Heart & Mediastinum Flashcards
What makes up the inferior boundary of the mediastinum?
Diaphragm
What makes up the anterior boundary of the mediastinum?
Sternum and costal cartilages
What makes up the posterior boundary of the mediastinum?
Thoarcic vertebrae
What makes up the lateral boundary of the mediastinum?
Pleura
What structures are found in the superior part of the mediastinum?
Vessels of the heart
Thoracic duct
Azygous system
Vagust nerves
Pulmonary, esophageal, cardiac & autonomic nerve plexuses
Thymus
Parts of trachea and esophagus
What is found in the inferior anterior art of the mediastinum?
Fat
Lymph tissue
Vessels
Thymus
What is found in the inferior middle part of the mediastinum?
The heart and its pericardial tissues
What is found in the inferior posterior part of the mediastinum?
Thoracic aorta
Esophagus
Pulmonary arteries and veins
Azygous system
Thoracic duct
Sympathetic trunk and thoracic splanchnic nerves
What are some arteries that are found in the mediastinum?
Brachioccephalic trunk
Left common carotid artery
Left subclavian artery
What are some nerves that are found in the mediastinum?
Phrenic nerve
Vagus nerve
Left recurrent laryngeal nerve
Sympathetic trunk
The thoracic sympathetic trunk is bilateral. It is continuous with ___ and ___ parts of the sympathetic trunk.
The thoracic sympathetic trunk is bilateral. It is continuous with cervical and lateral parts of the sympathetic trunk.
What type of ganglia run rlong the course of the mediastinum?
Paravertebral ganglia.
What is the mediastinum lateral to?
Vertebral bodies
What do the thoracic splanchnic nerves emerge from?
Thoracic sympathetic trunks.
What do the greater, lesser and least thoracic splanchnic nerves provide sympathetic innervation to?
Viscera inferior to the diaphragm.
The thoracic splanchnic fibers are all presynaptic fibers. What do they synapse with?
Prevertebral ganglia in the abdomen.
The arch of aorta, left main bronchus and the diraphragm are all areas of ______ where swallowed foreign objects are most likely to lodge and where a stricture may develop (e.g. After drinking a caustic liquid).
Constriction
Arteries carry blood ___ from the heart
Away
Veins carry blood ____ the heart
To the heart
Arteries carry blood ____ in oxygen (except for the pulmonary arteries).
High
Veins carry blood ____ in oxygen (except for the pulmonary veins).
Low
What are arteries and veins entering and leaving the heart called?
Great vessels.
Backflow of blood is prevented by what structures found within the heart?
Valves
What are the functions of the two independent, side-by-side pumps found in the heart?
One directs blood to the lungs for gas exchange.
The other directs blood to body tissues for nutrient delivery.
Alternate cycyles of heart wall contraction and relaxation produce what?
Blood pressure
What does the pulmonary circuit consist of?
Chambers on the right side of the heart (right atrium and ventricle) as well as the pulmonary arteries and veins.
What is the function of the pulmonary circuit?
It conveys blood to the lungs via pulmonary arties to reduce carbon dioxie and replenish oxygen levels in the blood before returning to the heart in pulmonary veins.
Blood that returns to the left side of the heart enters what circuit?
The systemic circuit
What does the systemic circuit consist of?
Chambers on the left side of the heart, along with all the other named blood vessels.
What is the function of the systemic circuit?
It carries blood to tall the peripheral organs and tissues of the body.
What is the largest systemic artery in the body?
Aorta.
Oxygenated blood from the left side of the herat is pumped into the aorta, and then into smaller systemic arteries.
Where does gas exchange in tissues occur?
From capillaries.
Most veins merge and drain into what vessel?
Superior and inferior vena cavae.
These two drain blood into the right atrium.
There, blood enters the pulmonary circuit and the cycle repeats.
In what portion of the mediastinum is the heart located?
Middle mediastinum.
How is the heart rotated in the body?
It is rotated such that its ride side or border (right atrium and ventricle) is located more anteriorly, while its left side or border (left atrium and ventricle) is located more posteriorly.
The base of the heart is primarily formed by the
Left atrium.
It is also known as the posterosuperior surface of the heart.
What is the inferior, conical end of the heart called?
The apex.
It projcts slightly anteoinferiorly toward the left side of the body.
The pericardium of the heart has three primary layers. If the pericardium of the heart is pierced by a needle, which of the primary layers would the needle first pass through?
Fibrous pericardium
What is the inner portion of the pericardium called?
Serous pericardium.
It contains a parietal and visceral layer.
What is the function of the pericardium?
It supports the the external walls superior to the heart and the diaphragm inferior to it.
It also restricts heart movements and prevents the heart from overfilling with blood.
What are the three layers of the heart wall?
External epicardium
Middle myocardium
Internal endocardium
What is the epicardium (outermost heart layer) also known as?
It is also known as the visceral layer of serous pericardium.