heart Flashcards
1
Q
the heart rests on what
A
the diaphragm
2
Q
how much of the heart is to the left of the midline
A
2/3
3
Q
where is the mediastinum
A
between the lungs
1st rib to diaphragm
sternum to vertebral column
4
Q
what does the mediastinum contain (6)
A
heart, ascending aorta, SVC
trachea
main stem bronchi
esophagus
5
Q
the mediastinum is bigger on (AP/PA)
and why
A
AP
magnification
6
Q
what can change the size of the mediastinum (4)
A
PA versus AP
SID (smaller is more mag)
rotation (LPO)
rather (bigger on exp)
7
Q
on what projection ONLY can you measure the CT ratio
A
PA
8
Q
how do you measure the CT ratio
A
the widest part of the heart, divided by the widest part of the thorax
9
Q
on a normal Chets, the ct ratio should be what
A
<50%
10
Q
what is CT ratio
A
cardiac thoracic ratio
11
Q
what is shown here
A
a MASSIVE mediastinum due to a tumour
12
Q
what is this “hole”
A
left main stem bronchus
13
Q
what is in the thoracic cavity
A
2 pleural cavities
pericardial cavity
pericardium
14
Q
what is the pericardium
A
the membrane that surrounds and protects the heart
15
Q
what is the difference between the pleura and and pericardium
A
the pericardium has 2 layers
16
Q
what are the 2 layers of the pericardium
A
fibrous pericardium
serous pericardium
17
Q
what is the fibrous pericardiumm
A
attaches to aorta, pulmonary trunk, and SVC
stabilizes position, prevents overstretching
18
Q
what is the serous pericardium
A
thinner, delicate layer
(parietal and visceral layers)
19
Q
what are the 2 layers of the serous pericardium
A
parietal and visceral layers
20
Q
what is between the parietal and visceral layers of the serous pericardium
A
pericardial fluid
21
Q
what are the 3 layers of the heart wall
A
epicardium
myoardium
endocardium
22
Q
(T/F) the visceral layer of serous pericardium and epicardium of heart wall are different things
A
false -same
23
Q
what type of muscle is the myocardium
A
striated muscle
not skeletal!!
24
Q
what % of the heart wall is made up of the myocardium
A
95%
25
what is the endocardium
the smooth inner layer
26
how many chambers does heart have
4 chambers
27
where does the base of the heart sit
towards the right shoulder
28
where does the apex of the heart sit
towards the left hip
29
what enters and exits the base of the heart
SVC/IVC enter
ascending aorta, pulmonary arteries/trunk exit
30
does the heart sits parallel in the chest?
NO!
it is rotated to the left and sits backwards
31
the base of the heart is formed by what
the atria
32
what do the sulci do (3)
separate the chambers
contain coronary vessels
contain fat
32
where do the coronary arteries travel through
the sulci
33
the coronary sulcus does what
separates the atria from the ventricles
34
what do the interventricular sulci do
separates the ventricles
35
on an AP/PA chest, do you ever see the left atrium
NO NEVER EVER EVER!!
36
what do you see on an AP/PA instead of the left atrium
the left auricle
37
what projection can you see the left atrium on
a lateral
38
what is the coronary sinus
a large vein that empties venous blood into the right atrium
39
where and what are auricles
on the anterior surface of each atrium
increases capacity
40
from where does the right atrium receive blood (3)
SVC, IVC, coronary sinus
41
SVC brings blood from where
head, neck and upper extremities
41
where does the IVC bring blood from
the lower extremities, abdomen, and thorax
42
where does the coronary sinus bring blood from
the deoxygenated blood from the heart
43
what is the fossa ovalis
remnant of the foramen ovale
from when fetus
43
what are the pectinate muscles
muscles on the aterior surface (inner wall) of R atrium and L auricle
44
the right AV valve is also known as:
the tricuspid valve
45
where is the tricuspid valve located
pointed down inside the ventricle, next to the atrium
46
what are trabeculae carnae
grooves in the endocardial part of heart wall
47
what do trabeculae carnae form
papillary muscles
48
papillary muscles connect what
the mitral and tricuspid valves (through chordae tendinae) to inner walls
49
chordae tendineae do what
the cusps of tricuspid valve to papillary muscles (prevents the tricuspid valve from folding up into the atrium)
50
what type of valve is the pulmonary valve
semilunar (3 cusps)
51
the pulmonary valve pushes blood to where
the pulmonary trunk
52
the pulmonary trunk branches into what
the right and left pulmonary arteries
53
the left atrium recieves blood from where
the 4 pulmonary veins
54
in the left atrium, pectinate muscles are only in the ___
auricle
55
what is the other name for the bicuspid valve
the mitral valve
56
the mitral valve has how many cusps
2
57
which valve is more superior (pulmonary/tricuspid)
the pulmonary valve
58
the left ventricle is 2-3x (thicker/thinner) than the right ventricle
why
thicker
needs to overcome the diastolic BP
59
the aortic valve has how many cusps
three
60
L1
superior vena cava
61
L2
right atrium
62
L3
inferior vena cava
63
R1
main pulmonary artery
64
R2
left atrial appendage
65
R3
left ventricle
66
can you see right ventricular enlargement? on AP/PA
no
67
can you see a left ventricular enlargement on an AP/PA
yes
68
what is the most anterior part of the heart
the right ventricle
69
how much of the heart touches the body of the sternum
1/3
70
what does 2/3 of the heart touching the sternum indicate
right ventricular enlargement
71
it is NOT the bicuspid valve, it is the ____
mitral valve
72
which valves are more superior
the aortic and pulmonary valves
73
when the mitral and tricuspid valves are open, the cusps project where
INTO the ventricle
74
when the ventricles are relaxed, what else is relaxed
papillary muscles
chordae tendinae
75
what happens when the ventricles contract?
ventricular pressure goes up
tricuspid and mitral valves are forced closed
papillary muscles contract, chordae tendineae contract
76
what do tightened chordae tendineae prevent
cusps from EVERTING into atria
backflow of blood into atria
77
what is it called when the chordae tendineae do not hold the valves fully closed
regurgitation
heart murmur
78
the free borders of the semilunar valves project where
into the lumen of the artery
79
semilunar valves open into what
the artery
80
what is normal BP
120/80
81
how much pressure does the ventricle have to build up before the blood is pushed out
80 (diastolic)
82
in 120/80 BP, what is each number
systolic/diastolic
83
semilunar valves prevent what
backflow into ventricles
84
what is stenosis
narrowing of a valve
85
what is insufficient or incompetent valves
valves that fail to completely close
86
why are the ? valves replaced more frequently
there's more pressure in the left side
87
what is the pressure in the pulmonary trunk
20
88
what is the pressure in the aorta
80
89
in a fetus, are the lungs functional?
how does this affects the heart
nope!
structured to bypass the lungs
90
what heart structures do fetuses have
foramen ovale
ductus arteriosus
91
what does PFO mean?
patent foramen ovale
didn't close around birth
92
what is the foramen ovale
FETAL
opening between the atria
93
what does the cardiac foramen ovale turn into
the fossa ovalis
94
what is the ductus arteriosis
FETAL
between pulmonary trunk and distal part of aortic arch
94
what does the ductus arteriosus turn into
ligamentum arteriosum
95
if the fetal heart openings do not close, what happens?
blod shunts left to right, pulmonary hypertension
96
what is pulmonary hypertension
excess BP in the lungs
97
in situ, what is the exposition of the heart (3)
rotated to the left
on angle, with apex further to the left
levocardia
98
what does levocardia mean
sits towards the left side of the body
99
what is the average size of an adult heart
the size of a closed fist
100
what is the average weight of the male/female hearts
male 310 g
female 225 g
101
what is it called when the heart is on the right side
dextrocardia
102
what forms the right border of the heart
mostly the right atrium
103
what forms the inferior border of the heart
some right atrium
right ventricle to apex
104
what forms the left border of the heart
left ventricle and some left auricle
105
L2
rt atrium
106
L3
rt ventricle
107
R1
ascending aorta
108
R2
pulmonary trunk
109
R3
lt ventricle
110
what is purple here
the left AURICLE.
NOT ATRIUM. YOU CANT SEE THE L ATRIUM ON AN AP EVERRRRRRRR
111
L1
SVC
112
why is this a bad heart image (and not on your test
not properly rotated!!
113
why is the interventricular sulcus important
where the coronary arteries and veins pass through
114
what are the 2fibre types of the conduction system of the heart
contractile fibers and autorhythmic fibres
115
what type of fibres make of 99% of the cardiac cells
contractile cells
116
what type of fibres make up only 1% of the cardiac cells
autorhythmic fibres
117
what are contractile fibers
make up 99%
the "working" fibers that create contractions
118
what are the 5 types of nodes and conducting cells
SAnode
AV node
AV bundle (bundle of His)
right and left bundles
purkinje fibres
119
what is the SA node
sinoatrial node
the pacemaker
120
does the Sa node contain autorhythmic fibres?
yes
121
where is the SA node
right atrial wall near the opening of SVC
122
what is the AV node
atrioventricular node
slows the travel speed of action potentials
123
HOW does the AV node slow the speed of action potential travel
smaller diameter of fibres
fewer gap junctions
124
what is the normal SA node discharge at rest
70-75 bpm
125
if the SAn were to fail, what takes over ht peacemaker function
the AVn
126
what is wrong with the AVn taking over the pacemaker fn
"ectopic pacemaker"
- means there is an issue with SAn
- fires more slowly
127
what is an ECG
electrocardiogram
monitors the electric currents generated by the heart
128
what are the 3 deflection waves
P wave
QRS wave
T wave
129
what are the times for the 3 deflection waves (roughly)
P wave - 0.08 sec
QRS wave - 0.08 sec
T wave - 0.16 sec (slow!!)
130
what is happening during the ECG P wave
atrial depolarization
131
what is happening during the ECG PR segment
AV nodal delay
132
what is happening during the ECG QRS complex
ventricular depolarization
(+ atria repolarize)
133
what is happening during the ECG ST segment
time when the ventricles are contracting and emptying
134
what is happening during the ECG T wave
ventricular repolarization
135
what is happening during the ECG TP interval
time when ventricles are relaxing and filling
136
during what wave doe the impulse move from the SA node through the atria
P wave
137
what is the average heart rate (resting)
75 bpm
138
what is the length of the average cardiac cycle
0.8 seconds
139
how long does atrial systole last
0.1 second
140
what happens during atrial systole (4)
- blood flows body to atria to ventrictles (105 ml)
- AV valves open, SL valves closed
- firing of SAn
- pushes the rest of blood into ventricles (25 ml)
141
what is EDV + amount
end diastolic volume
ventricles contain 130 ml at end of diastole
142
how much blood do ventricles contain at the end of diastole
130 ml
(105 + 25)
143
how long does ventricular systole last
0.3 sec
144
what happens during ventricular systole (4)
- ventricular depolarization, then contraction
- isovolumetric contraction
- ventricular ejection (when pressure in ventricle > pressure in artery)
- SL valves open
145
what is the ESV
60 ml
146
explain ventricular diastole
- pressure in vents dec, closing SL valves
- when
147
what is stroke volume
amount of blood pumped out by heart, each beat
148
SV = ?
SV = EDV - ESV
149
SV = (numbers)
70ml = 130ml - 60ml
150
what is the EF formula
EF = SV/EDV x 100
151
what is a normal ejection fraction
50-70
152
what EF value is the threshold to be considered heart failure
< 40
153
what are the 4 coronary veins
great cardiac vein
middle cardiac vein
small cardiac vein
anterior cardiac vein
154
the coronary veins all Crain into what
the CORONARY SINUS
155
what does the great cardiac vein do
drain area of heart supplied by left coronary artery
156
what does the middle cardiac vein do
drains area supplied by the posterior interventricular branch
157
what are the treatments for blocked arteries?
stent
bypass (cabg)
158
what is a cabg
coronary artery bypass graft
159
what is the most frequently bypassed coronary artery
left coronary artery
160
is there ever a time where all 4 valves are clsoed
isovolumetric contraction/relaxation
161
will anything be ejected if afterload is not reached during ventricular systole
no!
162
what is the afterload in the pulmonary trunk
20
163
what is the afterload in the aorta
80
164
what is cardiac output
amount of blood pumped out by each side of heart in ONE MINUTE
165
CO = ?
CO = HR x SV
166
CO = ? (numbers)
CO = 75 x 70
= 5.25 L/min
167
what is the average CO
5.25 L/min
168
what factors affect stroke volume
1. preload
2. contractilit
3. afterload
169
170
what is preload
the degree of stretch on the heart before it contracts
170
what is contractility
the forcefulness of the contraction
171
what is afterliad
the pressure threshold that must be exceeded before ejection of blood from ventricles is able to occur
172
what does the Frank-Starling Law state
greater preload leads to a greater contraction
preload is proportional to EDV
173
what keeps the 2 ventricles in balance
Starling's law
174
EDV is affected by what
duration of ventricular diastole (filling time)
venous return
175
what increases contractility (3)
- ANS (symp: epi and norepi)
- increased Ca++ levels
- adrenergic drugs
176
what decreases contractility (3)
- calcium channel blockers
- anoxia
- acidosis
177
what are the afterload values in the R/L ventricles
right vent - 20 mmhg
left vent - 80 mmhg
178
an increase in afterload causes...
a decrease in stroke volume
179
what can increase afterload
hypertension
atherosclerosis
180
measuring actual stroke volume requires what
catheterization
181
the following may modify what: hormones, neural influences, age, gender, physical fitness, body temp
heart rate !!
182
what part of the brain controls the heart rate
cardiovascular centre in the medulla oblongata
183
what parts of the ANS control the HR
sympathetic
parasympathetic and vagus nerve (+ acetylcholine)
184
where are the chemoreceptors and baroreceptors that affect HR
aortic arch
carotid sinus
185
where is the carotid sinus
first part of internal carotid artery
186
how do chemicals reglate HR
- epi and norepi from adrenal glands
- exercise, stress, excitement stimulates release of more hormones
- increases both rate and contraction stength
187
what are arteries
carry blood AWAY from heart
188
what are veins
carry blood TO heart
189
what are capillaries
exchange vessels
190
what ensures the same volume of blood flows in each circuit
Starling's Law
191
explain the pulmonary circuit (3)
- R side of heart is the pump
- deoxy from body is pumped out of pulmonary trunk
- oxy is returned to left atrium view pulmonary veins
192
explain the systemic circuit (3)
- L side of heart is the pump
- oxy is pumped to the entire body
- deoxy is returned to the right atrium
193
what does coronary circulation do
supplies blood to the muscles of the heart
194
state blood flow in the coronary circuit when the heart relaxes (5)
coronary arteries
capillaries
coronary veins
coronary sinus
right atrium
195
what are the 2 parts of the left coronary artery
LAD left ant desc artery
circumflex branch
196
where is the LAD
part of L coronary artery
anterior interventricullar sulcus
197
what does the LAD do
supplies oxy blood to walls of both ventricles
198
where is the circumflex branch
part of L coronary artery
coronary sulcus
199
what does the circumflex branch do
supplies oxy blood to walls of left ventricle and atrium
200
what are the 2 parts of the right coronary artery
PDA - posterior descending artery
marginal branch
201
where is the PDA
part of R coronary artery
posterior interventricular sulcus
202
what does the PDA do
supplies oxy blood to walls of both ventricles
203
where is the marginal branch
part of R coronary artery
in coronary sulcus
204
what does the marginal branch do
supplies oxy blood to the wall of the right ventricle
205
how does arterial anastomosis protect the heart
helps restore healthy circulation when blood vessels have been damaged
206
what is imaged here?
dextrocardia
207
what is shown here
pleural effusion
