Cardiovascular anatomy Flashcards
What is the pericardium?
It is a membrane which covers the heart it consists of two layers.
What is the serous pericardium divided into?
- visceral serous pericardium (in contact with heart).
2. parietal serous pericardium ( in contact with fibrous pericardium).
What does the epicardium secrete?
Pericardial fluid lubricant - allows for movement of the heart
What is the epicardium also known as?
Visceral serous pericardium.
What is haemopericardium
ii. What is the name of the process to treat this?
When the pericardium fills with blood.
ii. Pericardiocentesis
What is the name of the condition when build up in pressure around the heart prevents contractions?
ii. where is the needle inserted?
cardiac tamponade.
ii. Via infrasternal angle and directed superopostierioly
What is the tranverse pericardial sinus?
why is this important?
Space within the pericardial cavity, posterosuperiorly
ii. Cardiac surgeons use this sinus to identify and isolate the great vessels in order to commence cardiopulmonary bypass
Name all the great vessels connected to the heart.
Veins.
- Superior vena cava
- inferior vena cava
- right and left pulmonary veins
arteries
- aorta
- right and left pulmonary arteries
pulmonary trunk ( divides into right and left pulmonary arteries
What are the heart’s surfaces?
- sternocostal surface (Anterior)
- posterior surface (posterior)
- diaphragmatic surface (inferior)
What are the boarders of the heart?
right (lateral) border
left (lateral) border
Inferior border
Superior border
What is the apex of the heart?
The base of the heart ( normally to the left side)
How do you find the palpation of the apex of the heart?
5th left intercostal space in the midclavicular line.
What shifts the apex beat to the left of the heart?
Cardiac enlargement (cardiomegaly)
Name the nerves related to the heart.
- Vagus nerve
2. phrenic nerve
What are the auricles used for ?
It is the extensions of both atrium allowing for extra blood to enter them
What is the coronary groove?
this groove indicates the surface marking for the tricuspid valve (boundary between right atrium and right ventricle)
Coronary sinus divides what surfaces?
Diaphragmatic on top of it and base bellow it.
Interatrial groove indicates what?
indicates boundary between the 2 atria
anterior interventricular groove indicates what?
the boundary between the 2 ventricles.
Name all the coronary arteries and branches.
- right coronary artery
- left coronary artery
- right marginal artery
- left marginal artery
- posterior interventricular artery
- circumflex artery
- lateral branch
What is the role of the coronary sinus?
short venous conduit which receives deoxygenated blood from most cardiac veins draining into the right atrium.
what are the two parts to the septum?
- interatrial septum
2. interventricular septum
What is a septal defect refer to?
hole in the septa which allows mixing of arterial and venous blood.
What is hypoxaemia?
reduction in the oxygen content of systemic arterial blood in the aorta
Name the 4 valves
ii. where are they located?
- Tricuspid valve-between right atrium and ventricle
- Pulmonary valve ( right ventricle and pulmonary trunk)
- Mitral valve ( left atrium and ventricle)
- Aortic valve (left ventricle and aorta)
Name the two types of valves.
ii. what type of sounds do they make
- Semilunar (dub sound 2nd) - when closed
2. leaflet ( lub sound 1st) - when closed
What are the roles of tendinous chords and papillary muscles ?
prevents prolapse of blood.
What is the role of the moderator band?
Carries fibres of right bundle branch to the papillary muscle of the anterior cusp. provides a electrical activity shortcut for the anterior papillary muscle so coordinated contraction of all papillary muscles associated with the tricuspid valve occurs.
What are the three layers of the heart?
Endocardium
Myocardium
Epicardium
What do the lub and dub sounds represent?
blood flow not valves
- Lub sound - transferring of blood from atria into ventricles.
- Dub sound - Ventricles expel blood from the heart.
Why do the ventricles produce a wringing motion when they contract?
Because f the double helical orientation of the cardiac muscle fibres.
What are the names of the two spirals associated with cardiac muscle fibre?
Basal spiral - (outer)
Apical spiral - (inner)
What makes up the skeleton of the heart?
ii. What do they cover?
- Four fibrous rings made of dense collagen.
ii. Each ring encircles a valve, two trigones and the membranous portions of the interatrial ,interventricular and atrioventricular septum.
What is the role of the skeleton of the heart?
- keeps the orifices of the AV and seminular valves patent and prevents them from being overly distended.
- Provides attachment for the myocardium.
- Provides attachment for the cusps of all the valves.
- Forms an electrical insulator by separating the myenterically conducted impulses of the atria and ventricles.
What is the apex beat?
Where the sound of the mitral valve closure are maximal.
Where is the apex beat located?
Lies posterior to the 5th intercostal space in adults. Usually a hands breadth (9cm) from the medial plane.
What is the difference between the base and apex of the heart?
Base of the heart is posterior aspect which is opposite to apex.
Where does the right atrium receive blood from?
- Inferior vena cava
- superior vena cava
- coronary sinus
What is the role of the right auricle?
Increases capacity of atrium.
What is the tranverse pericardial sinus?
ii. What is it used for?
A “space” within the pericardial cavity,posterosuperiorly
ii. By surgeons to isolate the great vessels for coronary bypass.
Where is the thoracic inlet found?
It is bounded by the rib 1, T1 vertebra and jugular notch
The sternal angle divides what?
the superior and inferior mediastinum.
What is the thymus replaced by after puberty?
Thymus involutes and becomes fatty forming adipose tissue.
Where do both vagal trunks pass through?
The diaphragm with the oesophagus onto the stomach.
The thoracic aorta is the only thoracic part of the aorta to be found where?
In the posterior mediastinum.
What is the first branch of the ascending aorta?
coronary arteries
What is the second branch of the ascending aorta?
Brachiocephalic trunk
Where does the thoracic duct drain lymph fluid?
The left venous angle
How does the lymph drain from the lungs?
tracheo-bronchial lymph nodes (around the bifurcation of the trachea
right lymphatic duct
thoracic duct
left venous angle
bronchopulmonary lymph nodes (surround the main bronchus at the lung root)
What are the role of the phrenic nerves?
formed from combined anterior rami of cervical spinal nerves 3, 4 & 5 somatic motor to the diaphragm somatic sensory to: mediastinal parietal pleura fibrous pericardium diaphragmatic parietal pleura diaphragmatic parietal peritoneum
What does the vagus nerves contain? e.g. cranial nerve X
somatic sensory nerves for the palate, laryngopharynx & larynx
somatic motor nerves for the pharynx & larynx
autonomic parasympathetic nerves for thoracic and abdominal organs
What is the fibrous pericadium lined with?
parietal serous pericardium
Where is the right coronary artery found in?
Coronary groove
where is the Left anterior descending artery?
anterior interventricular groove
What do the coronary branches supply?
epicardium and myocardium
What are coronary branches normally embedded in?
Adipose tissues
What is the main stem of the coronary arteries?
Left coronary artery
Where do the coronary arteries arise from?
aortic sinuses of the ascending aorta
where is the left coronary artery found?
Left atrioventricular groove between pulmonary trunk and left auricle
Where is the right coronary artery found?
right atrioventricular groove
where is the coronary sinus found?
atrioventricular groove posteriorly
What do the grooves of the heart septums show?
position of the heart septum which divides the left and right heart
divides the Internal chambers too
Which groove shows where the interatrial septum is?
interatrial groove
which groove shows where the interventricular septum is?
anterior interventricular groove
What is the difference between the semi lunar and atrioventricular valves?
semilunar valves’ cusps don’t have tendinous chords attached and are smaller
semilunar valves have chordae tendinae
Which valves are the semilunar valves?
Pulmonary and aortic valves
Which valves are the leaflet valves?
Mitral and tricuspid
How many cusps has the pulmonary valve got?
3 - anterior, right and left
How many cusps has the aortic valve got?
3- right, left and posterior
How many cusps has tricuspid got?
3 - anterior, posterior and septal
How many cusps has mitral valve got?
2- anterior and posterior
what is the general rule when auscultating cardiac valves?
Follow direction of normal blood flow through the valve until the edge of the sternum is located and auscultate
(slightly different for mitral)
Where is the anatomical position of the aortic valve?
2nd right intercostal sternal edge
Where is the anatomical position of the pulmonary valve?
2nd left intercostal sternal edge
What is the anatomical position of the tricuspid valve?
4th left intercostal sternal edge ( lower left edge)
Where is the anatomical position of the mitral valve?
5th left intercostal space on the midclavicular line
How do autonomic innervation and visceral afferent nerves reach the heart?
via cardiac plexus
What controls visceral reflex afferents?
barorecptors
How do reflex afferents mainly travel?
mainly via vagus nerve (CN X)
however
some do travel via glossopharyngeal nerve ( CN IX)
Describe the course of sympathetic signals from the CNS heart.
- Travels inferiorly within spinal cord tracts
- Travels both the superior, middle and inferior cervical sympathetic ganglia
- synapse at T1-T5 ganglia and cervical ganglia
- bilateral postsynaptic fibres travel via cardiopulmonary splanchnic nerves
- travel through cardiac plexus and end at SA and AV nodes in relation to the termination of parasympathetic fibers on the coronary arteries
Describe the course of parasympathetic signals to the heart?
- Presynaptic parasympathetic fibres originate in the vagus nerve
- Synapses onto postsynpatic neurones. Postsynaptic cell bodies are located in the atrial wall and interatrial septum near the SA and AV nodes. along the coronary arteries.
what do action potentials originating at the precentral gyrus of frontal lobe cause?
Contractions of body wall skeletal muscle
What do action potentials arriving at the postcentral gyrus of pareital love cause?
Body wall sensations into the consciousness
What separates the frontal lobe and parietal lobe?
central sulcus
Where do sensory APs arrive when the left side of the chest wall is touched?
Postcentral gyrus of right cerebral hemisphere
What is the pathophysiology of herpes zoster (shingles)
Reactivation of dormant virus in posterior root ganglion
Where is pain felt with Herpes zoster?
- Anywhere in that dermatome
2. If in T4/5 dermatome pain may be central chest pain
Give example of musculoskeletal causes for central chest pain?
- Pectoralis major or intercostal muscle strain
- dislocated costocondral joint
- Costovertebral joint inflammation
- ‘Slipped’ thoracic intervertebral disc
What are the main sourse of dull (visceral) central chest pain?
- Trachea - tracheitis
- aorta - ruptured aneurysm of aortic arch
- oesophagus - oesophagitis
- heart ( angina and myocardial infarction)
- Abdominal viscerae (Gastritis,cholesystitis, pancreatitis,hepatitis)
What are the subdivisions of the mediastinum?
- Superior
inferior
- anterior
- middle
- posterior
where is the heart found?
middle mediastinum
What are the main structures found in the right side of the mediastinum?
(VENOUS SIDE)
- Oesophagus
- trachea
Right Lung
- Right vagus nerve
- SVC
- IVC
- right phrenic nerve
- diaphragm
- azygous vein
- right sympathetic chain
- right abdominopelvic splanchnic nerves
What are the main structures of the left side of the mediastinum
(ARTERIAL SIDE)
- Thoracic duct
- Arch of aorta
- recurrent laryngeal branch of left vagus nerve
- Ligamentum arteriosum- remant of ductus arteriosus
- Left lung
- Diaphragm
- oesophagus
- thoracic aorta
- left sympathetic chain
10 Left phrenic nerve
- Left abdominopelvic splanchnic nerves
What are the main structures of the posterior mediastinum?
- Oesophagus
- trachea and the 2 main bronchi
- Thoracic aorta
- Azygous vein
- right and left sympathetic chains
- thoracic duct
- 2 vagus nerves
- both vagal trunks
What is difference between the role of cardiopulmonary splanchnic nerves for sympathetic signals and pain visceral afferents?
- sympathetic nerves travel to chest organs
2. Pain visceral afferents travel from chest organs
what happens to the visceral afferent’s APs once it arrives at the brain?
- Pass bilaterally to the thalamus and hypothalamus
2. Then diffuses tot areas of the cortex
What is the difference between radiating and referred pain?
Radiating pain - pain felt both at the actual site of the pathology and also radiates
referred pain - sensation of pain is felt only at a site remote from the actual area of injury or disease
Describe the physiology of referred pain?
- Afferent (sensory) fibres from soma and afferent fibres from visceral afferents enter spinal cord at the same levels
- brain chooses to believe that the pain signals coming from the organ are from the soma
What are the classic examples of cardiac referred pain?
- Upper limbs (especially left)
- Back
- neck
- jaw
Where does the right marginal artery come from?
right coronary artery
Where does the Left anterior descending artery come from?
left coronary artery
Where does the posterior interventricular artery come from?
70% of patients - right coronary artery
others can be circumflex or anastomesis of left and right coronary artery
where does the lateral branch come from?
left coronary artery
Where does the circumflex artery come from?
left coronary artery
Where does the left marginal artery come from?
left coronary artery
What are the main sites of coronary atherosclerosis?
- LAD of LCA
- RCA
- circumflex branch of LCA
- LCA
Describe the process of Coronary artery bypass grafting? (CABG)
- grafts anastomosed proximally to ascending aorta
2. Grafts anastomosed to coronary artery distal to narrowing (bypassed it)
What are the main vessels used for CABG graft?
- Radial artery
- great saphenous vein (superficial vein of the lower limb)
- internal thoracic artery
Where does the SA nodal branch from?
RCA - near RCA origin in 60% of patients
where does the AV nodal branch from?
RCA - near PIV origin in 80% of patients
Which arteries supply the interventricular septum?
left side: LAD
right side: PIV
what is the thoracic inlet bounded by?
ribs 1, T1 vertebra and jugular notch
Where is the transverse thoracic plane found?
Sternal angle
T4/5 intervertebral disc
Where is the anterior mediastinum found?
Sternum and fibrous pericardium
What is found in the anterior mediastinum?
thymus
What is found in the middle mediastinum?
- Pericardium
- Heart
- parts of the great vessels which connect with the heart:
Inferior part of SVC
Superior part of IVC
pulmonary trunk
pulmonary arteries
pulmonary veins
ascending aorta
What does azygous vein arch over anteriorly inorder to drain into it?
SVC
What are the main branches of the arch of aorta
- Brachiocephalic trunk
- left common carotid
- Left subclavian
What are the branches from the thoracic aorta’s anterior surface?
- bronchial arteries
- oesophageal arteries
- mediastinal arteries
- pericardial arteries
- Phrenic arteries
What are the main contents found in the superior mediastinum?
- thymus
- arch of aorta and the roots of its major branches
- Trachea
- oesophagus
- thoracic duct and lymphatic trunks
- SVC and brachiocephalic veins
- from lateral to medial
phrenic nerves
vagus nerves
recurrent laryngeal nerves
What is the thymus?
A primary lymphoid organ
after puberty the thymus undergoes gradual involution and is largely replaced by fat.
Where is the thymus found?
Inferior part of neck
anterior part of superior mediastinum
What are the main branches of the ascending aorta?
Right and left coronary arteries
What is the origin of the arch of aorta?
Continuation of ascending aorta
What is the origin of the thoracic (descending) aorta?
continuation of arch of aorta
How does the aorta pass through the diaphragm?
aortic hiatus
What vertebral level is the aortic hiatus?
T12
When does the thoracic aorta become the abdominal aorta?
Once it has passed through the diaphragm (T12)
what is the origin of the posterior intercostal arteries?
thoracic aorta
What vertebral level does the thoracic aorta start?
Inferior border of the bod of the T4 vertebra
At what level does the SVC join the right atrium?
at the third intercostal cartilage
What does the right lymphatic duct drain into?
Right venous angle
What does the thoracic duct drain into?
left venous angle
What are the main lymph nodes of the lung?
- Tracheobronchial lymph nodes
2. bronchopulmonary lymph nodes
Where are the tracheo-bronchial lymph nodes found?
Around the bifurcation of the trachea
where are the bronchopulmonary lymph nodes found?
Surrounding the main bronchi at the lung root
What is the swollen start of the thoracic duct in the abdomen called?
Cisterna chyli
How does the oesophagus pass through the diaphragm?
Via the oesophageal hiatus
the right phrenic nerve passes the diaphragm with what blood vessel in order to supply the diaphragm from the inferior aspect?
IVC
what nerve passes under the ligamentum arteriosum and back to the larynx?
recurrent laryngeal branch of the left vagus nerve
How does the left phrenic nerve supply the diaphragm?
like the right phrenic nerve it passes through and supplies it from the inferior aspect
Define central veins
Veins which are close enough to the heart that pressure within them reflects the pressure of the right atrium
What are the central veins?
internal jugular veins subclavian veins brachiocephalic veins superior vena cava right atrium inferior vena cava iliac veins femoral veins
Which central veins are the most common access points in central venous cannulation?
Internal jugular vein
femoral vein
name the 3 nerves that pass through the mediastinum?
lateral to medial
- Right and left phrenic nerves
- Right and left vagus nerves
- right and left recurrent laryngeal nerves
Explain the anatomical differences between the right and the left recurrent laryngeal nerves.
- Right recurrent laryngeal nerve hooks under the right subclavian artery
- Left recurrent laryngeal nerve hooks under the arch of the aorta
- Right recurrent laryngeal nerve does not enter the chest
- Left recurrent laryngeal nerve does enter the chest
What are the phrenic nerves formed from?
combined anterior rami of cervical spinal nerves 3,4,5
What is the role of the phrenic nerves?
- Somatic motor to the diaphragm
- Somatic sensory to;
mediastinal parietal pleura
fibrous pericardium
diaphragmatic parietal pleura
diaphragmatic parietal peritoneum
What does the supraclavicular nerves supply?
Dermatomes over the shoulder tip
What verterbral level does the supraclavicular nerves originate from?
C3 and C4
What type of nerves does the vagus nerve contain?
- Somatic sensory- palate,larynx and laryngopharynx
- somatic motor- pharynx and larynx
- autonomic parasympathetic - throracic and abdominal organs
Which branches of the vagus nerve are responsible for the supplying somatic sensory and motor stimulation?
recurrent laryngeal nerves
What does the left recurrent laryngeal nerves supply?
muscles of the larynx
What is used to record the peripheral pulse in the neck?
Bifurcation of the common carotid artery
also site for auscultating carotid bruits
Discuss the anatomical relationships of the bifurcation of the common carotid artery.
Anterior to sternocleidomastoid muscle at the level of the superior border of thyroid cartilage
What is used to record the peripheral pulse in the upper limbs?
- brachial artery (proximal)
2. radial artery (distal)
Discuss the anatomical relationships of the radial artery.
lateral to the tendon of the flexor carpi radialis
Discuss the anatomical relationships of the brachial artery.
medial to biceps brachii tendon in the cubital fossa
What is used to the record the peripheral pulse in the lower limbs?
From promixal to distal
- Femoral artery
- Popliteal artery
- Posterior tibial
- dorsalis pedis (dorsal artery of the foot)
Discuss the anatomical relations of the femoral artery.
Inferior to midpoint of inguinal ligament
Discuss the anatomical relations of the popliteal artery.
found in the popliteal fossa
immediately posterior to the knee joint
Discuss the anatomical relations of the posterior tibial artery.
Found between the posterior border of the medial malleous and the achilles tendon
Discuss the anatomical relations of the dorsalis pedis artery.
medial to tendon of extensor hallucis longus on the dorsum of the foot
What other important roles does the radial artery have?
- Used for monitoring arterial blood pressure
2. ABG sampling
What other important roles does the femoral artery have?
used for Intravascular interventions
What other important roles does the subclavian artery have?
It is where cardiac pacing wire is inserted under US guidance
What other important roles the femoral vein have?
- Where insertion of central line occurs
2. intravascular interventions
What over role does the internal jugular vein have?
where cardiac pacing wire is inserted under US guidance
What is the origin of the anterior intercostal arteries?
Internal thoracic artery
What is the origin of the posterior intercostal arteries?
thoracic aorta
What does the anterior intercostal vein drain into?
internal thoracic vein
What does the posterior intercostal vein drain into?
azygous vein
what does the cephalic vein drain?
upper limbs (superficial vein)
what are the three main germ layers in embryo development?
- Endoderm
- mesoderm
- Ectoderm
Where does the heart originate from?
visceral mesoderm
What are two main processes which occur to allow the heart to move into its final position during development?
- Lateral folding
2. Cranio-caudal folding
What fuses together to form the primitive heart?
the two endocardial tubes in the embryo
What are the 5 main features of the primitive heart?
cranial to caudal
- truncus arteriosus
- bulbus cordis
- ventricle
- atrium
- sinus venosus
What do each of the 5 main features of the primitive heart go on to form?
- Truncus arteriosus- aorta and pulmonary trunk
- Bulbus cordis -Trabeculated part of right ventricle and Outflow part of both ventricles
- Ventricle- Trabeculated part of left ventricle
- Atrium - both atria
- Sinus venosus -coronary sinus and smooth part of the right atrium
What is the direction of blood flow in the primitive heart?
caudal to cranial
What occurs around day 23 in heart development?
cardiac looping
Discuss what happens during cardiac looping
atrium- moves dorsal and cranial
ventricle- is displaced left
bulbus cordis - moves inferiorly, ventrally to the right
Discuss how the heart chambers form.
- Atrioventricular groove constricts the atrioventricular canal at its waist
- Endocardial cushions extend and form a column separating the atrium and ventricle
- Proliferating ventricular septum primum moves to the base of the heart.
- simultaneously a proliferating atrial septum primum moves to the endocardial cushions- constricts foramen primum
- Foramen secundum forms in the atrial septum allowing shunting of blood between the atria in both directions.
- septum secundum (second interatrial septum) forms over the septum primum covering most of the foramen secundum leading to the foramen ovale. This only allows shunting of blood from right to left atrium
- ridges from truncus arteriosus spirals down and fuse with ventricular septum allowing for blood to leave the heart.
What do the 6 pairs of the developing aortic arches form?
1 and 2 are obliterated
5 is absent
Ones that matter:
- 3 - carotid artery
- 4- right subclavian vein and part of arch of aorta
- 6 - sprout branches which form pulmonary artery
Are the three main veins during embryonic development?
- Vitelline vein - drain yolk sac
- Umbilical vein - carry oxygenated blood from placenta
- cardinal vein- give systemic venous system
What does the vitelline vein develop into?
- forms part of the portal venous system which drains gut
- forms hepatic sinusoids and veins
- forms hepatic portion of IVC
What does the umbilical vein develop into?
Left one is the only that remains. Becomes the definitive umbilical vein
What do the cardinal veins develop into?
- Anterior: drain HEAD and NECK
Jugular system and Left brachiocephalic vein
SVC
- Posterior: drain trunk
Azygos and Hemiazygos systems (Body wall)
Gonadal and Renal veins
Iliac veins
IVC
Explain the difference between the IVC in foetal circulation and neonatal circulation.
Foetal:
carries oxygenated blood from the placenta to the liver and drains into the left atrium
Neonatal:
carries deoxygenated blood from the tissues (e.g. from the liver) and drains into right atrium
what are the three layers of the blood vessels?
(from deep to superficial)
ii. what do they consist of?
- Tunica intima- endothelium
- Tunica media- smooth muscle and elastic fibres
- Tunica externa- connective tissue
what is an anastomses?
ii. give an example
where arteries connect with each other without a capillary network
ii. circle of willis (in the brain)- prevents stokes
where is the name for alternative routes in an anastomesis?
collateral
What are the main parts of the aorta?
- Ascending aorta
- Arch of aorta
- Descending (thoracic aorta)
- Abdominal aorta
where does the brachial artery branch from?
axillary artery
Where does the axillary artery branch from?
subclavian artery
What does the brachial artery bifurcate into?
ii. where does this occur?
i. radial and ulna
ii. Anterior to elbow joint
Where does superficial lymphatics drain into?
Deep lymphatics
Which is bigger superficial or deep veins?
deep veins
What does the LAD artery supply?
Apex
anterior aspect of interventricular septum
anterior aspect of right and left ventricles
Describe the layers of a medium sized artery. Deep to superficial
Tunica intima
internal elastic membrane
tunica media
external elastic membrane
tunica adventitia
What is the femoral triangle?
ii. what vasculature bundle is found here?
is the area on the anterior aspect of the thigh. Formed by the crossing of various muscles to form a triangular shape.
ii. Femoral artery, vein and nerve