Anatomy Flashcards
what is haemopericardium?
if the pericardial cavity fills with blood
what is cardiac tamponade?
when haemopericardium occurs and the pressure around the heart prevents cardiac contraction
what is a pericardiocentesis?
drainage of fluid from the pericardial cavity
needle is inserted via the infrasternal angle and directed superoposteriorly, aspirating continuously
what is the transverse pericardial sinus?
a space within the pericardial cavity, posteorsuperiorly
surgeons use it to isolate and identify the great vessels for open heart surgery
where is the transverse pericardial sinus?
it lies posterior to the ascending aorta and pulmonary trunk
what are the surfaces of the heart?
anterior (sternocoatsal) surface
base (posterior) surface
inferior (diaphragmatic) surface
what are the borders of the heart?
right (lateral) border
left (lateral) border
inferior border
superior border
where can the apex beat be palpated?
5th left intercostal space in the midclavicular line
when would the apex beat be shifted?
cardiomegaly often shifts it to the left
what does the coronary groove indicate?
the surface marking for the tricuspid valve
what does the anterior interventricular groove indicate?
the boundary between the two ventricles
where are the nerves of the heart?
the vagus nerves are closer the the heart and the phrenic nerves are further away
what does the right common carotid artery and the right subclavian artery come together to form?
the brachiocephalic trunk
what does the interatrial groove indicate?
the boundary between the 2 atria
what are the coronary arteries and their branches?
the arterial blood supply to the epicardium and myocardium
where can the coronary arteries be found?
they course just deep to the epicardium, usually embedded in adipose tissue and arise from the ascending aorta
describe the right coronary artery
in the coronary (right atrioventricular) groove
forms the right marginal artery and the posterior interventricular artery
describe the left (main stem) coronary artery
in the left atrioventricular groove between the pulmonary trunk and the left auricle
name the branches of the left coronary artery
circumflex artery
left marginal artery
lateral (diagonal) branches
posterior interventricular artery
what is the coronary sinus?
a short venous conduit (in the atrioventricular groove posteriorly) which receives deoxygenated blood from most of the cardiac veins and drains into the right atrium
what divides the heart into a right and left side
a septum
what is the part of the septum between the 2 atria?
interatrial septum
what is the part of the septum between the 2 ventricles?
interventricular septum
describe a septal defect
it can allow the mixing of arterial and venous blood in the heart
can be life threatening because it reduces the oxygen content of systemic arterial blood in the aorta causing hypoxaemia
describe the interior of the right atrium
opening of the superior vena cava location of the SA node crista terminalis oval fossa opening of the coronary sinus opening go the inferior vena cava
how does the heart ensure unidirectional flow?
the 4 cardiac valves
one valve at the exit from each cardiac chamber
describe the tricuspid valve
between the right atrium and the right ventricle
has anterior, posterior and septal cusps
describe the mitral valve
between the left atrium and left ventricle
has anterior and posterior cusps
describe the pulmonary valve
between the right ventricle and the pulmonary trunk
has anterior right and left cusps
describe the aortic valve
between the left ventricle and the aorta
has right, left and posterior cusps and sinuses
describe the interior of the left atrium
the left auricle
bilateral openings of superior and inferior pulmonary veins
remains of the valve of foramen ovale may be visible
cusps of mitral valve
what is the 1st heart sound?
the closure of the tricuspid and mitral valves
what is the 2nd heart sound?
closure of pulmonary and aortic valves
how do sympathetic nerve fibres get from the CNS to the organs?
a presynaptic fibre connects between CNS and ganglion
the ganglion is aceytlcholine (neurotransmitter)
the post synaptic fibre is noradrenaline
describe the route of presynaptic fibres from the brain
they travel inferiorly within spinal cord tracts and then exit the spinal cord in one of the T1-L2/3 spinal nerves
describe the T1-T5 ganglia and cervical ganglia
cardiopulmonary splanchnic nerves which are the sympathetic nerves to the heart and lungs
how do postsynaptic sympathetic fibres reach the heart?
there is bilateral sympathetic innervation (preodminalty left sided)
how do parasympathetic signals from the CNS reach the organs?
a presynaptic fibre connects between CNS and ganglion
the ganglion is acetylcholine
the postsynaptic fibre is acetyl choline
what is a ganglion?
a synapse between the axon of the presynaptic neurone and the cell body of the postsynaptic neurone
what is a postsynaptic fibre?
connects between the ganglion and the organ
how do parasympathetic signals reach the organs?
through the cranial nerves III, VII, IX + X
how do parasympathetic signals reach the heart?
CN X (the vagus nerve) presynaptic parasympathetic fibres in vagus nerve then synapse onto postsynaptic neurones
describe the nature of somatic pain
sharp
stabbing
well localised
sources of somatic pain
muscular joint bony intervertebral disc fibrous pericardial nerve
nature of visceral pain
dull
aching
nauseating
poorly localised
sources of visceral pain
heart and great vessels
trachea
oesophagus
abdominal viscerae
nature of radiating pain
felt in centre of chest and felt spreading from there
sources of radiating pain
upper limbs
back
neck
nature of referred pain
only felt at site remote from area of tissue damage in the chest
sources of referred pain
upper limbs
back
neck
describe acute or chronic pain
repeated acute episodes vs chronic pain
where in the brain does the sensation of pain reach consciousness?
the cerebral cortex
where do APs arrive to bring body wall sensations into consciousness?
postcentral gyrus of the parietal lobe
somatosensory
where do APs originate to bring about contractions of skeletal muscle?
precentral gyrus of the frontal lobe
somatomotor
what are somatic central chest pain sources?
herpes zoster (shingles) muscle, joint and bone parietal pleura and fibrous pericardium
what is herpes zoster (shingles)?
reactivation of dormant virus in posterior root ganglion
pain can be felt anywhere in that dermatome
pain precedes shingles
patient with it developing in T4/T5 dermatome may present with central chest pain
what are muscle, joint and bone causes of chest pain?
pectorals major or intercostal muscle strain
dislocated costochondral joint
costovertebral joint inflammation
‘slipped’ thoracic intervertebral disc
what can cause chest pain associated with the parietal pleura and the fibrous pericardium?
pleurisy
pericarditis
what are visceral central chest pain sources?
oesophagus heart abdominal visceral aorta trachea
what causes chest pain from the oesophagus?
oesophagitis
what causes chest pain from the heart?
angina
MI
what causes chest pain from the abdominal viscerae?
gastritis
cholecystitis
pancreatitis
hepatitis
what causes chest pain from the aorta?
ruptured aneurysm of aortic arch
what causes chest pain from the trachea?
tracheitis
what are the sub divisions of the mediastinum?
superior inferior
anterior
middle (heart location)
posterior
how do pain signals from the organs reach the brain?
cardiopulmonary splanchnic nerves plus pain afferents from chest organs
visceral afferent action potentials pass bilaterally to thalamus and hypothalamus then diffuse areas of the cortex
where is radiating pain originating from a somatic structure?
along the affected dermatome(s)
where is radiating pain from the heart?
to the dermatomes supplied by the spinal cord levels at which the cardiac visceral afferents enter the spinal cord ie bilaterally to cervical and upper thoracic dermatomes
what is visceral radiating pain?
although it is felt in a dermatomal pattern, it is still dull, aching nd poorly localised in nature
what causes referred pain?
due to afferent fibres from soma and afferent fibres from viscera entering the spinal cord at the same levels
the brain chooses to believe that the pain signals coming from the organ are actually coming from the soma
what is cardiac referred pain?
the brain chooses to believe the pain signals are coming from the upper limbs (especially left side) or from the back, neck or jaw
where is the most common site of coronary atherosclerosis?
anterior interventricular branch of LCA
where is the second most common site of coronary atherosclerosis?
RCA
where is the third most common site of coronary atherosclerosis?
circumflex branch of LCA
where is the least common site of coronary atherscelrosis?
LCA
where are commonly used grafts for coronary arteries?
radial artery/ internal thoracic artery
great saphenous vein
what is the arterial blood supply of the interventricular septum?
left anterior descending or anterior interventricular artery
left and right bundle branches
posterior interventircular artery
