyzes the conversion of fibrinogen to fibrin.
hemophilia
A life-threatening disease that causes excessive bleeding and bruising
leeches
can be used as a form of medical treatment
- leech saliva contains anticoagulants to prevent blood clotting
- helps promote blood flow to aid in wound healing
Protozoans
unicellular animal
- rely on the movement of gas via simple diffusion within the cell
Cnidarians
body walls are 2 cells thick, so all cells are in direct contact with either internal or external environment
ex: Hydra
arthropods
open circulatory system: pumps blood into an internal cavity call the hemocoel, which bathes tissue in oxygen and nutrients containing fluid called hemolymph
- hemolymph returns to the heart through holes called ostia
Mullusks
- arthropods
- have open circulatory system except for cephalopods
- cephalopods: have a large oxygen demand, so they are closed system
annelids
including earthworms
- closed circulatory system in which blood confined to vessels
Path of circulation in closed system
Away from heart: aorta → arteries → arterioles → capillaries
Back to heart: capillaries → venules → veins
Right Atrium
chamber where deoxygenated blood enters via the superior and inferior vena cava
Right Ventricle
blood is squeezed into this chamber through the right AV (atrioventricular)/tricuspid valve, which contracts and pumps blood into the pulmonary artery via the pulmonary semilunar valve
Left ventricle
after traveling through
the left AV/mitral/bicuspid valve, blood from the left ventricle enters the aorta
through the aortic semilunar valve into the rest of the body:
AV node
located in the lower wall of
the right atrium / interatrial septa; sends impulse through the Bundle of His → passes between both ventricles → branches into ventricles via the purkinje fibers which results in contraction of both ventricles simultaneously
Ventricular Contraction
when the ventricles contract (ventricular systole
phase), blood is forced through the pulmonary arteries and aorta.
Semilunar valves
Aortic and pulmonary valves
Atrioventricular valves
Tricuspid/right AV valves and bicuspid/left AV/mitral
Blood serum
the same as plasma minus any clotting factor components
Phosphate buffer system
maintains pH of internal fluids of all cells; H2PO4- and HPO4 2- act as acid and base (amphoteric), and bicarbonate acts as an extracellular buffer!
Hemorrhage
Excessive bleeding
- results in a decrease in arterial pressure, which is sensed by arterial baroreceptors. The body wants to compensate for this reduced blood pressure, and does so by
increasing the heart rate and system vascular resistance
