Cardiovascular - Anatomy Flashcards
What is the sternocostal (anterior) surface of the heart?
RA + RV
What is the diaphragmatic (inferior) surface of the heart?
RV + LV (RV in front of LV)
What is the base (posterior) surface of the heart?
LA
What is the right border of the heart?
RA
What is the left border of the heart?
LV
What is the inferior border of the heart?
RV (+LV)
What is the apex of the heart?
LV
What is the covering of the heart called?
Pericardium
What are the two layers of the pericardium called?
Fibrous outer layer, serous inner layer
What are the 3 roles of the fibrous layer?
- Protect heart
- Anchor heart to other structures
- Prevent heart from overfilling
What is the structure and function of the serous layer?
- Parietal layer runs beneath fibrous pericardium, attaches to great vessels and loops back on itself to run along the heart muscle and form the visceral layer.
- Space between = pericardial cavity, full of pericardial fluid for lubrication.
What are the 2 layers of the heart muscle called?
Myocardium and endocardium
Describe the myocardium
- Middle contractile layer
- Made up of cardiac muscle fibres and connective tissue
What is the role of connective tissue in the myocardium?
- Creates a fibrous skeleton, reinforced in areas of high blood velocity.
- Electrically silent to limit spread of action potential
Describe the endocardium
- Inner layer
- White sheets of squamous epithelium
- Lines chambers of heart and covers valves
- Continuous with endothelium of blood vessels
Describe where the transverse pericardial septum is
Between aorta and pulmonary trunk posteriorly and superior vena cava anteriorly
Describe where the oblique pericardial septum is
Blind ending tract, formed by the serous pericardial reflection onto the pulmonary veins
Describe the internal structure of the atria
- Smooth posterior wall
- Ridged anterior wall
- Separated by crista terminalis
- Shallow depression on right side of interatrial septum = fossa ovalis
What is the crista terminalis?
- Separates smooth and ridged walls of atria
What causes the ridged walls of the atria?
- Pectinate muscles
Where does the right atrium receive blood from? Oxygenated or deoxygenated?
- Superoir and inferior vena cava
- Drainage of coronary artery through myocytes
- Deoxygenated
Where does the left atrium receive blood from? Oxygenated or deoxygenated?
- The four pulmonary veins
- Oxygenated
Describe the internal structure of the ventricles
- Irregular ridges of muscle called trabeculae carnae
Which valves have papilary muscles and chordae tendinae?
AV valves (mitral and tricuspid)
Descrube how papilary muscles, chordae tendinae, and valves function
Papilary muscles anchored to valves via chordae tendinae
Describe the structure of all valves in the heart
- AV:
- Left = mitral = 2 cusps
- Right = tricuspid = 3 cusps
- Has papilary muscles and cordinae tendinae
- Semilunar
- Aortic
- Pulmonary
- Both has 3 cusps
- No papilary muscles or cordinae tendinae
Where do the left and right coronary arteries originate form?
Base of the aorta - aortic sinuses
When is the myocardium of the coronary arteries perfused?
During diastole
What is the general rule about what areas the coronary arteries supply?
The part it passes over is the part it supplies
Where is the path of the right coronary artery?
Follows the coronary sulcus (AV groove)
What is the coronary sulcus?
Separates the atria and ventricles
What is the interventricular septum?
Separates the ventricles
What does the right coronary artery branch into and where does each branch run?
- Right marginal artery: runs at bottom of heart towards apex.
- Posterior descending artery: follows interventricular septum on posterior surface of heart towards apex
What does the left coronary artery branch into and where does each branch run?
- Left anterior descending: follows interventricular septum on anterior surface of heart towards apex
- Circumflex: Passes straight to posterior surface of heart
What does the right coronary artery supply?
Right atrium, SAN and AVN
What does the right marginal artery supply?
Right ventricle and apex
What does the posterior descending artery supply?
Right and left ventricle and IVS (as runs along this)
What does the left coronary artery supply?
Left atrium and ventricle and IVS
What does the left anterior descending supply?
Left ventricle and IVS (as runs along this)
What does the circumflex artery supply?
Left atrium and ventricle
What is right dominance?
When the right coronary artery forms the posterior descending artery (90% of people)
What is left dominance?
When the circumflex artery forms the posterior descending artery (10% of people)
Which 2 arteries anastomose on the posterior surface of the heart?
PDA and LAD
What are the three parts of the aorta called?
- Ascending
- Arch
- Descending
What comes off of the ascending aorta?
The right and left coronary arteries
What 3 branches come off of the aortic arch in order?
- Brachiocephalic artery
- Left common carotid artery
- Left subclavian artery
What does the braciocephalic artery split into in order?
- Right subclavian artery
- Right common carotid
What level does the aortic arch begin at?
T4
What branches off the descending aorta?
Intercostal arteries
What do the 3 branches of the aortic arch supply?
The head, neck and upper limbs
Where does the aorta dissect the diaphragm and what does it become after this?
At T12, becomes the abdominal aorta
What is codominance?
When the PDA is formed by both the RCA and circumflex artery
What does the pulmonary trunk branch into?
Left and right pulmonary arteries
What does the superior vena cava branch into, working from the SVC upwards?
Left and right brachiocephalic veins, then each one = subclavian vein on outside and internal jugular on inside
Which valve is between the RA and RV?
Right AV valve (tricuspid valve)
Which valve is between the LA and LV?
Left AV valve (mitral valve)
Which valve is at the start of the pulmonary trunk?
Pulmonary valve (semilunar valve)
Which valve is at the start of the aorta?
Aortic valve (semilunar valve)
What is the mediastinum?
Central thoracic compartment, between the 2 pleural sacs
What separates the superior and inferior mediastinum?
Line from sternal angle to T4
Where does superior mediastinum end superiorly?
Thoracic inlet
Where does the inferior mediastinum end inferiorly?
Diaphragm
What areas make up the inferior mediastinum?
Middle, posterior and anterior
What are the borders of the superior mediastinum?
- Superior = Thoracic inlet
- Inferior = Continuous with inferior mediastinum
- Anterior = Manubrium (top part) of sternum
- Posterior = T1 - T4 vertebrae
- Lateral (sides) = Pleaurae of lungs (top parts)
Which great vessels are in the superior mediastinum?
- Arch of aorta
- Superior vena cava (from where it splits into brachiocephalic veins and above)
Describe the path of the right vagus nerve in the superior mediastinum?
Runs parallel to trachea, behind SVC and right bronchus
Describe the path of the left vagus nerve in the superior mediastinum?
Enters superior mediastinum between left common carotid and left subclavian arteries and descends anterior to aortic arch but posterior to left bronchus.
Branches off at aortic arch to form left recurrent laryngeal nerve which loops back around arch of aorta to supply muscles of larynx
Describe the path of the right phrenic nerve in the superior mediastinum?
- Formed in cervical plexus from C3, 4, 5
- Runs lateral to great vessels down to diaphragm
Describe the path of the left phrenic nerve in the superior mediastinum?
- Formed in cervical plexus from C3, 4, 5
- Passes lateral to aortic arch and in front of hilum of lungs
What does the phrenic nerve supply, and what type of innervation?
Diaphragm (motor), pericardium, pleura and peritoneum (sensory)
Where does the vagus nerve leave the diaphragm?
Through the oesophageal hiatus
What are the borders of the middle mediastinum?
- Anterior: Anterior surface of pericardium
- Posterior: Posterior surface of pericardium
- Laterally: Pleurae of lungs
- Superior: Continuous with superior mediastinum
- Inferior: Superior surface of diaphragm
What organs are in the middle mediastinum?
Heart and pericardium
What nerves are in the middle mediastinum?
Phrenic and vagus
What are the borders of the anterior mediastinum?
- Lateral: Pleurae of lungs
- Anterior: Body of sternum
- Posterior: Anterior surface of pericardium
- Superior: Continuous with superior mediastinum
- Inferior: Diaphragm
What are the borders of the posterior mediastinum?
- Lateral: Pleurae of lungs
- Anterior: Posterior surface of pericardium
- Posterior: T5 - T12
- Superior: Continuous with superior mediastinum
- Inferior: Diaphragm
What structures does the posterior mediastinum contain?
- Thoracic aorta
- Oesophagus
What do the thoracic aorta and oesophagus pass through in the diaphragm?
- Aortic and oesophageal hiatuses
Where does the oesophagus pass when entering the posterior mediastinum?
Behind heart and arch of aorta