Ch 9: The Circulatory, Lymphatic, and Immune Systems (Princeton Review)

Question 1

What are the very first branches from the aorta?

Answer 1

the coronary arteries

p. 331

Question 2

What is the only deoxygenated blood that does not end up in the vena cavae?

Answer 2

blood in the coronary sinus; instead, the coronary sinus drains directly into the right atrium

p. 331

Question 3

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…

Answer 3

….lower than the pressure in the great arteries.

p. 333

Question 4

What is another term for the mitral valve?

Answer 4

the bicuspid valve

Question 5

What is a syncytium?

Answer 5

a tissue in which the cytoplasm of different cells can communicate via gap junctions

p. 334

Question 6

In cardiac muscle, the gap junctions are found in the ____________ ______, the connections between cardiac muscle cells.

Answer 6

intercalated disks

p. 334

Question 7

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.

Answer 7

fast sodium
slow calcium

p. 335

Question 8

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.

Answer 8

T tubules
sarcoplasmic reticulum

p. 335

Question 9

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.

Answer 9

longer
longer

p. 335

Question 10

Is the strength of contraction by cardiac muscle affected by the extracellular concentration of calcium ions?

Answer 10

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.

Question 11

The affinity of hemoglobin for oxygen is influenced by…

Answer 11

…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)

Question 12

Over which blood vessel is the drop in blood pressure the greatest?

Answer 12

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)

Question 13

Which types of muscle are striated?
Which are not?

Answer 13

cardiac and skeletal muscle
smooth muscle is not

Question 14

What is the difference between serum and plasma?

Answer 14

They are the same EXCEPT the serum excludes the fibrinogen and other clotting factors.

Question 15

What is plasma made up of?

Answer 15

90% water
8% proteins (albumin, antibodies, fibrinogen, lipoproteins)
2% hormones, electrolytes, nutrients, glucose

[From Khan Academy video: “What’s Inside of Blood?”]

Question 16

State the Bohr effect simply.

How about more complex?

Answer 16

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.

Question 17

State the Bohr vs Haldane effect

Answer 17

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.

Question 18

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?

Answer 18

Phase 0, phase 3, and phase 4

(other cardiac myocytes have phases 1 and 2, but the SA node does not)

Question 19

Skeletal muscle cells and other myocytes depolarize because of a ___ ______, not __ like the SA node.

Answer 19

Na⁺ influx

Ca²⁺

p. 335

Question 20

Why don’t potassium leak channels cause spontaneous action potential in neurons are muscle cells?

Answer 20

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

Question 21

The cardiac muscle cells of the heart have a resting membrane potential of about ___ __, very close to the K+ equilibrium potential.

Answer 21

• 90 mV
  p. 336

Question 22

Why do cardiac muscle cells have a plateau phase (phase 2) in their membrane potential?

Answer 22

Because during this phase, the influx of Ca²⁺ ions balances the K⁺ efflux from phase 1.

p. 337

Question 23

What happens during phase 0 of the membrane potential in cardiac muscle cell?

Answer 23

fast Na+ channels open

Na+ influx

p. 337

Question 24

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.)

Answer 24

Na+ channels inactivate

K+ channels open

K+ efflux

p. 337

Question 25

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.)

Answer 25

Ca²⁺ channels open

Ca²⁺ influx

K⁺ channels still open

K⁺ efflux

Question 26

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.)

Answer 26

Ca²⁺ channels close

K⁺ channels still open

K⁺ efflux

Question 27

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.)

Answer 27

K+ channels close

Question 28

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.

Answer 28

contracts first

p. 338

Question 29

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.

Answer 29

rate of contraction

inhibits depolarization

p. 339

Question 30

The vagus nerve contains preganglionic axons which synapse in ganglia near the SA node. The postganglionic neurons innervate the SA node releasing __________.

Answer 30

acetylcholine

Question 31

The sympathetic nervous system affects the heart in what 2 ways?

Answer 31

1. Sympathetic postganglionic neurons directly innervate the heart, releasing norepinephrine.
2. Epinephrine secreted by the adrenal medulla minds to receptors on cardiac muscles cells.

p. 339

Question 32

State Ohm’s law as it pertains to hemodynamics.

Answer 32

ΔP = Q x R

ΔP is the pressure gradient, Q is blood flow (a.k.a. cardiac output), and R is resistance

p. 339

Question 33

Blood pressure can be varied by increasing the _____ or _____ of cardiac contraction.

Answer 33

force

rate

Question 34

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.

Answer 34

dissipated

p. 341

Question 34

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.

Answer 34

dissipated

p. 341

Question 35

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.

Answer 35

exert pressure

driving force

p. 342

Question 36

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.

Answer 36

local autoregulation

coronary

p. 342

Question 37

Large veins do have ______ ______, although much less than arteries, and can constrict in response to sympathetic stimulation.

Answer 37

smooth muscle

p. 342

Question 38

What is the purpose of lipoproteins in the blood?

Answer 38

To transport lipids in the bloodstream.

p. 343

Question 39

What is bilirubin?

Answer 39

A breakdown product of heme (the oxygen-binding component of hemoglobin).

Question 40

What does erythropoietin do?

Answer 40

It stimulates RBC production in the bone marrow.

Question 41

Since red blood cells lack mitochondria, what do they rely on for ATP synthesis?

Answer 41

glycolysis

Question 42

The ABO blood group consists of glycoproteins that are coded for by 3 different alleles:

Answer 42

• I^A, I^B,* and i
  p. 344

Question 43

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-.

Answer 43

dominant

expression

p. 344

Question 44

What is unique about the production of antibodies to the A and B blood antigens?

Answer 44

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).

Question 45

In contrast to A and B antibodies, antibodies to the Rh antigen do not develop unless…

Answer 45

…a person with Rh- blood is exposed to Rh+ blood.

p. 344

Question 46

hemolytic disease of the newborn is also known as…

Answer 46

….erythroblastosis fetalis.

p. 345

Question 47

Which antibodies do blood type AB+ individuals make against other blood group antigens?

Answer 47

None, since their red blood cells possess all three of the antigens. They are the “universal recipients”.

p. 345

Question 48

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.

Answer 48

anti-A and anti-B

p. 345

Question 49

Name of the three main categories of leukocytes.

What are all 6 subtypes and where do they fall?

Answer 49

Monocytes, lymphocytes, granulocytes

Monocytes → macrophages

Lymphocytes → B and T cells

Granulocytes → basophils, eosinophils, neutrophils

p. 346

Question 50

Platelet have no ______, and are derived from the fragmentation of ________.

Answer 50

nuclei

megakaryocytes

p. 346

Question 51

In the United States, the most common blood type is ___, and the least common is ___

Answer 51

O+

AB-

Question 52

Why is oxygen unable to dissolve in the plasma in significant quantities?

Answer 52

It is too hydrophobic. 

Question 53

When hemoglobin assumes a tense conformation it has a _____ affinity for oxygen.

Answer 53

low

Question 54

Which factors stabilize the tense configuration of hemoglobin?

Answer 54

1. Decreased pH 2. Increased PCO2 3. Increased temperature

Question 55

What is the beautiful truth of the Bohr effect and how does it relate to exercise?

Answer 55

Hemoglobin is most ready to release its load of oxygen in regions of the body where oxygen is most needed. 

Question 56

What is interesting and necessary about fetal hemoglobin that is different from adult hemoglobin?

Answer 56

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.

Question 57

What percent of carbon dioxide is transported by the conversion of CO2 to carbonic acid?

Answer 57

73% Carbonic acid, bicarbonate, and hydrogen ions are extremely water soluble and easily carried in the blood

Question 58

Does CO2 bind to the oxygen-binding sites on hemoglobin?

Answer 58

No, it binds to other sites on the protein.

Question 59

Approximately _% of carbon dioxide is transported by directly dissolving in the blood. This is possible because CO2 is more water soluble than O2.

Answer 59

7%

Question 60

What does the hepatic portal vein connect?

Answer 60

Two capillary beds: the one in the intestinal wall and the one inside the liver p. 349

Question 61

Why do you see localized swelling in states of inflammation?

Answer 61

Inflammation causes capillaries to dilate, increasing the size of the intercellular clefts. 

Question 62

Which two of the six types of white blood cells can squeeze through the intercellular clefts? 

Answer 62

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. 

Question 63

The lymphatic vessels have _______, and the larger lymphatic ducts have ______ muscles in their walls.

Answer 63

valves

smooth

p. 351

Question 64

Where does the thoracic duct empty into the venous system?

Answer 64

At the junction of the L IJ and L subclavian veins

Question 65

Lymphatic vessels from the intestines dump dietary fats in the form of __________ into the thoracic duct.

Answer 65

chylomicrons

Question 66

Which bodily fluids contain lysozyme, the enzyme that can kill some bacteria by destroying their cell walls?

Answer 66

tears, saliva, blood

Question 67

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).

Answer 67

innate

humoral

Question 68

The __________ system is a group of about 20 blood proteins that can nonspecifically bind to the surface of foreign cells, leading to their destruction.

Answer 68

complement

p. 352

Question 69

Each antibody molecule is composed of _ copies of _ different polypeptides, the light chains and the heavy chains, joined by ________ bonds.

Answer 69

2

2

disulfide

p. 352

Question 70

There are several different class of immunoglobulins, differentiated by their _______ regions.

The 5 classes are:

Answer 70

constant

IgG, IgA, IgM, IgE, IgD

(remember GAMED)

Question 71

IgE is located in the _____ and is involved in ________ ________.

Answer 71

blood

allergic reactions

p. 353

Question 72

IgA has a _______ structure, and found in __________. (examples?)

Answer 72

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

Question 73

B-cells attack invaders _______ the cells, while T-cells attack invaders ______ the cells.

Answer 73

outside

inside

Question 74

The cell-mediated response is mediated by _______, and acts on cells that are infected by invaders.

Answer 74

T-cells

Question 75

Which two immunoglobins can be found on the B cell surface and serve as antigen receptors?

Answer 75

IgM and IgD

Question 76

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)

Answer 76

IgM

(remember M is for morph, as in it changes structure)

Question 77

Which antibody accounts for the majority of antibody in the blood and can also cross the placental barrier?

Answer 77

IgG

Question 78

Each antibody forms a unique variable region that has a different _______ _________.

Answer 78

binding specificity

p. 353

Question 79

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 _______.

Answer 79

epitope

Question 80

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?

Answer 80

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

Question 81

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 ______.

Answer 81

carrier

hapten

p. 354

Question 82

The 2 types of B cells are ______ _____ and ______ cells.

Answer 82

plasma cells and memory cells

Question 83

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.

Answer 83

immature

differentiate

p. 354

Question 84

Do all cells of the immune system possess the same copy of the genome?

Answer 84

No, recombination during development makes B and T cells an exception to the rule.

p. 354

Question 85

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.

Answer 85

clone

single

p. 354

Question 86

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”.

Answer 86

week

primary immune response

p. 355

Question 87

Does the failure of vaccination to protect against some viruses indicate a failure in the ability to produce memory cells?

Answer 87

No, it’s likely a result of mutation by the virus so that the antigen is not recognized by the immune system.

p. 355

Question 88

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.

Answer 88

CD4 cells and CD8 cells

helper

killer

cytotoxic

p. 355

Question 89

The T helper cell acts as a central controller of the immune system. What does this role entail?

Answer 89

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

Question 90

What does CD stand for (as in CD4 cell)?

Answer 90

cell differentiation

p. 355

Question 91

T cells are also specific for a particular antigen. Do T cells release antibodies that bind to the antigen?

Answer 91

No, only B cells make antibodies. A T helper cell will activate B cells or T killer cells to destroy the antigen.

p. 355

Question 92

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.

Answer 92

MHC

MHC I

p. 355

Question 93

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….

Answer 93

….become activated and proliferate.

p. 355

Question 94

What does the suffix -kine mean?

Answer 94

to move or activate

p. 355

Question 95

Which proteins prevent viral replication and dispersion and are produced by cells that have already been infected by a virus?

Answer 95

interferons

Question 96

Antigen-presenting cells include what 3 kinds of cells?

What is unique about these cells?

Answer 96

macrophages, dendritic cells, and B cells

They have MHC II proteins.

p. 356

Question 97

All nucleated cells have MHC I proteins on their surface. Which are the non-nucleated cells and do they have MHC I proteins?

Answer 97

RBCs and platelets are non-nucleated. RBCs do NOT have MHC I, but platelets DO.

Question 98

Name some of the gut-associated lymphoid tissues in the body.

Answer 98

tonsils, adenoids, appendix, and Peyer’s patches in the small intestine, and the many lymph nodes along the GI tract

Question 99

Why do lymph nodes swell during acute infection?

Answer 99

proliferation and recruitment of lymphocytes

(MCAT Self-Prep cards)

Question 100

Lymph coming from the liver is high in proteins, while lymph coming from the small intestine is high in ______.

Answer 100

fat

Question 101

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.

Answer 101

decrease

Question 102

Lymph from what portions of the body are drained by the right lymphatic duct?

Answer 102

the right upper extremity and right side of the face and neck

Question 103

While movement of fluid into lymphatic capillaries does depend on the body’s hydrostatic pressure, the lymphatic system does not ________ ________ blood pressure

Answer 103

directly regulate

Question 104

Why can’t fat just be directly absorbed from the GI tract into the bloodstream?

Answer 104

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.

Question 105

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.

Answer 105

activation

Question 106

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.

Answer 106

apotosis

anergic

autoimmune

p. 357

Question 107

Elimination of self-reactive lymphocytes is referred to as “_________ _________”.

Answer 107

developing tolerance

Question 108

The mechanism of cell destruction by killer T cells does NOT involve __________.

Answer 108

antibodies

Question 109

Antibodies can mark an antigen for destruction by __________ and other __________.

Answer 109

macrophages

phagocytes

p. 365

Question 110

DiGeorge syndrome is also known as ______ _______. These individuals are more susceptible to infection.

Answer 110

thymic aplasia

p. 365