Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT Biology > Ch 7 - The Cardiovascular System > Flashcards

Ch 7 - The Cardiovascular System Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards AP® Biology flashcards Biology 101 flashcards
1
Q

What is the heart composed of and what does it support?

A
  • composed of cardiac muscle and supports 2 different circulations: the pulmonary and systemic circulation
  • each side of the heart consists of an atrium and a ventricle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is the atria separated from the ventricles?

A

by the atrioventricular valves (tricuspid on the right, bicuspid - mitral - on the left)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How are the ventricles separated from the vasculature?

A

by the semilunar valves (pulmonary on the right, aortic on the left)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the pathway of blood starting from the R atrium?

A
  • R atrium through tricuspid valve to R ventricle
  • through pulmonary valve to pulmonary artery
  • to lungs to pulmonary veins to L atrium
  • through mitral valve to L ventricle
  • through aortic valve to aorta
  • to arteries to arterioles to capillaries to venules to veins to vena cava to R atrium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Why does the right side of the heart have less cardiac muscle than the left side?

A
  • R side pumps blood into a low-resistance circuit and must do so at lower pressures; therefore, it requires less muscle
  • L side pumps blood into a higher-resistance circuit at higher pressures, requiring more muscle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the pathway for the electrical conduction of the heart?

A
  • starts at the SA node through both atria (contracting both) then goes to the AV node (slowing down conduction allowing completion of atrial contraction and ventricular filling)
  • from AV, electrical impulses travel to the bundle of His before traveling through the Purkinje fibers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the difference between systole and diastole?

A
  • systole refers to the period during ventricular contraction when the AV valves are closed
  • during diastole, the heart is relaxed and the semilunar valves are closed
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the cardiac output?

A

product of heart rate and stroke volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does the sympathetic and parasympathetic NS affect the heart rate?

A
  • sympa: increases HR and contractility

- para: decreases HR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are arteries?

A
  • thick, highly muscular structures with an elastic quality (smooth muscle present, no valves)
  • allows for recoil and helps to propel blood away from heart
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are arterioles?

A
  • small muscular arteries

- control flow into capillary beds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What are capillaries?

A
  • have walls that are one cell thick, making them so narrow that RBCs must travel through them single file
  • the sites of gas and solute exchange
  • carry blood from arterioles to venules (no smooth muscle or valves)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are veins?

A
  • inelastic, thin walled structures that support blood to the heart
  • able to stretch in order to accomodate large volumes of blood but do not have recoil capability
  • compressed by surrounding skeletal muscles and have valves to maintain one way flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are venules?

A

small veins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How does blood travel in the hepatic portal system?

A

blood travels from the gut capillary beds to the liver capillary bed via the hepatic portal vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How does blood travel in the hypophyseal portal system?

A

blood travels from the capillary bed in the hypothalamus to the capillary bed in the anterior pituitary

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How does blood travel in the renal portal system?

A

blood travels from the glomerulus to the vasa recta through an efferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is blood composed of?

A

cells and plasma, an aqueous mixture of nutrients, salts, respiratory gases, hormones, and blood proteins

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What do erythrocytes lack and why?

A
  • RBCs lack mitochondria, a nucleus, and organelles in order to make room for hemoglobin, a protein that carries oxygen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Where are leuckocytes formed?

A

WBCs are formed in the bone marrow (crucial part of the immune system)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the difference between granular leukocytes and agranulocytes?

A
  • granular such as neutrophils, eosinophils, and basophils play role in nonspecific immunity
  • agran, including lymphocytes and monocytes, also play a role in immunity, with lymphocytes playing a large role in specific immunity
22
Q

What are thrombocytes?

A

platelets are cell fragments from megakaryocytes that are required for coagulation (no nucleus)

23
Q

What is the difference between the surface antigens A, B, O, and Rh (D) factor in blood?

A
  • A and B alleles are codominant and O allele is recessive
  • an individual has antibodies for any AB alleles he or she does not have
  • positive Rh is dominant
  • Rh-negative individual will only create anti-Rh antibodies after exposure to Rh-positive blood
24
Q

What is blood pressure and how is it measured?

A
  • the force per unit area that is exerted on the walls of blood vessels by blood
  • divided into systolic and diastolic components
  • measured with a sphygmomanometer
25
Q

How is a stable blood pressure determined?

A

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

26
Q

How is blood pressure maintained?

A

by baroreceptor and chemoreceptor reflexes

27
Q

What does low and high blood pressure promote?

A
  • low BP promotes aldosterone and antidiuretic hormone (ADH or vasopressin) release
  • high blood osmolarity also promotes ADH release
  • high BP promotes atrial natriuretic peptide (ANP) release
28
Q

Where does gas and solute exchange occur and what does it rely on?

A
  • occurs at the level of the capillaries
  • 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
29
Q

What is the difference between hydrostatic and osmotic (oncotic) pressure in starling forces?

A
  • hydro: pushes fluid out of vessels and is dependent on blood pressure generated by the heart and the elastic arteries
  • osmo: pulls fluid back into the vessels and is dependent on the number of particles dissolved in the plasma (mostly proteins - oncotic pressure)
  • O > H at the venous end of capillary bed
30
Q

What carries oxygen?

A

hemoglobin

31
Q

What is cooperative binding?

A
  • in the lungs, there is a high partial pressure of oxygen, resulting in loading of oxygen onto hgb
  • in the tissues, there is a low partial pressure of oxygen, resulting in unloading
  • with cooperative binding, each successive oxygen bound to the hgb increases the affinity to the other subunits, while each successive oxygen released decreases the affinity of the other subunits
32
Q

How is carbon dioxide carried in blood and why?

A
  • largely carried in the blood in the form of carbonic acid, or bicarbonate and hydrogen ions
  • it is nonpolar and not particularly soluble, while bicarbonate, hydrogen ions, and carbonic acid are polar and highly soluble
33
Q

What is coagulation a result of?

A

activation cascade

34
Q

When is there a shift in the oxyhemoglobin dissociation curve?

A
  • a high PaCO2, high [H+], low pH, high temperature, and high concentration of 1,3-BPG can cause right shift, reflecting a decreased affinity for oxygen (exercise)
  • left shift can be seen for fetal hgb compared to adult hgb (fetal has higher affinity for oxygen)
35
Q

What happens when the endothelial lining of a blood vessel is damaged?

A
  • the collagen and tissue factor underlying the endothelial cells are exposed
  • resulting in a cascade of events (coagulation cascade), restingin in the formation of a clot over the damaged area
  • plt bind to the collagen and are stabilized by fibrin, which is activated by thrombin
36
Q

How can clots be broken down?

A

by plasmin

37
Q

What would happen if all autonomic input to the heart were cut?

A
  • the heart would continue beating at the intrinsic rate of the pacemaker (SA node)
  • the individual would be unable to change HR via the sympathetic or parasympathetic NS, but the heart would not stop beating
38
Q

What are antigens?

A
  • the stimuli for B cells to make antibodies

- after exposure of a B cell to its specific antigen, the cell becomes an antibody-producing factory

39
Q

Who could a B+ blood type receive blood from? Who could they donate to?

A
  • could receive from B+, B-, O+, or O-

- donate to B+ or AB+

40
Q

What does hematocrit measure and what are the units?

A
  • measures the percentage of a blood sample occupied by RBCs

- percentage points

41
Q

Where does the largest drop in BP occur?

A

across arterioles; critical because the capillaries are thin walled and unable to withstand the pressure of the arterial side of the vasculature

42
Q

Where is amount of oxygen delivery indicated on the oxyhemoglobin dissociation curve?

A

seen as a drop in the y value (percent hgb saturation)

43
Q

What is the chemical equation for the bicarbonate buffer system and what enzyme catalyzes it?

A

CO2 (g) + H2O (l) H+ (aq) + HCO3- (aq)

catalyzed by carbonic anhydrase

44
Q

What effect does bacterial sepsis have on the blood pressure and heart?

A
  • opening up more capillary beds will decrease the overall resistance circuit
  • the cardiac output will therefore increase in an attempt to maintain constant BP which is a risk to the heart because the increased demand on the heart can eventually tire it leading to an MI or a precipitous drop in BP
45
Q

How is Ohm’s law applied to circulation?

A

pressure differential across the circulation = cardiac output x total peripheral resistance (TPR)

46
Q

How is hemoglobin’s affinity to O2 affected according to Bohr’s effect?

A

decreasing pH in the blood decreases hgb affinity to O2

- affinity generally lowered in exercising muscle to facilitate unloading of oxygen to tissues

47
Q

How is blood pressure in the aorta compared to the superior vena cava?

A
  • aorta BP (between 120 and 80 mmHg) > superior vena cava BP (0) always
48
Q

Which feature of veins allows there to be more blood in the venous system than the arterial system at any given time?

A
  • relative lack of smooth muscle in venous walls allows stretching to store most of the blood in the body
49
Q

Which vascular structure creates the most resistance to blood flow?

A

arterioles; they are highly muscular and have the ability to contract and dilate in order to regulate BP

50
Q

Where are the electric conduction system components located?

A
  • SA node near the top of R atrium
  • AV node between the 2 AV valves
  • bundle of His within the wall between the ventricles

MCAT Biology (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions