Module 4 Flashcards
(141 cards)
1
Q
How does the cardiovascular system address the challenge of transporting oxygen molecules, nutrients, and waste products over long distances?
A
it performs bulk transport of these things through the bloodstream.
2
Q
Why are diffusion, osmosis, and active transport inadequate for transporting oxygen from the lungs to distant cells?
A
They are slow and inefficient for long-distance transport
3
Q
What triggers vascular spasms?
A
Damage to a blood vessel.
4
Q
How does the sympathetic nervous system contribute to hemostasis?
A
reinforces vascular spasms to increase resistance and decrease blood flow.
5
Q
What 6 things do receptors monitor in the blood that help in maintaining homeostasis?
A
monitors:
1. pressure
2. volume
3. osmolarity
4. pH
5. O2 and CO2 levels
6. hormone levels
6
Q
Why is vascular spasm alone insufficient to stop bleeding entirely?
A
it minimizes blood loss, but does not completely halt bleeding.
7
Q
What is the significance of thrombus in hemostasis?
A
forms a blood clot to seal the damaged vessel and prevent further bleeding as final step of process
8
Q
How are platelet plugs formed?
A
the von Willebrand factor (vWf) binds to collagen fibers exposed by vessel damage, activating platelets.
9
Q
Substances that activated platelets secrete are
A
serotonin
epinephrine
ADP
thromboxane A2
10
Q
What does blood regulation adjust to ensure proper tissue function?
A
pressure, volume, & composition to meet the body’s needs.
11
Q
How does platelet aggregation occur?
A
ADP secretion
12
Q
What is the protective function of white blood cells and antibodies found in the blood?
A
protect the body from foreign invaders including
1. viruses
2. bacteria
3. parasites
4. toxins.
13
Q
What do healthy endothelial cells produce to regulate platelet aggregation?
A
prostacyclin and nitric oxide to prevent excessive plug formation.
14
Q
What is the role of vasoconstriction in platelet plug formation?
A
it’s reinforced by serotonin, epinephrine, and ADP secreted by activated platelets.
15
Q
What are the components of the cardiovascular system?
A
- heart
- arteries
- arterioles
- veins
- venules.
- capillaries
16
Q
What is the third event of hemostasis?
A
Blood/Fibrin clotting
17
Q
role of the heart in the cardiovascular system.
A
right side: pumps blood to the lungs for oxygenation
left side: pumps oxygen-rich blood to the rest of the body.
18
Q
What is the coagulation cascade?
A
sequence of reactions leading to fibrin formation
19
Q
Explain the intrinsic pathway.
A
Factor XII activated by collagen and phospholipids, leading to factor X activation.
20
Q
Function of Lymphatic system
A
collects fluid leaked from the cardiovascular system and returns it to the bloodstream.
21
Q
Describe the extrinsic pathway.
A
Tissue factor activates factor VII (7), which then activates factor X (10)
22
Q
Lymphatic Capillaries
A
transport and filter lymphatic fluid
23
Q
How do intrinsic and extrinsic pathways converge?
A
Both activate factor X, leading to thrombin formation and fibrin production.
24
Q
What surrounds the heart?
A
The pericardium, a membranous sac.
25
Where do white blood cells congregate in the lymphatic system, and what do they do?
In lymph nodes, to deal with foreign matter present in the lymph fluid.
26
Where is the heart located?
In the thoracic cavity.
27
Which chambers form the pump for the pulmonary circuit?
Right atrium and right ventricle.
28
What are the 4 components of blood and their % of volume?
1. plasma (55%)
2. erythrocytes (45% red blood cells)
3. leukocytes ( < 1% white blood cells)
5. platelets (< 1%)
29
What are the valves at the ventricles' exits?
Pulmonary and aortic semilunar valves.
30
What is the function of albumin(protein) in plasma?
maintaining plasma osmotic pressure.
31
What vessels connect to the heart?
Superior and inferior venae cavae, pulmonary trunk, and aorta
32
What are the 5 main types of white blood cells?
1. neutrophils
2. lymphocytes.
5. monocytes
4. eosinophils
5. basophils
(Never Let Monkeys Eat Bananas)
33
How does blood flow through the cardiovascular system?
One-way, aided by valves, from higher to lower pressure.
34
Describe the path of blood from the body back to the heart.
Superior and inferior vena cavae -> right atrium -> right AV valve -> right ventricle -> pulmonary semilunar valve -> pulmonary trunk -> pulmonary arteries.
35
What happens in the lung capillaries?
Gas exchange: Oxygen in, carbon dioxide out.
36
How does oxygenated blood return to the heart from the lungs?
Right and left pulmonary veins -> left atrium -> left AV valve -> left ventricle.
37
Where does blood go from the left ventricle?
Through the aortic semilunar valve into the aorta.
38
How does blood reach the body's organs and tissues?
Via arteries, arterioles, and capillary beds.
39
What 2 things distinguish erythrocytes from other blood cells?
1. lack nuclei, mitochondria and other organelles
2. specialized for oxygen transport.
40
What type of blood flow occurs in the body?
Parallel flow, delivering oxygenated blood directly to each organ.
41
Describe the return path of blood to the heart.
Capillary beds -> venules -> veins -> superior and inferior vena cavae.
42
What is the lifespan of erythrocytes?
120 days before being removed from circulation.
43
What supplies the heart muscle with oxygen and nutrients?
coronary arteries branching from the aorta.
44
What is the role of platelets in blood?
forming clots to stop bleeding.
45
Why does blood move forward in vessels?
Pressure difference or valve closure.
46
Define erythropoiesis.
production of red blood cells in the bone marrow
47
How do leukocytes defend the body against pathogens?
phagocytosis and the release of toxic molecules.
48
What is the most abundant cell in the blood?
Erythrocytes
49
Describe why blood flows into the right atrium.
Higher pressure in vena cavae.
50
What causes blood to move into the right ventricle?
Lower pressure.
51
How does the right atrium assist in filling the right ventricle?
Contracts slightly.
52
What prevents backflow in the heart?
Valve closure.
53
How do AV valves stabilize?
Chordae tendineae and papillary muscles.
54
What closes when ventricular pressure is high?
AV valves.
55
What is the average internal diameter of an artery?
A vein?
4.0 mm.
5.0 mm.
56
Plasma consists of what two things?
Water (90%)
Proteins (8%)
57
match the blood vessel type to the anatomical feature (artery, vein, arteriole, capillary, venule)
1. Muscular; highly elastic
2.Muscular; well innervated
3.Thin-walled; highly permeable
4.Thin-walled; some smooth muscle
5. Thin-walled (compared to arteries); fairly muscular; highly distensible
1. artery
2. arteriole
3. capillary
4. venule
5. vein
58
What type of proteins are globulins?
Clotting and transfer proteins
59
What is the role of leukocytes in the blood?
1. phagocytosis
2. attacking parasites
3. releasing toxic molecules
4. mounting specific immune responses.
60
Function of erythrocyte
transport oxygen and carbon dioxide
61
What are blood vessels composed of (arteries, arterioles, veins)
Endothelial cells, connective tissue, smooth muscle
62
What do all blood vessels contain in their lumen?
Endothelial cells.
63
Function of Neutrophil
phagocytosis of foreign material
64
What drives synchronized contractions of atria and ventricles?
Precise order of excited muscle cells.
65
Function of eosinophil
kill parasites
66
What secretes chemical mediators in inflammation and allergic reactions?
basophil
67
Monocytes function in _________
Phagocytosis
68
What supports immune response of other cells; secrete factors that kill infected or tumor cells?
Lymphocytes
69
Define myogenic and autorhythmic
Heart muscle generates own contraction signal.
70
How do pacemaker cells initiate action potentials?
Continuously, sweeping across heart.
71
Why doesn't the heart need external input to contract?
Repolarization triggers next action potential.
72
Function of platelets
hemostasis
73
Describe intercalated disks.
Specialized junctions enabling rapid communication.
74
What is the origin of all blood cells and platelets?
Hematopoietic stem cells in the bone marrow
75
Why is rapid communication between heart cells crucial?
Ensures smooth blood flow through circuits.
76
What is the location of the sinoatrial node (SA node)?
Upper wall of right atrium.
77
What is the innate rate of action potentials in the SA node?
About 100 impulses per minute.
78
What 2 things does hematopoietic stem cells differentiate into?
Lymphoid and Myeloid stems
79
Describe the size and shape of the SA node.
Small flattened ellipsoid, 3 mm wide, 15 mm long, 1 mm thick.
80
Where is the atrioventricular node (AV node) located?
Near the right AV valve, interatrial septum.
81
What role do colony-stimulating factors and interleukins play in blood cell development?
They stimulate the development of white blood cells.
82
What is the innate rate of action potentials in the AV node?
About 50 impulses per minute.
83
What initiates action potentials in the heart?
Sinoatrial node (SA node)
84
What 5 things stimulate the production of erythropoietin?
1. Hypoxia (low oxygen)
2. high testosterone
3. norepinephrine
4. epinephrine
5. prostaglandins.
85
How do action potentials travel from the SA node to the AV node?
Internodal pathway.
86
What happens when the signal reaches the AV node?
Pause for approximately 0.1 second.
87
Why does the signal pause at the AV node?
Slower transmission speed.
88
Factors that decrease oxygenation
Low blood volume
anemia
low hemoglobin
poor blood flow
pulmonary disease
very high altitude
89
What is Cardiac Output?
rate at which a ventricle pumps blood.
90
How do ventricular muscle cells contract?
action potentials triggered by the signal
91
Describe the movement of muscle contraction in the ventricles.
Like a wave, pushing blood out of the exits.
92
What initiates the opening of T-type calcium channels? (pacemaker cells)
Initial depolarization.
93
Why are the numbers of red blood cells regulated within narrow limits?
To ensure sufficient oxygen transport without impeding blood flow.
94
How is cardiac output calculated?
Cardiac output (CO) = Heart rate (HR) x Stroke volume (SV).
95
What follows the closing of potassium channels? (contractile cells)
Funny channels open, allowing sodium entry.
96
How do the sympathetic and parasympathetic nervous systems affect cardiac output?
They can affect the rate and force of heart muscle contraction
97
What happens when L-type calcium channels open? (contractile cells)
Further depolarization occurs
98
How does increased sympathetic activity affect heart rate and cardiac output?
increased frequency of action potentials in the SA node, speeding up depolarization and increasing heart rate and cardiac output.
99
What triggers the opening of voltage-gated potassium channels? (contractile cells)
Depolarization.
100
What leads to the closure of T-type calcium channels? (contractile cells)
Increased depolarization.
101
What occurs during repolarization? (contractile cells)
Closure of calcium channels.
102
How do potassium channels contribute to repolarization? (contractile cells)
Exit of potassium from the cell
103
What channels open during the initial period of depolarization? (contractile cells)
Funny channels.
104
Increased activity in sympathetic neurons leads to an __________in heart rate and cardiac output.
Increase
105
What ions move into the cell during the initial period? (contractile cells)
Sodium.
106
Which channels open during the later period of depolarization? (contractile cells)
T-type calcium channels.
107
Increased activity in the parasympathetic neurons leads to a ___________ in heartrate and cardiac output.
decrease
108
In contractile cells, what ion moves into the cell during rapid depolarization?
Sodium.
109
What happens to sodium movement during small repolarization in contractile cells?
sodium movement decreases into the cell
110
Epinephrine leads to an __________in heart rate and cardiac output.
increase
111
Thyroid hormones, insulin, and glucagon ____________ heart rate and cardiac output
increase
112
Decreases in heartrate and, therefore, cardiac output can be achieved by ____________ sympathetic nervous activity or ______________ parasympathetic nervous activity.
decreasing
increasing
113
increases in heartrate and, therefore, cardiac output can be achieved by ____________ sympathetic nervous activity or ______________ parasympathetic nervous activity.
increasing
decreasing
114
What 3 factors change the amount of blood that comes out of the ventricles of the heart in one beat?
1. Changes in ventricular contractility
2. end-diastolic volume
3. afterload
115
Increased sympathetic activity, epinephrine, insulin, glucagon, and thyroid hormones _________ ventricular contractility to _________ stroke volume and, therefore, cardiac output.
Increase
Increase
116
During the plateau phase in contractile cells, what happens to potassium inward rectifier channels?
They close.
117
What channels open during the plateau phase in contractile cells?
Calcium L-type channels open
118
What ions move into the contractile cell during the plateau phase?
Calcium.
119
Increases in end-diastolic volume cause greater stretch in the heart muscle which triggers increases in force of contraction of heart muscle cells to increase stroke volume and, therefore, increase cardiac output.
What is this known as
the Starling effect
120
In contractile cells, what channels open during repolarization?
Potassium delayed rectifier channels.
121
What ions move out of the cell during repolarization in contractile cells?
Potassium.
122
: What happens to calcium movement during repolarization in contractile cells?
calcium movement decreases into the cell
123
__________ in arterial pressure (against which the heart must work to pump blood out of the heart) cause decreases in stroke volume which lead to ____________in cardiac output.
Increase
Decrease
124
In the resting potential of contractile cells, what channels open?
Potassium channels (both types)
125
What 2 factors determine blood flow through the cardiovascular system?
pressure difference and resistance to flow
126
What is an ECG?
Record of heart's electrical activity.
127
How is blood flow calculated?
Blood flow = pressure difference / resistance
128
How are ECGs produced?
Multiple electrodes on skin
129
Define Pressure difference
a measure of the force pushing blood through a blood vessel
130
What do P waves represent?
Atrial depolarization.
131
a measure of the force that hinders blood flow thorugh a blood vessel is defined as ___________
resistance
132
What does the QRS complex represent?
Ventricular depolarization.
Atrial repolarization
133
What does the T wave represent?
Ventricular repolarization.
134
Does absolute pressure affect blood flow?
No, except in the respect that it influences the pressure difference between two areas
135
What is mean arterial pressure (MAP)?
average pressure in the aorta during the cardiac cycle
136
WHy is MAP typically used as a measure of our pressure gradient?
Because the pressure in the superior and inferior vena cavae is so low
137
What does Poiseuille's Law describe?
resistance to flow in individual blood vessels.
138
How is resistance (R) calculated in Poiseuille's Law?
R = 8Lη/πr^4
L is the length of the tube
η is the viscosity of the fluid
r is the radius of the tube.
139
How does tube length affect resistance according to Poiseuille's Law?
Longer tubes have more resistance.
140
What is the overall resistance of a network of blood vessels called?
Total peripheral resistance (TPR)
141
How is cardiac output (CO) calculated using MAP and TPR?
CO = MAP/TPR.
