S1_L3: Mediastinum and Heart Flashcards
It divides the mediastinum into the superior and inferior mediastinum
Sternal angle of Louis (T4-T5)
It is a thick movable partition that extends superiorly from the thoracic outlet and root of neck to the diaphragm inferiorly
Mediastinum
Fibroserous sac enclosing the heart and roots of the great vessels that is found in the middle of the mediastinum.
Pericardium
It occurs when coronary flow is suddenly reduced or stopped and cardiac muscle undergoes necrosis
Myocardial infarction
Cardiac pain that occurs on exertion and relieved by rest
Angina pectoris
Connection of the umbilical vein and inferior vena cava in the fetus
Ductus venosus
Connection of the pulmonary artery and arch of the aorta in the fetus. Allows oxygenated blood to go to the arch of the aorta.
Ductus arteriosus
Determine the corresponding descriptions of the walls of the heart
- Most superficial layer
- Lines the heart and creates the valves
- Striated muscle but is innervated by autonomics
- A layer of endothelium
- Part of the serous pericardium (visceral layer)
A. Endocardium
B. Myocardium
C. Epicardium
- C
- A
- B
- A
- C
The borders of the heart are used when recognizing a radiograph of the heart. The (1)___ marks the right border, the (2)___ marks the left border, the (3)___ marks the lower/inferior border, and the (4)___ marks the apex.
- Right atrium
- Left auricle and left ventricle
- Right ventricle and right atrium
- Left ventricle
The heart is a muscular organ made up of cardiac muscle. It is about the size of a (1)___ that moves with the diaphragm. It is (2)___ in shape, with its base above and apex below. It is found in the middle of the mediastinum, connected at the base to the great vessels.
- Fist
- Pyramidal
Upon measuring a radiograph for the biggest horizontal diameter of the heart, it was noted that the heart is abnormally enlarged. What is this condition called?
Cardiomegaly
Determine the corresponding descriptions of the surfaces of the heart.
- Has the posterior interventricular groove
- Directed downward, forward, and to the left
- Anterior surface formed by (R) atrium & ventricle, and part of (L) ventricle & auricle
- Sitting on the diaphragm, formed by right and left ventricles
- Posterior surface found opposite the apex, formed by left atrium where the 4 pulmonary veins open
A. Apex
B. Base
C. Sternocostal
D. Diaphragmatic
- D
- A
- C
- D
- B
The apex of the heart is at the level of the ___ intercostal space 3.5 inches from midline midclavicular line.
5th
The largest cardiac vein where venous blood of heart goes in.
Coronary sinus
Determine the corresponding descriptions of the right and left coronary arteries.
- It is from left posterior aortic sinus of ascending aorta
- Larger of the two
- Supplies the atrioventricular bundle
- It is from anterior aortic sinus of ascending aorta
- Supplies the right bundle branch of AV bundle
A. Right coronary artery
B. Left coronary artery
- B
- B
- A
- A
- B
Determine the corresponding descriptions of the right and left coronary arteries.
- Supplies diaphragmatic surface of left ventricle
- Supplies a small part of right ventricle
- Supplies posteroinferior third of ventricular septum
- Supplies parts of left atrium
- Supplies anterior ⅔ of ventricular septum
A. Right coronary artery
B. Left coronary artery
- A
- B
- A
- A
- B
TRUE OR FALSE: The left bundle branch of the AV bundle is supplied by the right and left coronary arteries.
True
Determine the corresponding descriptions of the right and left atria.
- Known as the primary pump
- Its ventral wall has rough pectinate muscle
- Receives O2-rich blood from four pulmonary veins
- On its interatrial septum, the remnant of Foramen Ovale (Fossa ovalis) is located
- One of its openings is the (L) atrioventricular orifice guarded by mitral valve
- Anatomically associated with the crista terminalis and sulcus terminalis
A. Right atrium
B. Left atrium
- A
- A
- B
- A
- B
- A
A vertical groove on the outside of heart at the junction between the right atrium and auricle
Sulcus terminalis
The inner part of the sulcus terminalis is called the crista terminalis
TRUE OR FALSE: The atrial portion has thick walls and is divided by the interatrial septum. The ventricular portion has thin walls and is divided by the interventricular septum.
False
Ventricles have thick walls, atria have thin walls
The heart’s “electricity” (conducting system) passes through this. It is also for attachments of structures that form the valves.
Skeleton of the heart / 4 fibrous rings
Enumerate the 3 branches of the arch of the aorta
- Brachiocephalic artery / Innominate artery
- Left common carotid artery
- Left subclavian artery
What is the largest branch of the arch of the aorta?
brachiocephalic artery / innominate artery
Where does the brachiocephalic artery divide into the right common carotid & right subclavian arteries (and occasionally thyroid ima artery)?
At the right sternoclavicular joint
What structure marks the beginning and end of the arch of the aorta, end of the ascending aorta, and beginning of descending aorta?
Sternal angle of Louis
Where does the aorta begin?
Left atrium
The inferior mediastinum is bounded anteriorly by the (1)___, posteriorly by the (2)____ thoracic vertebrae, and laterally by the pleura.
- Body of sternum
- Lower 8 thoracic (T5-T12)
At what landmark does the esophagus begin?
6th cervical vertebra / pharynx
Enumerate the 3 constrictions of the esophagus
- Where the pharynx joins the upper end of esophagus
- Where the aortic arch and left bronchus cross
- As the esophagus passes the diaphragm
Determine the corresponding blood supply of the esophagus
- Upper third
- Middle third
- Lower third
A. Gastric artery
B. Branches of the descending thoracic aorta
C. Inferior thyroid artery
- C
- B
- A
At what level / landmark does the esophagus pass the diaphragm to join the stomach?
10th thoracic vertebra / Esophageal opening
It is a smooth and muscular organ that is tubular in shape and 10 inches long.
Esophagus
Determine the appropriate locations of the superior mediastinum boundaries
- plane of thoracic outlet
- mediastinal pleura
- anterior surface of bodies of T1-T4 vertebrae
- plane of sternal angle of Louis
- manubrium of the sternum
A. Anterior
B. Posterior
C. Superior
D. Inferior
E. Lateral
- C
- E
- B
- D
- A
What is the nerve supply to the diaphragm and pleura?
Phrenic nerve
What is the primary function of the thymus gland?
Secretes T cells / lymphocytes;
Site for development of T (thymic) lymphocytes
A flattened bilobed structure between the sternum and pericardium. It is an endocrine gland found in the most anterior part of the superior mediastinum. It is large in children and atrophies after puberty.
Thymus
Additional: Supplied by inferior thyroid and internal thoracic arteries
TRUE OR FALSE: In adults, the thymus is at the inferior part of the anterior mediastinum. In children, it is in the superior part of the anterior mediastinum.
True
What is the remnant of the ductus arteriosus called in adults?
Ligamentum arteriosum
What is the remnant of the umbilical vein called in adults?
Round ligament of liver / Ligamentum teres of liver
What is the remnant of the umbilical artery (within fetus) and umbilical cord (leaving fetus) called in adults?
Medial umbilical ligaments
What is the term for ligamentum venosum in the fetus?
Ductus venosus
In the fetus, what brings oxygenated blood to the liver?
Umbilical vein