Review Questions Flashcards
(216 cards)
1
Q
How does blood help regulate body temperature and fluid levels in the body?
A
-absorbing heat from body cells, especially muscle, as it passes through vessels in body tissues. Heat is released from the blood at the body surface as itpasses through vessels in the skin.
- helps maintain fluid balance as water is added to it from the gastrointestinal tract to replace the fluid lost in urine, sweat and respired air. A constant exchange of fluid occurs between blood plasma in capillaries and interstitial fluid surrounding
cells in body tissues.
2
Q
What are the three components visible in a centrifuged blood sample?
A
(from bottom to top)
erythrocytes, buffy coat, and plasma
3
Q
How does hematocrit vary among adults, and how may dehydration affect hematocrit?
A
Individuals with higher levels of testosterone (typically, males) tend to have higher
hematocrit ranges of 42-56%, whereas individuals with lower levels of testosterone
(typically, females) tend to have lower hematocrits (range from 38-46%). A dehydrated
individual will have a higher percentage of erythrocytes compared to plasma, so that person
will have a higher hematocrit than when that same individual is well hydrated.
4
Q
What is the precursor cell for all formed elements and what are the 2 lines of development? What
mature formed elements are derived from each?
A
Hemocytoblasts give rise to two different lines for blood cell development: 1) the myeloid line that
forms erythrocytes, all leukocytes except lymphocytes (this means that they form granulocytes
and monocytes), and megakaryocytes (cells that produce platelets), and 2) the lymphoid line
(cells that produce only lymphocytes).
5
Q
What is the main function of an erythrocyte, and in what ways is an erythrocyte designed to
efficiently carry out its function?
A
to transport oxygen and carbon dioxide between the tissues
and the lungs.
They are designed to carry out this function efficiently by
1) being small and
flexible, and having a biconcave disc shape (and thus they stack to pass through the smallestblood vessels) and
2) lacking a nucleus and organelles, and being filled with hemoglobin
molecules (optimized to more efficiently transport respiratory gases).
6
Q
What are the structural differences between type A+ blood and type B- blood?
A
Type A+ blood has both the surface antigen A (type A) and the surface antigen D (type Rh+) on the
surface of erythrocytes. Type B- has only the surface antigen B (type B) on the surface of
erythrocytes.
7
Q
What type of leukocyte may increase in number if you develop “strep throat” (an acute infection
of the throat by Streptococcus bacteria)?
A
Neutrophils
8
Q
What is the general function of platelets, and what is their life span?
A
- aid in hemostasis
- 8 to 10 days
9
Q
What occurs during a vascular spasm, and how long does this phase last?
A
During a vascular spasm a blood vessel constricts suddenly and, in so doing, limits the amount of
blood that can leak from the damaged vessel. The vascular spasm phase usually lasts from a few
to many minutes.
10
Q
In what ways do the intrinsic and extrinsic pathways of the clotting cascade differ?
A
The intrinsic pathway is initiated by damage to the inside of the vessel wall and is initiated by
platelets. This pathway typically takes approximately 3 to 6 minutes. In contrast, the extrinsic
pathway is initiated by damage to the tissue that is outside of the vessel, and this pathway
usually takes approximately 15 seconds.
11
Q
What is fibrinolysis, and what is its purpose?
A
The degradation of fibrin strands in a clot by plasmin, resulting in the destruction of
the fibrin framework of the clot. Thus, fibrinolysis helps break down a clot when it is no longer
needed.
12
Q
What type of leukocyte increases during allergic reactions and parasitic work infections?
A
Eosinophil
13
Q
Which cell type forms platelets in red bone marrow?
A
Megakaryocyte
14
Q
Which of the following is NOT a function of blood?
a. Prevention of fluid loss
b. Transport of nutrients and waste
c. Maintenance of constant pH levels
d. Production of hormones
A
D. blood does not produce hormones
15
Q
A person with blood type A has what type of antibodies in their blood plasma?
A
Anti-B antibodies
16
Q
Oxygen attaches to which ion in hemoglobin?
a. Calcium
b. Sodium
c. Iron
d. Potassium
A
Oxygen attaches to Iron ions
17
Q
During the recycling of components following the normal destruction of erythrocytes, globin is
broken down. What happens to these components of globin?
a. They are used to synthesize new proteins
b. They are stored as iron in the liver
c. They are eliminated from the body in the bile
d. They are removed in urine
A
a. They are used to synthesize new proteins
18
Q
The extrinsic pathway of coagulation is initiated by which of the following?
a. Platelets
b. Fibrinogen
c. Factor VIII
d. Damage to tissue
A
d. Damage to tissue
19
Q
When blood is centrifuged, a thin, whitish-grey layer called the buffy coat covers the packed
erythrocytes. What are the components of the buffy coat?
A
Leukocytes and Platelets
20
Q
What are the anatomic characteristics of each type of leukocyte? How can you tell these
leukocytes apart when you view a blood smear with light microscopy?
A
- Neutrophils have a multilobed nucleus (as many as five lobes) and cytosol with pale-colored
granules.
-Lymphocytes have a round nucleus that fills the cell; the nucleus is darkly stained and
surrounded by a thin rim of cytosol.
These four leukocytes are about one and a half times the
diameter of an erythrocyte.
-Monocytes have a kidney-bean shaped or C-shaped pale-staining
nucleus with abundant cytosol. They are almost three times the diameter of an erythrocyte.
-Eosinophils have a bilobed nucleus and cytosol with pink-orange to reddish
granules.
-Basophils have a bilobed nucleus and cytosol with deep-purple granules.
21
Q
How do the functions of basophils differ from those of lymphocytes?
A
Basophils are involved in the release of histamine and heparin during anti-inflammatory or allergic reactions.
Lymphocytes attack pathogens, destroy cancer cells, coordinate
immune cell activity, and produce antibodies.
22
Q
Describe the 3 main phases of hemostasis and list the major events of each phase.
A
1) vascular spasm, 2) platelet plug formation, and 3) coagulation.
1)The vascular spasm involves constriction of the damaged blood vessel, limiting blood loss.
2)Platelet plug formation begins with adhesion of platelets to exposed collagen fibers at the site of
the damage, forming the initial plug in the vessel wall.
3)The subsequent coagulation phase is characterized by the production of an insoluble fibrin mesh, formed from plasma fibrinogen and
numerous formed elements within the blood and ultimately yielding a blood clot.
23
Q
Define perfusion. Why would it be significant if the cardiovascular system failed to maintain
adequate perfusion?
A
Perfusion is the amount of blood delivered to a body tissue, which is typically expressed in
milliliters per minute per gram (mL/min/g). If the cardiovascular system fails to maintain
adequate perfusion tissues will be deprived of needed oxygen and nutrients, waste products
accumulate, and cell death may occur.
24
Q
What generalization can be made about all arteries? What generalization can be made about all
veins?
A
Arteries always transport blood
away from the heart. In comparison, veins always transport blood toward the heart.
25
Sketch a heart and label the structures (chambers, great vessels, and valves) that are associated
with the right side and left side of the heart.
The free version doesn't let me add pictures lol
Left AV Valve = Mitral/Bicupside Valve
Right AV Valve = Tricupsid Valve
Aortic Semilunar Valve = b/w LV and Aorta
Pulmonary Semilunar VAlve = b/w RV and Pulmonary Trunk
26
What path does blood follow through the heart and through the two circulations? Identify all
structures that it passes through, including each chamber, valve, and great vessel. Begin at the
right atrium
Deoxygenated blood returning from the systemic circulation
1) enters the right atrium from the
superior vena cava, the inferior vena cava, and the coronary sinus. This blood is now in the
pulmonary circulation. It flows through the
2) right AV valve into the
3) right ventricle. The blood then passes through the
4) pulmonary semilunar valve and enters into the
5) pulmonary trunk and then into the 6) pulmonary arteries that go to both lungs. In the lungs the blood enters the
7) pulmonary capillaries for gas exchange. This blood is now oxygenated
and returns to the heart through the 8) right and left pulmonary veins. This oxygenated blood
enters the
9) left atrium and is now in the systemic circulation. It then passes through the
10) left AV valve into the
11) left ventricle. The blood then passes through the
12) aortic semilunar valve and enters the
13) aorta. Blood is then distributed throughout the body
by the
14) systemic arteries and eventually enters the
15) systemic capillaries.Deoxygenated
blood leaves the systemic capillaries and ultimately drains into the
16) superior vena cava,
inferior vena cava, and coronary sinus before re-entering the right atrium
27
Which of the great vessels is an artery and transports deoxygenated blood? Which of the great
vessels is a vein and transports oxygenated blood?
pulmonary trunk; pulmonary veins
28
What is the bony structure that protects both the heart and the lungs?
the thoracic cage (ribs, sternum, vertebrae)
29
Where is the heart positioned, and how is it oriented within the thoracic cavity?
Within the thoracic cavity posterior to the sternum and anterior to the
thoracic vertebrae within the mediastinum with the heart slightly to the left of the midline. The
heart is oriented within the thoracic cavity with the base positioned superiorly to the apex,
which projects inferiorly to the left side.
30
Describe the three layers that cover the heart. Where is the pericardial cavity relative to these
layers?
The pericardium is composed of three layers:
1) an outer fibrous pericardium (tough, dense
irregular connective tissue enclosing the heart but not attached to it; rather, it is attached
inferiorly to the diaphragm and superiorly to the base of the great arterial trunks);
2) the parietal layer of the serous pericardium (a simple squamous epithelium and an underlying delicate layer
of areolar connective tissue) that adheres to the inner surface of the fibrous pericardium; and
3) the visceral layer of the serous pericardium (composed of a simple squamous epithelium and an
underlying delicate layer of areolar connective tissue) that directly adheres directly to the heart.
(Note that the serous pericardium is also called the epicardium.)
31
What are the layers of the heart (in order) that a scalpel would pass through during dissection?
What are the two names given to the outer layer of the heart wall?
1) the epicardium, 2) the myocardium, and 3) the
endocardium. The outer layer of the heart wall is called either the epicardium or visceral
pericardium
32
How are the papillary muscles, tendinous cords, and atrioventricular valve positioned relative to
one another?
Papillary muscles are anchored to the internal wall of a ventricle. Tendinous cords are attached to
the free end of the papillary muscles on one end and to the free end of an AV valve on the other
end. Thus, tendinous cords extend between the papillary muscles and an AV valve. These
structures are located within both the right ventricle and left ventricle.
33
What are the functions of the tendinous cords and papillary muscles?
The tendinous cords (or chordae tendineae) are thin strands of collagen fibers that extend
between the papillary muscles and the cusps of the atrioventricular valves. They function to
prevent the valve from prolapsing (inverting and flipping into the atrium) when the ventricle is
contracting. Thus, blood flow back into the atrium from the ventricle is prevented
34
What areas of the heart are deprived of blood when there is a blockage in the posterior
interventricular artery?
The posterior surfaces of the right and left ventricles
35
What is the function of the coronary sinus?
receives deoxygenated blood from the myocardium that has drained into several cardiac veins (the great cardiac vein, middle cardiac vein, and small cardiac vein). It
then returns this deoxygenated blood directly into the right atrium of the heart.
36
Why is the SA node referred to as the pacemaker?
The cells of the sinoatrial node initiate the heartbeat
37
Which autonomic division is associated with the cardioacceleratory center in the brainstem, and
how does it affect heart activity?
The cardioacceleratory center is the origin of sympathetic innervation for the heart. Stimulation
by the sympathetic division increases both heart rate and the force of heart contraction. There is
also some sympathetic innervation to the coronary arteries, causing dilation of these vessels to
support increased blood flow to the myocardium.
38
What is the resting membrane potential (RMP) value of nodal cells?
–60 mV
39
What is autorhythmicity? Describe how nodal cells function as autorhythmic cells to serve as the pacemaker of the heart.
Autorhythmicity refers to the ability of the SA nodal cells to depolarize and generate an action
potential spontaneously without any external influence.
This process involves three steps.
1) Reaching threshold: an initial influx of Na+ into the cell through slow voltage-gated Na+ channels
that open in response to repolarization from the previous action potential. The cell membrane
potential changes from –60 mV to its threshold of –40mV.
2) Depolarization: changing of
membrane potential triggers the opening of fast voltage-gated Ca2+ channels. This allows Ca2+
entry into the nodal cell, causing a change in membrane potential from -40 mV to a slightly
positive membrane potential (just above 0 mV). This reversal in polarity is the depolarization.
3) Repolarization: calcium channels close and voltage-gated K+ channels open, allowing K+ to flow
out to change the membrane potential from a positive value (just above 0 mV) to -60 mV (the
resting membrane potential) and once again triggering the opening of slow voltage-gated Na+
channels
40
What is the path of an action potential through the conduction system of the heart?
1) The action potential is generated in the sinoatrial node and spreads via gap junctions betweencardiac muscle cells throughout the atria to the atrioventricular (AV) node.
2) The action potentialis delayed at the AV node before it passes to the AV bundle within the interventricular septum.
3)The AV bundle conducts the action potential along the left and right bundle branches to the Purkinje fibers in the ventricles.
4) The action potential is spread via gap junctions between cardiac
muscle cells throughout the ventricles.
41
In which direction does Ca2+ move in response to the opening of voltage-gated Ca2+ channels: into or out of the cardiac muscle cells?
Slow voltage-gated Ca2+ channels within the sarcolemma allow calcium to enter cardiac muscle
cells.
42
What three electrical events occur at the sarcolemma of cardiac muscle cells? Explain each event.
. 1) Depolarization: fast voltage-gated Na+ channels open and Na+ rapidly enters the cell, reversing
the polarity from negative to positive (-90 mV to +30 mV).
2) Plateau: voltage-gated K+ channels
open and K+ flows out of cardiac muscle cells. Slow voltage-gated Ca2+ channels open and Ca2+
enters the cell. This results in no electrical change in the membrane potential and the depolarized
state is maintained.
3) Repolarization: voltage-gated Ca2+ channels close while voltage-gated K+
channels remain open; K+ moves out of the cardiac muscle cell and polarity is reversed from
positive to negative (+30 mV to -90 mV).
43
What is the significance of the extended refractory period in cardiac muscle?
The plateau phase of cardiac muscle cell contraction allows for a prolonged refractory period
which delays repolarization. There is an extended period of time in which the cardiac muscle cell
cannot be re-stimulated, allowing the cardiac muscle to both contract and relax before it is
stimulated again. This prevents cardiac muscle cells from developing a sustained contraction (or
tetany)
44
What events in the heart are indicated by each of the following: P wave, QRS complex, and T
wave? Identify the two segments of an ECG that reflect the plateau.
P wave - electrical changes of atrial depolarization that originates in the SA node.
QRS - electrical changes associated with ventricular depolarization. (Note
that the atria are simultaneously repolarizing; however, this repolarization signal is masked by the
greater electrical activity of the ventricles.)
T wave - the electrical change associated with
ventricular repolarization.
The two segments between the waves correspond with the plateau (where there is
essentially no electrical change in the membrane potential at the sarcolemma). During
these time periods, the sarcomeres are shortening within the cardiac muscle cells. The PQ segment is associated with the atrial plateau at the sarcolemma when the cardiac
muscle cells within the atria are contracting, and the S-T segment is the ventricular
plateau when the cardiac muscle cells within ventricles are contracting
45
What pressure changes cause the closing of the AV valves and the opening of the semilunar
valves?
Ventricular contraction causes both the AV valves to close and then the semilunar valves to open.
Ventricular contraction results in an increase in ventricular pressure during isovolumetric
contraction; this rise in pressure first closes the AV valve and then opens the semilunar valves
(which results in ventricular ejection).
46
What are the two factors that determine cardiac output?
Cardiac output is the amount of blood that is pumped by one ventricle in one minute. It is
typically expressed as liters per minute. It is determined by the product of heart rate (number of
beats per minute) times stroke volume (volume of blood ejected during one beat).
47
What is the cardiac output at rest and during exercise, and the cardiac reserve, if (a) the heart rate is 75 beats per minute and stroke volume is 70 mL at rest, and (b) if the heart rate is 150 beats per minute and stroke volume is 100 mL during exercise?
The resting cardiac output would be (75 beats/min × 70 mL/beat) = 5.25 L/min. The cardiac
output during exercise would be (150 beats/min × 100 mL/beat) = 15.0 L/min. The cardiac
reserve is the increase in cardiac output above its level at rest. In the example given here, the
cardiac reserve would be 9.75 L/min: 15.0 L/min – 5.25 L/min = 9.75 L/min.
48
Distinguish the effect of a positive chronotropic agent from that of a negative chronotropic agent on heart rate, and give examples of each
A positive chronotropic agent increases heart rate. Examples of positive chronotropic agents
include: norepinephrine released from sympathetic axons and epinephrine and norepinephrine
from the adrenal medulla (which stimulate opening of Ca2+ channels, allowing additional entry
of Ca2+ into nodal cells), nicotine (which increases release of norepinephrine from sympathetic
axons), cocaine (which decreases reuptake of norepinephrine so that it remains in the synaptic
cleft longer), and caffeine (which inhibits breakdown of cAMP so that calcium channels remain
open). A negative chronotropic agent decreases heart rate. Examples of negative chronotropic
agents include acetylcholine released from parasympathetic axons (which stimulates opening of
K+ channels, allowing efflux of K+ that hyperpolarizes the nodal cells. Also, drugs that block
the receptors (β1-receptors) for norepinephrine; these drugs are called β-blockers.
49
Which of the following increases stroke volume: (a) increased venous return, (b) increased Ca2+ in sarcoplasm, or (c) afterload? Explain
Increased venous return causes stretching of the heart walls, causing an increased preload,
which increases the force of the subsequent contraction, and therefore increases stroke
volume. (Increased calcium in the sarcoplasm increases the number of Ca2+ ions available to
bind to troponin, also increasing the force of contraction. Afterload is the resistance in
arteries to the ejection of blood by the ventricles. As arteries become narrower in diameter,
there is an increase in the resistance to pump blood into the arteries and stroke volume
decreases.)
50
If both heart rate and stroke volume increase, does cardiac output (a) stay the same, (b) increase, or (c) decrease? Thus, is the relationship between these two variables and cardiac output direct or
inverse?
Stroke volume and heart rate have a direct relationship; therefore, as both variables
increase, so does cardiac output.
51
Which of the following is the correct circulatory sequence for blood to pass through part of the
heart?
a. Right atrium - left AV valve - right ventricle - pulmonary semilunar valve
b. Right atrium - right AV valve - right ventricle - pulmonary semilunar valve
c. left atrium - right AV valve - left ventricle -aortic semilunar valve
d. left atrium - left AV valve - left ventricle - pulmonary semilunar valve
b. Right atrium - right AV valve - right ventricle - pulmonary semilunar valve
52
Where is the pericardial cavity located?
a. Between the fibrous pericardium and the parietal layer of the serous pericardium
b. Between the parietal and visceral layers of the serous pericardium
c. Between the visceral layer of the serous pericardium and the epicardium
d. Between the myocardium and the visceral layer of the serous pericardium
b. Between the parietal and visceral layers of the serous pericardium
53
How is the blood prevented from backflowing from the pulmonary trunk into the right ventricle?
a. Closing the right AV valve
b. Opening of the pulmonary semilunar valve
c. Contraction of the right atrium
d. Closing of the pulmonary semilunar valve
d. Closing of the pulmonary semilunar valve
54
What vein drains blood from the heart wall into the right atrium
a. Coronary sinus
b. Inferior vena cava
c. Pulmonary veins
d. Superior vena cava
a. Coronary sinus
55
What is the function of calcium channels in an SA nodal cell?
a. They cause depolarization
b. They ensure that excess calcium can leave the cell
c. They bring the cell quickly to its resting membrane potential
d. They sustain contraction of the cell
a. They cause depolarization
56
What structures allows action potentials to spread rapidly between cardiac muscle cells?
a. Sarcomeres
b. Intercalated discs
c. Chemical neurotransmitters
d. The fibrous skeleton
b. Intercalated discs
57
Why is it necessary to stimulate papillary muscles in the ventricle slightly earlier than the rest of
the ventricular wall myocardium?
a. To ensure rapid conduction speed of the action potential
b. To pull on the AV valve cusps to prevent backflow
c. To ensure that blood will surge toward the semilunar valves
d. To ensure coordinated contraction of the ventricular myocardium
b. To pull on the AV valve cusps to prevent backflow
58
What is preload a measure of?
a. Stretch of the heart chamber prior to contraction
b. Contraction rate in cardiac muscle
c. Reduced filling during exercise
d. Autonomic nervous stimulation of the heart
a. Stretch of the heart chamber prior to contraction
59
Which of the following occurs when the ventricles are relaxed?
a. The AV valves close
b. Blood is ejected from the aorta
c. The semilunar valves open
d. Blood from each atrium enters the ventricle
d. Blood from each atrium enters the ventricle
60
Describe and compare the differences between the pulmonary and systemic circulations.
pulmonary - carries deoxygenated blood from the right ventricle to the lungs through pulmonary arteries and then oxygenated blood through pulmonary veins back to the
left atrium
systemic - carries oxygenated blood from the left ventricle through
systemic arteries to all regions of the body, and then deoxygenated blood back to the left atrium through systemic veins
61
Compare the structure, location, and function of the parietal and visceral layers of the serous
pericardium.
The parietal layer of serous pericardium is a serous membrane (simple squamous epithelium with
underlying areolar connective tissue) that adheres to the inner surface of the fibrous pericardium,
which is itself composed of dense irregular connective tissue and encloses the heart but does not
attach to it.
The visceral layer of serous pericardium (also called the epicardium) is a serous
membrane (simple squamous epithelium with underlying areolar connective tissue) that adheres
directly to the heart. Together, both layers produce serous fluid in the pericardial cavity to reduce
friction as the heart moves during beating
62
Why are the tendinous cords required for proper functioning of the AV valves?
Tendinous cords are thin strands of collagen fibers that anchor into papillary muscles and attach
to the cusp of the atrioventricular valves to prevent these valves from prolapsing (inverting and
flipping into the atrium) when the ventricle is contracting.
63
Explain why the walls of the atria are thinner than those of the ventricles, and why the wall of the right ventricle is relatively thin when compared to the wall of the left ventricle.
The atria are thin walled because they do not need to generate high pressure to push blood into
the ventricles. Most of the filling of the ventricles is passive, and the ventricles are inferior to the
atria so moving blood into the ventricles from the atria is assisted by gravity.
The right ventricle
wall is relatively thin with respect to the left ventricle wall because the right ventricle only has
to pump blood through the pulmonary circuit to the adjacent lungs immediately lateral to the
heart, whereas the left ventricle must generate enough pressure to drive blood through the entire
systemic circuit
64
Explain the general location and function of coronary vessels.
The right and left coronary arteries are positioned within the coronary sulcus of the heart to
supply the heart wall. Branches of these coronary arteries supply specific regions of the heart
(example: anterior and posterior interventricular arteries within sulci between the ventricles).
Coronary vessels transport oxygenated blood to the wall of the heart (coronary arteries) and
deoxygenated blood away from the heart wall (coronary veins). The coronary sinus transports
deoxygenated blood from the myocardium back to the right atrium.
65
Describe the functional differences in the effects of the sympathetic and parasympathetic
divisions of the ANS on the activity of the heart
Parasympathetic innervation comes from the cardioinhibitory center within the cardiac center in
the medulla oblongata. It decreases heart rate, but generally has no direct effect on the force of
contraction.
Sympathetic innervation comes from the cardioacceleratory center within the cardiac center in the medulla oblongata. It increases heart rate and increases the force of the heart
contractions.
66
Provide an overview of the 2 events for cardiac muscle contraction that include the conduction
system and cardiac muscle cells.
Conduction system: Spontaneous depolarization of cells within the sinoatrial node initiates an
action potential that is propagated through gap junction across the cells of the left and right atria,
causing atrial systole. As the atria are contracting, the action potential stimulates the
atrioventricular node at the base of the right atrium. From here it travels along the AV bundle
and the bundle branches within the interventricular septum, and finally to the Purkinje fibers.
The slow conduction through the AV node ensures that the signal does not reach the ventricles
until atrial diastole, at which point the Purkinje fibers generate an action potential within the
myocardium of the ventricles, causing ventricular systole.
a. Cardiac muscle cells: Three electrical events occur at the sarcolemma of cardiac muscle
cells that include 1) depolarization, which is due to the opening of fast voltage-gated
Na+ channels that allows rapid entry of Na+ into the cell that reverses the polarity from
negative to positive (-90 mV to +30 mV), 2) plateau, which is due to a) the opening of
voltage-gated K+ channels that allows outflow of K+ and b) the opening of slow voltage- gated Ca2+ channels that allows inflow of Ca2+, resulting in no electrical change
(depolarized state is maintained); and 3) repolarization, which is due to the closing of
voltage-gated Ca2+ channels while voltage-gated K+ channels remain open, and this
allows continued outflow of K+ to reverse polarity from positive to negative (+30 mV to -90 mV).
b. The entry of Ca2+ into the sarcoplasm from both the interstitial fluid and SR initiates the
internal mechanical events of muscle contraction. Calcium ions now bind to troponin to
begin crossbridge cycling within a sarcomere, similar to the way in which skeletal
muscle contracts.
67
List the 5 phases of the cardiac cycle, and indicate for each if the atria are contracted or relaxed, if the ventricles are contracted or relaxed, if the AV valves are open or closed, and if the semilunar valves are open or close.
Atrial Relaxation and Ventricular Filling:
i. Atria relax / Ventricles relax, AV valves open / Semilunar valves closed
Atrial Contraction and Ventricular Filling:
ii. Atria contract / Ventricles relax, AV valves open / Semilunar valves closed
Isovolumetric Contraction:
iii. Atria relax / Ventricles contract, AV valves closed / Semilunar valves closed
Ventricular Ejection:
iv. Atria relax / Ventricles contract, AV valves closed / Semilunar valves open
Isovolumetric Relaxation:
v. Atria relax / Ventricles relax, AV valves closed / Semilunar valves closed
68
Define cardiac output, and explain how it is influenced by both heart rate and stroke volume.
Cardiac output is the amount of blood ejected from the heart in 1 minute. It is a function of
the number of times that the heart contracts per minute (heart rate) and the amount of blood
ejected with each contraction (stroke volume). Thus, CO = HR x SV
69
What are three differences in anatomic structure between arteries and veins?
Arteries compared to veins have:
1) a thick tunica media
2) a narrower lumen
3) more elastic and collagen fibers.
70
What changes are seen in the composition of the tunic wall of arteries as they branch into smaller and smaller vessels?
As arteries branch to progressively smaller vessels, their luminal diameter decreases. The
composition of the tunics also changes; their walls contain relatively less elastic fibers and
relative more smooth muscle.
71
What type of capillary is the most permeable, and where in the body are these capillaries found?
Sinusoids are the most permeable capillaries. They are located within red bone marrow as well
as the liver, spleen, anterior pituitary gland, and parathyroid glands. (A common feature is their
reddish color.)
72
Make a flowchart that lists the pathway of blood through the different types of arteries,
capillaries, and different types of veins
Elastic arteries - muscular arteries - arterioles - capillaries - venules - veins - heart
73
What is the difference between hydrostatic pressure and osmotic pressure?
Hydrostatic pressure is the physical force exerted by a fluid on a structure.
In contrast,
osmotic pressure is the “pull” of water into an area by osmosis due to the higher relative concentration of solutes.
74
How does the hydrostatic pressure change from the arterial end of a capillary to the venous end of a capillary? Do you see similar changes in colloid osmotic pressure?
Blood hydrostatic pressure is greater at the arterial end of the capillary (35 mm Hg) and less at the venous end (16 mm Hg). In contrast, the net colloid osmotic pressure remains
relatively constant (21 mm Hg) at both the arterial and venous ends of the capillary
75
Explain the myogenic response to an increase in system blood pressure.
Blood flow into a tissue remains relatively constant because of the myogenic response, which is
the contraction and relaxation of smooth muscle in response to changes in stretch. If there is an
increase in systemic blood pressure, an additional volume of blood enters the vessel resulting in
the stretching of vessel wall smooth muscle cells. In response the smooth muscle cells contract
causing vasoconstriction. Decreased size of the vessel lumen offsets the change and blood flow
into the tissue remains constant.
76
A 55-year-old female has an arterial blood pressure reading of 155/95 mm Hg. What are her pulse pressure and mean arterial pressure?
The pulse pressure is 60 mm Hg
(155 mm Hg – 95 mm Hg = 60 mm Hg).
The mean arterial pressure is 115mm Hg
(95 mm Hg + [1/3 × 60 mm Hg] = 95 + 20 =115 mm Hg.
77
How is the small pressure gradient in veins overcome?
The relatively small pressure gradient (only 20 mm Hg) of veins is overcome by the skeletal
muscle pump and the respiratory pump. The skeletal muscle pump assists the movement of
blood primarily within the limbs. Skeletal muscles there contract, which squeezes veins to help
propel the blood toward the heart. This movement is restricted to only one direction by one-way
venous valves within the veins. The respiratory pump assists movement of blood within the
thoracic cavity. During inhalation, 1) the diaphragm contracts/flattens and intra-thoracic cavity
pressure decreases, and 2) intra-abdominal pressure increases and places pressure on abdominal
cavity vessels. Blood is propelled from the vessels in the abdominopelvic cavity into the vessels
in the thoracic cavity. Exhalation reverses the pressure differences so that blood moves from
vessels in the thoracic cavity back into the heart (and allows blood to move from the vessels
within the lower limbs into the blood vessels within the abdominal cavity).
78
How is resistance defined?
The amount of friction the blood experiences as it is transported
through the blood vessels. (This friction is due to the contact between blood and the blood
vessel wall.)
79
What are the three factors that alter resistance? How does each affect blood flow in vessels?
1) blood viscosity - the resistance of a fluid to its flow. Increase in fluid viscosity causes an
increase in its resistance to flow
2) vessel length -The longer the vessel, the greater the friction the fluid experiences as it travels
through the vessel
3) vessel radius- there is an inverse relationship between the diameter of blood vessels and resistance. As vessel diameter increases, the resistance to flow decreases
80
In general, would you predict a higher blood pressure, lower blood pressure, or normal blood pressure in individuals with sustained increased resistance? Explain.
Higher.
Individuals with sustained increased resistance generally exhibit elevated arterial blood pressure
readings. This condition occurs because a greater pressure gradient must be produced to
overcome the higher resistance and ensure normal blood flow and adequate perfusion of all
tissues.
81
What is the initial change to blood pressure when you arise in the morning? Describe the
autonomic reflex to maintain your blood pressure when you arise.
As a person arises in the morning her blood pressure will initially drop, but then it will quickly
be reestablished to normal levels throughout the following mechanism: 1) Decreased stretch in
the blood vessel wall is detected by baroreceptors in aortic arch baroreceptors and carotid
sinuses.
2) The baroreceptors decrease their firing rate along the vagus and glossopharyngeal
nerves, signaling the cardiac center and vasomotor center in the medulla oblongata.
3) The cardioacceleratory center of the cardiac center increases stimulation to the SA node, AV node,
and myocardium, while at the same time the cardioinhibitory center decreases parasympathetic
stimulation to the SA and AV nodes. The resulting increase in both heart rate and stroke volume
produces a greater cardiac output.
4) Simultaneously, the vasomotor center stimulates
vasoconstriction and an increase in peripheral resistance, along with a shifting of blood from
venous reservoirs. The resulting increase in cardiac output, increase in resistance, and larger
circulating blood volume quickly elevate blood pressure
82
How is angiotensinogen activated to become angiotensin II? How does angiotensin II influence blood pressure?
The liver continuously produces an inactive protein called angiotensinogen and releases it into
the blood. Renin is an enzyme produced by the kidneys that is released into the blood when the
kidney is stimulated, either by low blood pressure or the sympathetic division. Within the
blood, renin converts angiotensinogen into angiotensin I. Angiotensin I is then converted to
angiotensin II by angiotensin-converting enzyme, which is found primarily within the
endothelium of capillaries in the lungs. Angiotensin II has several effects: it 1) raises blood
pressure by causing vasoconstriction, 2) stimulates the thirst center to cause a sensation of
thirst, and 3) induces the release of aldosterone and antidiuretic hormone. Since both of these
hormones cause fluid retention in the kidneys, they increase blood volume and therefore raise
blood pressure
83
Which of the four hormones (angiotensin II, antidiuretic hormone, aldosterone, atrial natriuretic peptide) decreases blood pressure?
Atrial natriuretic peptide
1) vasodilation, which lowers the total peripheral resistance, and
2) increases urine production, which decreases blood volume. Both responses lower
blood pressure.
84
How does blood pressure in the pulmonary circulation compare to the pressure in the systemic circulation?
Blood pressure is lower throughout the pulmonary circulation in comparison to the
systemic circulation because pulmonary vessels are shorter and the lungs are close to the
heart so the pressure to drive the blood through the circuit does not have to be as high
85
Draw the aortic arch and the three main branches that arise from it. What areas in general do these three branches serve?
The brachiocephalic
artery supplies the right upper limb and right side of the head and neck, the
left common carotid
artery supplies the left side of the head and the neck, and
the left subclavian artery supplies the
left upper limb
86
Which body regions are drained by (a) the superior vena cava and (b) the inferior vena cava?
The superior vena cava drains the head, neck, upper limbs, and thoracic and abdominal
walls. The inferior vena cava drains blood from the lower limbs, pelvis, perineum, and
abdominal structures.
87
What major arteries supply the head and neck? What primary veins drain these regions?
The major arteries that serve the head include the common carotid arteries and vertebral
arteries. These regions are then drained by the internal jugular veins, external jugular veins,
and vertebral vein
88
What is the function of the dural venous sinuses?
The dural venous sinuses drain most of the venous blood of the cranium. These are large
modified veins formed between the two layers of dura mater and they also receive excess
cerebrospinal fluid. Blood from the dural venous sinus system is drained primarily into the
internal jugular veins.
89
Does the azygos system, which receives venous blood from the thoracic and abdominal walls,
drain into the superior vena cava or the inferior vena cava?
superior vena cava
90
What are the three branches off of the celiac trunk, and which organs do these vessels supply?
1) left gastric artery - supplies blood to parts of the stomach and esophagus
2) splenic artery - supplies blood to the spleen, part of the stomach and pancreas
3) common hepatic artery - supplies blood to the liver, gallbladder, duodenum, as well as to parts of the
pancreas and stomach
91
What are the three primary veins that drain into the hepatic portal vein of the hepatic portal
system? What is the function of the hepatic portal system?
1) splenic vein
2) inferior mesenteric vein
3) superior mesenteric vein
The hepatic portal system drains blood from digestive organs and the spleen into the liver before the blood drains to the inferior vena cava
92
What arteries supply the kidneys? The adrenal glands? The female uterus?
kidneys - renal arteries
adrenal glands - renal, middle suprarenal, and inferior phrenic arteries
uterus - uterine artery
93
What are the primary superficial veins of the upper limb?
basilic, cephalic, and median cubital
veins
94
Draw a flowchart that lists the blood flow through the lower limb, beginning with the external iliac artery and ending with the digital arteries going to the toes.
External iliac artery - femoral artery - popliteal artery- anterior and posterior tibial
arteries. Posterior tibial artery - medial and lateral plantar arteries, while anterior tibial
artery - dorsalis pedis artery. Medial plantar artery & dorsalis pedis artery form the plantar
arterial arch - digital arteries
95
Which of the following is an accurate statement about capillaries?
a. Fenestrated capillaries allow for formed elements to exit the blood
b. Sinusoid capillaries are the main type of capillary in the liver and spleen
c. Capillaries often are arranged in a capillary bed that is supplied by a venule
d. The capillary wall consists of 3 tunics
b. Sinusoid capillaries are the main type of capillary in the liver and spleen
96
Which statement is accurate about veins?
a. Veins always transport deoxygenated blood
b. Veins drain into smaller vessels called venules
c. The largest tunic in a vein is the tunica externa
d. The lumen of a vein tends to be smaller than a comparable sized artery
c. The largest tunic in a vein is the tunica externa
97
Which of the following has the smallest pressure gradient that has to be overcome by contraction
of skeletal muscles and breathing
a. Artery
b. Vein
c. Capillary
d. Sinusoid
b. Vein
98
An increase in which variable will result in an increase in blood flow to an area?
a. Vessel length
b. Vessel diameter
c. Blood viscosity
d. The concentration of formed elements
b. Vessel diameter
99
Which of the following is accurate about total blood flow?
a. Total blood flow increases with a steeper pressure gradient
b. Total blood flow decreases with increased resistance
c. Total blood flow is significant in maintaining adequate perfusion of all tissues
d. All of these are correct
d. All of these are correct
100
Velocity of blood flow is slowest in which type of vessel?
a. Muscular arteries
b. Capillaries
c. Veins
d. Elastic arteries
b. Capillaries
101
List and describe the 3 tunics found in most blood vessels.
1) The innermost layer is the tunica intima. It consists of an endothelium (simple squamous epithelium)
and a subendothelial layer of areolar connective tissue.
2) The middle tunic, or tunica media, is composed predominantly of layers of smooth muscle.
3) The outermost tunic is the tunica externa and it consists primarily of areolar connective tissue containing elastic and collagen fibers.
102
Compare and contrast arteries and veins with respect to function, tunic size, lumen size and blood pressure.
Arteries transport blood away from the heart. Veins return blood to the heart. Relative to veins,
arteries have smaller luminal diameters and experience greater blood pressure. The tunica
media is the predominant layer in arteries. Without a significant layer of smooth muscle, veins
instead have a thicker tunica externa.
103
Describe the relationship between vessel radius, vessel length, blood viscosity and blood pressure to blood flow
The major way resistance to blood flow may be regulated is by altering vessel lumen
radius. The smaller the vessel radius (thus its diameter), the greater the resistance to blood
flow. As a vessel increases in length, resistance to blood flow increases. As blood
viscosity increases there is a greater resistance to its blood flow. An inverse relationship is
observed between resistance and blood flow. As resistance increases, blood flow decreases
and as resistance decreases, blood flow increases.
104
Briefly explain how changes in cardiac output, resistance, and blood volume influence blood
pressure.
Increased blood volume, increased cardiac output, and increased resistance will all raise blood
pressure.
105
Compare how the cardiac center and vasomotor center regulate blood pressure and flow.
Together the cardiac center and the vasomotor center are called the cardiovascular center. The
cardiac center is composed of both the cardioacceleratory center and the cardioinhibitory center.
Sympathetic pathways from the cardioacceleratory center extend to the SA node, AV node, and
myocardium. Increased nerve signals along these pathways cause release of norepinephrine from
the ganglionic neurons, which results in an increase in heart rate and stroke volume and this then
increases cardiac output and blood pressure. Parasympathetic pathways from the cardioinhibitory
center innervate the SA node and AV node. Increased nerve signals along these pathways cause
release of acetylcholine from the ganglionic neurons, which results in a decrease in heart rate.
The vasomotor center regulates the degree of vasoconstriction, generally through sympathetic
pathways that extend to most blood vessels of the body. The smooth muscle within the blood
vessel walls of the different vascularized tissues of the body have either alpha1 receptors (which
contract and cause vasoconstriction of the blood vessel in response to stimulation by the
sympathetic division) or beta2 receptors (which relax and cause vasodilation of the blood vessel
in response to stimulation by the sympathetic division). Consequently, there is a net increase in
blood pressure, movement of blood from venous reservoirs, and redistribution of blood flow.
(The reverse occurs when there is a decrease in stimulation by the sympathetic division.)
106
Which respiratory structure is associated with the exchange of respiratory gases?
Alveoli
107
What four structures compose the upper respiratory tract? What three structures compose the respiratory zone?
Nose, nasal cavity, pharynx and larynx
Respiratory bronchioles, alveolar ducts and alveoli
108
In what ways does the epithelium of the upper respiratory tract differ from the epithelium in the alveoli?
The epithelium lining the nasal cavity is a pseudostratified ciliated
columnar epithelium with goblet cells (that function in producing mucus), whereas the
epithelium lining the alveolar ducts and alveoli is a simple squamous epithelium.
109
What changes occur to inhaled air as it passes through the nasal cavity? What is the function of the nasal conchae in this process?
Air is warmed, cleansed, and humidified as it passes through the nasal cavity. The function of
nasal conchae is to create turbulence as the air enters the nasal cavity so that the air is more
effectively conditioned.
110
How are the paranasal sinuses connected to the nasal cavity?
Paranasal sinuses are spaces within the skull bones. Ducts connect the paranasal sinuses to the
nasal cavity.
111
What two regions of the pharynx contain tonsils? What is their purpose?
The nasopharynx contains both the lymphatic nodules called the tubal tonsils and the single pharyngeal tonsil. The oropharynx contains the paired palatine tonsils on its lateral
walls and the lingual tonsils at the base of the tongue
112
What is the function of the C-shaped tracheal cartilages? How do the trachealis muscle and elastic ligamentous membrane that complete each ring posteriorly function?
These C-shaped tracheal cartilages reinforce and provide structural support for the anterior
and lateral walls of the trachea to ensure that the trachea remains open (patent). The more
flexible trachealis muscle and ligamentous membrane on the posterior aspect of the trachea
allows for distension during swallowing of food through the esophagus. In addition, the
trachealis muscle contracts during coughing to reduce the diameter of the trachea, thus
facilitating the more rapid expulsion of air, helping to dislodge material (foreign objects or
food) from the air passageway
113
What are the significant structural differences between bronchi and bronchioles?
Bronchi have incomplete rings or plates of hyaline cartilage to support their walls and ensure
that they remain open. Unlike bronchi, bronchioles have no cartilage in their walls, because
their small diameter alone normally prevents collapse. However, bronchioles have a
proportionately thicker layer of smooth muscles than bronchi. Contraction of this smooth muscle
narrows the bronchiole diameter and decreases the amount of air passing through the bronchial
tree.
114
Which of the following respiratory structures are supported by cartilage: nose, larynx, trachea, bronchi, bronchioles, and alveolar sacs?
nose, larynx, trachea, and bronchi
115
What is the function of serous fluid within the pleural cavity?
Acts as a lubricant, ensuring the pleural surfaces slide by each other with minimal friction during breathing.
116
Why is the intrapleural pressure normally lower than intrapulmonary pressure? What is the
function of this difference in pressure?
The pressure in the pleural cavity, called the intrapleural pressure, is lower than the pressure
inside the lungs, called the intrapulmonary pressure. It occurs because of the contrasting
outward pull of the chest wall and the opposing inward pull of the lungs due to the lungs elastic
tissue. This causes a vacuum or “suction” within the pleural cavity. The greater intrapulmonary
pressure keeps the lungs inflated and prevents collapse of the lung
117
What are the general steps of pulmonary ventilation, beginning with the autonomic nuclei?
Autonomic nuclei in the brainstem stimulate the skeletal muscles involved with breathing to
rhythmically contract and relax, resulting in thoracic cavity volume changes.
Dimensional changes within the thoracic cavity during breathing result in pressure changes, establishing a changing pressure gradient between the lungs and the atmosphere.
Air moves down the pressure
gradient either to enter the lungs during inspiration or to exit the lungs during expiration.
118
Describe the sequence of events of quiet inspiration
1) The diaphragm contracts and changes from its domed position to a flattened position and
external intercostal muscles contract, elevating the ribs.
2) The vertical lateral, and anterior- posterior dimensions of the thoracic cavity increase, which collectively increases the thoracic
cavity volume. Both the pleural cavity volume increases and the lungs expand, which increases alveolar volume.
3) The intrapleural pressure decreases (with the increase in pleural cavity volume
3) the intrapulmonary pressure decreases (with the increase in alveolar
volume) from 760 mm Hg to 759 mm Hg.
4) When the intrapulmonary pressure decreases below atmospheric pressure, a pressure gradient is established and air moves down the pressure gradient from the environment into the alveoli, until the intrapulmonary pressure is once again equal to atmospheric pressure
119
How are larger amounts of air moved between the lungs and atmosphere during forced inspiration
and forced expiration? Is more energy expended during forced breathing? Why?
Forced inspiration and expiration involve steps similar to quiet breathing; however, they are
both active processes that require the recruitment of additional muscles. Their activity causes
greater changes in both the thoracic cavity volume and intrapulmonary pressure; thus, more air
moves into and out of the lungs and more energy is expended during forced breathing
120
Which of the following stimuli will cause an increase in the respiratory rate: (a) increase in blood Pco2, (b) increase in blood H+
, (c) increase in H+ within the CSF, and (d) increase in blood Po2?
increase in blood PCO2 and an increase in blood H+ (in either the blood or CSF) will increase the respiratory rate.
121
The two factors that determine airflow are the pressure gradient and resistance. What are the
major factors that increase resistance to airflow? What changes to breathing must occur to maintain adequate airflow if resistance is increased?
Resistance to airflow may be caused by
1) a decrease in elasticity of the chest wall and lungs,
2) a decrease in the bronchial diameter or the size of the passageway through which air
moves, or
3) the collapse of alveoli. In order to overcome this resistance, the muscles of inspiration must work harder, and a greater amount of the body’s metabolic energy must be
spent on breathing.
122
How do the partial pressures of oxygen and carbon dioxide in blood change during pulmonary gas exchange?
During alveolar gas exchange, oxygen will diffuse into the blood (within the pulmonary capillaries) from the alveoli until the partial pressure of oxygen reaches equilibrium at 104 mmHg. Carbon dioxide will diffuse out of the blood (within the pulmonary capillaries) into the alveoli, until the partial pressure of carbon dioxide reaches equilibrium at 40 mm Hg.
123
Which of the following would decrease pulmonary gas exchange: loss of alveoli, fluid
accumulation in the lungs, arteriole vasoconstriction, and bronchiole dilation? Explain.
1) Loss of alveoli (which decreases the surface area of the respiratory membrane)
2) fluid accumulation in the lungs (which increases the distances the respiratory gases must diffuse
across the respiratory membrane),
3) arteriole vasoconstriction (which allows less blood to enter the pulmonary capillaries)
124
How do the partial pressures of oxygen and carbon dioxide in blood change during tissue gas exchange?
During systemic gas exchange, oxygen will diffuse from the blood (within the systemic capillaries) into systemic cells until the partial pressure of oxygen reaches equilibrium at 40mm Hg. Carbon dioxide will diffuse out of the systemic cells into the blood (within the systemic capillaries) until the partial pressure of carbon dioxide reaches equilibrium at 45 mmHg.
125
Why is such a small percentage (about 2%) of oxygen dissolved in plasma and most transported on hemoglobin?
The solubility of oxygen in blood plasma is very low so only small amounts are dissolved in
plasma. Most oxygen (98%) must be transported within erythrocytes where it attaches to the iron within hemoglobin, where it is called oxyhemoglobin.
126
How is the majority of carbon dioxide transported within the blood?
approximately 70%, diffuses into erythrocytes and combines
with water to form bicarbonate ions. The bicarbonate then diffuses into the plasma where it is
transported to the lungs
127
How does oxygen movement occur during pulmonary gas exchange, gas transport, and tissue gas exchange?
1) During alveolar gas exchange, oxygen diffuses down its concentration gradient from alveoli
into the blood.
2) Over 98% of the oxygen is transported as oxyhemoglobin, bound to iron hemoglobin; less than 2% of the oxygen is transported dissolved within blood plasma.
3) During systemic gas exchange oxygen diffuses from hemoglobin into the blood and then into tissues
down its concentration gradient.
128
How does carbon dioxide movement occur during tissue gas exchange, gas transport, and
pulmonary gas exchange?
1) During systemic gas exchange carbon dioxide leaves tissue and enters the blood, down its
concentration gradient.
2) About 23% of the carbon dioxide in the blood is transported bound to
hemoglobin, as carbaminohemoglobin, while 7% of the carbon dioxide is transported dissolved in blood plasma. The majority of carbon dioxide (70%) is converted to bicarbonate (HCO3
- and transported in plasma.
3) During alveolar gas exchange, carbon dioxide is regenerated from both carbaminohemoglobin and bicarbonate; and then it enters the alveoli from blood down the
concentration gradient.
129
Does hemoglobin saturation increase or decrease during pulmonary gas exchange?
The affinity of hemoglobin for oxygen increases with increased PO2. Therefore, as the partial
pressure of oxygen in the blood increases with alveolar gas exchange, so does the oxygen saturation of hemoglobin
130
How does blood Pco2 change if an individual is hyperventilating? What happens to oxygen
delivery to the brain and why?
During hyperventilation the PCO2 decreases (hypocapnia). Systemic blood vessels throughout
the body vasoconstrict, including those vessels that deliver blood to the brain. Consequently,
less blood flow—and less oxygen-- reaches the brain
131
How do blood Po2 and Pco2 change during exercise? Explain.
During exercise blood PO2 and PCO2 levels stay relatively constant. This is because breathing depth changes to provide the additional oxygen required and to eliminate the
additional carbon dioxide waste that is produced during cellular respiration.
132
Which answer correctly orders the divisions of the lungs from largest to smallest?
a. Lobes, bronchopulmonary segments, lobules, alveoli
b. Lobes, alveoli, lobules, bronchopulmonary segments
c. Alveoli, lobules, bronchopulmonary segments, lobes
d. Lobules, bronchopulmonary segments, lobes, alveoli
a. Lobes, bronchopulmonary segments, lobules, alveoli
133
What normally prevents the lungs from collapsing?
a. The lungs are attached to the thoracic wall with parietal ligaments
b. The lungs are attached to the thoracic wall with visceral ligaments
c. The pressure in the intrapleural cavity is lower than the pressure in the intrapulmonary
space
d. The pressure in the intrapleural cavity is greater than the pressure in the intrapulmonary
space
c. The pressure in the intrapleural cavity is lower than the pressure in the intrapulmonary
space
134
Which of the following correctly represents the sequence of events associated with the thoracic
cavity to produce inspiration?
a. Muscle contraction, increase in volume, decrease in pressure
b. Decrease in pressure, increase in volume, muscle contraction
c. Muscle contraction, decrease in pressure, increase in volume
d. Increase in volume, muscle contraction, decrease in pressure
a. Muscle contraction, increase in volume, decrease in pressure
135
Which areas of the brain contain the respiratory centers?
a. Medulla oblongata and hypothalamus
b. Hypothalamus and pons
c. Medulla oblongata and pons
d. Medulla oblongata and cerebrum
c. Medulla oblongata and pons
136
The movement of oxygen from the blood into the systemic cells is referred to as what process of
inspiration?
a. Pulmonary ventilation
b. Pulmonary gas exchange
c. Tissue gas exchange
d. Gas transport
c. Tissue gas exchange
137
Which of the following statements is accurate about hemoglobin?
a. It carries oxygen on the globin
b. It carries carbon dioxide on the Fe ion
c. It carries most of the total carbon dioxide in the blood
d. It releases oxygen at the level of the cell, making hemoglobin less saturated
d. It releases oxygen at the level of the cell, making hemoglobin less saturated
138
Describe the relationship between the visceral pleura, parietal pleura, and serous fluid to keep the lungs inflated.
The visceral pleura is a serous membrane that tightly adheres to the lung surface. The parietal
pleura is a serous membrane that lines the internal thoracic wall, the lateral surface of the
mediastinum, and the superior surface of the diaphragm. The pleural cavity is a potential space
located between the visceral and parietal pleurae. The serous fluid is an oily product of the
serous membranes that acts as a lubricant, ensuring the pleural surfaces slide by each other with
minimal friction during breathing. During pulmonary ventilation, the contrasting outward pull of
the chest wall and the opposing inward pull of the lungs form a vacuum within the pleural cavity.
Consequently, the pressure generated in the pleural cavity, called the intrapleural pressure, is
lower than the pressure inside the lungs, called the intrapulmonary pressure. This difference in
pressure keeps the lungs inflated
139
List the four processes of respiration, in order, for moving oxygen from the atmosphere to the
body’s tissues.
1) pulmonary ventilation
2) alveolar gas exchange
3) gas transport in the blood
4) systemic gas exchange
140
Describe the muscles, volume changes, and pressure changes involves with quiet inspiration and expiration.
For quiet inspiration, the diaphragm and external intercostal muscles contract; this increases the
volume of the thoracic cavity with an accompanying decrease in the intrapulmonary pressure
(and intrapleural pressure), resulting in air moving into the lungs.
For quiet expiration, the diaphragm and external intercostals relax (and thoracic wall recoils); this decreases the volume of the thoracic cavity with an accompanying increase in the intrapulmonary pressure (and
intrapleural pressure), resulting in air moving out of the lungs
141
Describe how quiet breathing is controlled by the respiratory center.
Neurons in the ventral respiratory group (VRG) of the medullary respiratory center
spontaneously depolarize, initiating nerve signals for inspiration. Nerve signals are relayed via
both the phrenic nerves (to the diaphragm) and intercostal nerves (to the intercostal muscles).
Inspiratory neuron stimulation causes both the diaphragm and external intercostal muscles to
contract, resulting in an increase in thoracic cavity volume. Ultimately, inspiratory neurons are
inhibited by expiratory neurons of the ventral respiratory group and the pontine respiratory
group. Inspiratory impulses cease. Lack of nerve stimulation causes both the diaphragm and
external intercostal muscles to relax, and then thoracic cavity volume decreases. The cycle is then
repeated about 12 to 15 times per minute.
142
List the two means by which oxygen is transported in the blood and the three means by which carbon dioxide is transported.
Over 98% of the oxygen is transported as oxyhemoglobin, attached to iron within hemoglobin;
less than 2% of the oxygen is dissolved in blood plasma.
Carbon dioxide has three means of
transport: 1) 23% of the carbon dioxide in the blood is transported bound to hemoglobin, as
carbaminohemoglobin; 2) 7% of the carbon dioxide is transported dissolved in blood plasma;
and 3) the majority of carbon dioxide (nearly 70%) is converted to carbonic acid by carbonicanhydrase (this spontaneously dissociates into bicarbonate ions and H+ which are readily dissolved in the blood).
143
Describe the relationship of PO2 and hemoglobin percent saturation.
The affinity of hemoglobin for oxygen increases with increased PO2. The binding of each O2 molecule causes a conformation change in hemoglobin that makes it progressively easier for
each additional O2 molecule to bind to an available iron
144
What substances typically are absorbed from the interstitial space into lymphatic capillaries?
water, dissolved solutes, and small amounts of protein, and
sometimes foreign materials including cell debris, pathogens, and perhaps metastasized cancer
cells.
145
How does fluid enter and become “trapped” in the lymphatic capillaries?
The hydrostatic pressure of interstitial fluid separates the endothelial cells that form the lymphatic capillaries, allowing the interstitial fluid to enter the lymphatic capillary lumen. Once inside the
lymphatic capillary, the fluid exerts hydrostatic pressure on the endothelial cells, closing the gaps
and trapping the fluid (now called lymph) in the lymphatic capillary.
146
What mechanisms are used to assist lymph movement through lymph vessels?
The lymphatic system lacks a pump, and thus it relies on several mechanisms to move lymph
through its vessels:
1) contraction of nearby skeletal muscles in the limbs (skeletal muscle
pump) and the respiratory pump in the torso
2) the pulsatile movement of blood in nearby arteries, and
3) rhythmic contraction of smooth muscle in walls of larger lymph vessels (trunks and ducts).
147
Which major body regions drain lymph to the right lymphatic duct?
1) the right side of the head and neck, 2) the right upper limb
3) the right side of the thorax
148
How are primary lymphoid structures and secondary lymphoid structures differentiated? What are examples of each?
Primary lymphatic structures- bone marrow and the thymus, are involved in the formation and maturation of lymphocytes
Secondary lymphatic structures are not involved in lymphocyte formation, but instead serve to house both lymphocytes and other immune cells following their formation, and they also provide the site where an immune response is initiated.
The major secondary lymphatic structures include the lymph nodes, spleen, tonsils, lymphatic
nodules, and MALT.
149
Why is red bone marrow considered a primary lymphoid structure?
because it is the site of
production of all formed elements in the blood, including all lymphocytes, whereas secondary lymphatic structures house lymphocytes following their formation.
150
How does lymph flow through a lymph node, and how is it monitored by macrophages and
lymphocytes?
Numerous afferent lymphatic vessels will deliver lymphatic fluid to a lymph node. The “collective diameter” of the numerous afferent vessels is greater than the diameter on the single
efferent vessel, resulting in the generation of a higher fluid pressure to help force the lymph
through the node. As the materials within the fluid percolate through the sinuses located within
the medulla of the lymph node, they will be exposed to macrophages and lymphocytes. Macrophages will remove foreign particles from the lymphatic fluid. Lymphocytes may be
stimulated to initiate an immune response upon exposure to the foreign particles.
151
What are the general functions of the spleen? Indicate whether red pulp or white pulp is
responsible for each function.
The spleen filters the blood. Trabeculae from the connective tissue capsule around the spleen
extend into it to partition the spleen into white pulp (clusters of T-lymphocytes, B-lymphocytes
and macrophages) and red pulp (houses erythrocytes, platelets, macrophages and Blymphocytes) that forms cords of cells with associated sinusoids. It serves several functions: 1) phagocytosis of bacteria and other foreign materials for body defense (red pulp and white pulp)
2) phagocytosis of old, defective erythrocytes and platelets from circulating blood (red
pulp)
3) creating a blood reservoir and storage site for both erythrocytes and platelets (red pulp)
152
Which lymphoid structures filter lymph? Which filters blood?
Lymph nodes filter lymph, whereas the spleen filters blood.
153
What are the three main groups of tonsils and their function?
Pharyngeal, palatine, and lingual tonsils.
Tonsils function to help protect against foreign substances that may be either inhaled or ingested.
154
What is the function of MALT in the mucosal linings of the gastrointestinal, respiratory, urinary, and reproductive tracts?
The lymphatic cells in the MALT help defend against foreign substances that come in contact with mucosal membranes
155
Lymph is drained into the thoracic duct from which of the following body regions?
a. Right lower limb
b. Right upper limb
c. Right side of the head
d. Right side of the thorax
a. Right lower limb
156
What is the function of the thymus?
a. Site of T-cell maturation
b. Filters lymph
c. Filters blood
d. Produces formed elements in the blood
a. Site of T-Cell Maturation
157
Which statement correctly describes lymph nodes?
a. Lymph nodes do not become swollen and tender
b. Lymph nodes filter blood
c. Lymph enters lymph nodes through afferent lymphatic vessels
d. Lymphatic sinuses are located in the cortex of the lymph node only
c. Lymph enters lymph nodes through afferent lymphatic vessels
158
Which structure removes aged erythrocytes from the blood?
a. MALT
b. Lymph nodes
c. Thymus
d. Spleen
d. Spleen
159
Describe the basic anatomy of a lymph node, how lymph enters and leaves the node, and the
functions of this organ.
Lymph nodes are small, round or oval encapsulated structures located along the pathways of
lymph vessels where they serve as the main lymphatic organ. Numerous afferent lymphatic
vessels will bring lymph into a lymph node. Lymph passes through the node sinuses located in
the medulla of the lymph node and then exits through the one efferent lymphatic vessel. The
function of the node is to expose lymph to macrophages and lymphocytes within the node.
Macrophages will remove foreign particles from the lymphatic fluid. Lymphocytes will initiate
an immune response upon exposure to the foreign particles.
160
Compare and contrast the red and white pulp of the spleen with respect to the anatomy and
functions of each.
. The spleen is surrounded by a connective tissue capsule from which trabeculae extend into
the organ. It lacks a cortex and medulla, but the trabeculae subdivide the spleen into red
pulp and white pulp. The red pulp is found within sinusoids. It contains erythrocytes,
platelets, macrophages, and B-lymphocytes. These cells are housed in reticular connective
tissue and form structures called splenic cords. The red pulp serves as a blood reservoir,
including a storage site for both erythrocytes and platelets, and also removes old
erythrocytes and platelets from circulation. The white pulp consists of spherical clusters of
T-lymphocytes, B-lymphocytes, and macrophages, which surround a central artery.
Lymphatic cells within the white pulp monitor the blood for foreign materials, bacteria, and
other potentially harmful substances
161
What is the general function of the tonsils and where is each of the tonsils located?
The general function of the tonsils is to help protein against foreign substances that may
be either inhaled or ingested.
The tonsils include the pharyngeal tonsils, which located in
the posterior wall of the nasopharynx, the palatine tonsil, which are located in the
posterolateral region of the oral cavity, and the lingual tonsils, which are positioned
along the posterior one-third of the tongue.
162
Describe the location and function of diffuse lymphoid nodules and MALT.
Lymphatic nodules are small, oval clusters of lymphatic cells with some extracellular matrix
that are not completely surrounded by a connective tissue capsule. They are found within
every organ of the body and within the wall of the appendix. In some areas of the body,
many lymphatic nodules will group together to form larger structures, such as MALT.
163
List 3 factors that influence an individuals hematocrit.
age, sex, altitude
164
The type of leukocyte that is very active during a bacterial infection is a(n)
Neutrophil
165
The “buffy coat" in a centrifuged blood sample is composed of ___ and ____.
platelets and leukocytes.
166
When over 10% of the body's blood has been lost, a survival response occurs involving activation of the _________ nervous syste
sympathetic
167
During platelet plug formation, platelets begin to stick to
collagen with the assistance of von Willebrand factor.
168
The first phase of hemostasis involves
blood vessel constriction.
169
Macrophage colony-stimulating factor stimulates the production of
monocytes from monoblasts.
170
Which term best describes the function of blood when considering the presence of carbon dioxide and endocrine hormones?
Transportation
171
Platelets play a key role in _________blank, but if they are not used they are broken down after about _________blank days.
hemostasis; 9 days
172
The smallest and most abundant plasma proteins are the
albumins
173
Which type of leukocyte releases histamine?
Basophil
174
Which clotting pathway involves more steps and takes more time (approximately 5 minutes)?
Intrinsic
175
Typically, an adult's body contains _________ of blood.
5 litres
176
Leukocytes are the _________ of the formed elements, and leukocytes have _________nuclei.
largest, prominent
177
T or F: Glucose is a polar molecule, and therefore it dissolves readily in plasma.
True
178
Which leukocytes are derived from the myeloid line?
Neutrophils, basophils, eosinophils, and monocytes
179
If a patient becomes dehydrated, the percentage of plasma in a centrifuged sample of his or her blood would likely
decrease.
180
How many globins (protein building blocks) are found in a single hemoglobin molecule?
4
181
T or F: Only under certain conditions will Rh (anti-D) antibodies be present in Rh negative blood.
True
182
T or F: Rh negative blood is dependant on the ABO group.
False
183
When blood is centrifuged and its components separate, the bottom of the tube holds the ____.
erythrocytes.
184
T or F: Metabolically, cardiac muscles relies on anerobic metabolism using many mitochondria and a rich supply of myoglobin.
False. Metabolically, cardiac muscles relies on aerobic metabolism using many mitochondria and a rich supply of myoglobin.
185
List 3 descriptors of the endocardium.
a: Has single layer of epithelium
b: Has layer of areolar connective tissue
c: Epithelial cells are squamous
186
What is the function of the coronary sinus?
Take blood from the coronary circulation to the right atrium.
187
What does the serious fluid within the pericardial cavity work to do?
lubricate membranes of the pericardium.
188
What is the sequence of events in the transmission of an impulse through the heart muscle?
SA node - through the atria - AV node - AV bundle - bundle branches - purkinje fibres - through the ventricles
189
The atria are separated from the ventricles externally by the ______.
Coronary sulcus
190
Which type of muscle cell exhibits a longer refractory period? Cardiac or Skeletal.
Cardiac
191
In an ECG, the P wave is generated when the
atria depolarize
192
Pectinate muscles are found on the
internal walls of the right and left atria.
193
The papillary muscles attach to the cusps of the atrioventricular valves by means of the
tendinous cords
194
What is referred to as the decreasing of the heart rate below its inherent rhythm by parasympathetic stimulation.
vagal tone
195
Atrial contraction occurs just before ______.
isovolumic contraction.
195
The term "epicardium" is another name for the
visceral layer of the serosal pericardium.
196
The posterior interventricular artery is a branch off of the _______.
right coronary artery.
197
The base of the heart faces in the _______ and ______ directions.
posterior and superior
198
The membrane of a contractile cardiac muscle cell contains ______ pumps that move calcium ____ the cell.
calcium; out of
199
Most of the calcium that triggers contraction of cardiac muscle comes from the ________.
sarcoplasmic reticulum of the cell.
200
Which vein drains the posterior aspect of the ventricles of the heart?
Middle cardiac vein
201
If P1 and V1crepresent the initial conditions, and P2 and V2
represent the changed conditions for pressure and volume, Boyle's law would state
P1V1 = P2V2
202
The open ends of the tracheal cartilages are attached posteriorly by both the _________ and an elastic ligamentous membrane
trachealis muscle
203
T or F: During lung inflation the lungs cling to the internal surface of the chest wall as it expands.
True
204
Airflow is a function of what two factors?
Pressure gradient and resistance
205
The main function of the sympathetic innervation on the lungs is _______.
bronchodilation.
206
Control of breathing muscles originates from
both autonomic and somatic nuclei in the brain.
207
During normal quiet breathing, the _________ is inactive and exhalation is a passive event that does not require nervous stimulation.
ventral respiratory group
208
T of F: The respiratory division of the respiratory system involves the exchange of oxygen and carbon dioxide between the air and blood.
True
209
Components of the respiratory mucous membrane include all of these except smooth muscle, basement membrane, lamina propria or epithelium.
smooth muscle
210
The greatest amount of air that can be taken into, and then expelled from, the lungs in 1 minute is
maximum voluntary ventilation.
211
An antibacterial enzyme is:
Lysozyme
212
Antimicrobial proteins are:
defensins
213
Cells that produce mucous:
Goblet
214
A protein that increases mucus viscosity:
Mucins
215
