Chapter 7: The Cardiovascular System Flashcards
1
Q
The cardiovascular system consists of a
A
1. A muscular four-chambered heart
2. Blood vessels
3. Blood
2
Q
The heart is composed of
A
Cardiac muscle and supports two different circulations:
1. The pulmonary circulation
2. The systemic circulation.
3
Q
The heart is composed of cardiac muscle and supports two different circulations:
A
1. the pulmonary circulation
2. the systemic circulation
4
Q
Each side of the heart consists of an
A
- Atrium
and aa
- Ventricle
5
Q
The atria are separated from the ventricles by the
A
atrioventricular valves (tricuspid on the right, bicuspid [mitral] on the left).
6
Q
The ventricles are separated from the vasculature by the
A
semilunar valves (pulmonary on the right, aortic on the left).
7
Q
The pathway of blood is:
A
picture:
Right atrium
tricuspid valve
right ventricle
pulmonary valve
pulmonary artery
lung
pulmonary veins
left atrium
mitral valve
left ventricle
aorta valve
aorta
arteries
arterioles
capillaries
venules
veins
venae cava
right atrium
8
Q
The left side of the heart contains
A
more muscle than the right side because the systemic circulation has a much higher resistance and pressure.
9
Q
Electrical conduction of the heart starts at the
A
sinoatrial (SA) node and then goes to the atrioventricular (AV) node. From the AV node, electrical impulses travel to the bundle of His before traveling through the Purkinje fibers.
10
Q
Systole refers to the?
During diastole?
A
Systole refers to the period during ventricular contraction when the AV valves are closed.
During distole, the heart is relaxed and the semilunar valves are closed.
11
Q
The cardiac output is the product of
A
heart rate and stroke volume.
12
Q
The sympathetic nervous system increases the ____ and the parasympathetic nervous system ___(does what to the heart rate).
A
*increase heart rate and contractility
*decreases heart rate
13
Q
The vasculature consists of
A
arteries
veins
capillaries
14
Q
Arteries are
A
Arteries are thick, highly muscular structures with an elastic quality.
This allows for recoil and helps to propel blood forward within the system. Small muscular arteries are arterioles, which control flow into capillary beds.
15
Q
Small muscular arteries are ____, which control flow into _____.
A
1. Arterioles
2. Capillary beds
16
Q
Capillaries have
A
Capillaries have walls that are one cell thick, making them so narrow that red blood cells must travel through them single-file. Capillaries are the sites of gas and solute exchange.
17
Q
Veins are
A
Veins are inelastic, thin-walled structures that transport blood to the heart. They are able to stretch in order to accommodate large volumes of blood but do not have recoil capability. Veins are compressed by surrounding skeletal muscles and have valves to maintain one-way flow. Small veins are called venules.
18
Q
A portal system is one in which
A
blood passes through two capillary beds in series.
19
Q
In the hepatic portal system
A
blood travels from the gut capillary beds to the liver capillary bed.
Gut–>Liver
20
Q
In the hypophyseal portal system
A
blood travels from the capillary bed in the hypothalamus to the capillary bed in the anterior pituitary.
Hypothalamus–>anteripr pituitary
21
Q
In the renal portal system
A
blood travels from the glomerulus to the vasa recta through an efferent arteriole.
Glomerulus –> vasa recta1
22
Q
In the _____, blood travels from the gut capillary beds to the liver capillary bed via the hepatic portal vein.
A
hepatic portal system
23
Q
In the ______, blood travels from the capillary bed in the hypothalamus to the capillary bed in the anterior pituitary.
A
hypophyseal portal system
24
Q
In the______, blood travels from the glomerulus to the vasa recta through an efferent arteriole.
A
renal portal system
25
Blood is composed of what?
Blood is composed of **cells** and **plasma**, an aqueous mixture of
1. nutrients
2. salts
3. respiratory gases
4. hormones
5. blood proteins
26
Red blood cells aka?
Red blood cells lack what? in order to do what?
**Erythrocytes** (red blood cells)
lack _mitochondria_, a _nucleus_, and _organelles_ in order to make room for **hemoglobin**, _a protein that carries oxygen._ Common measurements include hemoglobin concentration and hematocrit, the percentage of blood composed of erythrocytes.
27
White blood cells aka?
White blood cells are formed in?
_Leukocytes_ (white blood cells) are formed in the _bone marrow_. They are a crucial part of the immune system.
* **Granular leukocytes** such as _**neutr**ophils_, _**eosin**ophils_, and _**baso**phils_ play a role in nonspecific immunity.
* **Agranulocytes**, including _**lymph**ocytes_ and _**mon**ocytes_, also play a role in immunity, with lymphocytes playing a large role in specific immunity.
28
_Granular leukocytes_ such as\_\_\_\_, play a role in\_\_\_\_\_?
Granular leukocytes such as _neutrophils, eosinophils, and basophils_ play a role in **_nonspecific immunity._**
29
**Agranulocytes**, including \_\_\_\_\_\_play a role in??
Agranulocytes, including **_lymphocytes_** and **_monocytes_**, also play a role in immunity, with _lymphocytes playing a large role in specific immunity._
30
**Thrombocytes** (platelets) are
Thrombocytes (platelets) are cell fragments from megakaryocytes that are required for coagulation.
31
Blood antigens include the
surface antigens A, B, and O, as well as Rh factor (D).
* The IA (A) and IB (B) alleles are codominant, while the i (O) allele is recessive. An individual has antibodies for any AB alleles he or she does not have.
* Positive Rh factor is dominant.
An Rh-negative individual will only create anti-Rh antibodies after exposure to Rh-positive blood.
------------------------
The **ABO** system is comprised of three alleles for blood type. In this particular class of erythrocyte cell-surface proteins, the **A** and **B** alleles are codominant, which means that a person may express _one_, _both_, or _none_ of the ABO antigens.
If the A allele (IA or simply A) is present on one chromosome and the B allele (IB or B) is present on the other chromosome, both will be expressed, and the person’s blood type will be **AB**.
The O allele (i or O) is recessive to both the A and B alleles. People with type O blood do not express either variant (A or B antigen) of this protein and have a _homozygous recessive genotype_. The naming system of blood types is based on the presence or absence of these protein variants. The four blood types are: A, B, AB, and O. Because the A and B alleles are dominant, the genotypes for _A may be I_A_I_A _or I_A_i,_ while the genotypes for _B may be I_B_I_B _or I_B_i._
32
Title: Physiology of the Cardiovascular System
START
33
**Blood pressure** refers to the
_force per unit area_ that is exerted on the walls of blood vessels by blood. It is divided into systolic and diastolic components.
34
Blood pressure must be high enough to do what?
It must be _high enough to overcome_ the resistance created by **arterioles** and **capillaries**, but _low enough to avoid damaging_ the **vasculature** and **surrounding structures**.
by vasculature they mean: arteries, veins, and capillaries
35
Blood pressure can be measured with a
sphygmomanometer.
36
Blood pressure is maintained by
Blood pressure is maintained by _baroreceptor_ and _chemoreceptor reflexes_.
**Low blood pressure promotes**
1. aldosterone
2. antidiuretic hormone (ADH or vasopressin) release
**High blood osmolarity** also promotes
1. ADH release.
2. atrial natriuretic peptide (ANP) release.
37
_Gas_ and _solute exchange_ occurs at the level of the
_capillaries_ and relies on the existence of _concentration gradients_ to _facilitate diffusion_ across the capillary walls.
Capillaries are also leaky, which aids in the transport of gases and solutes.
38
Starling forces consist of
**hydrostatic pressure** and **osmotic (oncotic) pressure.**
Hydrostatic pressure is the pressure of the fluid within the blood vessel, while osmotic pressure is the “sucking” pressure drawing water toward solutes. Oncotic pressure is osmotic pressure due to proteins. Hydrostatic pressure forces fluid out at the arteriolar end of a capillary bed; oncotic pressure draws it back in at the venule end.
39
Hydrostatic pressure is the
pressure of the fluid within the blood vessel, while osmotic pressure is the “sucking” pressure drawing water toward solutes.
40
**Oncotic pressure** is
is osmotic pressure due to proteins.
41
Oxygen is carried by \_\_\_\_\_, which exhibits \_\_\_\_\_\_\_.
hemoglobin
cooperative binding
Oxygen is carried by hemoglobin, which exhibits cooperative binding.
In the lungs, there is a high partial pressure of oxygen, resulting in loading of oxygen onto hemoglobin. In the tissues, there is a low partial pressure of oxygen, resulting in unloading. With cooperative binding, each successive oxygen bound to hemoglobin increases the affinity of the other subunits, while each successive oxygen released decreases the affinity of the other subunits.
42
Carbon dioxide is largely carried in the blood in the form of
**carbonic acid**, or **bicarbonate** and **hydrogen ions**.
_Carbon dioxide is nonpolar_ and _not particularly soluble_, while **bicarbonate, hydrogen ions, and carbonic acid** are _polar and highly soluble._
43
A high PaCO2, high [H+], low pH, high temperature, and high concentration of 2,3-BPG can cause a
right shift in the **oxyhemoglobin dissociation curve**, reflecting a decreased affinity for oxygen.
* In addition to the opposites of the causes of a right shift, a left shift can also be seen in the dissociation curve for **fetal hemoglobin c**ompared to **adult hemoglobin.**
* Nutrients, wastes, and hormones are carried in the bloodstream to tissues for use or disposal.
44
Coagulation results from an
activation cascade.
* When the endothelial lining of a blood vessel is damaged, the _collagen_ and _tissue factor_ underlying the endothelial cells are exposed. This results in a cascade of events known as the coagulation cascade, ultimately resulting in the formation of a clot over the damaged area.
* Platelets bind to the collagen and are stabilized by fibrin, which is activated by thrombin.
* Clots can be broken down by plasmin.
45
When the endothelial lining of a blood vessel is damaged, the
collagen and tissue factor underlying the endothelial cells are exposed. This results in a cascade of events known as the **coagulation cascade**, ultimately resulting in the formation of a clot over the damaged area.
46
Platelets bind to the collagen and are stabilized by \_\_\_\_, which is activated by \_\_\_\_.
**fibrin**
**thrombin**
47
Clots can be broken down by\_\_\_\_\_.
**plasmin**
48
1� Starting from entering the heart from the venae cavae, what are the four chambers through which blood passes in the heart? Which valve prevents backflow into each chamber?
see pic
49
2� Starting with the site of impulse initiation, what are the structures in the conduction system of the heart?
**Sinoatrial (SA) node** → **atrioventricular (AV) node** → **bundle of His (AV bun-dle) and its branches** → **Purkinje fibers**
50
Compare and contrast arteries, capillaries, and veins:
SEE PIC
51
4� Why does the right side of the heart contain less cardiac muscle than the left side?
4. The right side of the heart pumps blood into a lower-resistance circuit and must do so at lower pressures; therefore, it requires less muscle. The left side of the heart pumps blood into a higher-resistance circuit at higher pressures; there-fore, it requires more muscle.
52
5� If all autonomic input to the heart were cut, what would happen?
5. If all autonomic innervation to the heart were lost, the heart would continue beating at the intrinsic rate of the pacemaker (SA node). The individual would be unable to change his or her heart rate via the sympathetic or parasympathetic nervous system, but the heart would not stop beating.
53
1� What are the components of plasma?
1. Plasma is an aqueous mixture of nutrients, salts, respiratory gases, hormones, and blood proteins (clotting proteins, immunoglobulins, and so on).
54
2� An individual with B+ blood is in an automobile accident and requires a blood transfusion� What blood types could he receive? The same individual is so thankful that, after recovery, he decides to donate blood. To which blood types could he donate?
* Could receive from:
* Could donate to:
2. A B+ person could receive blood from a B+, B−, O+, or O− person. A B+ person could donate blood to a B+ or AB+ person.
55
3� What does a hematocrit measure? What are the units for hematocrit?
3. Hematocrit measures the percentage of a blood sample occupied by red blood cells. It is measured in percentage points.
56
4� Which types of leukocytes are involved in the specific immune response?
4. Lymphocytes are involved in specific immune defense.
57
5� Where do platelets come from?
5. Platelets are cellular fragments or shards that are given off by megakaryocytes in the bone marrow.
58
6� Which cell type(s) in blood contain nuclei? Which do not?
* Contain nuclei:
* Do not contain nuclei:
6. Only leukocytes (including neutrophils, eosinophils, basophils, monocytes/ macrophages, and lymphocytes) contain nuclei. Erythrocytes and platelets do not.
59
1� In bacterial sepsis (overwhelming bloodstream infection), a number of capillary beds throughout the body open simultaneously. What effect would this have on the blood pressure? Besides the risk of infection, why might sepsis be danger-ous for the heart?
1. Opening up more capillary beds (which are in parallel) will decrease the overall resistance of the circuit. The cardiac output will therefore increase in an attempt to maintain constant blood pressure. This is a risk to the heart because the increased demand on the heart can eventually tire it, leading to a heart attack or a precipitous drop in blood pressure.
60
2� What is the chemical equation for the bicarbonate buffer system? What enzyme catalyzes this reaction?
2. The bicarbonate buffer system equation is
61
3� Where should you look on the oxyhemoglobin dissociation curve to determine the amount of oxygen that has been delivered to tissues?
3. The amount of oxygen delivery can be seen as a drop in the y-value (percent hemoglobin saturation) on an oxyhemoglobin dissociation curve. For example, if the blood is 100% saturated while in the lungs (at 100 mmHg O2) and only 80% saturated while in tissues (at 40 mmHg O2), then 20% of the oxygen has been released to tissues.
62
4� What direction does the oxyhemoglobin dissociation curve shift as a result of exercise? What physiological changes cause this shift and why?
4. The oxyhemoglobin curve shifts to the right during exercise in response to increased arterial CO2, increased [H+], decreased pH, and increased temperature. This right shift represents hemoglobin’s decreased affinity for oxygen, which allows more oxygen to be unloaded at the tissues.
63
5� Exposure of which subendothelial compounds start the coagulation cascade? What protein helps stabilize the clot?
* Starts the cascade:
* Stabilizes the clot:
5. The coagulation cascade can be started by the exposure of collagen and tissue factor to platelets and coagulation factors. The clot is stabilized by fibrin.
64
The two major antigen families relevant for blood groups are the\_\_\_\_ and \_\_\_\_.
ABO antigens and the Rh factor.
65
a recipient who is type O will produce both anti-A and anti-B antibodies and can
Because type O blood cells express neither antigen variant, they will not initiate any immune response, regardless of the recipient’s actual blood type; people with type O blood are therefore considered **universal donors** because their blood will not cause ABO-related hemolysis in any recipient.
However, a recipient who is **type O** will produce both _anti-A and anti-B antibodies_ and can only receive blood from other type O individuals.
On the other hand, people with type AB blood are considered **universal recipients** because they can receive blood from all blood types: no blood antigen is foreign to AB individuals, so no adverse reactions will occur upon transfusion. A more thorough description of each blood type is given in Table 7.1. Note that whole blood is almost never given in a transfusion; rather, packed red blood cells (with no plasma) are generally given. Thus, we care only about the donor’s red blood cell antigens (and not his or her plasma antibodies) when determining whether hemolysis will occur.
66
The most common blood type in the United States is
O+
67
The least common blood type in the United States is
AB−
68
During childbirth, no matter how good the obstetrician is, women are exposed to a small amount of fetal blood. If a woman is Rh− and her fetus is Rh+, she will become
sensitized to the Rh factor, and her immune system will begin making antibodies against it. This is not a problem for the first child; by the time the mother starts producing antibodies, the child has already been born.
However, any subsequent pregnancy in which the fetus is Rh+ will present a problem because maternal anti-Rh antibodies can cross the placenta and attack the fetal blood cells, resulting in **hemolysis** of the fetal cells. This condition is known as **_erythroblastosis fetalis_** and can be fatal to the fetus. Today, we can use medicine to prevent this condition. There is less concern with ABO mismatching between mother and fetus because these maternal antibodies against AB antigens are of a class called IgM, which does not readily cross the placenta (unlike anti-Rh IgG antibodies, which can).
69
When an Rh− woman is pregnant with her first Rh+ fetus, the risk of erythroblastosis fetalis in subsequent Rh-mismatched pregnancies can usually be avoided by giving the Rh− mother
**Rh-immunoglobulin (RhoGAM)** during pregnancy and immediately after delivery . Administration of immunoglobulin (which is a type of passive immunization) will absorb the fetus’s Rh+ cells, preventing the production of anti-Rh antibodies by the mother .
