Anatomy Flashcards
Location of the heart in the mediastinum
Middle mediastinum, within the fibrous pericardium.
Layers of the heart wall
Inner –> Outer
Endocardium
Myocardium
Epicardium
Endocardium composition
SIMPLE SQUAMOUS EPITHELIUM sitting on BASEMENT MEMBRANE sitting on CONNECTIVE TISSUE
Endocardium Function/Location
Lines heart chambers,
Forms valves
Myocardium composition
Cardiac muscle
Myocardium fibre orientation
Muscle bundles are orientated in different planes to be able to close down on the chamber lumen
Epicardium Composition
(nearest to pericardial cavity) SIMPLE SQUAMOUS EPITHELIUM* BASEMENT MEMBRANE CONNECTIVE TISSUE (nearest to myocardium)
Contains main branches of coronary arteries
*= visceral layer of serous pericardium
Blood enters the coronary arteries during…
Diastole - when myocardium relaxes.
at systole the openings are shielded by aortic valve cusps
Basic structure of a blood vessel
layers inside –> outside
Tunica intima,
Tunica media,
Tunica adventitia/externa
Tunica intima composition
Simple squamous epithelium,
Basement membrane,
Connective tissue
Tunica media composition
Smooth muscle,
Elastic tissue
Tunical adventitia/ externa composition
Fibrous connective tissue
Structure of elastic arteries
Many layers/ laminae of elastic fibres in T. media.
Thick T. intima
Thinner T. adventitia
Conducting arteries
Structure of muscular arteries
Thick T. media with much smooth muscle
Thick T. adeventitia (w/ vasa vasorum)
Elastic fibres concentrated in the internal and external elastic laminae (very prominent)
Distributing arteries
Structure of arterioles
No elastic fibres.
1-2 layers smooth muscle in T. media.
Rich sympathetic nerve innervation ( to regulate regional distribution of blood)
No T. adventitia
General structure of capillaries
Very thin walled, only T. intima.
Pericytes (incomplete layer of contractile cells surrounding BM that control flow)
Continuous capillaries
Material must pass through/ between cells or in selective transport mechanisms.
Can control what is exchanged.
e.g. in muscle
Fenestrated capillaries
Have fenestrations (pores).
sometimes have protein diaphragms that can filter molecules by M/W or charge
e.g. endocrine glands, kidney renal corpuscle
Discontinuous capillaries
Have gaps between endothelial cells and basement membrane cells (allows free passage of fluids and cells)
e.g. liver, spleen, bone marrow
Sinusoids
Large diameter discontinuous capillaries used for large amounts of exchange.
T. intima contains phagocytic cells.
e.g. liver, some endocrine glands
Structure of veins
Thin T. intima.
IEL, OEL and T. media thin or absent.
Thick T. adventitia = collagenous tissue.
Valves to prevent backflow
thicker wall in more superficial veins as no surrounding support.
Arteriovenous shunts
Vessels that bypass capillary beds.
E.g. in skin for thermoregulation.
Posterior border of the superior mediastinum
T1 - T4
Surface marking of apex beat
5th intercostal space, left mid-clavicular line
Heart chamber at the right border
Right Atrium
Heart chamber at left border
Left Ventricle
Heart chamber at inferior border
Right Ventricle
Heart chambers at superior border
Left and Right Atria
Heart chamber forming the anterior/sternocostal surface
Right Ventricle
Heart chamber forming posterior surface/ base of heart
Left atrium
Heart chamber forming inferior/ diaphragmatic surface of heart
Left ventricle
The heart is anterior to which vertebrae
T5 - T8
Vertebral level of the aortic arch
T4
Vertebral level of the bifurcation of the abdominal aorta
+what does it form
L4
Forms the common iliac arteries
Vertebral level of the bifurcation of the common iliac arteries
+what do they form
L5
Forms the internal and external iliac arteries
Branches of the descending thoracic aorta
Bronchial arteries,
Oesophageal arteries,
Pericardial arteries,
Posterior intercostal arteries*
*Only these are identifiable
Tributaries of the superior vena cava
Left and right brachiocephalic veins,
Azygous vein
Tributaries of the inferior vena cava
Left and right common iliac veins
Branches of the aortic arch
ascending to descending
- Bracheocephalic artery/trunk
(splits into right common carotid and right subclavian arteries) - Left common carotid artery
- Left subclavian artery
Hemiazygous vein drains into the azygous vein at vertebral level
T8/9
hemiazygous comes from the left
Name progression of main artery in arm
Subclavian,
Axillary,
Brachial,
Radial + Ulnar
The subclavian artery becomes the axilla at…
The lateral border of the 1st rib
The brachial artery bifurcates at the…
cubital fossa (inside elbow)
Ultimate venous drainage of the limbs
Superficial veins drain into deep veins and then into the inferior/ superior vena cava
The posterior tibial artery enters the sole of the foot…
where it can be palpated
inferior to the medial malleolus
Layers covering the heart
inside to outside
Visceral serous pericardium (epicardium),
(pericardial cavity)
Parietal serous pericardium,
Fibrous pericardium
Protective role of the fibrous pericardium
Prevents the heart from overfilling with blood
Innervation of the parietal serous and fibrous pericardium
Phrenic nerve
+ pain fibres
Autonomic + sensory innervation of the visceral pericardium and heart wall
(nerves and route)
Motor fibres travel via the cardiac plexus to…
Spinal cord segments T1 - T4 (sympathetic)*
+ vagus nerve (parasympathetic)
Where they innervate the AV and SA node
(*Sensory and pain fibres from the heart travel back to spinal cord levels T1-T4 in these sympathetic fibres)
Function of the auricles
Increase capacity of the atria
Thicker ventricular wall
Left = 3x thicker
Moderator band (septomarginal trabeculum) function
Caries part of the right branch of the bundle of His to the anterior papillary muscle on the anterior wall of the right ventricle
Trabeculae carneae
Muscular columns on the walls of the ventricles.
e.g. moderator band, papillary muscles (many are just ridges).
Prevent suction that would occur with a flat surface and impair the heart’s function.
Musculi pectinati
Ridges of muscle in the atrial walls.
LA: few, small, on the inside of the auricle.
RA: inside of auricle and on the lateral wall from the crista terminalis
Crista terminalis
A vertical smooth muscular ridge on the lateral wall of the right atrium.
Connects the right sides of the orifices for the SVC and IVC.
The origin of the musculi pectinati
Function of the papillary muscles
contract to prevent inversion of the valves into the atria on systole.
Function of chordae tendineae
Connect papillary muscles to valve cusps
Arteries in the coronary/ atrioventricular sulcus
Right coronary artery and circumflex
Arteries in the interventricular sulcus
Anterior and posterior interventricular arteries
The right coronary artery supplies…
Right Atrium,
Right Ventricle,
AV node + Bundle of His,
SA node (sometimes)
The left coronary artery supplies…
Both Ventricles,
Interventricular septum,
Left Atrium,
SA node (usually)
Venae cordis minimae
Small veins which drain the heart wall directly into each chamber of the heart
Lymphatics from the heart drain to…
nodes, location + return to venous circulation
TRACHEOBRONCHIAL nodes* (at bifurcation of the trachea)
Bronchopulmonary nodes* (at hilum of each lung)
Paratracheal nodes* (at sides of trachea)
Drained in bronchomediastinal trunks
*These are all mediastinal lymph nodes
Aortic sinuses
dilatations between the wall of the ascending aorta and the cusps of the aortic valve.
Left and right aortic sinuses give rise to the left and right coronary arteries
Location of the sino-atrial node
In the right atrium, near the opening of the SVC
Location of the atrioventricular (AV) node
The inferior interatrial septum
location of the bundle of His (atrioventricular bundle)
Within each side of the interventricular septum
Valves in veins are formed from…
the tunica intima
Main pulse points in the upper limb
Brachial,
Radial
Main pulse points in the lower limb
Femoral,
Popiteal,
Posterior tibial,
Dorsalis pedis
Location to palpate the brachial pulse
Halfway down the medial side of the arm,
Midway between the anterior and posterior muscle compartments
location to palpate the radial pulse
In front of the distal end of the radius
Location to palpate the femoral pulse
Mid-inguinal point:
Halfway between the pubic symphysis and anterior superior iliac spine.
Location to palpate the popliteal pulse
Popliteal fossa
Location to palpate the dorsalis pedis
Just lateral to the extensor tendon of the great toe
Main pulse points in the neck
Subclavian,
Carotid
Location to palpate the carotid pulse
Upper neck,
Between the sternomastoid and trachea
At the level of cricoid cartilage
Location to palpate the subclavian pulse
Against 1st rib
Recurrent laryngeal nerves
Branches of the vagus nerve that travel to the cardiac plexus and supply the larynx
LEFT: branches off at the aortic arch
RIGHT: branches off at the right subclavian artery
Attachments of the fibrous pericardium
Central tendon of the diaphragm,
The adventitia of all the great vessels (except IVC),
The sternopericardial ligaments
Veins used for venepuncture and cannulation
Medial cubital vein - becomes more prominent by compressing veins proximal to it
Divisions of the mediastinum
SUPERIOR
INFERIOR:
- anterior
- middle (heart, pericardium + great vessels)
- posterior
The brachial plexus
A network of nerves formed by the anterior rami of spinal nerves C5 - T1
Located in the axilla
Right anterior supply and drainage of the thorax
sequence of vessels
Aorta, Brachiocephalic branch, Right subclavian artery, Right internal thoracic artery, Right anterior intercostal arteries
Right anterior intercostal veins, Right iInternal thoracic vein, Right subclavian vein, Right brachiocephalic vein, SVC
Left posterior supply and drainage of the thorax
sequence of vessels
Aorta,
Left posterior intercostal arteries,
Left posterior intercostal veins,
Hemizygous and accessory hemizygous veins,
Azygous vein,
SVC
Right posterior supply and drainage of the thorax
sequence of vessels
Aorta,
Right posterior intercostal arteries,
Right posterior intercostal veins,
Azygous vein,
SVC
Left anterior supply and drainage of the thorax
Sequence of vessels
Aorta,
Left subclavian artery,
Left internal thoracic artery,
Left anterior intercostal arteries,
Left anterior intercostal veins
Left interior thoracic vein,
Left brachiocephalic vein
SVC
Veins of the upper limb
Cephalic (lateral side)
Basilic (medial side)
Median Cubital (connects them)
Arterial supply of the lower limb
External iliac –> (Deep femoral) + superficial femoral
Superficial femoral –> Popliteal
Popliteal –> Anterior + Posterior tibial
Anterior tibial artery –> Dorsalis pedis
Superficial veins of the lower limb
Great saphenous (medial) Small saphenous (posterior)
Venous drainage of the lower limb
Small saphenous + posterior tibial –> Popliteal
Popliteal + Great saphenous–> Femoral
Femoral –> External iliac
Cardiac vein accompanying the marginal artery
Small cardiac vein
Veins and arteries in the anterior interventricular groove
Great cardiac vein
Anterior interventricular artery
Veins and arteries in the posterior interventricular groove
Middle cardiac artery
posterior interventricular artery
Veins and arteries in the coronary sulcus
Right coronary artery
Circumflex artery
Coronary sinus
Coronary sinus drains into…
The right atrium
Posterior border of the inferior mediastinum
T5 - T12
Plane separating the superior and inferior mediastinum
Sternomanubrial plane
Location of the thymus
Anterior mediastinum
involutes (decreases in size and functional activity) after puberty
Position of the azygous vein
Immediately to the right of the descending thoracic aorta
Position of the thoracic duct
On the vertebral bodies, between the azygous vein and the descending thoracic aorta
Origin of the thoracic duct
At L1 as cisterna chyli
The thoracic duct drains into
the medial end of the left subclavian vein
at its junction with the left internal jugular vein
The right lymphatic duct drains into
The medial end of the right subclavian vein
at its junction with the right internal jugular vein
Where does the popliteal artery branch into the anterior and posterior tibial arteries
Lower border of the popliteus muscle
Heart chamber forming the apex of the heart
left ventricle
Number of papillary muscles in the right ventricle
3,
To connect to 3 valve cusps of the tricuspid valve
Number of papillary muscles in the left ventricle
2
To connect to 2 valve cusps of the mitral valve
location within the heart of the coronary arteries
Initially distributed embedded within the epicardium.
Then pierce the myocardium and give off branches that surround each myocyte
Location of the cardiac plexus
Bifurcation of the trachea
rib levels of the pericardial sac
rib 2 - 6
Borders of the base of the heart
Superior = bifurcation of the pulmonary trunk Inferior = coronary sulcus
Heart chamber forming the left pulmonary surface
Left ventricle
Heart chamber forming the right pulmonary surface
Right atrium
Superior border of the heart
surface anatomy
inferior border of the 2nd, left costal cartilage
to superior border of the 3rd, right costal cartilage
Right border of the heart
surface anatomy
3rd right costal cartilage
to 6th right costal cartilage
(slightly convex)
Inferior border of the heart
surface anatomy
6th right costal cartilage
to 5th intercostal space, left midclavicular line
Left border of the heart
surface anatomy
5th intercostal space, left midclavicular line
to inferior border of the 2nd, left costal cartilage
Aortic valve auscultation site
2nd intercostal space
Right of the sternal border
Pulmonary valve auscultation site
2nd intercostal space
Left of the sternal border
Tricuspid valve auscultation site
5th/6th intercostal space
Near left sternal border
Mitral valve auscultation site
5th intercostal space
Left midclavicular line
Location to palpate the abdominal aorta
Just above and very slightly to the left of the umbilicus
