Ch 9: The Circulatory, Lymphatic, and Immune Systems (Princeton Review) Flashcards
What are the very first branches from the aorta?
the coronary arteries
p. 331
What is the only deoxygenated blood that does not end up in the vena cavae?
blood in the coronary sinus; instead, the coronary sinus drains directly into the right atrium
p. 331
At the end of systole when the ventricles stop contracting, blood begins to flow backward from the aorta into the left ventricle, but very little backflow actually occurs, because the semilunar valves slam shut when the pressure in the ventricles becomes…
….lower than the pressure in the great arteries.
p. 333
What is another term for the mitral valve?
the bicuspid valve
What is a syncytium?
a tissue in which the cytoplasm of different cells can communicate via gap junctions
p. 334
In cardiac muscle, the gap junctions are found in the ____________ ______, the connections between cardiac muscle cells.
intercalated disks
p. 334
Voltage-gated sodium channels, also called ____ ______ channels, play an important role in cardiac muscle, as in neurons, but, in addition, another type of voltage-gated channel, the ____ _______ channel, is involved in the cardiac muscle action potential.
fast sodium
slow calcium
p. 335
To maximize the entry of calcium in the cell, cardiac muscle has involutions of the membrane called _ _______. The action potentials travel down along T tubules, allow the entry of calcium from the extracellular environment, and induce the _______ _______ to release calcium.
T tubules
sarcoplasmic reticulum
p. 335
Cardiac muscle action potentials last much (longer/shorter) than neuronal or skeletal muscle action potentials, and will therefore have a (longer/shorter) absolute refractory period.
longer
longer
p. 335
Is the strength of contraction by cardiac muscle affected by the extracellular concentration of calcium ions?
Yes, a significant portion of the calcium that stimulates contraction comes from the extra cellular pool, entering the cell as part of the action potential.
The affinity of hemoglobin for oxygen is influenced by…
…temperature, carbon dioxide levels, and pH.
(from Khan Academy https://www.khanacademy.org/test-prep/mcat/biological-sciences-practice/biological-sciences-practice-tut/e/circulatory-system—passage-2?_ga=2.12146039.2119758222.1652986581-826931683.1648912754)
Over which blood vessel is the drop in blood pressure the greatest?
arterioles
(https://www.khanacademy.org/test-prep/mcat/biological-sciences-practice/biological-sciences-practice-tut/e/circulatory-system—passage-2?_ga=2.12146039.2119758222.1652986581-826931683.1648912754)
Which types of muscle are striated?
Which are not?
cardiac and skeletal muscle
smooth muscle is not
What is the difference between serum and plasma?
They are the same EXCEPT the serum excludes the fibrinogen and other clotting factors.
What is plasma made up of?
90% water
8% proteins (albumin, antibodies, fibrinogen, lipoproteins)
2% hormones, electrolytes, nutrients, glucose
[From Khan Academy video: “What’s Inside of Blood?”]
State the Bohr effect simply.
How about more complex?
CO2 and H+ affect the affinity of hemoglobin for oxygen.
Stated not simply:
The Bohr effect describes hemoglobin’s lower affinity for oxygen secondary to increases in the partial pressure of carbon dioxide and/or decreased blood pH. This lower affinity, in turn, enhances the unloading of oxygen into tissues to meet the oxygen demand of the tissue.
State the Bohr vs Haldane effect
The Bohr Effect is a decreased affinity of Hb for O2 when the concentration of CO2/H+ is high.
The Haldane Effect is a decreased affinity of Hb for CO2/H+ when the concentration of O2 is high.
The SA node exhibits automaticity and its action potential is commonly divided into 3 separate phases. Name them.
Why is this different from other cardiac myocytes?
Phase 0, phase 3, and phase 4
(other cardiac myocytes have phases 1 and 2, but the SA node does not)
Skeletal muscle cells and other myocytes depolarize because of a ___ ______, not __ like the SA node.
Na+ influx
Ca2+
p. 335
Why don’t potassium leak channels cause spontaneous action potential in neurons are muscle cells?
Potassium leak channels allow potassium to leave the cell, down a gradient, polarizing the membrane.
In contrast, sodium is at a higher concentration outside of the cell, so sodium leak channels allow sodium to enter the cell and depolarize the membrane.
p. 336
The cardiac muscle cells of the heart have a resting membrane potential of about ___ __, very close to the K+ equilibrium potential.
- 90 mV
p. 336
Why do cardiac muscle cells have a plateau phase (phase 2) in their membrane potential?
Because during this phase, the influx of Ca2+ ions balances the K+ efflux from phase 1.
p. 337
What happens during phase 0 of the membrane potential in cardiac muscle cell?
fast Na+ channels open
Na+ influx
p. 337
What happens during phase 1 of the membrane potential in cardiac muscle cell?
(Note: all ion movement is through voltage-gated channels; all channels open and close at the beginning of the phase.)
Na+ channels inactivate
K+ channels open
K+ efflux
p. 337
What happens during phase 2 of the membrane potential in cardiac muscle cell?
(Note: all ion movement is through voltage-gated channels; all channels open and close at the beginning of the phase.)
Ca2+ channels open
Ca2+ influx
K+ channels still open
K+ efflux
What happens during phase 3 of the membrane potential in cardiac muscle cell?
(Note: all ion movement is through voltage-gated channels; all channels open and close at the beginning of the phase.)
Ca2+ channels close
K+ channels still open
K+ efflux
What happens during phase 4 of the membrane potential in cardiac muscle cell?
(Note: all ion movement is through voltage-gated channels; all channels open and close at the beginning of the phase.)
K+ channels close
Since the Purkinje fibers spread over the inferior portion of the ventricles (paradoxically called the apex of the heart), the result is that this region of the ventricles ________ _____, and blood is pushed toward the superior region of the heart.
contracts first
p. 338
The autonomic nervous system does not initiate action potentials in the heart, but it does regulate the _____ of ______. The intrinsic firing rate of the SA node is about 120 bpm. The reason the normal heart rate is only 60 to 80 bpm is that the parasympathetic nervous system continually ______ ________ of the SA node.
rate of contraction
inhibits depolarization
p. 339
The vagus nerve contains preganglionic axons which synapse in ganglia near the SA node. The postganglionic neurons innervate the SA node releasing __________.
acetylcholine
The sympathetic nervous system affects the heart in what 2 ways?
- Sympathetic postganglionic neurons directly innervate the heart, releasing norepinephrine.
- Epinephrine secreted by the adrenal medulla minds to receptors on cardiac muscles cells.
p. 339
State Ohm’s law as it pertains to hemodynamics.
ΔP = Q x R
ΔP is the pressure gradient, Q is blood flow (a.k.a. cardiac output), and R is resistance
p. 339
Blood pressure can be varied by increasing the _____ or _____ of cardiac contraction.
force
rate
The highest pressures in the circulatory system are achieved in the left ventricle, aorta, and other large arteries. Every large artery branches, giving rise to many small arterioles, and then to many capillaries. The result of all this branching is that the pressure generated by the heart is _______ throughout the system.
dissipated
p. 341
The highest pressures in the circulatory system are achieved in the left ventricle, aorta, and other large arteries. Every large artery branches, giving rise to many small arterioles, and then to many capillaries. The result of all this branching is that the pressure generated by the heart is _______ throughout the system.
dissipated
p. 341
When the heart contracts, the arteries distend like balloons. During diastole, the arteries _____ ________ on the blood, just as an inflated balloon exerts pressure on the air it contains. This maintains diastolic pressure, which is important because it provides a continued _______ _____ for blood.
exert pressure
driving force
p. 342
The nervous system does not control blood flow to every single region of the body. Instead, tissues in need of extra blood flow are able to requisition it themselves. This phenomenon is known as _____ ___________. This mechanism is the principal determinant of _____ blood flow.
local autoregulation
coronary
p. 342
Large veins do have ______ ______, although much less than arteries, and can constrict in response to sympathetic stimulation.
smooth muscle
p. 342
What is the purpose of lipoproteins in the blood?
To transport lipids in the bloodstream.
p. 343
What is bilirubin?
A breakdown product of heme (the oxygen-binding component of hemoglobin).
What does erythropoietin do?
It stimulates RBC production in the bone marrow.
Since red blood cells lack mitochondria, what do they rely on for ATP synthesis?
glycolysis
The ABO blood group consists of glycoproteins that are coded for by 3 different alleles:
- IA, IB,* and i
p. 344
Expression of the rhesus (Rh) factor follows a classically ________ pattern. RR and Rr genotypes lead to the __________ of the protein on the surface of RBCs (meaning the patient is Rh+), and the rr genotype means the patient will be Rh-.
dominant
expression
p. 344
What is unique about the production of antibodies to the A and B blood antigens?
They are produced without prior exposure to the antigen. Typically the immune system needs to be exposed to an antigen before it produces antibodies against it.
These antibodies are produced early in infancy and can cause clumping and destruction of red blood cells bearing the incorrect antigen (transfusion reaction).
In contrast to A and B antibodies, antibodies to the Rh antigen do not develop unless…
…a person with Rh- blood is exposed to Rh+ blood.
p. 344
hemolytic disease of the newborn is also known as…
….erythroblastosis fetalis.
p. 345
Which antibodies do blood type AB+ individuals make against other blood group antigens?
None, since their red blood cells possess all three of the antigens. They are the “universal recipients”.
p. 345
While we call people with O- blood type the universal donors, they do make _____ and _____ antibodies, which is why it’s always best to match blood types between donors and recipients when possible.
anti-A and anti-B
p. 345
Name of the three main categories of leukocytes.
What are all 6 subtypes and where do they fall?
Monocytes, lymphocytes, granulocytes
Monocytes → macrophages
Lymphocytes → B and T cells
Granulocytes → basophils, eosinophils, neutrophils
p. 346
Platelet have no ______, and are derived from the fragmentation of ________.
nuclei
megakaryocytes
p. 346
In the United States, the most common blood type is ___, and the least common is ___
O+
AB-
Why is oxygen unable to dissolve in the plasma in significant quantities?
It is too hydrophobic. 
When hemoglobin assumes a tense conformation it has a _____ affinity for oxygen.
low
Which factors stabilize the tense configuration of hemoglobin?
- Decreased pH 2. Increased PCO2 3. Increased temperature
What is the beautiful truth of the Bohr effect and how does it relate to exercise?
Hemoglobin is most ready to release its load of oxygen in regions of the body where oxygen is most needed. 
What is interesting and necessary about fetal hemoglobin that is different from adult hemoglobin?
The fetus must be able to steal oxygen away from the mother’s blood, as a result the oxygen dissociation curve for fetal hemoglobin is left-shifted relative to the curve for adult hemoglobin.
What percent of carbon dioxide is transported by the conversion of CO2 to carbonic acid?
73% Carbonic acid, bicarbonate, and hydrogen ions are extremely water soluble and easily carried in the blood
Does CO2 bind to the oxygen-binding sites on hemoglobin?
No, it binds to other sites on the protein.
Approximately _% of carbon dioxide is transported by directly dissolving in the blood. This is possible because CO2 is more water soluble than O2.
7%
What does the hepatic portal vein connect?
Two capillary beds: the one in the intestinal wall and the one inside the liver p. 349
Why do you see localized swelling in states of inflammation?
Inflammation causes capillaries to dilate, increasing the size of the intercellular clefts. 
Which two of the six types of white blood cells can squeeze through the intercellular clefts? 
Neutrophils and macrophages. They can only do this because they are capable of amoeboid motility and can squeeze through. In contrast, RBCs are not capable of independent motility. 
The lymphatic vessels have _______, and the larger lymphatic ducts have ______ muscles in their walls.
valves
smooth
p. 351
Where does the thoracic duct empty into the venous system?
At the junction of the L IJ and L subclavian veins
Lymphatic vessels from the intestines dump dietary fats in the form of __________ into the thoracic duct.
chylomicrons
Which bodily fluids contain lysozyme, the enzyme that can kill some bacteria by destroying their cell walls?
tears, saliva, blood
It is important not to confuse the indiscriminate phagocytization of microorganisms (which is ______ immunity) with the highly specific phagocytization of an antigen that has been coated with antibodies (_______ immunity).
innate
humoral
The __________ system is a group of about 20 blood proteins that can nonspecifically bind to the surface of foreign cells, leading to their destruction.
complement
p. 352
Each antibody molecule is composed of _ copies of _ different polypeptides, the light chains and the heavy chains, joined by ________ bonds.
2
2
disulfide
p. 352
There are several different class of immunoglobulins, differentiated by their _______ regions.
The 5 classes are:
constant
IgG, IgA, IgM, IgE, IgD
(remember GAMED)
IgE is located in the _____ and is involved in ________ ________.
blood
allergic reactions
p. 353
IgA has a _______ structure, and found in __________. (examples?)
dimeric
secretions: saliva, mucus, tears, breastmilk
(remember it’s a di-meric structure bc di- means 2, a pair, and a mom and baby are a pair)
p. 353
B-cells attack invaders _______ the cells, while T-cells attack invaders ______ the cells.
outside
inside
The cell-mediated response is mediated by _______, and acts on cells that are infected by invaders.
T-cells
Which two immunoglobins can be found on the B cell surface and serve as antigen receptors?
IgM and IgD
Which antibody can also be found in the blood, is involved in the initial immune response, and changes its structure based on where it is located?
(pentameric structure in the blood; monomeric structure on B cell as antigen receptor)
IgM
(remember M is for morph, as in it changes structure)
Which antibody accounts for the majority of antibody in the blood and can also cross the placental barrier?
IgG
Each antibody forms a unique variable region that has a different _______ _________.
binding specificity
p. 353
Antigens are often large molecules which have many different recognition sites for different antibodies. The small site that an antibody recognizes within a larger molecule is called an _______.
epitope
Why might an antibody that binds tightly to a small region of a protein, say 5 amino acids out of 200, have a very low affinity for the same 5 amino acids of the protein when presented as an isolated peptide?
In the intact protein the 5 amino acids assume a specific three-dimensional conformation that is recognized well by the antibody. The 5 amino acids as a small peptide likely don’t fold the same way and will probably not be recognized.
p. 353
Very small molecules often do not elicit the production of antibodies on their own but will when bound to an antigenic large molecule like a protein. The protein in this case is called a _______, and the small molecule that becomes antigenic is known as a ______.
carrier
hapten
p. 354
The 2 types of B cells are ______ _____ and ______ cells.
plasma cells and memory cells
When antigen binds to the antibody on the surface of a specific ________ B cell, that cell is stimulated to proliferate and _____________ into plasma cells and memory cells. Plasma cells actively produce and secrete antibody protein into the plasma.
immature
differentiate
p. 354
Do all cells of the immune system possess the same copy of the genome?
No, recombination during development makes B and T cells an exception to the rule.
p. 354
The mechanism that produces a specific antibody in response to antigen exposure is this:
antigen stimulates proliferation of a specific B cell _____ expressing a ______ antibody protein that recognizes that antigen.
clone
single
p. 354
The first time a person encounters an antigen during an infection, it can take a ____ or more for B cells to proliferate and secrete significant levels of antibody. This is known as the _______ ______ ________ and is too slow to prevent symptoms of the infection from occurring. In contrast, the second time a person is exposed, the secondary immune response is much swifter and stronger, so much so that the person is said to be “immune”.
week
primary immune response
p. 355
Does the failure of vaccination to protect against some viruses indicate a failure in the ability to produce memory cells?
No, it’s likely a result of mutation by the virus so that the antigen is not recognized by the immune system.
p. 355
The 2 kinds of T cells are ___ cells and ___ cells. The former is also known as T ______ cells, and the latter is also known as T ______ cells or _________ T cells.
CD4 cells and CD8 cells
helper
killer
cytotoxic
p. 355
The T helper cell acts as a central controller of the immune system. What does this role entail?
T helper cells activate B cells and T killer cells
They also release lymphokines and interleukins, which are hormones that communicate with many other cells of the immune system.
p. 355
What does CD stand for (as in CD4 cell)?
cell differentiation
p. 355
T cells are also specific for a particular antigen. Do T cells release antibodies that bind to the antigen?
No, only B cells make antibodies. A T helper cell will activate B cells or T killer cells to destroy the antigen.
p. 355
Our cells are all programmed to have ___ proteins on their surface so that the immune system can keep an eye on what is going on inside every cell. ____ _ proteins are found on the surface of every nucleated cell in the body. These proteins randomly pick up peptides from inside the cell and display them on the cell surface. This allows T cells to monitor cellular components.
MHC
MHC I
p. 355
If a T killer cell detects (by binding to) a cell infected with a virus that is displaying a piece of virus-specific protein on its MHC I, it will….
….become activated and proliferate.
p. 355
What does the suffix -kine mean?
to move or activate
p. 355
Which proteins prevent viral replication and dispersion and are produced by cells that have already been infected by a virus?
interferons
Antigen-presenting cells include what 3 kinds of cells?
What is unique about these cells?
macrophages, dendritic cells, and B cells
They have MHC II proteins.
p. 356
All nucleated cells have MHC I proteins on their surface. Which are the non-nucleated cells and do they have MHC I proteins?
RBCs and platelets are non-nucleated. RBCs do NOT have MHC I, but platelets DO.
Name some of the gut-associated lymphoid tissues in the body.
tonsils, adenoids, appendix, and Peyer’s patches in the small intestine, and the many lymph nodes along the GI tract
Why do lymph nodes swell during acute infection?
proliferation and recruitment of lymphocytes
(MCAT Self-Prep cards)
Lymph coming from the liver is high in proteins, while lymph coming from the small intestine is high in ______.
fat
Capillaries are more permeable to water than to fats, proteins, etc. Increased blood pressure does not increase protein movement across capillaries, but it does increase the amount of water that gets squeezed out. The increased amount of fluid pushed into the lymphatic vessels will _________ the concentration of proteins in the lymph.
decrease
Lymph from what portions of the body are drained by the right lymphatic duct?
the right upper extremity and right side of the face and neck
While movement of fluid into lymphatic capillaries does depend on the body’s hydrostatic pressure, the lymphatic system does not ________ ________ blood pressure
directly regulate
Why can’t fat just be directly absorbed from the GI tract into the bloodstream?
Fat chylomicrons are too large to be absorbed normally. Instead, they get picked up by the lacteals and transported through the lymphatic system and dumped into the bloodstream by one of the lymphatic ducts.
Full _________ of T cells only occurs when the T cell binds to both antigen (displayed on MHC I or II) and the MHC molecule itself.
activation
A selection process eliminates B and T cells which bind to normal cell surface proteins. These cells undergo _________. If the lymphyocyte binds a normal SOLUBLE protein, is becomes unresponsive or ________. Only those B cells whose surface receptors bind to no normal proteins during their maturation are released into circulation. If this process were perfect, however, there would be no such thing as __________ diseases.
apotosis
anergic
autoimmune
p. 357
Elimination of self-reactive lymphocytes is referred to as “_________ _________”.
developing tolerance
The mechanism of cell destruction by killer T cells does NOT involve __________.
antibodies
Antibodies can mark an antigen for destruction by __________ and other __________.
macrophages
phagocytes
p. 365
DiGeorge syndrome is also known as ______ _______. These individuals are more susceptible to infection.
thymic aplasia
p. 365
