24 Flashcards
Where is the inferior anterior mediastinum ?
Sternum —> pericardium
What does the inferior anterior mediasteinum contain
- fat
- sternopericardial ligaments
- lymphatics
- lymphatic vessels
- parasternal lymph nodes
- internal thoracic vessesl
Inferior thymus ?? Children
- can extend as far as the level of the 4th costal cartilages
- immunity
What are sternoperocaridal ligaments
Connective tissue which attaches the pericardium to surrounding structures (vertebra, sternum, xiphiod, diaphragm)
Two sternopericatidal ligaments in the anterior inferior medeiasteinum
Superior: sternopericardial
Inferior: xipho-pericardial
What do the sternopericatidal and xipho-pericardial do?
- helps retain the heart in its posterior in the thoracic cavity
The superior sternopericardial ligament crosses both…
Inferior and superior mediastinum
Lymphatic vessels from anterior thoracic wall (and the medial breast) drainage pathway
- Anterior thoracic wall (and medial breast) lymphatic vessels drain into parastertnal lymph nodes (which are associated with internal thoracic vessels) (at lymph node they are filtered of debris)
- then drains into bronchomediastinal trunks
- then drains into subclavian veins
What do internal thoracic arteries branch from?
Subclaivian artery (left and right)
What do internal thoracic arteries branch to?
Anterior intercostal arteries
What do the internal thoracic arteries supply?
- intercostal muscles
- diaphragm
- pericardium
- thymus
Where do the internal thoracic arteries run?
With the artery
What do the internal thoracic veins drain into?
Brachiocephallic veins
Location of the heart
Inferior-middle mediastrinum
Features of the base of the heart
- proximal
- broad, towards right shoulder
- left and right atria
Features of the apex of the heart
- distal
- pointed
- located mid-clavicular line and 5th intercostal space
- formed primarily by the left ventricle
Location of the apex of the heart
- mid-clavicular line and 5th intercostal space
How many heart chambers
4
The _ atria ____ blood
2
Recive
The _ ventricles ____ blood
2
Pump
Features of blood on the right side of the heart
- deoxygenated
- flow directed to the lungs
Features of blood on the left side of the heart
- oxygenated
- flow directed to the body
Where does the right atria collect blood from
Deoxygenated
Superior and inferior vena Cava
Where does the left atria receive blood from
Oxygenated
Pulmonary veins
What do the AV valves do?
Close on ventricular contraction, prevents back flow
What is the right AV valve called
Tricuspid
What is the left bicuspid called?
Bicupsid (mitral)
What does the pectinate muscles do?
Move the last bit of blood from atria to ventricle
Indentation in the right atrium ?
Fossa ovalis
Features of the fossa ovalis
- covered with connective tissue
- interatrial septum ?
- feral blood flow?
Whats going on in the fetal heart?
- circulation bypasses the lungs (oxygenated blood is coming from the ambilical cord)
- foramen ovale is a hole connecting right and left atria
- ductus arteriosus is an artery connecting the pulmonary artery and aorta (in the superior mediasteinum
Both close after birth (the first breath)
- foramen ovale becomes the fossa ovalis
- ductus arteriosis becomes ligamentum arteriossum
Where does the right ventricle pump blood to?
Lungs, pulmonary trunk, arteries
Where does the left ventricle pump blood to?
To the rest of body, ascending aorta
Which side has a larger muscular wall?
Left
What is the particular muscle arrangement of the heart walls?
Trabeculae carnae (function to add to strong muscle contraction without adding too much muscle mass)
What do papillary muscles do
Attach cordanae tendinae to the ventricle wall
What are chordae tendinae ?
- heart strings that attach onto AV valves
Function of cordage tendinae and papillary muscle
Stop AV valves from opening backwards into the atria
What is the name of the semilunar valve on the right?
Pulmonary valve
What is the name of the semilunar valve on the left
aortic valve
What chambers are part of the anterior external heart
- right atrium
- right ventricle
- left ventricle
What are the sulci
Indentations between chambers
What are the two sulci of the anterior side of the external heart
- coronary (AV valves lies deep to this) (right)
- interventricular
What are the two sulci of the anterior side of the external heart
- coronary (AV valves lies deep to this) (right)
- interventricular
Vessels you can see form the anterior ventral heart
- superior vena cava
- ascending aorta
- pulmonary trunk
- coronary arteries and veins
What side of the external heart is ligamentum arteriosum ?
Anterior
What chambers can you see on the posterior surface of the external heart?
Left atrium
Left ventricle
External heart posterior sulci
- coronary (left AV vlavle lies deep to this)
- posterior interventriculat
Vessels on the posterior of the external heart
- inferior vena cave
- pulmonary veins
- coronary arteries and veins
Primary coronary/ cardiac blood vessels on the right of the heart
ARTERIES
- coronary
- posterior interventricular
Primary coronary/cardiac blood vessels on the left of the heart
ARTERIES
- coronary
- circumflex
- anterior interventricular
VEIN
- coronary sinus
Layers of the heart wall
- endocardium
- myocardium
- epicardium
- pericardium
What kind of epithelium and tissue is the endocardium?
- simple squamous epithelium
- areolar tissue
Features of the endocardium
- inner myocardial surface
- lines chambers, valves
- continuous with endothelium of great vessels
Featues of the myocardium
- heart muscle
- striated
- arranged in spiral bundles
- intercalated discs
Featues of the myocardium of the heart muscle
- concentric layers
- blood vessels and nerves
- thicker on the left (1.5cm vs 0.5cm)
Featues of intercollated discs
- joins muscle fibres end to end
- contains gap junctions
- allows rapid spread of excitation
Features of the epicatdium
- outer surface
- continuous with the visceral layer of serous pericardium
Two layers
- areola tissue (closest to myocardium)
- mesothelium (closest to pericardial cavity)
- secretes serous fluid
Featues of the pericardium
- sac of CT coverring the heart
- parietal cavity
- serous fluid for low friction
-parietal serous pericardium - mesothelium (inner)
- areola tissue (outer)
- continuous with visceral serous layer at the root of the great vessels
- serous fluid for low friction
- parietal fibrous pericardium (Dense fibrous connective tissue)
Features of the (parietal) fibrous pericardium
- cone-shaped
- base —> diaphragm
- apex continuous with adventitia of great vessels (root)
- sternopericardial ligaments
- limits disteniton
Blood supply of the heart and visceral pericardium
Coronary arteries and veins
Blood supply of the parietal pericardium and fibrous pericardium
Internal thoracic arteries and veins
Nerve supply of the heart and visceral pericardium
- cardiac plexus, vagus nerve, sympathetic trunk
Nerve supply of parietal and fibrous pericardium
Phrenic nerve
