Anatomy of the Heart Flashcards
What are the different surfaces of the heart?
- Sternocostal
- Diaphragmatic
- Apex (points towards left hip)
What is the coronary sulcus?
Groove between two atria and ventricles
- Circumnavigates the heart
What are the three grooves found on the heart?
- Coronary sulcus
- Anterior inter ventricular sulcus
- Posterior inter ventricular sulcus
What is the anterior interventricular sulcus?
- Groove between R+L ventricles
What is the posterior inter ventricular sulcus?
- Groove between right and left ventricles posteriorly
What are the names of the AV valves?
- Right- tricuspid- 3 cusps
- Left- bicuspid- 2 cusps
What are the names of the semi-lunar valves?
- Pulmonary trunk valve
- Aortic valve
What is the function of the connective tissue skeleton/.
- Protects the heart and maintains shape during contraction- increases collagen
Describe the arrangement of vessels and valves in the heart
- Pulmonary trunk is more anterior to aorta and heart
- Two cusp valves are posterior to the aorta
Describe the pressure of blood in the right ventricle
- Low pressure
- High pressure would burst capillaries around alveoli
Describe cardiac muscle
- Involuntary striated muscle
- Pulls in one direction
- Curved around the heart
- Striated means linear contraction but circular wrapping allows constriction of the heart
What are the three layers of muscle around the ventricles?
- Outer spiralling longitudinal fibres
- Inner spiralling longitudinal fibres
- Middle circular
Describe outer spiralling longitudinal fibres
- Arise from cardiac skeleton
- Run towards apex (also known as vortex)
Describe inner spiralling longitudinal fibres
Trabeculae carnae and papillary muscles
Describe middle circular fibres
- Strong fibres
What are the openings of right atrium?
- Superior vena cava
- Inferior vena cava
- Coronary sinus (drains supply to the heart)
- Tricuspid valve
What is the crista terminalis?
- Groove in heart muscle
- Define pectinate from smooth (separates)
Describe pectinate muscles of right atria
- Textured
- Ridges of muscle on anterior wall of atria
- Not found in ventricles
Where is the smooth region of the right atrium found?
- In posterior end of atrium
Where is sinoatrial node found?
- At the point where superior vena cava enter the right atrium
What is the name of the valve between the coronary sinus and right atrium?
Thebesian valve
What is the name of the valve between the inferior vena cava to the right atrium?
Eustachian valve
What is an auricle?
- Projection from atria (pouch)
- Increased in pectinate muscles
- Allow for extra filling of atrium and due to large pectinate muscles
- Increased pressure entering
Where is the tendon of todaro found?
- Between Thebesian and Eustachian valve
What are the components of the right ventricle?
- Tricuspid valve
- Papillary muscles
- Chordae tendinae
What is the origin of the papillary muscles?
- From the wall of the right ventricle
What is chordae tendinae?
- Heart strings
- Attached to papillary muscles
- Anchor leaflet of tricuspid valves to the papillary muscles to prevent tricuspid folding back inwards
What are the trabeculae carnae?
- Wall of ventricles
- More developed version of pectinate muscles
- Increase efficiency efficiency of the pumping
Describe the left atrium
- 4 pulmonary veins
- Also has fossa ovalis- in foetal stages the fossa ovalis was a hole between the right and left atrium
- Bicuspid valve
- Auricle- with pectinate muscles
Describe the components of the left ventricle
- Opening of aorta
- Bicuspid valve (mitral)
- Papillary muscles + chordae tendinae + trabecular carnae
Describe the mitral valve
- 2leaflets (anterior and posterior)
- Anterior is 1/3 of the hole, posterior 2/3
Briefly describe innervation of the heart
- Sympathetic
- Parasympathetic
- Both are carried as visceral fibres (pain)
Describe the vagus nerve
- Parasympathetic
- Also joins cardiac plexus
- Left and right
- Right supplies SAN
- Left supplies the AVN and sometimes purkinje fibres
Describe the sympathetic innervation of the heart
- Comes from L+R sympathetic chain
- All over the heart
- T1-T5- ventral rami–> connect with sympathetic trunk –> cardiac plexus –> over surface of heart
What does sympathetic innervation result in?
- Increase in contractility and strength of contractions and rate of contractions
Describe the superficial cardiac plexus
- Anterior surface under arch of aorta
- Close to ligamentum arteriosum
- Close to deep cardiac plexus (indistinguishable from pulmonary plexus)
What is the ligamentum arteriosum?
- Ligament between aorta and pulmonary artery
What is referred pain?
- Visceral pain projected to other regions
- E.g. visceral afferents from arm- ischaemic attack from blockage of coronary arteries and necrosis of muscles in the arm
What are the spinal levels for intercostal nerves?
- T3, 4, 5
- Sensory supply to the heart has the same dorsal roots
- Therefore during heart attacks pain can be felt in a band across the chest (intercostal nerve) and in part of the upper limb as T1 extends into brachial plexus
Why might pain from a heart attack be felt more in the left arm than in the right?
- Heart is more to the left
- 2/3 more
- The brain cannot distinguish visceral pain location
What are the two sinuses found in the pericardium?
- Transverse pericardial sinus
- Oblique pericardial sinus
What is transverse pericardial sinus?
- Runs transversely are separates cardiac veins and arteries from everything else
What is oblique pericardial sinus?
- Folds around veins coming into the left atrium from the lung
What is the fluid in the pericardial cavity and what is its function?
- Serous fluid
- Lubricates layers between beats
What are the layers of the heart?
- Fibrous pericardium
- Serous pericardium parietal layer
- Serous pericardium visceral layer (or epicardium- usually cannot separate between two layers)
- Cardiac muscle
- Endocardium
What is a cardiac tamponade?
- Leakage of fluid between epicardium and parietal layer (into pericardial cavity)
- Build up of pressure- fibrous pericardium is very thick so pressure directed inwardly
What is the consequence of the high pressure in a cardiac tamponade?
- Heart cannot expand/fill effectively
- Less blood leaves heart
- Less oxygen getting to tissues
- Heart compensated by increasing rate of beats
- Also a fall in bp, back up of blood in jugular veins- swelling
- Loss of consciousness and sudden death
Where would you place the stethoscope for pulmonary valve sounds?
- 2nd intercostal space on left joins sternum
Where would you place the stethoscope for mitral valve sounds?
- Apex beat 3/4 cm to the left of the diploid process in 5th intercostal space
Where you place the stethoscope for tricuspid valve sounds?
- Where 5th rib makes contact with sternum
Where do you place the stethoscope for aortic valve sounds?
- where 2nd intercostal space on right joins sternum
