Anatomy Flashcards
What is contained within the hilum of the lung?
PA
PVs x 2
Main bronchus
Pulmonary lymphatics and bronchopulmonary lymph nodes
Pulmonary visceral afferents and autonomic motor nerves
What is the path of the phrenic nerves?
From C3-C5 descends across the lateral borders of the pericardium to the diaphragm
Describe the positions of the phrenic and vagus nerves in relation to the hilum
Phrenic nerve anterior to hilum
Vagus nerve posterior to hilum
What internally lines the fibrous pericardium?
Lined internally by parietal serous pericardium
What covers the anterior surface of the heart?
Epicardium
What does the epicardium secrete?
Pericardial fluid lubricant
Where is the pericardial cavity?
Located between the 2 layers of the serous pericardium - parietal and visceral
What is haemopericardium and what does it lead to?
When pericardial cavity fills with blood, increasing pressure around heart and can prevent contraction = cardiac tamponade
What does the pericardial cavity contain?
Pericardial fluid
What is pericardiocentesis?
Drainage of fluid from the pericardial cavity
Where is the needle inserted in a pericardiocentesis?
Into ‘bare area of pericardium’ via infrasternal angle and directed superoposteriorly, aspirating continuously
Where is the bare area of the pericardium?
Below the sternal angle and costal cartilages
Describe the transverse pericardial sinus
A space within the pericardial cavity, posterosuperiorly, lies posterior to the ascending aorta and pulmonary trunk
What vessels are enclosed within the pericardium
The most proximal segments of the ascending aorta and pulmonary trunk
How does the pericardium close around the ascending aorta and pulmonary trunk
Blends with their adventitia
Why is the transverse pericardial sinus clinically important?
Cardiac surgeons use this sinus to identify and isolate the great vessels in order to commence cardiopulmonary bypass (for open heart surgery)
Where does a surgeons finger emerge from the TPS?
Anterior to the SVC
What are the three surfaces of the heart?
Anterior (sternocostal) surface,
Base (posterior) surface, inferior (diaphragmatic) surface
What are the borders of the heart? What chambers are at these borders?
Right - RA
Left - LV
What surface of the heart is in contact with the diaphragm? What chamber covers most of this surface?
Inferior
RV
What vessel of the heart can only be visualised posteriorly?
Left atrium - on posterior surface
Where can the apex beat normally be felt?
5th left intercostal space in the midclavicular line (mitral area)
What does cardiac enlargement do to the heart?
Cardiomegaly- often shifts the apex beat to the left
What does the coronary groove indicate?
Surface marking for the tricuspid valve (boundary between right atrium and right ventricle)
What does the anterior interventricular groove indicate?
The boundary between the 2 ventricles
Holds LAD artery (branch of left coronary artery)
What combines to form the brachiocephalic veins? What combines to form the brachiocephlic trunk?
Bilateral internal jugular and subclavian veins
RIGHT CCA and RIGHT subclavian arteries (unilateral)
What combines to form the SVC?
Brachiocephalic veins
What is the right auricle?
(ear like structure) Extension of the right atrium
What is the left auricle?
Extension of the left atrium
Where does the right coronary artery travel?
Within the coronary groove
What is the coronary sinus?
Short venous conduit which receives deoxygenated blood from most of the cardiac veins
Where does the coronary sinus drain into?
Right atrium
Where does the coronary sinus travel?
Within the atrioventricular groove posteriorly
What does the posterior interventricular groove contain?
Posterior interventricular artery (branch of right coronary artery) and posterior interventricular vein
What does the posterior interventricular groove indicate?
The boundary between the 2 ventricles
What is the first branch off the aorta?
Coronary arteries
What connects the left and right coronary arteries?
Anastomoses
What is the septum between the 2 atria called and indicated by on the surface?
Interatrial septum- interatrial groove
What is the septum between the 2 ventricles called and indicated by on the surface?
Interventricular septum- interventricular groove
What can an atrial or ventricular septal defect cause?
Hypoxaemia due to mixing of atrial and venous blood
What does the mixing of arterial and venous blood do?
Reduces the oxygen content of systemic arterial blood in the aorta
What does the crista terminalis separate
Rough and smooth textures
Where is the tricuspid valve?
Between right atrium and right ventricle
Where is the pulmonary valve?
Between the right ventricle and pulmonary trunk
Where is the mitral (bicupsid) valve?
Between the left atrium and left ventricle
Where is the aortic valve
Between the left ventricle and the aorta
Describe the pulmonary valve
Has anterior right and left cusps
Describe the aortic valve
Has right, left and posterior cusps and sinuses (spaces within cusps)
Describe the tricuspid valve
Has anterior, posterior and septal cusps
Describe the mitral valve
Has anterior and posterior cusps
What attached the valve leaflets to papillary muscles?
Tendinous chords
What causes the first heart sound?
Mitral and tricuspid valves closing closing
What causes the second heart sound?
The closure of the aortic and pulmonary valves
What are the sinuses within the aortic valves for?
The coronary arteries
What are semilunar valves?
Cusps look like half moons; pulmonary and aortic
What are leaflet valves ?
Have valve leaflets held down with teninous chords which attach to papillary muscles, prevent reflux, mitral and tricuspid
What does the fibrous skeleton do to the valves?
Provides them with stability
What does a moderator band do?
Carries fibres of right bundle branch to the papillary muscle of the anterior cusp (shortcut for electrical activity to make sure all cusps contract and close tricuspid at same time)
What is a foetal remnant that can be seen in the right atrium?
Foramen ovale
Where do you auscultate for the aortic valve?
2nd right ICS sternal edge
Where do you auscultate for the pulmonary valve?
2nd left ICS sternal edge
Where do you auscultate for the tricuspid valve?
4th left ICS sternal edge (lower left sternal edge)
Where do you auscultate for the mitral valve?
5th left ICS midclavicular line
Describe diastole
Blood returns via vena cave to RA and pulmonary veins to LA
Tricuspid & mitral valves open so blood drains into RV & LV
Impulse originates at SA node and spreads across atria
Atrial contraction completes ventricular filling
Describe systole
Impulse spreads across ventricles
Ventricles begin to contract – once pressure in ventricles > pressure in atria tricuspid & mitral valves snap shut
Ventricles continue to contract – once pressure in ventricles > pressure in PT & aorta pulmonary and aortic valves forced open and blood ejected into great arteries
Impulse spreads across ventricles
Ventricles begin to contract – once pressure in ventricles > pressure in atria tricuspid & mitral valves snap shut
Ventricles continue to contract – once pressure in ventricles > pressure in PT & aorta pulmonary and aortic valves forced open and blood ejected into great arteries
How does autonomic innervation and visceral afferent nerves reach the heart?
Via cardiac plexus
What are the two components of the visceral afferent nerves?
Pain fibres travel to spinal cord alongside sympathetic nerves(visceral) Reflex afferents (e.g. from baroreceptors) travel mainly in the vagus nerve (some in CN XI)
What do pain fibres travel to the spinal cord in?
Cardiopulmonary splanchnic nerves and cardiopulmonary plexus
Where is the cardiac plexus located?
Behind the great vessels of the heart
What connects the CNS to the ganglion (synapse)?
Presynaptic fibre/ preganglionic fibre
What connect the ganglion to the organ?
postsynaptic fibre
What is a ganglion?
Collection of nerve cell bodies outside the CNS
What are the neurotransmitters of the sympathetic ganglion and post synaptic fibres?
Ganglion=acetyl choline
PSF= noradrenaline
How do sympathetic signals leave the CNS?
- travel inferiorly within spinal cord tracts and then…
2. exit the spinal cord in one of T1-L2/3 spinal nerves (thoracolumbar)
What are the 3 most likely options for a sympathetic signal once it leaves the CNS
- go into the ganglion of that level & synapse
- travel superiorly in the sympathetic chain to another ganglion & synapse
- travel inferiorly in the sympathetic chain to another ganglion & synapse
What do the cardiopulmonary splanchnic nerves supply?
Sympathetic nerves to heart and lung from spinal cord
What type of innervation will a midline organ (e.g. the heart) have?
Bilateral sympathetic innervation
What three types of nerve fibres make up the cardiac plexus and where do they come from?
Sympathetic fibres from the cardiopulmonary splanchnic nerves
Parasympathetic fibres from the vagus
Visceral afferent fibres (pain fibres etc)
What are the neurotransmitters for the ganglion and post synaptic fibres of the PS system?
Both acetylcholine
What are PS post sympathetic fibres very short in the innervation of the heart?
As ganglion on heart wall so PGF dont have to travel very far
How do PS signals reach the organs
via Cranial Nerves III, VII, IX & X
What is CN III?
Oculomotor nerve
What is CN VII?
Facial nerve