Exam 3 Flashcards
Cardiovascular Respiratory
1
Q
Cardiac: Widowmaker
A
left anterior descending artery
– supplies left ventricle
2
Q
Spontaneous depolarization of Heart
A
purkinje < bundle HIS < AV < SA
**SA to purkinje
3
Q
Location of the Heart
A
Thoracic cavity: Mediastinum between lungs
- medial to lungs
- posterior to sternum
- anterior to ventral column
- superior to diaphragm
4
Q
Location of the apex of the heart (distal end)
A
- distal end (apex) points to left (5th intercostal)
* hear heartbeat
5
Q
Layers of the Heart wall
A
- Endocardium (inner)
- Myocardium: Muscle, middle tissue – hardest working muscle in the body
- Epicardium: Adipose
6
Q
The pericardial cavity is located between what layers of the heart?
A
Parietal layer of serous peicardium) and cisceral layer of serous pericardium (Epicardium)
Pericardial effusion: fluids in heart muscle, heart wall = occurs in pericardial cavity
7
Q
The Epicardium is also known as the _______ layer of the serous pericardium
A
visceral layer of the serous pericardium
8
Q
The Pericardium (pericardial sac) is composed of two layers: fibrous and serous
What are the faetures?
A
- fibrous: sac w/tough CT
- serous: double layer
- parietal peri
- visceral peri (epicardium covers heart)
-serous fluid fills pericardial cavity
9
Q
3 layers of the wall of the heart
A
- Epicardium (outside layer of CT)
- Myocardium (cardiac muscle)
- Endocardium (inner epithelial and CT lining heart and valves)
10
Q
Chambers of the Heart
A
- Atria
- receive blood
* auricle (ext. chamber) - Ventricle
- expel blood
- separated by septum
* interatrial
* interventricular
11
Q
Chambers of the Heart
A
- Atria
- receive blood
* auricle (ext. chamber) - Ventricle
- expel blood
- separated by septum
* interatrial
* interventricular
12
Q
True/False: The heart valves are flaps that allow blood to flow in only one direction
A
True
13
Q
Describe the Atrioventricular (AV) valves of the heart
A
- between atrium and ventricle
- blood from atrium to ventricle
- bicuspid (mitral; left))
- tricuspid (right side)
14
Q
The semilunar valves of the heart separate the ventricles from the major heart arteries, allowing blood flow out of each ventricle.
List the semilunar valves
A
- pulmonary (RV and R pulmonary trunk)
2. aortic valve (LV and aorta)
15
Q
The valve cusps are held in place by “heart strings” known as ______ which originate from papillary muscles (inside ventrical wall)
A
chordae tendinae
16
Q
True/False: When a chamber wall contracts, blood is pumped through a valve. Backflow increases pressure on the cusps and closes the valves.
A
True
17
Q
AV valves close during _____ contraction.
A
Ventricular contraction
To prevent backflow, papillary muscles contract (chordae tendinae) – keep valve cusps from prolapse
18
Q
Blood returns to heart via
A
superior and inferior vena cava into right atrium
19
Q
End diastolic area describes
A
final contraction of the atria to pump last bit of blood into ventricle
20
Q
Oxygen exchange between blood and tissues occurs at the
A
capillaries
21
Q
Describe cardiac circulation (coronary, pulmonary)
A
Vena cava – RA – RV – pulmonary artery – pulmonary vein – LA –LV – aorta – systemic
22
Q
When does the heart feed itself?
A
Diastole
-coronary artery flaps are open
23
Q
The right coronary artery gives rise to
A
right marginal artery and posterior descending artery
24
Q
the left coronary artery gives rise to the
A
left circumflex and left anterior descending artery
25
The ______ vessels provide oxygenated blood to the heart
Coronary vessels
26
The left circuflex artery supplies blood to
lateral and posterior walls of the left ventricle
27
The PDA branches off of the left circuflex artery 10% of the time. These patients are considered to have ____-dominant circulation
Left
28
The left anterior descending artery supplies blood to
ant. wall of LV and anterior 2/5 of interventricular septum
29
The ______ gives rise to the posterior descending artery (PDA) in patients with right dominant circulation
right coronary artery (RCA)
30
The right marginal artery supplies the
RV
- papillary muscles
- posterior wall of heart
31
Pulmonary arteries carry ______
Pulmoanry veins carry
Arteries: deox blood to lungs
Veins: ox blood to LV of heart
32
______ refers to the series of contractions and relaxations of the heart to produce a complete heartbeat
Cardiac cycle
systole: vent. contraction
Diastole: vent. relax
33
During diastole, the atria and ventricles fill with blood. The atria contract to complete ventricular filling. During this time the ventricles are
relaxed
34
During systole the ventricles ______ forcing blood up and out of the heart arteries. The AV valves shut
Ventricles contract
- Av valves shut "lup"
- Semilunar valves shut"dup"
35
Conduction system of the heart
1. SA "pacemaker" - wall of atrium
2. AV node - septum at junction of RA and LA
3. AV bundle of HIS - interventricular septum
4. bundle branches (R and L)
5. Purkinje fibers - myocardium wall
36
Spontaneous depolarization:
SA --AV--HIS--purkinje
37
Conduction velocity
time required for an electrical signal to spread through cardiac tissue
Speed: Purkinje fibers > SA > AV
38
Describe the Pacemaker action potential
Pacemaker: No phases 1 and 2
Phase 4: HCN “Funny current”
- -T-type Calcium channels
- -Inc. Na2+ influx
- -Dec. K+
Phase 0 (slope): L-type Ca2+ channels
Phase 3: Voltage-gated K+ channels
39
Describe depolarization of Heart
Phase 0 (upstroke): Na2+ influx
Phase 1: K+ efflux (out)
Phase 2: Plateau
- -Influx of Ca2+
- -L-type channels
Phase 3 (down-slope; rapid repolarization):
- Ca2+ channels close
- K+ channels (out)
Phase 4: Na, Ca2+ closed
--K+ open
40
EKG
1. P wave: depol of atria
2. QRS interval: depol of ventricles
3. T wave: ventricular repol.
PR interval: Delay of AV
--ventricles fill
ST segment: ventricle repol starts
41
Describe the conducting zone of the lungs
1. Conducting (airways)
- air in and out
- mucociliary escalatory
- SM lining
- Parasympathetic: Ach: Gq - bronchoconstriction
- Sympathetic: NE - bronchodilation
42
Describe the respiratory zone of the lungs
gas exchange
- alveoli
- elastic fibers and epithelial cells (type I, II)
- alveolar macrophages
43
Type I epithelial (pneumocytes)
squamous cells
- 95% of alveolar surface
- gas exvhange
44
Type II pneumocytes
- granular, cuboidal
- 5%
- surfactant (inc. compliance)
- replace type I
45
Conducting zone volume vs. Respiratory zone volume
Conducting: 150mL
Respiratory: 350mL
46
Emphysema is a desease of the
alveoli
47
Gas exchange begins at
respiratory bronchioles
48
Rhonci (low pitched wheezing) is an obstruction or secretion of the
largeer airways
*COPD, bronhiectasis, pneumonia, cystic fibrosis
49
Rales (crackles) are caused by the opening of the
small airways and alveoli (fluid)
*pulmonary edema, heart failure, pulmonary fibrosis or Resp. distress syndrome
50
Conducting zone are composed of
- cartilage (stops at trachea)
- goblet cells
- cilia (to resp. bronchioles)
- SM (to bronchioles)
*vocalization
51
Terminal bronchioles to alveoli are composed of
elastic fibers
| no cartilage
52
Describe the epithelium in the conducting zone vs. respiratory zones
Conducting:
1. pseudostratified ciliated columnar
2. simple ciliated columnar
Respiratory:
3. respiratory epithelium (ciliated simple cuboidal)???
53
Dead Space is air that you breathe in, but does not participate in gas exchange. What are the two divisions?
1. anatomic: nose to bronchioles
- no gas exchange
- "last air in, first air out"
2. Physiologic
- anatomic + functional
- air in resp. zone
- no gas exchange
54
Physiologic Dead Space
Taco Paco Peco Paco
Vd = VT PaCO2 - PeCO2/PaCO2
*If PeCO2 = 0 then no gas exchange
55
Preload is determined by
EDV
- EDV is proportional to right atrial pressure
* inc. RAP = inc. preload
56
Afterload is determined by what the ventricle is working against when ejecting blood. For the left ventricle, afterload is determined by
Aortic pressure
* higher aortic pressure = higher afterload
* RV = pulmonary artery
57
Stroke Volume is the volume of blood pumped out (LV) with every contraction (heartbeat)
*What are the factors affecting stroke volume?
Contractility
Preload
- inc. preload: inc. SV
- inc. contract: inc. SV
- dec. afterload: inc. SV
58
Calculate SV
SV = EDV - ESV
59
Cardiac output is the volume of blood pumped by the heart every minute.
Calculate CO
CO = SV x HR
CO = rate of O2 consump/arterial O2 - venous O2
60
Ejection fraction is a comparison of the volume of blood pumped out of the LV to the colume of the blood that remains in the LV after contraction
Calculate EF
EF = EDV -ESV/EDV
61
Stroke work is the work the heart performs on a single beat
Calculate stroke work
Stroke work = aortic pressure x stroke volume
62
Resistance is affected by
viscosity, length of blood vessel = direct proportion
radius = indirect proportion
*small radius: high resistance
63
Mean arterial pressure is a function of the hydrostatic forces exerted by the volume of blood in the circulation and the resistance within the vessel.
Calculate mean arterial pressure in the heart
MAP = CO x TPR
-
64
Pulse pressure
Systolic - diastolic
normal: 30-50
65
Blood flow describes the movement of blood over a given period of time
Calculate blood flow
Q = ΔP / R
Velocity:
V = Q/A
66
Compliance (of the heart) indicates the ability of the tissue to expand as the pressure rises
Calculate compliance
C = V/P
67
Elastance (of the heart) is the ability to recoil
Calculate elastance
E = P/V
68
Minute Ventilation is the amount of air breathed in per minute
VT x breaths/min
* 500
* Normal Respiratory rate: 12-20 bpm
ex: 500 x 12
69
Alveolar ventilation is the rate of air movement into and out of the lungs/minute
*corrects for dead space
(VT - VD) x breaths/min
ex; 500 -150 x 12 = 4200ml/min
70
What can be used to measure Residual volume?
Helium or Nitrogen
*can't use spirometry
71
_______ is the volume inspired or expired with each normal breath. (at rest)
Tidal volume
500mL
72
______ is the volume that can be inspired over and above the tidal volume. Used during exercise.
Inspiratory reserve volume
*3000mL
73
_____ is the volume that can be expired after the expiration of a tidal volume.
Expiratory reserve volume
*1000mL
74
_______ is the volume that remains in the lungs after a maximal expiration. (cannot be measured by spirometry)
Residual volume
*1200mL
75
_____ the sum of tidal volume and IRV.
Inspiratory capacity
ICV: VT + IRV
76
_____ is the sum of ERV and RV. The volume remaining in the lungs after a tidal volume is expired. Includes the RV, so it cannot be measured by spirometry.
Functional residual capacity
FCR: ERV + RV
77
_____ is the max volume of air that can be expired after inspiration. It is the sum of tidal volume, IRV, and ERV.
Vital capacity
VC = VT + IRV + ERV
78
_____ is the sum of all four lung volumes. The volume in the lungs after a maximal inspiration.
*(includes RV, so it cannot be measured by spirometry).
Total Lung capacity
TLC = VT + ERV + IRV + RV
79
Obstructive vs. restrictive lung disease
Obstructive diseases: move flow volume loop to the left
- can't fully exhale
- inc. RV
- inc. TLC
- dec. VT
ex: asthma, bronchitis, emphysema
Restrictive:
- move to right
- can't fully inhale
- dec. TLC
- dec. RV
ex: fibrosis
80
FEV1/FVC ratio is acquired by performing the Forced expiration test: inhale as much as possible and rapidly exhale. What are the values for obstructive and restrictive lung diseases compared to normal?
FEV is forced expiratory volume in 1 sec.
Normal: 4/5 = 0.7 - 0.8
Restrictive: 3/3
Obstructive: 1/3
Obstruction (barrel chest): <70%
Restrictive: >70% or normal
81
Boyle's law
volume of gase is inversely proportional to pressure
82
True/False: Pulmonary pressures are expressed relative to atmospheric pressure
True
83
Atmospheric pressure is the pressure of outside air. What is the normal atm?
760mmHg
84
At rest, the lung volume is equal to
FRC
85
Intralveolar pressure is within alveoli. At rest, the intralveolar pressure is equal to
atmospheric pressure
0
86
During inspiration
- diaphragm and external intercostals _____
- Alv p. ____ atm P.
- Lung vol = _____
- diaphragm and EIC's contract
- Alv. pressure < atm. P.
- Lung volume = FRC + 1TV
87
Intrapleural pressure inside the pleural space is always ____ than intraalveolar pressure
Less than
*always negative during breathing
88
During expiration:
- diaphragm and external intercostals _____
- Alv p. ____ atm P.
- Lung vol = _____
- Diaphragm and EIC's relax
- Thoracic space dec.
- Intrpleural pressure returns to normal
- Alv. P. > atm P
- lung vol. return to FRC
89
True/False: large sized alveoli have a less tendency to collapse
True
*surfactant dec. pressure and thus dec. tendency to collapse in small alveoli
90
Compliance (lungs) is a measure of distensibility. How is it calculated?
C = V/P
91
Compliance vs. Elastance
Distensibility vs. recoil
1. Inc. elastance (dec. compliance)
- restrictive lung diseases (fibrosis)
- dec. surfactant
2. inc. compliance (dec. elastance)
- aging
- asthma
- obstructive (emphysema)
92
Hypoventilation vs. Hyperventilation
Hypoventilate:
- -retain CO2
- -dec. O2 (< 100mmHg)
Hyperventilate:
- -dec. CO2 (>40mmHg)
- -inc. O2 (>100mmHg)
93
Hb affinity for O2 is affected by:
1. CO2
2. Acidity (pH)
3. DPG
4. Exercise
5. Temperature
Shift right: CADET (inc.)
Shift left: dec. all
94
The majority of CO2 is not bound to Hb, rather it is converted to HCO3 in RBC's. Describe this process
- converted to H2CO3 via carbonic anhydrase
- H2CO3 breaks into H+ and HCO3-
- HCO3- exchange w/chloride shift into plasma
95
Chemoreceptors in the respiratory respond to chemical changes causing inc. breathing rate. List the types of receptors and the chemicals they respond to
Central:
- medulla
- dec. pH
- inc. CO2
Peripheral:
- carotid and aortic bodies
- dec.PO2
- inc. PCO2
- dec. pH
96
Resistance to blood flow equation
F = deltaP/R
- P = pressure
- Resistance
97
Which of the following provides oxygenated blood supply to the lungs?
1. pulmonary arteries
2. bronchial arteries
Bronchial arteries:
-supply bronchi and pleura
98
True/False: the pulmonary circulation has the capacity to accomodate two-fold to three-fold inc. in CO with little change in the pulmonary artery pressure
TRue
*ex: exercise
99
Fetal shunts: (R to L)
- Foramen ovale
- Ductus arteriosus
FO: R atrium to L atrijm
DA: shunt from pulmonary artery to aorta
*High pulm. pressure
100
True/False: In a standing position, gravity causes blood to naturally flow downward towards Zone 3
True
| Zone 3: alveolar pressure less than venous pressure
high gas exchange
101
Sight of highest airway resistance in lungs
*turbulent flow
Conducting zone: Medium sized Bronchi
102
Normal V/Q ratio
Normal: 0.8
-exercise = 1
103
What happens when V/Q is infinite?
--Ventilation, no perfusion
*pulmonary embolism - obstructed pulmonary artery
**dead space problem
104
What happens when V/Q is zero?
--Perfusion, no ventilation
- shunt problem
- complete airway obstruction, ARDS
105
What happens when V/Q is low?
wasted perfusion
- low compliance
- fibrosis, bronchitis, asthma
106
What happens when V/Q is high?
some wasted ventilation
e.g. emphysema
107
Hypoxia is decreased O2 in the _____
Hypoxemia is decreased O2 to the
Hypoxia: tissues
-dec. organ perfusion
Hypoxemia: arteries
< 60mmHg
<90%
108
The following are potential causes of what disease?
- Ischemia
- Hypoxemia
- Decreased O2-carrying capacity of blood
Hypoxia
Ischemia:
- A clot
- V clot
- shock
Dec.O2
- anemia
- CO poisoning
- cyanide (ox phos)
- Methhemoglobineia
109
Why is hypoxia bad?
Decr. ATP
- reversible cell. injury and swelling (Na2+)
- irreversible injury and death (membrane damage; Ca2+)
- acidosis
110
Hypoxemia caused by
dec. PIO2
- hypoventilation
- high altitude
- diffusion
- V/Q defects
- R to L shunt
111
At a high altitude, what would you expect the A-a gradient to be?
normal
112
When you have low oxygen levels in the lungs, Hypoxic vasoconstriction occurs in the lungs. What does this cause?
Inc. resistance
- redirect blood flow from poorly ventilated alveoli, to good alveoli
* more perfusion to good areas
113
Aa gradient:
PAO2 - PaO2
What is the normal range?
PAO2 = partial pressure of O2 in the alveoli
PaO2 = partial pressure in arteries
5-15mmHg
114
Dec. PaO2 + Normal Aa gradient is caused by
extrapulmonary (hypoxemia)
| hypoventilation - benzos, opiates or high altitude
115
Dec. PaO2 + Inc. Aa gradient is caused by
V/Q mismatch
R to L shunt
Diffusion impairments
116
Effect of 100% O2 on the A-a gradient on:
1. High altitude
2. Hypoventilation
3. R to L shunt
1. Altitude: normal
2. Hypo: normal
3. R to L: Inc; no improvement
117
1. CO2, N2O and O2 (normal conditions) are all ____ limited gases
2. CO and O2 (during exercise) are ____ limited gases
1. perfusion
| 2. diffusion
118
Describe adaptations to dec. O2 availability at high altitude
Short term:
1. inc. respiration rate (hyperventilation)
*resp. alkalosis
2. Inc. heart rate
- relieve perfusion limitation
Long term:
3. HCO3- excretion
- -dec. pH
4. inc. EPO (RBC #)
- inc. carrying capacity
5. Inc. DPG
119
Response to smoking (lungs)
1. squaous metaplasia
2. goblet cell hypertophy, mucous hypersecretion
3. chemotaxis (protease-anti-protease imbalance); inc. free radicals
4. inactivate AAT and anti-oxidants
5. inc. laryngeal cancer
120
Acidosis is characterized by too much acid in the body.
"not blowing off enough in lungs"
not excreting enough acid or inc. H+ ion formation
121
Alkalosis is characterized by less acidity
-lungs blow off too much
| -excrete too much
diuresis, diarrhea
122
Metabolic acidosis
- high H+
- low HCO3-
* lungs: hyperventilate
* kidneys: excrete acids
123
Normal ranges
pH: 7.35-7.45
PCO2: 35-45
PO2: 95-100
HCO3-: 22-26
124
Metabolic alkalosis
*metabolic: H+ and HCO3- are opposite
- low H+
- high HCO3-
Lungs: hypO
kidneys: excrete HCO3-
125
Respiratory acidosis:
- high CO2
- High H+
- high HCO3-
--inc. renal HCO3- reabsorption
126
Respiratory alkalosis
-low CO2
-low H+
=low HCO3-
-dec. renal HCO3- reabsorption
127
Which of the following vessels would have the highest velocity?
a. aorta
b. arteries
c. capillaries
V = Q/A
- highest: aorta
- lowest: capillaries (exchange)
128
Ohm's law describes that blood flow is determined by the pressure difference of a vessel and resistance.
Which of the following vessels has the higest resistance?
A. aorta
B. arteries
C. arterioles
D. capillaries
Q = P/R
Highest: Arterioles
129
Poiseulle's law describes resistance to blood flow as being dependent on the arrangement of the blood vessesl (series vs. parallel)
What other factors affect flow?
R = 8nl/pi r2
n=viscosity
l=length
r=radius
Increase viscosity = inc. resistance
Increase length = increase resistance
Increase radius = dec. resistance
130
Reynold's number describes flow of blood (laminar vs. turbulent). It is determined by the following equation:
N = pdv/n
```
p = density of blood
d= diamter of vessel
v = velocity of flow
n = viscosity
```
If N < 2000 what kind of flow would we expect?
Laminar flow
>2000 would be turbulent
NOTE: max velocity at center of vessel
131
Vascular compliance (capacitance) is determined by the equation: C = V/P
```
C= compliance
V= volume
P= pressure
```
Which vessels have the highest compliance? The lowest?
HIghest: veins
Lowest: aging arteries
132
How do you determine pulse pressure?
Systolic - Diastolic
*highest in large arteries
133
If a patient presents with arteriosclerosis, what happens to PP and systolic pressure?
inc. PP, inc. SyS, inc. MAP
134
If a patient presnts with aortic stenosis, the aorta cannot easily pump blood to the system. What happens to pulse pressure (PP), MAP, and systolic pressure?
all decrease
135
True/False: greater fraction of time is spend in diastole than in systole
True
136
How do you calculate mean arterial pressure?
| MAP
Diastolic + 1/3 Pulse pressure
137
The dichrotic notch on a curve represents
aortic valve closing
138
Which phase of the SA node action potential sets the heart rate?
Phase 4
139
When the SA node is dysfunctional, a latent pacemaker can assume the job. What is the term for this?
ectopic pacemaker (AV, HIS, Purkinje)
140
Contraction of the SM of vessels requires which adrenergic receptor?
a1
| M3
141
Heart function is under the control of which adrenergic recptor?
B1
rate, conduction velocity, contractility
(M2)
142
SK muscle vessels are under the control of which adrenergic receptor?
a1 - constrict
B2 - dilate
(M3)
