01-12: Heart and Mediastinum Flashcards
(198 cards)
1
Q
Which of the following structures makes up the superior boundary of the mediastinum? A) Thoracic inlet B) Pleura C) Diaphragm D) Thoracic vertebrae E) Costal cartilage
A
A) Thoracic inlet
Bony hole where the 1st rib attaches
2
Q
Which of the following structures is/are found in the middle part of the inferior mediastinum? A) Fat and lymph tissue B) Cardiac and autonomic nerve plexuses C) Heart and its pericardial tissues D) Thoracic aorta E) Thoracic splanchnic nerves
A
C) Heart and its pericardial tissues
3
Q
What are the boundaries of the mediastinum?
Superior: Inferior: Anterior: Posterior: Lateral:
A
Superior: Thoracic inlet
Inferior: Diaphragm
Anterior: Sternum and Costal cartilages
Posterior: Thoracic vertebrae
Lateral: Pleura
4
Q
What are the 10 Superior contents of the mediastinum?
A
- Great vessels of the heart
- Thoracic duct (Left)
- Superior parts of azygos system
- R&L Vagus nerves (recurrent laryngeal nerves)
- Pulmonary nerve plexus
- Esophageal nerve plexus
- Cardiac nerve plexus
- Thymus
- Parts of trachea
- Parts of esophagus
5
Q
What are the 4 Inferior Anterior contents of the mediastinum?
A
- Fat
- Lymph tissue
- Vessels
- Thymus (in children)
6
Q
What are the 2 Inferior Middle contents of the mediastinum?
A
- Heart
- Heart’s pericardial tissues
7
Q
What are the 8 Inferior Posterior contents of the mediastinum?
A
- Thoracic aorta
- Esophagus
- Pulmonary arteries
- Pulmonary veins
- Azygos system
- Thoracic duct
- Sympathetic trunk
- Thoracic splanchnic nerves
8
Q
Where is the Thoracic Sympathetic Trunk located?
A
- Bilateral
- Lateral to the vertebral bodies
9
Q
What is the Thoracic Sympathetic Trunk continuous with?
A
Cervical and lumbar parts of sympathetic trunk
10
Q
What runs along the Thoracic Sympathetic Trunk?
A
Paravertebral ganglia
11
Q
Where are the Thoracic Splanchnic Nerves located?
A
- Bilateral
- Emerge from Thoracic Sympathetic trunks
12
Q
What are the 3 Thoracic/Abdominopelvis Splanchnic Nerves?
A
- Greater
- Lesser
- Least
13
Q
What do the Thoracic Splanchnic Nerves provide sympathetic innervation to?
A
Viscera inferior to the diaphragm
14
Q
What do the Thoracic Splanchnic Nerves (presynaptic fibers) synapse with?
A
Prevertebral ganglia in the abdomen
15
Q
Arteries carry blood _______ the heart
A
AWAY from
16
Q
Veins carry blood ______ the heart
A
TO
17
Q
Arteries carry blood _______ in oxygen
A
HIGH
18
Q
What arteries are the exception and do not carry blood that is high in oxygen?
A
Pulmonary arteries (deox blood)
19
Q
Veins carry blood ______ in oxygen
A
LOW
20
Q
What veins are the exception and do not carry blood that is low in oxygen?
A
Pulmonary veins
21
Q
What are great vessels?
A
Arteries and veins entering and leaving the heart
22
Q
What kind of blood flow through the heart and the blood vessels does the heart ensure?
A
Unidirectional
23
Q
How is back flow of blood prevented within the heart?
A
valves
- Between Atria & Ventricles
- Between Ventricles & Great Vessels
24
Q
The heart acts like 2 independent, side-by-side _______ that work independently but ___________
A
- Pumps (Right=Pulmonary) (Left=Systemic)
- At the same rate
25
One side of the heart directs blood to the lungs for what?
gas exchange = Pulmonary
26
One side of the heart directs blood to the body tissues for what?
nutrient delivery = Systemic
27
What is essential to push blood through blood vessels to the body tissues for nutrient and waste exchange?
Minimum blood pressure
28
How does the heart develop blood pressure?
Through alternate cycles of heart wall contraction and relaxation
29
Thinking about pulmonary circulation, the systemic pathway of this circuit involves which part of the heart?
A) Right atrium, SVC, and IVC
B) Right atrium and pulmonary veins
C) Left atrium and pulmonary arteries
D) Left atrium and pulmonary veins
D) Left atrium and pulmonary veins
30
Thinking about the position of the heart in the mediastinum, which of the following heart structures is located more posteriorly and makes up most of what is called the base of the heart?
A) Right atrium
B) Right ventricle
C) Left atrium
D) Left ventricle
C) Left atrium
31
Pericardium of the heart has 3 primary layers. If the PERICARDIUM of the heart is pierced by a needle, which of these primary layers would the needle first pass through?
```
A) Visceral pericardium
B) Pleural pericardium
C) Parietal pericardium
D) Fibrous pericardium
E) Epicardium
```
D) Fibrous pericardium
32
Which of the following heart structures is a framework of dense collagen that anchors and provides support for the atrioventricular AND semilunar valves of the heart?
A) Chordae tendineae
B) Papillary muscles
C) Fibrous skeleton
D) Fossa ovalis
C) Fibrous skeleton
33
Pericardium of the heart has 3 primary layers. If the heart WALL is pierced by a needle, which of these primary layers would the needle first pass through?
```
A) Visceral pericardium
B) Pleural pericardium
C) Parietal pericardium
D) Fibrous pericardium
E) Epicardium
```
A) Visceral pericardium
34
What makes up the pulmonary circuit?
- Right atrium
- Right ventricle
- Pulmonary arteries
- Pulmonary veins
35
What is the function of the pulmonary circuit?
Conveys blood to the lungs (via pulmonary arteries) to reduce CO2 and replenish O2 levels in the blood before returning to the heart in the pulmonary veins
36
Coming from the pulmonary circuit, which side of the heart does the blood flow through?
Left side of the heart
37
Where does the blood flow after it goes from the pulmonary circuit and through the left side of the heart?
it enters the systemic circuit
38
What makes up the systemic circuit?
- Left atrium
- Left ventricle
- All other named blood vessels
39
What is the function of the systemic circuit?
Carries blood to all the peripheral organs and tissues of the body
40
Oxygenated blood from the Left side of the heart is pumped into __________ and then into smaller systemic ___________
- the aorta
| - arteries
41
Where does gas exchange in the tissues occur?
in the capillaries
42
Is deoxygenated blood high or low in CO2?
HIGH
43
Are systemic veins oxygenated or deoxygenated?
deoxygenated
44
What 2 things do systemic veins carry?
- deoxygenated blood
| - waste products
45
Where do most veins merge and drain into?
SVC and IVC
46
Where do the SVC and IVC drain blood into?
Right atrium
47
When blood enters the Right Atrium, what circuit is it entering?
Pulmonary circuit
48
Where is the heart located?
- Left of the body midline
- Posterior to the sternum
- In the middle mediastinum
49
The heart is rotated so that the Right side/border (Right atrium and Right ventricle) is located more _________, while its Left side/border (Left atrium and Left ventricle) is located more ___________
- Anteriorly (RIGHT)
| - Posteriorly (LEFT)
50
What rib outlines the superior aspect (base) of the heart?
3rd rib
51
What rib outlines the inferior aspect (apex) of the heart?
6th/7th
behind the body of the sternum
52
What does the anterior part of the heart sit on?
The diaphragm
53
What makes up the base of the heart?
The posterosuperior surface of the heart
| primarily the Left Atrium
54
What veins border the base of the heart?
The pulmonary veins that enter the Left Atrium
55
What is the inferior, conical end of the heart called?
The apex
56
Which way does the apex of the heart project slightly?
Anteroinferiorly towards the Left side of the body
57
Is the coronary sinus anterior or posterior to the base of the heart?
Anterior
58
Does the circumflex branch of the Left Coronary artery on the anterior or posterior surface of the heart?
Posterior surface of the heart
59
Is the Anterior Interventricular artery located on the anterior or posterior surface of the heart?
Anterior surface of the heart
60
What do arterioles do?
Help prevent pooling by keeping blood flowing
61
Where are the auricles of the heart located?
Bilaterally on the sides of the heart
62
What are the functions of the pericardium?
- Restricts heart movements so it doesn't bounce and move in the thoracic cavity
- Prevents heart from overfilling with blood
63
What is the fibrous pericardium?
- Outer portion of pericardium
- Tough
- Dense connective tissue
- Attached to sternum and diaphragm
64
What is the serous pericardium?
- Inner portion of pericardium
- Thin
- Double layered serous membrane
65
What are the 2 layers of the serous pericardium?
- Parietal layer
| - Visceral layer
66
What are the 3 layers of the heart wall?
- Epicardium
- Myocardium
- Endocardium
67
What is the outermost layer of the heart called?
Epicardium or Visceral layer of serous pericardium
68
As we age, what layer of the heart is more fat deposited?
Epicardium
69
What layer of the heart is thickest in the Left Atrium?
Myocardium
70
What are the layers of the pericardium and heart from outside to inside?
- Fibrous pericardium
- Parietal layer of serous pericardium
- Pericardial cavity
- Visceral layer of serous pericardium (Epicardium)
- Myocardium
- Subendocardial layer (areolar CT)
- Endocardium
71
What kind of tissue composes the myocardium?
Cardiac muscle tissue
72
Which heart wall layer is the thickest?
Myocardium
Left ventricle
73
Where is the myocardium located?
- Deep to the epicardium
| - Superficial to the endocardium
74
Which heart wall layer covers the internal surface of the heart and the external surfaces of the heart valves?
Endocardium
75
Where is the subendocardial layer?
Between the endocardium and myocardium
76
What is the subendocardial layer composed of?
Areolar connective tissue
77
What are the auricles?
Wrinkled, flap-like extensions of the anterior part of each atrium
78
Where does the Right Atrium receive blood from?
Systemic circuit
79
Where does the Left Atrium receive blood from?
Pulmonary circuit
80
What 2 large arteries exit the heart at the basal surface (posterior to ventricles)?
- Pulmonary trunk
| - Aorta
81
The pulmonary trunk carries blood from the ________ to the _________.
- Right ventricle
| - Pulmonary circuit
82
The aorta conducts blood from the _________ to the __________
- Left ventricle
| - Systemic circuit
83
What separates the atria from the ventricles?
The Coronary Sinus/Atrioventricular Sulcus
84
Where are the Anterior Interventricular Sulcus and the Posterior Interventricular Sulcus located?
- Anterior and Posterior heart surfaces
| - Between the Left and Right Ventricles
85
The Anterior Interventricular Sulcus and the Posterior Interventricular Sulcus extend inferiorly from the _________ toward the ________ of the heart
- Coronary sulcus
| - Apex
86
Where is the fibrous heart skeleton located?
Between the atria and the ventricles
Around all the valves
87
What kind of tissue forms the fibrous heart skeleton?
Dense irregular connective tissue
88
What are the functions of the fibrous heart skeleton?
- SEPARATES atria and ventricles
- ANCHORS valves (forming supportive rings at their attachment points
- ELECTRICAL INSULATION between atria and ventricles
- RIGID FRAMEWORK for the attachment of cardiac muscle tissue
89
What is the function of the electrical insulation between the atria and ventricles that is provided by the fibrous skeleton of the heart?
- Ensures the muscles impulses are not spread randomly throughout the heart
- Prevents all the heart chambers from beating at the same time
90
What permits the passage of blood in one direction and prevents its back flow?
valves
91
From where does the Right Atrium receive venous blood?
- Systemic circuit
| - Heart muscle
92
What are the 3 major vessels that empty into the Right Atrium?
- SVC
- IVC
- Coronary sinus
93
What does the SVC drain blood from?
- Head
- Upper limbs
- Superior regions of the trunk
94
What does the IVC drain blood from?
- Lower limbs
| - Trunk
95
What does the Coronary Sinus drain blood from?
-The heart wall
96
What does the Interatrial septum do?
Forms a wall between the Right and Left Atria
97
What kind of muscle does the Right Atrium have?
Pectinate muscle
98
What does the Right Atrioventricular Valve separate?
Right atrium from the Right ventricle
99
What is another name for the AV valve?
Tricuspid valve
100
When is the AV valve forced closed?
When the Right Ventricle begins to contract
101
What does the Right Ventricle receive blood from?
Right atrium
102
What kind of blood does the Right Ventricle receive from the Right Atrium?
Deoxygenated venous blood
103
What does the Interventricular Septum do?
Forms wall between the Right and Left Ventricles
104
What are the 3 cone-shaped, muscular projections on the internal wall surface of each ventricle called?
Papillary muscles
105
What do the papillary muscles do?
Anchor chordae tendineae
106
What do the chordae tendineae attach to?
The cusp of the Right AV valve
107
What do the chordae tendineae do?
Prevent everting and flipping of the Right AV valve into the atrium when contracting
108
The ligamentum arteriosum, a fetal remnant of the ductus arteriosis is located where?
A) Between the Right and Left Atria
B) Between the SVC and IVC
C) Between the Pulmonary Trunk and Aorta
D) Between the Pulmonary Arteries and Pulmonary Veins
C) Between the Pulmonary Trunk and Aorta
109
What is the conus arteriosus?
- Smooth-walled
- Conical region
- At the superior end of the Pulmonary Trunk
110
What marks the end of the Right Ventricle and the entrance into the Pulmonary Trunk?
Pulmonary Semilunar Valve
111
What does the Pulmonary Trunk divide shortly into?
Right and Left Pulmonary Arteries
112
What kind of blood does the Right and Left Pulmonary arteries carry to the lungs?
Deoxygenated
113
Where are the semilunar valves located?
within the walls of both ventricles (immediately before the connection of the ventricle to the pulmonary trunk and aorta)
114
How many thin pocket like semilunar cusps are there in each Semilunar Valve?
3
115
How do the Semilunar Valves open?
Blood that is pumped into the arterial trunks pushes against the cusps, forcing the valves to open
116
What happens to the Semilunar Valves when ventricular contraction ceases?
- Blood enters the pockets of the semilunar valves between the cusp and the chamber wall
- Blood is prevented from flowing back into the ventricles from the arterial trunk
- Causes the cusps to INFLATE and meet at the artery center/close (blocking blood back flow)
117
Once gas exchange occurs in the lungs, the oxygenated blood flows through the Pulmonary Veins to _____________
The Left Atrium
118
Where are the 4 Pulmonary Veins located?
On the smooth posterior wall of the Left Atrium
119
What kind of muscles are located within the Left Atrium?
Some pectinate muscles
120
What does the Left Atrioventricular Valve separate?
Left Atrium from the Left Ventricle
121
What are 2 other names for the Left AV Valve?
- Bicuspid valve
| - Mitral valve
122
Does oxygenated or deoxygenated blood flow from the Left Atrium to the Left Ventricle?
Oxygenated blood
123
What happens to the Left AV valve when the Left Ventricle begins to contract?
- The valve is forced closed
| - Prevents blood back flow into the Left Atrium
124
Which is the largest heart chamber?
Left Ventricle
125
How thick is the Left Ventricle wall?
3x thicker than the Right Ventricle wall
126
Why does the Left Ventricle need a thick wall?
In order to generate enough pressure to force the oxygenated blood from the Lungs > Aorta > Systemic circuit
*Right Ventricle only has to pump blood to the lungs
127
What is more prominent on the Left Ventricle compared to the Right Ventricle?
Trabeculae Carneae
128
What 2 muscles attach to the chordae tendineae in the Left Ventricle to help support the Left AV valve?
2 Large Papillary Muscles
129
What marks the end of the Left Ventricle and the entrance into the Aorta at the superior end of the Left Ventricular cavity?
Aortic Semilunar Valve
130
What nervous system innervates the heart?
Autonomic
131
What are the sympathetic and parasympathetic components of the innervation of the heart called?
Cardiac plexus
| Coronary plexus
132
What does sympathetic innervation do to the heart rate and the force of contractions?
- Increases HR
| - Increases force of contraction
133
What does the parasympathetic innervation do to the heart rate and the force of contractions?
- Decreases HR
| - NO effect on force of contraction (Except in special circumstances)
134
Where do the Left and Right Coronary arteries travel in to supply the heart wall?
In the Coronary Sulcus (Atrioventricular Groove)
135
What are the only branches of the ascending aorta?
The Left and Right Coronary arteries
136
The Left and Right Coronary arteries are located immediately superior to what valve?
Aortic Semilunar Valve
137
What does the Right Coronary Artery branch into?
- Marginal artery
| - Posterior interventricular artery
138
What does the Marginal artery supple?
The right border of the heart
139
What does the Posterior Interventricular artery supply?
Both the Left and Right Ventricles
140
What does the Left Coronary Artery branch into?
- Anterior Interventricular artery (LAD)
| - Circumflex artery
141
What does the Anterior Interventricular artery supply?
- Anterior surface of both ventricles
| - Most of the interventricular septum
142
What is another name for the Anterior Interventricular artery?
Left Anterior Descending Artery (LAD)
143
What does the Circumflex artery supply?
- Left Atrium
| - Posterior aspect of Left Ventricle
144
The main tributary of the coronary sinus/sulcus is the:
A) Great cardiac vein
B) Middle cardiac vein
C) Great vein of Galen
D) Small cardiac vein
A) Great cardiac vein
145
What 3 venous structures drain into the Right Atrium?
- SVC
- IVC
- Coronary sinus
146
What initiates the heartbeat?
Cardiac muscle fibers of the Sinoatrial node
147
Where is the SA node located?
- Posterior wall of the Right Atrium
| - Adjacent to the entrance of the SVC
148
How many times does the SA node initiate an impulse per minute?
70-80 times per minute
149
The impulse from the SA node travels to both atria, stimulating ______________
Atrial Systole
150
Where is the AV node located?
In the floor of the Right Atrium between the Right AV valve and the Coronary Sinus
151
Where does the impulse travel through within the internodal conduction pathway?
Through an opening in the fibrous skeleton to the AV node
152
After the impulse travels to the AV node, where does it go?
To the AV Bundle/Bundle of His
153
Where is the Bundle of His located?
-Extends into the Interventricular Septum
154
How many branches does the Bundle of His divide into?
1 RBB
2 LBB
BB = Bundle Branches
155
What are the fibers located in the heart apex that the Bundle of His conducts impulses to?
Purkinje fibers
156
Which fibers are larger, Purkinje fibers or other Cardiac Muscle Fibers?
Purkinje fibers
157
After the impulse travels to the Purkinje fibers, where does it spread to?
Spreads immediately throughout the Ventricular Myocardium
158
What does the phrenic nerve sit in?
the fascia of the anterior scalene muscle
159
What does the Right recurrent laryngeal nerve go around?
the brachiocephalic duct
160
What does the Left recurrent laryngeal nerve go around?
the aortic arch
161
What is the Left recurrent laryngeal nerve just posterior to?
ligamentum arteriosum
162
What does the Right lymphatic duct drain?
Right head, neck, UE, and right side of upper thorax
**Rest drains via the Thoracic duct
163
What does the Right lymphatic duct lie between?
- Right subclavian vein
| - Right internal jugular vein
164
What does the Left lymphatic duct lie between?
- Left subclavian vein
| - Left internal jugular vein
165
As you descend down the mediastinum, what does the L vagus nerve become?
Anterior vagal trunk
166
As you descend down the mediastinum, what does the R vagus nerve become?
Posterior vagal trunk
167
Where do the Greater Splanchnic Nerves synapse?
NOT in the paravertebral ganglia
-Descend and synapse when they are below the diaphragm
168
Where do the Lesser Splanchnic Nerves synapse?
Descends to the superior mediastinum
169
Where do the Least Splanchnic Nerves synapse?
Descends to the inferior mediastinum
170
What ganglion is near the esophagus posterior to the mediastinum?
cervicothoracic ganglion (Stellate ganglion)
171
What 3 areas can become constricted when a swallowed foreign object is lodged?
- Aortic arch
- Left main bronchus
- Diaphragm
172
What are the intercostal arteries directly supplied by?
aorta
173
Where do the intercostal veins drain?
azygos system
174
Which side is the azygos vein on?
right
175
Which side are the Hemiazygos and Accessory Hemiazygos vein on?
left
176
What does the Left Superior Intercostal vein drain directly into?
Left Brachiocephalic Vein
177
Which intercostal veins drain through the Accessory Hemiazygos?
Left 5, 6, 7, 8
178
Which intercostal veins drain through the Hemiazygos?
Left 9, 10, 11, 12
179
On both the Left and Right side, what do intercostal nerves 2, 3, and 4 drain into?
Left and Right Superior Intercostal
180
What is a Mitral Valve prolapse?
Blood leaks back into the Left atrium when it should be going into the aorta
181
Which arteries make up the first part of the systemic circuit?
coronary arteries
182
What does the SVC and Azygos vein drain?
- Upper limbs
- Head
- Neck
- Thorax
183
What does the IVC drain?
Everything from below the diaphragm
184
What is the manubrosternal joint also called?
sternal angle
185
What artery is the Left coronary artery associated with?
Anterior interventricular artery (LAD- Left Anterior Descending Artery)
186
What kind of pleura does the fibrous pericardium sit up against?
mediastinal pleura
187
What are not covered by endocardium?
valves
188
What does the Right coronary artery run between?
Right atrium
| Right ventricle
189
What does the pulmonary trunk come off of?
Right ventricle
190
What are the 2 branches of the Left Coronary Artery?
- Circumflex artery
| - Anterior interventricular artery (LAD)
191
What is the Fossa Ovalis a remnant of?
Chordae ovali
Visible in Right Atrium
* *Infants = Foramen Ovali
* *Adults = Fossa Ovali
* *Adults = Patent Foramen Ovali
192
Does the Azygos vein drain into the Right Atrium?
NO.... It drains into the SVC
193
How many cusps does the Right atrioventricular valve have?
3 (tricuspid valve)
194
How many cusps does the Left atrioventricular valve have?
2 (bicuspid valve)
195
What is the christa terminalis?
- Smooth ridge on the Right atrium
- Just before the opening to the Right ventricle
- Mitigates blood flow into the Right ventricle
196
The atria have __________ muscles and the ventricles have ____________
```
Atria = Pectinate muscle
Ventricles = Trabeculae carnae
```
197
Which cardiac vein does the LAD travel with and drains the Left side of the heart?
great cardiac vein
198
Which cardiac vein drains the Right side of the heart?
small cardiac vein
