Lecture 3: Middle Mediastinum Flashcards
what are the boundaries of the middle mediastinum
anterior: anterior pericardium
posterior: posterior pericardium
lateral: mediastinal pleura
inferior: diaphragm
superior: T4/T5
contents of the middle mediastinum
- heart and pericardium
- ascending aorta
- pulmonary trunk and arteries
- pulmonary veins
- nerves: cardiac plexus and phrenic nerve
what do the auricles do
- “ears”
- allow extra volume of blood to enter atrium
what are the regions of the atria
- sinus venarum (smooth wall) is where blood flows
- pectinate muscle to help with contraction of heart
- left atrium is mostly sinus venarum
what are the veins draining into the right atrium
- coronary sinus
- superior vena cava
- inferior vena cava
what are the walls of the ventricle made of and what do they do
trabeculae carnae to prevent surface adhesion and help in contraction
functions of the pericardium
- prevents heart from overfilling (cardiac distension)
- retains heart in position through pericardio-sternal ligaments
what are the layers of the pericardium
- serous pericardium consisting of parietal layer and visceral layer
- fibrous pericardium
what are the pericardial sinuses
- transverse between outflow and inflow vessels
- oblique sinus between pulmonary veins
what do purkinje fibres travel through in the right ventricle
moderator band
what is the fibrous skeleton
- framework of 4 fibrous rings of dense connective tissue
- provides attachment for atrioventricular and semilunar valves
- forms an electrical insulator between atria and ventricles
how does the parasympathetic supply travel in the heart
from vagus nerves to cardiac plexus to SA node
how does the sympathetic supply travel in the heart
from sympathetic trunk levels T1-T5 to cardiac plexus to SA node
where are the cardiac plexi
- superficial underneath arch of aorta
- deep underneath bifurcation of trachea
