Anatomy Flashcards
Pericardium; Cardiac chambers; Principal arterial vessels; Principle venous vessels; Coronary circulation; Heart valves; Cardiac conduction system
What is the external structure of the heart?
Endocardium → Myocardium → Pericardium (Visceral→parietal→fibrous)
What is the endocardium and where is it found?
One cell thick layer of tissue
Attached to the basement membrane of myocardium
INSIDE the heart
Acts as an interface between the blood and the myocardium
What is the myocardium?
Thick layer of cardiac muscle cells
What is the pericardium?
Fibrous sac formed from layers of fibrous tissue that hold the heart in place
Keeps heart within thoracic cavity by sternopericardial and pericardiophrenic ligaments
Protects it from damage and infection
What are the two types of pericardial tissue that are found in the pericardium?
Serous - secretes serous fluid
Fibrous - dense connective tissue
What are the 4 layers of the pericardium and their purposes?
Epicardium/Visceral pericardium
- separates muscle from pericardial fluid
Pericardial cavity filled with pericardial fluid
-protects heart from external forces and shock
-allows visceral and parietal layers to move without friction
Parietal pericardium
-layer of serous tissue lining fibrous pericardium and facing pericardial space
Fibrous pericardium
-connective layered tissue
-protect heart and anchor it to the mediastinum
-prevent overfilling
How are the pericardial cavity and sinuses formed?
Visceral and parietal serous pericardium layers are continuous
Oblique sinus
-Reflection of the serous pericardium onto pulmonary veins
Transverse sinus
-Reflection of the serous pericardium that separates arteries and veins
-Superior to the left atrium
What is pericarditis?
Inflammation of the pericardium
What is pericarditis?
Inflammation of the pericardium
How would you normally distinguish between the left and right ventricle?
Left ventricular wall thicker than right
Left has to pump blood to the entire body - far distance compared to the right ventricle
How does blood travel through the right atrium?
Receives blood from IVC and SVC
Delivers blood to right ventricle
DEOXYGENATED BLOOD
How does blood travel through the right ventricle?
Receives blood from the right atrium
Delivers blood to the pulmonary arteries via the pulmonary trunk which bifurcates into the left and right pulmonary arteries
DEOXYGENATED BLOOD
How does blood travel through the left atrium?
Receives blood from the pulmonary veins
Delivers blood to the left ventricle
OXYGENATED BLOOD
How does blood travel through the left ventricle?
Receives blood from the left atrium
Delivers blood to the aorta
OXYGENATED BLOOD
Why are valves necessary in the heart?
Ensures unidirectional flow down a pressure gradient
What are the 4 heart valves and where are they found?
Mitral valve -left atrioventricular -2 cusps anterior and posterior Tricuspid valve -Right atrioventricular -3 cusps anterior posterior septal Pulmonary valve -right semilunar -3 semilunar cusps left right anterior Aortic valve -left semilunar -3 semilunar cusps left right posterior
Where do coronary arteries arise from?
Left and right sinuses of the aortic valve
Left → left circumflex and left anterior descending
Right → right coronary artery (and right conus artery)
What is the purpose of the chordae tendinae?
Attach to papillary muscles and the atrioventricular valves to stop the valves everting
How are valves forced closed?
After contraction the sinuses of the cusps fill with blood and force the valves closed to stop the blood flowing backwards
What are the coronary arteries?
Vessels that supply the myocardium
What are the coronary sulci?
Produced from the internal partitions that create the chambers
Coronary sulcus circles the heart to separate the atrium and ventricles
Anterior interventricular sulcus separates ventricles anteriorly
Posterior interventricular sulcus separates ventricles posteriorly
What are the branches of the coronary arteries?
RCA→atrial branch (sinoatrial node branch), marginal branch, posterior interventricular branch (Posterior descending artery)
LCA→anterior interventricular branch (left anterior descending(2 diagonal branches)), cirucmflex (left marginal)
Where do coronary veins drain to?
Collect blood and feed to the coronary sinus at the back of the heart which drains into the right atrium
What are the principle arterial vessels?
Pulmonary arteries that carry deoxygenated blood to lungs
ascending aorta→aortic arch→right brachiocephalic trunk, left common carotid and subclavian, thoracic aorta
right brachiocephalic bifurcates into a common carotid and subclavian
At what level does the aortic arch start and end?
Level of the sternal angle
At which level do the common carotid arteries divide and what do they become?
C4
Internal - brain
External - face
How do venous vessels join to form the superior vena cava?
Left subclavian + left internal jugular = left brachiocephalic
right subclavian + right internal jugular = right brachiocephalic
left + right brachiocephalic + azygos vein = SVC
How many pulmonary arteries are there?
4, 2 on each side
List the principle arterial vessels in a logical order
Aortic arch -brachiocephalic trunk *right common carotid *right subclavian (branches same as left subclavian) -left common carotid artery -left subclavian *axillary *brachial *radial *ulnar Thoracic aorta Abdominal aorta -coeliac trunk -splenic artery -hepatic artery -superior mesenteric artery -renal artery -inferior mesenteric artery Common iliac artery Internal and external iliac arteries femoral artery popliteal artery posterior and anterior tibial arteries
List the principle venous vessels in a logical order
anterior tibial → femoral
+great saphenous = iliac vein
2 iliac veins = IVC - branches for renal and hepatic veins, superior and inferior mesenteric
ulnar + radial→medial antecubital fossa→basilic vein +cephalic vein→subclavian veins
Subclavian + internal + external jugular veins= SVC
