9. Heart & Vascular System (Part 2) Flashcards
What is the first vessel to branch off the aorta?
Coronary arteries
At what height does the arch of aorta begin and end?
2nd sternocostal joint
Describe the relative position of the aortic arch as it ascends and descends.
- The arch ascends anterior to the right pulmonary artery and bifurcation of the trachea.
- It descends posterior to the root of the left lung.
Describe the structure of the thoracic aorta, including branches.
- Ascending aorta arises from left ventricle
- First gives off coronary artery
- Aortic arch bends over the pulmonary veins and gives off:
- Brachiocephalic artery -> Divides into right subclavian and right common carotid arteries
- Left common carotid artery
- Left subclavian artery
- Descending aorta gives off:
- Oesophageal arteries -> Supply the middle third of the oesophagus.
- Bronchial arteries -> Supply the lung parenchyma.
- Posterior intercostal arteries -> Supply the intercostal spaces from the dorsal aspect.
- Superior phrenic arteries [EXTRA]
- Pericardial branches [EXTRA]
- Descending aorta leaves thorax at the the aortic hiatus of the diaphragm at T12
At what level does the descending aorta cross the diaphragm?
T12
Describe the aortic supply of the thoracic cage.
- Each subclavian arteries give off the internal thoracic arteries that run down the anterior side of the thorax
- The internal thoracic arteries give off the anterior intercostal arteries
- The descending aorta gives off the posterior intercostal arteries
What do the bronchial and oesophageal arteries arise from?
Descending thoracic aorta
Where is the ligamentum arteriosum found?
Between the aorta and pulmonary vein
What is a thoracic aortic aneurysm?
- A ballooning of the aorta above the diaphragm, which predisposes the vessel to rupture due to weakening of the vessel wall.
- If a rupture occurs, the mortality rate is as high as 80%.
- 20% of these aneurysms are linked to family history.
- Aneurysms may be treated using either open surgery or endovascular stent graft insertion.
At what level does the abdominal aorta begin and end?
- Begins at T12, at the diaphragmatic hiatus
- Ends at L4 by dividing into the left and right common iliac arteries
Where in the abdomen does the abdominal aorta descend?
Anterior to the vertebral bodies within the retroperitoneum.
What are the 3 types of branches arising from the descending abdominal aorta?
- Unpaired visceral
- Paired visceral
- Paired segmental branches
Describe the branches of the abdominal aorta.
- Unpaired visceral:
- Coeliac (T12) -> Supplies derivatives of the foregut. Branches into the left gastric artery, splenic artery and common hepatic artery.
- Superior mesenteric artery (L1) -> Supplies derivatives of the midgut. Branches include jejunal, ileal, ileocolic, right colic and middle colic arteries.
- Inferior mesenteric artery (L3) -> Supplies derivatives of the hindgut. Branches include the left colic, sigmoid and superior rectal arteries.
- Paired visceral:
- Middle adrenal (suprarenal) artery (L1) -> Help supply to adrenal glands along with the superior and inferior suprarenal arteries.
- Renal artery (L1/2) -> Supplies kidneys.
- Gonadal artery (L2) -> Either the testicular artery or the ovarian artery.
- Paired segmental [EXTRA]
- Inferior phrenic artery -> Supplies the underside of the diaphragm.
- Lumbar arteries -> Multiple sets of paired arteries that supply the muscles of the back, vertebrae and intervertebral discs.
Describe an abdominal aortic aneurysm.
- Abdominal aortic aneurysms are far more common than thoracic aortic aneurysms and all men aged 65 are invited to an ultrasound screening scan to identify those at risk.
- Aneurysms can interfere with the blood supply of many of the structures reliant on the abdominal aorta, including the kidneys and GI tract.
- Rupture of these aneurysms can be rapidly fatal.
What does the abdominal aorta bifurcate into and at what level?
Into the common iliac arteries at L4
What do the common iliac arteries divide into?
- Internal iliac artery
- External iliac artery
What are the branches of the internal iliac arteries and what do they supply?
- To pelvic organs:
- Middle rectal
- Vesical
- Uterine
- To body wall:
- Superior gluteal
- Inferior gluteal
- Obturator
- To perineum:
- Pudendal
What does the external iliac artery become and where?
Femoral artery at the inguinal ligament
For the inferior epigastric artery, describe:
- Origin
- Function
- Importance
- Origin -> External iliac artery
- Function -> Supplies the anterior abdominal wall, deep abdominal wall of the pubic and lower umbilical regions, and spermatic cord
- Importance -> Forms the lateral border of the inguinal triangle
Describe the structure of the vena cava and what it drains.
- Superior vena cava drains the head and upper limbs
- Drains the right brachiocephalic and left brachiocephalic veins, which each drain their corresponding internal jugular and subclavian veins
- Inferior vena cava drains the abdomen, pelvis and lower limbs
- Drains multiple tributaries, including the common iliac veins
Describe the organisation of major veins in the thorax and abdomen.
- Superior vena cava:
- Confluence of right and left brachiocephalic veins, which are confluences of:
- Internal jugular veins (drain head) and subclavian veins (drain external jugular veins and upper limb)
- Drain the azygos vein just before the SVC enters the right atrium
- Intercostal veins drain into the azygos vein on the right and the hemi-azygos veins on the left side of the thorax. The hemi-azygous veins drain into the azygous vein.
- Confluence of right and left brachiocephalic veins, which are confluences of:
- Coronary sinus drains heart
- Inferior vena cava:
- Drains the hepatic portal vein, which drains liver and alimentary tract (indirectly, via the hepatic portal veins)
- Drains the adrenals, kidneys, gonads, pelvic organs (corresponding veins to arteries)
- Drains the common iliac veins
Describe the venous drainage of the thoracic cage.
- Posterior intercostal veins drain into the azygos, hemiazygos and accessory hemiazygos veins
- The hemiazygos and accessory hemiazygos veins drain into the azygos veins
- The azygos vein drains into the superior vena cava
What are some easy ways to remember the level at which these structures cross the diaphragm:
- Vena cava
- Aorta
- Vegus nerve
- Oesophagus
- Vena cava -> T8 -> There are 8 letters in vena cava
- Aorta -> T12 -> Idk good luck
- Vagus nerve -> T10 -> There are 10 letters in vagus nerve and it is the 10th cranial nerve
- Oesophagus -> T10 -> There are 10 letters in oesophagus
How many pulmonary arteries are there?
2 -> A left and a right one.
Describe the venous drainage of the lungs and bronchi.
- Pulmonary veins drain the lungs -> Drain into the left atrium of the heart.
- Bronchial veins drain the larger bronchi and structures at the roots of the lungs -> The right side drains into the azygos vein, while the left side drains into the left superior intercostal vein or the accessory hemiazygos vein.
How many pulmonary veins are there?
4 -> A superior and inferior on each side.
Label the hila of the right and left lungs.
(Right is on the left and left is on the right)
Note: The posterior is in the middle, the anterior is to the sides.
Summarise the venous drainage of the abdomen.
Much of the venous system of the abdomen follows the same pattern as the arteries, although there are some exceptions:
- There are no inferior vena cava tributaries from the spleen, pancreas, gallbladder or abdominal GI tract, as these structures drain into the hepatic portal system first.
- There is no coeliac vein – instead, in most individuals, the splenic vein and superior mesenteric vein join together to form the hepatic portal vein behind the neck of the pancreas. The inferior mesenteric vein usually drains into the splenic vein before it forms the hepatic portal vein, although there is a lot of anatomical variation.
- The left gonadal and left adrenal veins drain into the left renal vein, rather than directly into the inferior vena cava.
Describe the lymph nodes of the thorax and abdomen.
- The cisterna chyli drains the chains of nodes around the aorta (found at the origin of the coeliac, superior mesenteric and inferior mesenteric arteries), as well as the external and internal iliac nodes
- The thoracic duct drains lymph from the cisterna chyli into the junction between the left internal jugular and left subclavian veins
Where in the lungs are lymph nodes found?
At the hilum.
Describe the position of the spleen. Include surface markings.
- Intra-peritoneal
- Found within the left upper quadrant of the abdomen, behind 9th-11th ribs.
- Inferiorly, the spleen is related to the colon at the splenic flexure.
Describe the arterial supply and venous drainage of the spleen.
- Arterial supply -> Splenic artery (arising from coeliac trunk)
- Venous drainage -> Splenic vein
Draw the surface anatomy of the spleen.
What is the carotid bifurcation?
- It is the point where the common carotid artery divides into the internal and external carotid arteries
- This usually occurs at the upper border of the thyroid cartilage, at around the level of the C4.
Compare what the internal and external carotid arteries supply.
- Internal carotid artery -> Supplies brain, eyes and forehead through the carotid canal in the skull
- External carotid artery -> Supplies areas of the head and neck that are exterior to the cranium
What are the branches of the external carotid artery?
- Superior thyroid artery -> Supplies the superior part of the thyroid and the larynx.
- Lingual artery -> Supplies the floor of the mouth, including the tongue.
- Facial artery -> Supplies the face.
- Maxillary artery -> Supplies deep structures of the face.
Extra:
- Ascending pharyngeal artery -> Supplies the tonsils.
- Superficial temporal artery -> Supplies temple and scalp.
The middle meningeal artery is a branch of which artery?
Maxillary artery
What artery is this?
Superior thyroid artery
What artery is this?
Facial artery
What artery is this?
Lingual artery
What artery is this?
Maxillary artery
Draw the carotid, facial and superficial temporal pulse points.
Note: The superficial temporal pulse point is over the zygomatic process.
Describe the venous drainage of the head and neck.
Superficial veins:
- Anterior jugular veins
- Drain the neck
- Drain into the external jugular vein just before they enter the subclavian veins
- External jugular veins
- Drain the superficial tissues of the skull and the posterior and deep parts of the face
- Drain into the subclavian veins (before they join with the internal jugular veins)
Deep veins:
- Internal jugular veins
- Drain the brain and parts of the face
- Drain into the subclavian veins, forming brachiocephalic veins
- Subclavian veins
The confluence of the brachiocephalic veins forms the superior vena cava.
Summary: Anterior jugular drains into external jugular, which drains into the subclavian. Subclavian and internal jugular join to form brachiocephalic, which join to form the SVC.
What are the different superficial lymph nodes of the head and neck?
- Submental -> Medial lower lip and chin
- Submandibular -> Medial orbit, cheek and upper lip and most the external nose
- Parotid (preauricular) -> Eyelids, external nose and lateral cheek
- Mastoid
- Occipital
What are the different deep lymph nodes of the head and neck?
Upper and lower deep cervical (labelled
How do the vertebral arteries enter the skull?
Through the foramen magnum, passing along the ventral side of the medulla.
Describe the path of the vertebral arteries and the arteries they form.
- Subclavian arteries give off the vertebral arteries, which enter the skull via the foramen magnum, passing along the ventral medulla.
- The vertebral arteries give off the posterior inferior cerebellar arteries (PICA) and also give off branches that join to form the anterior spinal artery.
- At the lower border of the pons, the vertebral arteries unite to form the basilar artery.
- The basilar artery gives off the anterior inferior cerebellar arteries, pontine arteries and the superior cerebellar artery.
- It then ends in the posterior cerebral arteries, which supply the occipital lobes and inferomedial temporal lobes.
- The posterior cerebral arteries at the start of their course give off the posterior communicating arteries, which form part of the Circle of Willis.
Summary:
- Subclavian
- Vertebral
- Posterior inferior cerebellar arteries
- Anterior spinal artery
- Basilar
- Anterior inferior cerebellar arteries
- Pontine arteries
- Superior cerebellar arteries
- Posterior cerebral arteries
- Posterior communicating arteries
Draw the path of the basilar artery.
Describe the path of the internal carotid arteries and the arteries they form.
- Common carotid arteries give off the internal carotid arteries, which enters the skull through the carotid canal (in the petrous portion of the temporal bone).
- First, the internal carotid arteries give off the ophthalmic artery that supply all the structures in the orbit as well as some structures in the nose, face and meninges.
- Then, the internal carotid arteries give off the posterior communicating arteries, which join the posterior cerebral arteries (originating from the vertebral arteries) as part of the Circle of Willis.
- Finally, the internal carotid arteries terminate as the anterior and middle cerebral arteries.
- Anterior cerebral arteries supply the frontal lobes and superior medial parietal lobes. They also give off the anterior communicating arteries (part of the Circle of Willis) that connect with the opposite anterior cerebral artery.
- Middle cerebral arteries supply the lateral cerebral cortex, anterior temporal lobes and the insular cortices.
Summarise the areas of the outer brain supplied by each of the cerebral arteries.
- Blue = Anterior cerebral artery
- Red = Middle cerebral artery
- Yellow = Posterior cerebral artery
Summarise the areas of the sagittal cross-section of the brain supplied by each of the cerebral arteries.
- Blue = Anterior cerebral artery
- Red = Middle cerebral artery
- Yellow = Posterior cerebral artery
What are pontine arteries?
A number of small vessels which come off from either side of the basilar artery and supply the pons and adjacent parts of the brain.
What are the posterior inferior cerebellar arteries?
- They are large branches of the vertebral arteries.
- They supply the cerebellum.
What are the spinal arteries and what do they arise from?
- They are the arteries that supply the spinal cord
- There is one anterior spinal artery -> It arises from the vertebral arteries sending branches that converge
- There are two posterior spinal arteries -> They arise from the vertebral artery in 25% of humans or the posterior inferior cerebellar artery (a branch of the vertebral artery) in 75% of humans.
What is the artery of Adamkiewicz?
- It is a major artery that joins the the anterior spinal artery in the lower one-third of the spinal cord, providing reinforcement of supply.
- It typically arises from a left posterior intercostal artery at the level of the 9th to 12th intercostal artery, which branches from the aorta, and supplies the lower two-thirds of the spinal cord via the anterior spinal artery.
What is the Circle of Willis?
- It is the joining area of several arteries at the inferior side of the brain.
- This is due to the anterior and posterior communicating arteries linking vessels derived from the internal carotid and vertebro-basilar systems.
Label this.
How do internal carotid arteries enter the skull?
- Through the carotid canal (in the petrous portion of the temporal bone).
- They then travel along the foramen lacerum.
What is the middle meningeal artery?
- It is one of the branches of the maxillary artery, which is a branch of the external carotid artery.
- It passes through the foramen spinosum to supply the dura mater.
What imaging technique is this?
MRI
What imaging technique is this?
Contrast CT
Label this angiogram.
What is the large artery seen in this angiogram?
Anterior cerebral artery
What artery is this?
Middle cerebral artery
What artery is this?
Posterior cerebral artery
What artery is this?
Anterior cerebral artery
Describe the relation of the internal carotid artery to the cavernous sinus and abducens nerve.
- It passes through the cavernous sinus
- It passes more medially than the abducens nerve
What blood vessel is this and what is the function?
- Vertebral arteries
- Supply the upper spinal cord, cerebellum, brainstem, occipital lobes and part of the temporal lobes.
What blood vessel is this and what is the function?
- Internal carotid arteries
- Supply the anterior and middle parts of the cerebrum and the diencephalon.
What blood vessel is this and what is the function?
- Basilar artery
- It supplies the cerebellum, brainstem, occipital lobes and part of the temporal lobes.
What blood vessel is this and what is the function?
- Middle cerebral arteries
- Supply the lateral cerebral cortex, anterior temporal lobes and the insular cortices.
What blood vessel is this and what is the function?
- Anterior cerebral arteries
- Supply the frontal lobes and superior medial parietal lobes.
What artery is this?
Anterior communicating artery
Draw the different CNS sinuses.
Note that the internal cerebral veins join to form the great cerebral vein just before the straight sinus.
