L26 - Mediastinum I Flashcards
where is the inferior anterior mediastinum?
anterior to the pericardium
what is the inferior anterior pericardium filled with and why?
fat/adipose tissue for protection
in children the inferior thymus is a lot larger, to where does it extend when you are younger?
4th costal cartilages
what are the 4 types of sternopericardial ligaments?
- xiphoid
- diaphragm
- sternum
- vertebra
what 2 types of sternopericardial ligament are found in the inferior anterior mediastinum?
sternum and xiphoid
what aspect of the inferior anterior mediastinum does the sternopericardial ligament cross and where are it’s attachments?
superior, pericardium to sternum
what aspect of the inferior anterior mediastinum does the xipho-pericardial ligament cross and where are it’s attachments?
inferior, pericardium to xiphoid process
what is the function of the sternopericardial and xipho-pericardial ligaments?
restrict unwanted movement, helps retain heart in it’s position in the thoracic cavity
what is the function of lymphatics?
to recycle fluid and maintain volume in the vascular system
what does the lymphatic vessels form?
anterior wall - medial breast
where does lymph drain into (3 steps) and at which location does toxin filtering occur?
lymph drains into parasternal lymph nodes (where filtering occurs) –> bronchomediastinal trunks –> subclavian veins to maintain volume of vasculature
where is the heart?
inferior-middle mediastinum
location of the apex
mid-clavicular line, 5th intercostal space
where is the right coronary sulcus?
between right atrium and right ventricle
where is the left coronary sulcus?
between left atrium and left ventricle
where is the posterior interventricular sulcus?
between the left and right ventricles on the posterior surface of the heart
where is the anterior interventricular sulcus?
between the left and right ventricles on the anterior surface of the heart
what enters and exits the right side of the heart?
in - superior and inferior vena cavae
out - pulmonary trunk
what enters and exits the left side of the heart?
in - 4x pulmonary veins
out - ascending aorta
what hole connects the right and left atria in fetal hearts?
foramen ovale
what artery connects pulmonary artery to aorta in fetal hearts?
ductus arteriosus
what closes after the first breath after birth in fetal hearts?
foramen ovale and ductus arteriosus
when foramen ovale closes, what is it covered by, what is it called and what does it act as?
covered by connective tissue, fossa ovalis, interatrial septum
what does the ductus arteriosus become and what is it made of?
becomes ligamentum arteriosum, made of connective tissue
what can happen to the ligamentum arteriosum if in an accident?
can tear and if it’s bad enough it can tear part of the aorta which can be fatal
what primary cardiac vessel is on the right side of the heart, where is it located and what is the associated sulcus?
coronary, found on posterior interventricular line, posterior interventricular sulcus
what primary cardiac vessel is on the left side of the heart, what does it split into, what sulcus is associated?
left coronary, found on anterior heart, splits into circumflex and anterior interventricular, anterior interventricular sulcus
what primary cardiac vessel do all other smaller branches drain into and where does it drain int next?
coronary sinus (vein), into right atrium
what moves blood from atria to ventricles?
pectinate muscles
what is the role of the atria? which atria collects from where
collects blood
right - superior and inferior vena cavae
left - pulmonary veins
what is the role of the ventricles? which ventricle pushes blood to where?
pumps blood out of the heart
right - to lungs –> pulmonary trunk –> arteries
left - to rest of body –> ascending aorta
which ventricle has a thicker muscle wall and why?
left has a thicker wall as it pumps blood to the whole rest of the body not just the lungs
why does the pectinate muscle have trabeculae carnae?
these struts of muscle increase force while decreasing muscle mass
what role do the papillary muscles have and what do they work with?
they attach from the ventricle wall to valves to keep the valves closed and prevent backflow, connect to the chordae tendineae which connect to the valve
which valves are the right and left semilunar valves?
right - pulmonary valve
left - aortic valve
what are the 4 layers of the heart wall
endocardium
myocardium
epicardium
pericardium
what surface is the endocardium, what does it line and what epithelia is it (2)?
inner myocardial surface
lines chambers and valves
simple squamous and areolar tissue (on outisde)
how is the myocardium arranged?
in spiral bundles to link all parts of the heart together?
in what layer of the heart can you find intercalated discs and what roles do they have?
myocardium
- joins muscle fibres
- contains gap junctions
- allows rapid spread of excitation
what surface is the epicardium, what epithelia (2) and where are they?
outer surface = visceral layer of serous pericardium
areolar tissue - closest to myocardium
mesothelium - closest to pericardial cavity and secretes serous fluid
what layer is the pericardium?
sac of CT covering the heart
what is in the pericardial cavity and what function does it serve?
serous fluid to prevent friction
what are the inner and outer layers of the parietal serous pericardium made from?
inner = mesothelium
outer = areolar tissue
what are the inner and outer layers of the parietal serous pericardium made from?
inner = mesothelium
outer = areolar tissue
what is the parietal fibrous pericardium made from
dense fibrous connective tissue
important function of parietal fibrous pericardium
limits distension and prevents overfilling of the heart
pericardiac blood supply
heart and visceral pericardium
coronary arteries and veins
pericardiac blood supply
parietal and fibrous pericardium
internal thoracic arteries and veins
pericardiac nerve supply
heart and visceral pericardium
cardiac plexus, vagus nerve, sympathetic trunk
pericardiac nerve supply
parietal and fibrous pericardium
phrenic nerve
