Circulatory System 1 Flashcards
1
Q
The circulatory system consists of two systems. What are they?
A
Cardiovascular system + Lymphatic system
2
Q
What does the cardiovascular system consist of
A
Heart
Blood vessels
Blood
3
Q
What does the lymphatic system consist of
A
Lymphoid tissue
Lymphatic vessels
Lymph
4
Q
Functions of circulatory system
A
- Transport:
- respiratory: oxygen and carbon dioxide
- nutritive: digest food materials
- excretory: metabolic wastes, excess water and ions - Regulation:
- hormonal: site of origin to target tissues
- temperature: diversion of blood between superficial and deep vessels - Protection:
- clotting: protection against blood loss when vessels are damaged
- immune: protection by white blood cells against pathogen
5
Q
Blood is about ______ % of the total body weight
A
8%
6
Q
Blood is either ___________ blood or __________ blood
A
Arterial blood
Venous blood
7
Q
Blood consists of:
A
- Plasma
- Formed elements
8
Q
What is plasma
A
Straw-colored (pale yellow) liquid which consists of water and dissolved solutes
9
Q
What is the liquid part of blood
A
Plasma
10
Q
We said plasma consists of water and dissolved solutes.
What are these dissolved solutes?
A
11
Q
Difference between serum and plasma
A
Plasma has fibrinogen + no blood clotting
Serum lacks fibrinogen due to blood clotting
NOTE:
Blood centrifuge + anticoagulant = plasma
Blood centrifuge - anticoagulant = serum
12
Q
What makes up most of the organic molecules in plasma ?
A
Protein
13
Q
What are some electrolytes in plasma
A
Na+
K+
Ca2+
Cl-
HCO3-
14
Q
What are some organic molecules in plasma
A
Cholesterol
Glucose
Protein
Urea
Lactic acid
15
Q
What are some hormones present in plasma
A
Insulin
Testosterone
Growth hormone
Etc
16
Q
What are some enzymes in plasma
A
Lactate dehydrogenase (LDH)
Creative phosphokinase (CPK)
17
Q
Plasma proteins make up ______% of plasma volume
A
7% - 9%
18
Q
What are some plasma proteins ?
A
Albumins
Globulins
Fibrinogen
19
Q
Which plasma protein accounts for 55% to 60% of the plasma proteins ?
A
Albumins
20
Q
Albumins account for _____% to _____% of the plasma proteins
A
55% to 60 %
21
Q
What is the function of albumin
A
Maintain blood volume and pressure
22
Q
What produces albumin
A
Liver
23
Q
We categorized globulins into 2 groups which are
A
- Alpha globulin and Beta globulin
- Gamma globulins
24
Q
Name a function of alpha globulin and beta globulin
A
Transport lipids and fat-dissolved vitamins
25
What organ produces alpha and beta globulins
Liver
26
What are gamma globulins ?
Antibodies
27
Function of gamma globulins
Immunity
28
What produces gamma globulins ?
B-lymphocytes
29
Function of fibrinogen
Blood clotting
30
What produces fibrinogen
Liver
31
Plasma proteins produced by the liver are
Albumins
Alpha and beta globulins
Fibrinogen
32
What are formed elements in blood?
Blood cells (erythrocytes, leukocytes, thrombocytes)
33
What are erythrocytes
Red blood cells
34
What are the most abundant cells in blood?
Erythrocytes (RBC)
35
What is the shape of RBC and why is this shape significant
Biconcave
Increases surface area for gas exchange
36
True or false
RBC does NOT have a nucleus
True
37
What does the RBC contain that gives blood its red color
Hemoglobin
38
Structure of hemoglobin
4 globin chains, each with iron-containing heme group
39
Function of hemoglobin
Carries oxygen around the body
40
Each hemoglobin can bind to how many oxygen molecules ?
4
41
True or false
The iron atom of the heme group can irreversibly bind oxygen as the blood travels between the lungs and the tissues
False
Reversibly
42
How long do RBCs live for?
120 days
43
What are thrombocytes
Platelets
44
What are the smallest of the formed elements in blood
Platelets
45
What are platelets
Fragments of large bone marrow cells called megakaryocytes
46
Do platelets have a nucleus ?
No
47
True or false
Platelets move in an amoeboid fashion
True
48
Function of platelet
Blood clotting
49
True or false
Platelets constitute most of the clot mass
True
50
What are leukocytes ?
White blood cells
51
Which blood cells are referred to as “protective cells” of the body
WBCs
52
Do WBCs contain a nucleus
Yes
53
True or false
WBCs move in amoeboid fashion
True
54
Why is it important that WBCs move in amoeboid fashion?
Allows them to cross the intact capillary wall to the site of tissue damage or infection (by diapedesis or extravasation)
55
What is diapedesis
Passage of blood cells through intact walls of the capillaries
56
What is extravasation
Leakage of blood, lymph, or other fluid from a blood vessel into the tissue
57
WBCs are either ________ or __________
Granular or Agranular
58
Granular leukocytes include :
(Hint: BEN)
Basophils
Eosinophils
Neutrophils
59
Agranular leukocytes include:
Monocytes
Lymphocytes
60
Which cells are the most abundant type of WBCs in the circulation (50-70%)
Neutrophils
61
Neutrophils make up ___ % - ____% of WBCs in circulation
50-70%
62
Which WBC type are the first cellular responders to tissue injury and infection
Neutrophils
63
There are certain molecules on the surface of RBCs; what are these molecules called
Antigens
64
Which WBC secretes antibodies as a part of our body’s defense system
B-lymphocytes
65
What happens when an RBC antigen is exposed to its corresponding antibody
Example: Antigen B and B antibodies
RBC agglutination and hemolysis
66
What antigen does blood type A have
Antigen A
67
What antigen does blood type B have
Antigen B
68
What antigen does blood type AB have
Antigens A and B
69
What antigen does blood type O have
No antigens
70
What antibody does blood type A have
Anti-B antibodies
71
What antibody does blood type B have
Anti-A antibodies
72
What antibody does blood type AB have
No antibodies against A and B
73
What antibody does blood type O have
Both Anti-A and Anti-B antibodies
74
What blood type can a person with Type A blood accept
A blood
O blood
75
What blood type can a person with Type B blood accept
B blood
O blood
76
What blood type can a person with Type AB blood accept
A blood
B blood
O blood
77
What blood type can a person with Type O blood accept
O blood only
78
Which blood type is the universal recipient
Type AB
79
What blood type is the universal donor
Type O
80
True or false
A person with type A blood can receive blood from a donor with Type AB
False
81
Can a person with a + Rh donate blood to a person with -Rh ?
No because a person with -Rh has Anti-Rh antibodies
82
Can a person with -Rh donate blood to a person with +Rh
Yes
83
Can O+ donate blood to O- ?
No because O- has anti-Rh antibodies
84
The cardiovascular system consists of two main sub-circuits; what are they
Systemic circulation
Pulmonary circulation
85
Arteries transport blood ___________ the heart
Away from
86
Veins transport blood _____________ the heart
Towards
87
What are capillaries
Delicate and small blood vessels that are the sites of gas, nutrient and waste exchange between blood and tissue
88
Arteries usually carry what kind of blood
Oxygenated
89
Veins usually carry what kind of blood
Deoxygenated
90
Which arteries do NOT carry oxygenated blood
Pulmonary arteries
91
Which veins do NOT carry deoxygenated blood
Pulmonary veins
92
Pulmonary circulation
Moves blood between HEART and LUNGS
(RA - RV - pulmonary arteries - lungs - absorbs O2 and releases CO2 - pulmonary veins - back to heart)
93
Systemic circulation
Moves blood between HEART and rest of the BODY
(LA - LV - Aorta - arteries - body - releases O2 and absorbs CO2 - veins - back to heart)
94
What is the heart
A cone-shaped muscular organ, located in the thorax between the lungs
95
How many chambers does the heart have
4
96
What are the 4 chambers of the heart
Right atrium
Left atrium
Right ventricle
Left ventricle
97
Where does the right atrium receive blood from?
Superior vena cava
Inferior vena cava
(Also coronary sinus but not mentioned)
98
Where does left atrium receive blood from
Pulmonary veins
99
Both ventricles receive blood from ________
The atria
100
The right ventricle pumps out blood into ___________.
Pulmonary arteries
101
The left ventricle pumps out blood into _____________.
Aorta
102
Describe the apex and base of the heart
Apex is located inferiorly whereas the base is located superiorly
103
Right and left atria open in corresponding ventricles via one way valves ; what are they ?
RA to RV : tricuspid valve
LA to LV: bicuspid valve (mitral valve)
104
What separates the right side of the heart from the left side
Septum
105
What is the importance of the septum that separates the right and left sides of the heart?
Prevents mixing of oxygenated and deoxygenated blood
106
How does blood flow through the heart
107
What ensures the one-way flow of blood through the heart?
Valves
108
What are the atrioventricular valves of the heart
Tricuspid valve (between RA and RV)
Bicuspid valve or mitral valve (between LA and LV)
109
Describe the structure of the valves
Valve cusps or leaflets are attached by fibrous cords called chordae tendineae to papillary muscle that are located on the inside of the ventricular walls
110
What is the significance of the valve’s structure
Prevents the cusps from swinging back into the atria during ventricular contraction
111
What are the semilunar valves
Aortic valve
Pulmonary valve
112
Cardiac valves are PASSIVELY operated by :
The difference in blood pressure between atria & ventricles OR between ventricles & outflow vessels
This is why they are one-way valves
113
True or False
Cardiac valves are analogous to doors that open in one direction, but not the other .
True
114
Compare the walls of arteries, veins, and capillaries
Arteries have muscular walls and smaller lumen
Veins have thinner walls and bigger lumen
Capillaries have a single layer wall of endothelial cells
115
What is the significance of the capillary’s single layer wall ?
Allows gas exchange
116
Compare the pressure in arteries and veins
Arteries have HIGH pressure
Veins have LOWER pressure
117
Since veins have lower pressure than of that in arteries, what aids venous flow to the heart?
Venous valves
118
Histology: both arteries and veins are composed of three layers ; what are they ?
Tunica interna (tunica intima)
Tunica media
Tunica externa (tunica adventitia)
119
What does tunica interna consist of
Elastic tissue fibers
Basement membrane
Inner endothelium
120
What does tunica media consist of?
Smooth muscle cells
Elastic tissue fibers
121
What does tunica externa consist of
Connective tissue
122
Functional role of arterial and venous vascular wall
Venous vascular wall:
- most blood is stored in veins
- HIGHLY distensible or compliant (expand easily)
Arterial vascular wall:
- contain less blood compared to veins
- wall has LIMITED ability to distend
123
Not a question . Just know this simple fact.
Flow path :
Artery - arteriole - capillary - venule - veins
124
What is the cardiac cycle
Repeating pattern of contraction (systole) and relaxation (diastole) of the atria and ventricles
125
Average heart rate
70-75 beat/min
126
Each cardiac cycle lasts ________
0.8 seconds
127
How much of the cardiac cycle (0.8 seconds) is diastole and systole
Diastole
128
Events of cardiac cycle
129
How long is diastole
0.5 seconds
130
How long is systole
0.3 seconds
131
What happens during diastole
Atria contract
Ventricles relax and fill
132
What happens in systole
Atria are relaxed
Ventricles contract
133
Describe ventricular filling during diastole
Ventricles are 80% filled with blood PASSIVELY
While the final 20% is added when atria contract
134
Systole and diastole refer to the contraction and relaxation of ________________.
Ventricles
135
When the ventricle fill up with blood , this blood volume is called
End diastolic volume EDV
(80% of EDV occurs passively and the final 20% is added with atrial contraction)
136
When ventricles contract during systole , how much blood is actually ejected from the EDV?
2/3 of EDV is ejected
(The blood volume that was ejected is called stroke volume)
137
What is stroke volume (SV)
Volume of blood ejected from each ventricle during one cardiac cycle (so each heartbeat)
138
Since the stroke volume (SV) is 2/3 of the EDV , what is the remaining volume of blood in the ventricle called ?
(The remaining 1/3 after ejection)
End systolic volume ESV
139
How to calculate stroke volume ?
140
What is the SV of a healthy man, if his EDV = 120 ml, and his ESV = 50 ml?
SV = 120 - 50 = 70 ml/beat
141
Understand this
During diastole, ventricles are being filled up
When ventricles are full, that volume of blood is called end diastolic volume EDV
During systole, blood is ejected and the volume of that blood ejected is stroke volume SV
At the end of systole, the volume of blood left in the ventricle is called end systolic volume ESV
142
What is the usual EDV in an adult human
120 ml
143
After ventricles ar filled with blood, ventricular muscle contracts WITHOUT a change in length. What is this contraction called
Iso-volumetric contraction
144
What is isovolumetric contraction
Ventricles contract with no corresponding volume change or change in length
145
Describe the ventricular pressure and volume changes during cardiac cycle
146
What is the purpose of iso-volumetric contraction
Increases intra-ventricular pressure so that it is eventually much higher than aortic pressure
147
What needs to happen in terms of pressure in order for ejection to occur
148
What happens to pressure and volume during ejection ?
149
What occurs after ejection?
Iso-volumetric relaxation
150
True or false
Iso -volumetric relaxation causes change in volume?
False
151
Purpose of isovolumetric relaxation
Decrease in intra-ventricular pressure to allow for filling of ventricle
152
Describe volume and pressure during filling .
153
At the end of passive ventricular filling what occurs and why?
Atrial systole (atrial contraction) to deliver the final (20%) volume of blood into ventricles
154
Notice the volume and pressure during systole and diastole
Systole :
Pressure increases then drops
Volume decreases to minimum
Diastole:
Pressure is low and constant
Volume increases
155
What produces heart sounds that can be heard through a stethoscope
Closure of valves
156
What do heart sounds sound like?
Lub-dub
157
What produces the FIRST heart sound (S1)
Closure of AV valves
(Which occurs when ventricular pressure exceeds atrial pressure)
158
What produces the SECOND heart sound (S2)
Closure of semilunar valves
(Which occurs when ventricular pressure falls below the pressure in arteries ; aorta + pulmonary arteries)
159
What is phase 1 of the cardiac cycle
Mid-to-late diastole
160
What occurs in Phase 1 of cardiac cycle
1. Ventricular filling
2. Atrial contraction
161
When is phase 2 of cardiac cycle ?
Systole (early systole)
162
What occurs during phase 2 of cardiac cycle
Iso-volumetric contraction
(To increase intra-ventricular pressure)
163
When is phase 3 of cardiac cycle
Systole
164
What occurs in phase 3 of cardiac cycle
Ventricular ejection
165
When is phase 4 of cardiac cycle
Diastole (early diastole)
166
What occurs in phase 4 of cardiac cycle
Isovolumetric relaxation
167
Understand what occurs in each phase
Phase 1: (mid-late diastole) ventricular filling + atrial contraction
Phase 2: (systole) iso-volumetric contraction
Phase 3: (systole) ventricular ejection
Phase 4: (early diastole) isovolumetric relaxation
168
State of valves during phase 1 of cardiac cycle
(Ventricular filling + atrial contraction)
AV: open
Semilunar: closed
169
State of valves during phase 2 of cardiac cycle
(Isovolumetric contraction)
AV: closed
Semilunar: closed
170
State of valves during phase 3 of cardiac cycle
(Ventricular ejection)
AV: closed
Semilunar: open
171
State of valves during phase 4 of cardiac cycle
(Isovolumetric relaxation)
AV: closed
Semilunar: closed
172
Function of heart
Contract and pump blood to the body
173
In order for the heart to contract and pump blood, it must be ________________ _____________ first.
Electrically activated
174
There are two main types of cells in the heart
Conducting cells (1%)
Contractile cells (99%)
175
What are conducting cells ?
Specialized muscle cells that initiate electrical impulses and conduct them rapidly through the heart
176
What are contractile cells
Cardiomyocytes which make up most of the atrial and ventricular tissue
Also known as “working cells of the heart”
177
Which type of cells in the heart are known as “working cells” of the heart?
Contractile cells (cardiomyocytes)
178
The heart shows automaticity ; what does that mean
No requirement for neural input
(So it can create electrical impulses on its own thus does not depend on the nervous system to be able to beat and pump blood)
179
What is sinoatrial node (SA node)
Pacemaker of the heart
A region of the heart that functions as a pacemaker and generates automatic electrical activity which stimulates the rest of the heart
180
The action potential spontaneously generated by the SA node is ___________ (same or different) from the action potentials produced by the rest of the heart cells.
Different
181
Adjacent cardiomyocytes are connected by electrical synapses called
Gap junctions
182
What is the importance of gap junctions between cardiomyocytes ?
Allows action potentials to directly and rapidly spread from one cell to another (synchronized contractions)
183
Where are electrical impulses generated in the heart
SA node
184
What is AV node and what is its importance ?
Atrioventricular node located in the inferior RIGHT atrium.
Purpose: gives SMALL DELAY before continuation of impulses to the bundle of His
185
Why is it important for the AV node to cause a small delay in conduction of impulses ?
So that the atria and ventricles don’t all contract at the same exact time , disrupting the one way flow of blood in the heart
186
Where is bundle of His
Located in the septum and sends fibers to the ventricles
187
What do purkinje fibers do
Spread the impulse through the ventricles rapidly
188
Know the conducting path in the heart
1. SA node: generates and conducts impulses
2. AV node: delays impulses before continuation
3. Bundle of His: sends impulse to ventricles
4. Purkinje fibers: spreads impulses throughout ventricles
189
What are the 3 phases of SA node
Phase 0 : upstroke
Phase 3: repolarization
Phase 4: spontaneous depolarization or pacemaker potential
190
What causes phase 0 (upstroke) of SA node action potential
Inward Ca2+ current
191
What causes phase 3 (repolarization) of SA node action potential
outward K+ current
192
What causes phase 4 (spontaneous depolarization or pacemaker potential) of SA node action potential
Influx of “funny” Na+ current through HCN channels
193
Which phase of the SA node action potential is the longest and accounts for the automaticity of the SA node?
Phase 4
194
What are the 5 phases of the myocardial action potential
Phase 0: upstroke
Phase 1: initial repolarization
Phase 2: plateau
Phase 3: repolarization
Phase 4: resting membrane potential
195
What causes Phase 0 of the myocardial action potential
Inward Na+ current
196
What causes Phase 1 of the myocardial action potential
Outward K+ current and closure of Na+ channels inactivation gates
197
What causes Phase 2 of the myocardial action potential
Net current flow across membrane is 0
198
What causes Phase 3 of the myocardial action potential
Outward K+ current
199
What causes Phase 4 of the myocardial action potential
Membrane potential returns to resting level -85 mV and is stable
(Inward and outward currents are equal)
200
Understand the phases of SA node action potential
201
Understand the 5 phases of the myocardial action potential
202
The electrical activity of the heart can be measured on the surface of the skin using an instrument called
Electrocardiograph
203
The recorded tracing from the electrocardiograph is called
Electrocardiogram (ECG or EKG)
204
True or false
ECG is a recording of action potentials
False !
Although it results from the production and conduction of action potentials in the heart, it actually reflects the overall spread of electrical activity during a cardiac cycle
205
_________ is a simple and fast test to evaluates the heart’s electrical system to assess for heart disease
ECG
206
Each cardiac cycle produces 3 distinct ECG waves
P wave
QRS complex
T wave
207
What does the P wave represent
Atrial depolarization
(Atria depolarize and contract)
208
What does the QRS complex represent
Ventricular depolarization
(Ventricles depolarize and contract)
NOTE: atria repolarize during ventricular depolarization
209
What does the T wave represent
Ventricular repolarization
(Ventricles repolarize and relax)
210
What wave is NOT visible in the ECG?
Atrial repolarization
211
Read ECG
Normal rhythm
212
Read ECG
Bradycardia
(HR < 60 beats/min)
213
Read ECG
Tachycardia (HR> 100 beats/min)
214
Bradycardia
Slow heart rate
215
Tachycardia
Fast heart rate
