Lecture 7 mediastinum Flashcards
Recommendation if you have chronic severe heartburn
Sleep on your left side
The pressure of the pleural cavity
-4mmHg; 760mmHg atmospheric pressure, 756mmHg in pleural cavity
The arterial and venous ends of the heart are brought together to form the
transverse pericardial sinus
How many pulmonary veins are there
between 3-5
Where does the apex of the heart end up pointing towards
the fifth intercostal space
Cranial nerve 10 =
Vagus nerve
enlargement of the pulmonary trunk can lead to
pulmonary hypertension and sometimes pulmonary embolism
HR above 100 is classified as ; below 60 is
tachycardia ; bradycardia
abnormal swelling or bulge along the aortic wall can cause a/an:
aneurysm
Ligament connecting arch of the aorta and pulmonary trunk
ligamentum arteriosum
When and how does the heart get blood
The diastole (relaxation of heart) is when It get blood, and the backflow of blood opens the L+R coronary arteries to the heart
how many people present right bicipital groove pain with heart issues
1/1000
Location of the mediastinum
between the L/R lungs, superior to the diaphragm, inferior to the thoracic aperture
Mediastinum divisions and their contents
Superior: neurovascular supply
Inferior:
Anterior: thymus (children)
Middle: heart
Posterior: bronchi, trachea, esophagus
What separates the bronchus into the left and right bronchi
The carina, a cartilaginous ridge
Where does the azygos vein drain?
Superior vena cava
Where is the pericardial cavity located
Middle inferior mediastinum
How is the heart fixed to the diaphragm?
Somatic structure fixes it to the central tendon of the diaphragm
Layers of the pericardial cavity from out to in
-fibrous pericardium
- parietal layer of serous pericardium (innervated by phrenic nerve; right bicipital groove pain)
- pericardial cavity
- visceral layer of serous pericardium (epicardium)
- myocardium (cardiac muscles)
- endocardium (endothelia or specialized epithelia)
What synchronizes the contraction of the heart
the gap junctions of cardiac muscles
Anatomy landmarks of the heart:
Anterior = L/R ventricles
Right vs left heart
R: R atrium/ventricle = low O2 blood
L: L atrium/ventricle = high O2 blood
Locations of Oblique and transverse pericardial sinus
Ob: apex to posterior left atrium
T: separates the veins/arteries
The major cardiac veins and functions
Superior vena cava and pulmonary veins; they drain blood back into the heart
Major cardiac arteries and functions
Pulmonary trunk (L/R pulmonary arteries); ascending aorta to aortic arch (R brachiocephalic trunk, left common carotid, left subclavian); they conduct blood out of the heart to the body
What kind of muscle makes up the right atrium auricle
pectinate muscle
The crista terminalis creates a smooth connection for
the two vena cava
The SA node is located at
the superior end of the vena cava
Which chamber of the heart contains openings for the superior and inferior vena cava and coronary sinus?
Right atrium
The (blank) is found in the right ventricle and is located anterior to the papillary muscle
septomarginal trabecula or moderate band
Popes hat/ has chrodae tendineae
Mitral valve
What plane do the valves of the heart occur across
The coronary sulcus
What is the function of the hearts valves
to prevent blood backflow
Name the hearts valves and its locations
Pulmonary valve (ant, L, R) anterior
Aortic valve (L, R, Post) middle
Tricuspid/ R atrioventricular (ant, septal, post) posterior right
Bicuspid/L atrioventricular/ Mitral (ant,post) posterior left
Auscultation of valves (locations)
Aortic = R 2nd intercostal space
Pulmonary = L 2nd intercostal space
Tricuspid = 5th int space, left of sternum
Bicuspid/Mitral = 5th int space, mid clavicle
Pulmonary circulation walkthrough (exchange of O2/CO2)
- Right Atrium ; low O2, High CO2
- R ventricle
- Pulmonary trunk
- R/L pulmonary arteries
- R/L lungs
- R/L pulmonary veins
- Left atrium ; high O2, low CO2
Systemic circulation walkthrough/ left heart (deliver O2 and nutrition to WHOLE body except heart)
- Left atrium ; high O2, low CO2
- L ventricle
- Ascending aorta
- Aortic arch (brachi, carotid, subclavian)
- Descending aorta
- Whole body (except heart)
- Veins drain back to sup/inf vena cava
- Right atrium ; low O2, high CO2
When do pulmonary and systemic circulation take place
They take place simultaneously
Two special systemic circulations
1) nutrition in the blood (liver)
2) waste out of blood (kidneys)
Cardiac circulation:
Coronary arteries are openings covered by aortic valves during systemic circulation
- R = nodal branch to SA node
- L = anterior interventricular/ L anterior descending+ circumflex branch
Venous drainage veins and locations
- great cardiac vein (anterior) - drain straight into R atrium
- Middle cardiac vein (posterior)
- Small cardiac vein (follows marginal branch to the coronary sinus, to the right atrium, to the inf vena cava)
Opens the atrioventricular valves and closes the pulmonary/aortic valves
Diastole
Opens the pulmonary/aortic valves and closes atrioventricular valves
Systole
SA and AV node heart beat pace
SA node (sinoatrial) = 60-100bpm
AV node = 40-60bpm
What makes up the cardiac muscle gap junctions
Purkinje fibers
Sympathetic vs Parasympathetic innervation of heart
Sym: increases HR; T1-T4
- cervical/thoracic cardiac sympathetic
Para: dec HR; vagus nerve
- cerv+thoracic cardiac branches
- L vagus nerve twisted anterior, R posterior
Visceral sensory information follows …
phrenic nerve to T1-T4 (symptoms of left chest and medial arm/forearm pain)
Somatic sensory follows….
phrenic nerve to C3-C5 (symptoms of R/L shoulder pain and left neck/mandible pain) ; specific = R bicipital groove pain
Umbilical circulation and umbilical vein function
high O2 from placenta filters through the liver; direct to the inferior vena cava through ductus venosus
Circulatory Changes at birth
- umbilical vein closes = ligamentum teres/round lig
- ductus venosus = ligamentum venosum
- foramen ovale = fossa ovalis
- ductus arteriosus = ligamentum arteriosum
- umbilical arteries to medial umbilical ligaments
Esophagus location
Anteromedial to descending aorta; leaves impression on left lung; behind the L atrium at esophageal hiatus (T10 level)
Heart burn =
gastroesophageal reflux at cardiac notch of stomach
Another function of the thoracic duct
absorption of lipids
Posterior mediastinum DATES
D= Descending aorta
A = Azygos veins
T = Thoracic duct
E = Esophagus
S = Sympathetics
