Heart + Mediastinum Flashcards
What are the superior and inferior boarders of the mediastinum?
● Superior: thoracic inlet
● Inferior: diaphragm
What are the anterior, posterior and lateral boarders of the mediastinum?
● Anterior: sternum
● Posterior: bodies of thoracic vertebrae
● Lateral: mediastinal parietal pleura
The mediastinum can be divided into :
superior and inferior mediastinum
the inferior mediastinum can be divided into:
anterior, middle and posterior
What is in the superior mediastinum?
thymus,
V: SVC, brachiocephalic vein
A: ABCS
trachea
esophagus
lymphatics
nerves: phrenic, vagus
What is in anterior mediastinum?
thumus, lymph nodes, fat
what is in the middle mediastinum?
heart, phrenic nerve
What is in the posterior mediastinum?
● Descending (Thoracic) aorta
● Azygos system of veins
● Thoracic duct
● Esophagus
● Sympathetic (parasympathetic) nerves
What is the role of the thymus?
growth through childhood, then site for T lymphocyte development (tumor on it could effect facial and eye muscles)
what are the great vessels of the superior mediasteinum?
-R/L brachiocephalic vein
-Aortic arch and branches
–Brachiocephalic artery
–Left common carotid artery
–Left subclavian artery
The trachea ends at the level of
the_________ by dividing into
the right and left main bronchi
sternal angle
the majority of the heart is on which side of the body?
left
the anterior surface of the heart is made up mostly of
right ventricle
the visceral pericardium is the same as the ____
epicardium
what is the layers of the pericardium?
● Fibrous pericardium
● Serous pericardium
-Parietal layer
-Visceral layer (deepest)
pulmonary veins carry what where?
oxygenated blood to the left atrium
where does the apex of the heart lie?
Lies posterior to the left 5th
intercostal space,
approximately 9 cm from the
median plane
where can you best hear the sound of the mitral value closing?
closest to the apex
How can you tell if someone has an enlarged heart?
you wont hear mitral valve in correct spot
where is the base of the heart and what forms it?
posterior aspect
Formed mainly by the left atrium, with lesser contributions by the right atrium
what great veins are found on the base of the heart?
Pulmonary veins (PV)
Superior vena cava (SVC)
Inferior vena cava (IVC)
the right atrium receives blood from?
SVC, IVC, and coronary sinus
right atrium Has a ________ which allows the discharge of blood into the right ventricle
right AV orifice (mitral valvue)
What muscles are in the right ventricle?
–trabeculae carneae (muscular elevations)
–Papillary muscles (prevent tricuspid valve from prolapsing)
what is the difference between the posterior and anterior walls of the right atrium?
● Posterior wall is smooth and contains openings for blood return
● Anterior wall is rough and composed of
pectinate mm
what do the chordae tendineae do?
arise from papillary muscles and attach to the free edges of the cusps
what valve connects the right atrium and ventricle, what valve connects the right ventricle and pulmonary trunk?
tricuspid
pulmonary SEMILUNAR valve
where is pectinate mm found?
both atria
what drains into the left atria?
four pulmonary veins
what is unique about the left ventricle and why does it have this feature?
2-3x thicker, covered with trabeculae carneae, papillary mm
are larger to pump blood to the rest of the body
what connects the left atrium to left ventricle and what connects the left ventricle to the aorta?
left AV orifice (or mitral or bicuspid valve)
aortic semilunar valve
where the pulmonary semilunar valve audible?
2nd left intercostal space
where the aortic semilunar valve audible?
2nd right intercostal space
where the tricuspid valve audible?
4th/5th left intercostal space
where the mitral valve audible?
5th left intercostal space
what is infective endocarditis?
● Microbial invasion of heart valves or endocardium with destruction of cardiac tissue.
● Bacteria associated with infective endocarditis originate from the oral cavity in 26–45% of cases
What supplies the heart itself with blood and where do they come from?
coronary arteries
first branches off the aorta
what is a myocardial infarction?
clot or clog in coronary arteries causes decrease in blood flow to heart and necrosis of heart tissue (since heart tissue does not regenerate)
what is the path of the conducting system of the heart?
SA node → AV node → AV bundle → Right & Left bundle branches →Purkinje fibers
The heart is supplied by autonomic nerve fibers from the _______
cardiac plexus
The cardiac plexus has which fibers?
sympathetic, parasympathetic, visceral afferent
What are some examples of cardiac referred pain?
● Visceral organs are insensitive to incisions, temperature, and touch
● They are sensitive to distension and ischemia
● Visceral sensory nerves travel through the sympathetic chain and enter the spinal cord at T1-4
Where does the descending aorta begin?
left side of T4 vertebra, descends on the left sides of the T5– T12 vertebrae
● Enters the abdomen through the aortic hiatus
what do the azygos and hemiazygos veins drain?
● Azygos: drains intercostal spaces on the right side
● Hemiazygos: drains intercostal spaces on left side
–BOTH Empties into SVC
what does the thoracic duct do?
Conveys most lymph of the body to the venous system, except that
from the right superior quadrant.
Where does the thoracic duct drain?
Empties into the venous system near the union of the left internal jugular and subclavian veins
where does the thoracic duct originate?
cisterna chyli
what are the three parts of the aorta?
cervical
thoracic
abdominal
the vagus nerve gives what type of innervation for the organs?
parasympathetic
The right recurrent laryngeal nerve loops under the ___ ____ ______, while the left RLN loops under the ___________
right subclavian artery
aortic arch
What controls the heart rate?
ANS
Thoracic splanchnic nerves
● ________ sympathetic fibers
● Pass through the diaphragm to synapse in _______ in the abdomen
Preganglionic
collateral ganglia
