CARDIAC ANATOMY Flashcards
1
Q
Where is the septo marginal trabecula located?
A
Right ventricle
The “moderator band” is important because it carries part of the right bundle branch of the AV bundle of the conduction system of the heart to the anterior papillary muscle. This shortcut across the chamber of the ventricle seems to facilitate conduction time, allowing coordinated contraction of the anterior papillary muscle.
2
Q
What are the contents of the middle mediastinum?
A
- Heart
- Great blood vessels
3
Q
Why can the mediastinum accommodate movement and volume changes?
A
due to the looseness of the connective tissue, combined with the elasticity of the lungs and pleura
4
Q
What does the pericardium enclose?
A
heart and roots of great vessels
5
Q
Layers of the pericardium:
A
- Outer fibrous layer (fibrous pericardium)
-
Inner double layered sac (serous pericardium):
- Parietal pericardium (outer layer)
- Visceral pericardium (inside layer) AKA epicardium
6
Q
Outer fibrous layer of the pericardium attaches to:
A
- Outer layer of the great vessels
- Central tendon of the diaphragm
7
Q
Function and contents of the pericardial cavity:
A
- Contains a thin layer of serous fluid.
- Allows the heart to beat in a frictionless environment
8
Q
Innervation of the parietal pericardium:
A
phrenic nerve
9
Q
innervation of the visceral pericardium
A
no innervation, insensitive to pain
10
Q
Inflammation of the pericardium:
presentation?
A
- Pericarditis
- Presents as substernal pain and can result in pericardial effusion
- Pericardial rub (auscultation)
11
Q
Location of the heart
A
2/3 to the left of the median plane
within the pericardial sac
12
Q
Where is the apex of the heart found?
A
- Most inferior portion of the heart
- 5th intercostal space
- midclavicular line in supine
13
Q
where is the point of maximun impulse located?
A
in the apex of the heart
(5th intercostal space)
14
Q
what is the point of maximal impulse?
A
Apex of the heart, is where the cardiac impulse can be best palpated on the chest wall. Frequently, this is at the 5th intercostal space
15
Q
What structure of the heart forms the apex?
A
tip of the left ventricle
16
Q
What structure of the heart forms the base?
A
2 atria
17
Q
where is the base of the heart located?
A
- The most superior portion of the heart
- 2nd intercostal space
18
Q
Aorta and pulmonary trunk exit and the superior vena cava enters the heart here:
A
Base of the heart (most superior portion)
2nd intercostal space
19
Q
layers of the heart
A
- Epicardium AKA visceral pericardium
- Myocardium
- Endocardium
20
Q
What is the shape of the R and L ventricles?
A
- R ventricle = crescent shaped
- L ventricle = conical in shape
21
Q
Myocardial cells are grouped in to 2 structural categories:
A
- Mechanical cells (myocytes)
- Conductive cells
22
Q
The metabolic processes of the myocardium are almost exclusively…
A
aerobic
23
Q
Intercalated disks join myocytes (mechanical cells) together to form a
A
syncytium
24
Q
what make up the 2 syncytiums of the heart?
A
the atria and ventricles
25
4 Properties of myocardial cells:
* **Automaticity:** Ability to initiate own depolarization, to contract in the absence of stimuli, w/o direct
stimulation needed from a nerve
* **Rhythmicity:** Ability to contract in a regular, rhythmic manner
* **Conductivity:** Ability to spread impulses to adjoining cells quickly
* **Excitability:** The cells transmit nerve impulses
26
Can myocardial cells replace injured cells?
NO
27
receives blood from the **veins of the heart** and delivers it to the right atrium
Coronary sinus
28
where is the coronary sinus located?
**Coronary sulcus** or groove (aka: atrioventricular sulcus/groove)
29
what is in the coronary sulcus?
the coronary sinus
30
what runs over the **anterior interventricular sulcus?**
blood vessels and fat
31
what is the **cardiac skeleton** made of?
**anulus fibrosus (fibrocartilaginous tissue)**
32
what is the function of the **anulus** **fibrosus**?
* Separates the atria from the ventricles
* Acts as electrical insulator between atria and ventricles so impulses only move through the AV node
33
what acts as electrical insulator between atria and ventricles so impulses only move through the AV node?
**anulus** **fibrosus**
34
5 types of WBC:
* **neutrophils**
* eosinophils
* basophils
* monocytes
* **lymphocytes**
35
leukocytes AKA
WBC
36
**erythrocytes** AKA
Red blood cells (RBC)
37
What is the plasma of the blood made of?
* Suspends RBC, WBC, and platelets
* Has gases, salts, carbohydrates, proteins, and lipids
38
Pulmonary arterial pressure is ______ that of systemic pressures
1/6th
39
Where is the **SA node** located?
Right atrium
40
what is the **fossa** **ovale** and where is it located?
* On the **right atrium**
* During fetal development, the foramen ovale allows blood to pass from the right atrium to the left atrium, bypassing the nonfunctional fetal lungs while the fetus obtains its oxygen from the placenta.
41
what is the main concern with **atrial septal defect**
can overflow the pulmonary system
42
Normal filling pressure of the right atrium AKA **central venous pressure (CVP)**
0 - 8 mmHg
43
Parallel muscle bundles that compose the inner wall of the right atrium – “comb like”
***pectinate muscles***
44
true or false: **orthotopic heart transplants** usually involve the excision of the RA (LA and great vessels are left in place) and the donor's heart is then attached to the RA
true
45
**right atrioventricular valve** AKA
composed of:
* **TRICUSPID VALVE**
* Composed of 3 cusps/leaflets: anterior, posterior and septal (medial)
* These are thinner than those of the mitral valve
46
AV valves system of structures:
* from the wall of ventricle:
1. Trabeculae carneae (aka: Rathke’s bundles)
2. Papillary muscles
3. Chordae tendineae
4. Valve leaflets/cusps
5. Valvular orifice surrounded by an annulus
47
Normal systolic pressure in the right ventricle = ?
End diastolic pressure = ?
* right ventricle = 15-28 mm Hg
* 0-8 mm Hg
48
which is the thickest layer in the veins?
How about in the arteries?
* Veins: *tunica adventitia or* *externa*
* Arteries: *tunica media*
49
In the right ventricle, resistance of pulmonary circulation is about ____ that of systemic circulation
1/10th
50
the right ventricle generates less than ____ the stroke work of the left ventricle
¼
51
right semilunar valve AKA
PULMONARY VALVE
52
left semilunar valve AKA
**AORTIC VALVE**
53
how many leaflets/cusps do the semilunar valves have?
3
54
true or false, semilunar valves open and close solely based on pressure gradient changes in the heart during the cardiac cycle
true
55
what is the location of the **right semilunar valve**?
**3rd costal cartilage to the left of the sternum**
(AKA pulmonary valve)
56
Contraction of the right ventricle pushes blood through the ________ into the pulmonary trunk
pulmonary valve
or right semilunar valve
57
the **left atrium** collects blood from where?
the right and left pulmonary veins
oxygenated blood
58
What represents the original heart tube and serves no function
Auricular appendage (or “dog ear”)
59
Blood flows through the left ______ into the left ventricle
AV orifice (mitral valve)
60
what is the normal filling pressure of the **left atrium**?
4-12 mm Hg
61
Forms most of the posterior surface of the heart
left atrium
62
**Collects** blood from right and left pulmonary veins:
– Carry oxygenated blood from the lungs
left atrium
63
Walls of the left atrium are slightly thicker than right atrium, why?
the left atrium does more work against the resistance of the sistemic circulation
64
In certain cardiac conditions (ex:
atrial fibrillation) a ________ can form on the wall of the left atrium and if it breaks off, it can travel to and occlude peripheral arteries (an occlusion of the artery of the brain can result in a stroke)
**thrombus**
65
**Mitral Valve** AKA
**Left AV Valve**
AKA **bicuspid valve**
66
what guards the opening between the left atrium and the left ventricle
**mitral valve** AKA **left AV valve** AKA **bicuspid valve**
67
the physician is listening with the stethoscope situated in 5th intercostal space and midline of the clavicle:
Mitral valve AKA bicuspid valve
68
where is the mitral valve (bicuspid valve) **located**?
Situated posterior to sternum at level of 4th left costal cartilage
69
which is the most frequently diseased valve in the heart?
Mitral Valve
70
what is **Mitral Valve Insufficiency?**
* Mitral insufficiency (MI), mitral regurgitation or mitral incompetence is a disorder of the heart in which the **mitral valve does not close properly** when the heart pumps out blood.
* It is the abnormal **leaking of blood backwards** from the left ventricle, through the mitral valve, into the left atrium, when the left ventricle contracts, i.e. there is regurgitation of blood back into the left atrium.
* MI is the most common form of valvular heart disease
71
Mitral Valve Prolapse:
displacement of an abnormally thickened mitral valve leaflet into the left atrium during systole
72
Mitral Stenosis
**narrowing of the orifice** of the mitral valve of the heart.
73
The **left ventricle** receives blood from left atrium via mitral valve and pumps blood into ______ via ________ .
**aorta** (and systemic circulation) via **aortic valve**
74
Makes up nearly entire left border and surface of the heart – “inferior wall”
Left Ventricle
75
The left ventricle has a thick muscular wall that is ____ times as thick as the right ventricular wall
2-3
76
Superior and anterior portion of the left ventricle is formed by the...
**aortic vestibule**
(is the entry way bellow the mitral valve)
77
in the left ventricle, 2 large papillary muscles give rise to _____ \_\_\_\_\_\_\_\_ which attach to the cusps of the mitral valve
**chordae** **tendinae**
78
Normal **systolic** and **end-diastolic** pressure of the left ventricle:
* systolic = **90-140 mmHg**
* end-diastolic = **4-12 mmHg**
79
**Wall** which partitions right and left ventricles and composed of muscular and membranous portions
Ventricular Septum
AKA: Interventricular Septum
80
does the interventricular septum contain **electrical conduction tissue**?
yes
81
functions of the ventricular sptum:
* Contains **electrical** conduction tissue
* Provides **stability** to the ventricles during contraction
82
Margins of the ventricular septum correspond with the...
anterior and posterior **interventricular grooves**
83
where is the **aortic valve** located?
2nd right intercostal space at the sternal border
84
Contraction of the left ventricle pushes blood through the _____ into the aorta
aortic valve
85
Guards the aortic orifice
Aortic Valve
86
The Great Vessels “Primary Blood Vessels”:
* **Vena Cava:** sup and inf
* **Pulmonary veins:** 4, two from each lung
* **Pulmonary arteries:** one to each lung
* **Aorta**
87
blood vessels have three layers of tissue called:
**TUNICS**
1. **Tunica Intima:** innermost layer
2. **Tunica Media:** mainly smooth muscle
* Makes up the bulk of the arterial wall
3. **Tunica Adventitia or Externa:** contains both elastic and collagenous fibers
* Thickest layer in veins
88
Types of arteries:
* Elastic (closer to the heart)
* Muscular (maintain BP)
* Arteriole (peripheral resistance, capillaries)
89
connections between arterial branches providing collateral circulation to capillary beds
**anastomoses**
90
Which arteries deliver deoxygenated blood?
the pulmonary and umbilical arteries
91
which blood vessel create anastomoses more easily?
**VEINS** create anastomoses more easily than arteries
92
types of veins:
– Venule
– Medium size
– Larger
93
Vein rely on a system of ____ and muscular contraction to ensure blood flow back to the heart
valves
94
**Oxygen**, **CO2**, **nutrients**, and **wastes** are exchanged through their thin walls
capillaries
95
what connects arterioles to venules?
capillaries
96
Capillary walls are thin and composed of \_\_\_\_\_\_\_\_
endothelium
97
Lymphatic contain ____ to ensure one way flow to the heart
valves
98
3 branches from of the aortic arch
1. Brachiocephalic or Innominate
2. L Carotid
3. L Subclavian
99
Parts of the **aorta**
* Ascending
* Aortic arch
* Descending:
* Thoracic aorta
* Abdominal aorta
100
Descending aorta, divides into:
* Thoracic aorta
* Abdominal aorta
101
This is one of the anatomic dilations of the ascending aorta, which occurs just above the aortic valve. These widenings are between the wall of the aorta and each of the three cusps of the aortic valve
**AORTIC SINUS** AKA **Sinus of** **Valsava**
102
Sinus of Valsalva
An anatomic dilation of the ascending aorta
103
# \*
what give rise to the right and left coronary arteries
Right and left sinus areas
104
Right atrium receives blood from the \_\_\_\_\_
systemic circulation
105
Right atrium contracts and
pushes blood through the ___________ → \_\_\_\_\_\_\_\_\_\_
tricuspid → R ventricle
106
when does the tricuspid valve close
when the right ventricle contracts (ventricular systole)
107
circulation of the right side of the heart
systemic circulation → right atrium → tricuspid valve → right ventricle → pulmonary valve → pulmonary trunk → pulmonary arteries → lungs
108
circulation of the left side of the heart
4 pulmonary veins → left atrium → mitral valve → L ventricle → aortic valve → systemic circulation
109
when does the mitral valve close?
when the L ventricle contract to prevent backflow into the left atrium
110
Blood is supplied to the muscle of the heart via
right and left coronary arteries
111
what is the **crux of the heart**?
where the **atrioventricular** and **interventricular** grooves meet at the posterior aspect of the heart
112
Right or left coronary dominance is determined by
which artery crosses the crux and **supplies the AV node**
113
coronary arteries travel around the heart in which structures?
* 2 grooves:
* **Atrioventricular groove (aka coronary sulcus)**
* **Interventricular groove**
114
Coronary arteries give rise to\_\_\_\_\_\_\_ arteries that travel deep into the myocardium
**perforating**
115
Capillary network of the heart is about _____ for each muscle cell
**1 capillary**
116
Which artery supplies the SA and AV nodes?
Right coronary artery
117
Which artery supplies blood to left atria and most of the left ventricle, parts of the right ventricle as well as the interventricular septum
Left Coronary Artery (LCA)
118
Left coronary artery (or Left Main) divides into 2 main branches
* Left Anterior Descending (LAD) or Anterior Interventricular Artery ("widow maker")
* Left Circumflex (LCX)
119
which artery travels in the anterior interventricular groove
Left Coronary Artery (LCA)
120
the LCA Anastomoses with the posterior branches of the
RCA
121
Left coronary artery supplies blood to:
* Anterior two-thirds and posterior parts of the interventricular septum
* Most of L ventricle, L atrium
* Parts of the R ventricle
122
which is the most commonly occluded coronary artery
**Left Anterior Descending**"widow maker"
| (a branch of the Left Coronary Artery)
123
which artery supplies most of the **left atrium** and the **posterior and lateral walls of the left ventricle**
**left circumflex**, a branch of the LCA
124
which artery supplies blood to the **right atrium**, **right ventricle**, **interventricular septum**, and **inferior wall of the left ventricle**
**Right Coronary Artery**
125
Terminal portion of the _____ descends towards the apex of the heart
RCA
126
Which artery supplies the SA and AV node?
**Right Coronary Artery**
* **SA Nodal Artery:** branches off of the RCA at the crux of the heart to pass anteriorly along base of atrial septum to supply to AV node
* Occurs in ~55% of hearts
* In the other 45% it comes from a branch of the LCX
* **AV Nodal Artery:** usually branches off of the distal RCA
* Occurs in ~85-90% of hearts
* In the other 10-15% it comes from a branch of the LCX
127
which is the main vein of the heart?
**Coronary sinus**
128
where is the coronary sinus located?
Located in the posterior portion of the coronary groove on the posterior surface of the heart
129
where does the coronary sinus empty its blood?
directly into the right atrium
130
the coronary sinus receives drainage from:
* Great cardiac vein
* Middle cardiac vein
* Small cardiac vein
* Thebesian veins are the smallest of the cardiac veins
131
which are the **smallest** of the cardiac veins?
Thebesian veins
132
Function of the heart and cardiovascular system
* Deliver O2 and nutrients to all tissues in the body and remove CO2 and waste products, via the blood
* Transport of heat to maintain body temp
* Transport of WBCs to fight infection
* Transport of hormones
133
Heart muscle cells called _________ are polarized, negatively charged, at rest
myocytes
What happens when myocytes become positive?
134
repolarization of myocytes (phase 3) =
relaxation
135
Depolarization of myocytes (phase 2)
* When the myocytes become positive they contract
* Move as a wave through the myocardium
136
Recovery phase following depolarization is called what?
Repolarization (relaxation)
Return to resting negative charge (phase 1)
137
Records the electrical activity of the heart and give information about heart’s function and structure
Electrocardiogram (EKG)
138
P wave, QRS, and T wave
* P wave – atrial depolarization
* QRS – ventricle depolarization
* T wave – ventricular repolarization
139
Conduction System of Heart
1. Sinoatrial (SA) Node
2. Internodal Conduction Pathways
3. Atrioventricular (AV) node
4. Bundle of His
5. Bundle branche
6. Purkinje fibers
140
what is the sinus rhythm?
* Sinoatrial (SA) NODE
* “Pacemaker of the heart” (normally) with the innate rate of impulse generation of 60-100 bpm
141
Where is the SA node located?
Located at the junction of the superior vena cava and the RA
142
The action potential travel from SA node to AV node via
internodal tracts
143
Initiate the cardiac cycle
**Sinoatrial (SA) NODE**
144
LCA supplies blood to
* Left atrium
* Left ventricle
* Parts of R ventricle
* Interventricular septum
145
RCA supplies blood to:
* R atrium
* R ventricle
* Apex of the heart
* Interventricular septum
* SA and AV node
146
Stroke volume is affected by
* **Preload** (compliance vs non compliance)
* **Contractility** (HR \> 120 bpm)
* **Afterload:** (total peripheral resistance: Resistance increases → force of contraction
decreases ➔SV decreases)
147
AV node is located in the ...
right atrial septal wall near the tricuspid valve
148
The AV node receives the electrical impulses originated at the SA node and conducts it to the
**Bundle of His**
149
In a normal heart the only way that the electrical impulse can spread from the atria to the ventricles is via the
AV node
150
innate rate of impulse generation of the SA node:
60-100 bpm
| (sinus rhythm)
151
Inherent rate of the AV node:
**40-60 bpm**
152
2 functions of AV NODE:
1. When impulse arrives at AV Node depolarization slows causing a delay of .04 sec to allow the ventricles to fill with blood from the atria—“atrial kick”
2. Controls the number of impulses going to the ventricles
153
Bundle of His:
* The cardiac impulse travels from the AV Node to the **Bundle of His** where it divides into right and left bundle branches, and terminates into **Purkinje fibers:**
* Continuous with cardiac muscle in the ventricles
* Stimulate ventricular contraction
* Inherent firing rate of 20 to 40 bpm
154
Myocardial infarction in the interventricular septum may result in a
“bundle branch block”
155
Heart Rate "pacemaker" summary:
**SA, AV,** **an** **Purkinje** **fibers rhythm**
* SA Node “pacemaker” = 60 - 100 bpm
* AV Node = 40 - 60 bpm
* Purkinje Fibers = 20 - 40 bpm
156
true or false: chambers of the heart are isolated both electrically and physically
true
157
The heart is controlled by **2 opposing divisions** of the autonomic nervous system (ANS):
* **SYMPATHETIC NERVOUS SYSTEM:**
* Dominates during stressful situations →leading to tachycardia, increased cardiac output (CO) and increased O2 demand
* “adrenergic” nerve cells of ANS that use _norepinephrine_ as neurotransmitter
* **PARASYMPATHETIC NERVOUS SYSTEM:**
* Dominates during relaxed states → leading to resting HR, baseline CO, and decreased O2 demand of the heart
* Controls heart through the vagus nerve (CN X) and the release of _acetylcholine_ (vagus nerve)
* “cholinergic”
158
What does the **cardiac plexus** consist of?
sympathetic and parasympathetic nerves
Serves as a conduit for neurotransmitters (ex: norepinephrine and acetylcholine) to reach target receptors in the heart
159
sympathetic and parasympathetic nerve supply to the heart:
* **Sympathetic (adrenergic):**
* Monitors SA, AV node
* Accelerates cardiac activity
* **Parasympathetic (cholinergic):**
* Also monitors SA node
* Slows cardiac activity
160
“Vaso-vagal event”
Syncope or fainting due to a trigger that increases vagal tone leading to decrease in HR and BP
161
Bainbridge Reflex
Stimulation of stretch receptors in the right side of the heart by increased venous return → increases the heart rate
162
The Bainbridge reflex, also called the atrial reflex, is an increase in
heart rate due to an increase in central venous pressure
163
Increased arterial blood pressure stimulates nerve endings in the carotid sinus and aortic arch → and will...
reduces the heart rate.
164
**Baroreceptors** sense changes in BP and “report” abnormal BP to the CNS →
* **High BP** or **arterial baroreceptors** respond to high BP very quickly by lowering rate and blood vessel resistance (dilate)
* **Low pressure** baroreceptors regulate blood volume in the body
165
**Chemoreceptors** function**:**
* detect levels of oxygen, pH and carbon dioxide in the blood to determine when someone needs to increase HR or RR
166
Cardiac Cycle — 5 Phases
* **Mid Diastole:** 80% of blood to ventricles; AV valves are open
* **Late Diastole:** remaining 20% of volume comes into ventricles; "atrial kick"; SA node has fired
* **Early Systole:** Impulse through AV Node → Ventricles; AV valves close, S1 Lub sound; _Isovolumetric contraction_
* **Late Systole:** Ventricular ejection (rapid); ejection fraction; end systolic volume
* **Early Diastole**: S2 DUB sound, pulmonic and aortic valves are shut; repolarization occurs; Isovolumetric relaxation
Each cycle lasts ~0.8 sec
167
S1 LUB sound occurs during
**Early Systole**
* AV valves close
* Isovolumetric contraction
168
S2 DUB sound occurs during
Early Diastole
**Pulmonic and aortic valves close**
169
Repolarization occurs during
Early Diastole
170
Resistance increases → force of contraction \_\_\_\_\_\_\_\_
decreases ➔ SV decreases
171
which artery supplies the bundles of Hi
Left Coronary Artery
172
Frank-Starling Mechanism:
the greater the volume in the ventricle → the greater the contractile strength of the ventricles
Because the myocardium will become more stretched → will increase sarcomere length and increase sensitivity to calcium ions → therefore, stronger contraction
173
afterload is dependent on:
* Volume and mass of blood ejected
* Size and wall thickness of ventricle
* Impedance of vasculature
(afterload is The resistance, impedance, pressure that the ventricle works against to eject blood)
174
afterload, as resistance increases force of contraction....
decreases → SV decreases
175
Pressure in LV before it contracts
Preload
176
LV End Diastolic Pressure
**preload:**
* Amount of muscle fiber stretch at end of diastole
* Amount of volume in the ventricle at this phase
* “pulling back the rubber band”
177
preload
178
Capillaries exchange \_\_\_\_\_\_(4 things)\_\_\_\_\_\_ through their thin walls
**Oxygen**, **CO2**, **nutrients**, and **wastes**
