W2: Great vessels, vasculature of thorax and abdomen Flashcards
What are the only branches of the ascending aorta?
The coronary arteries
Where does arch of aorta begin and end?
2nd sternocostal joint
3 major arteries coming from aortic arch. Draw
Brachiocephalic trunk – the first branch, which ascends superolaterally to divide into the right common carotid and right subclavian arteries.
Left common carotid artery – the second branch, which arises posterior to the manubrium and ascends anterior to the left subclavian artery to enter the neck.
Left subclavian artery – the third branch, which ascends through the superior mediastinum to enter the root of the neck, posterior to the left sternoclavicular joint.
What is the ligamentum arteriosum?
Remnant of ductus arteriosus
Shunts blood away from the lungs during development
Aorta -> pulmonary artery
Where does aorta leave the thorax?
Aortic hiatus in diaphragm at T12
Discuss brachiocephalic
Right subclavian - head, neck, arm
Right common carotid - in the carotid sheath, bifurcates at C4 into external and internal
Discuss branching of subclavian
3 parts
- Prescalene
- Vertebral
- Internal thoracic (anterior thoracic wall)
- Thyrocervical (thyroid - oesphagus) - inferior thyroid comes from this
- Scalene
* Costocervical trunk - posterior intercostal arteries - Postscalene
* Dorsal scapular
Dicuss the internal thoracic arteries
Emerge from 1st portion of the subclavian artery
Froms the anterior intercostal arteries
Anterior chest wall and breasts
Discuss aortic coarctation
A narrowing of the aorta, which typically occurs at the junction of the aortic arch and the descending aorta.This constriction forces the heart to pump harder than usual, in order to propel blood beyond the stenosis. This results in high blood pressure in the head, neck and upper limbs, and low blood pressure in the lower limbs. Consequences of coarctation include premature heart disease, cerebral aneurysms, organ failure, arterial rupture and death.
Mild forms are asymptomatic
Severe forms - breathing difficulties
What are the branches of the thoracic aorta?
Unpaired:
- Bronchial
- Pericardial
- Esophageal
- Mediastinal
Paired:
- Intercostal
- Superior phrenic
Discuss oesphagus supply
Superior = inferior thyroid which derived from thyrocervical trunk which is derived from subclavian
Middle = oesophageal arteries
Lower = left gastric derived celiac trunk
What do the bronchial arteries do?
Tissue not exposed to atmospheric oxygen are supplied by bronchial arteries.
- Vessels converge on posterior trachea
- Bronchi and glands.
Two go to the left lung and one to the right lung
Discuss posterior intercostal arteries
Branch of the descending thoracic aorta
The 1st and 2nd emerge from the costocervical trunk of the subclavian artery
Running down the spine
Thoracic Aortic Aneurysm
This is 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 aneu- rysms are linked to family history.Aneurysms may be treated using either open surgery or endovascular stent graft insertion.
Where does the abdominal aorta start and end?
T12-L4
Mneumonic for branches of abdominal aorta
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Inferior phrenic
Coeliac
Superior mesenteric
Middle suprarenal (adrenal)
Renal
Testicular (gonadal)
Lumbar
Inferior mesenteric
Middle sacral
Common iliac
Draw branches of descending aorta
Discuss celiac trunk
Left hand side
Left gastric artery (the right comes off the proper or common hepatic) - stomach, oesophagus
Splenic artery - spleen pls - spleen, stomach, pancreas
Common hepatic artery (right gastric comes off this) - liver, stomach, gallbladder, duodenum, pancreas
At what level is the coeliac trunk?
T12
At what level is the superior mesenteric?
L1
What does the superior mesenteric supply?
distal duodenum, jejuno-ileum, ascending colon and part of the transverse colon
At what level is inferior mesenteric? What does it supply? Give examples of branches
L3
It supplies the large intestine from the splenic flexure to the upper part of the rectum.
Derivatives of the hindgut.
Branches include colic, sigmoid, superior rectal arteries
Which abdominal are paired?
Which abdominal are unpaired?
Unpaired
- Coeliac
- Superior mesenteric
- Inferior mesenteric
Paired
- Suprarenal
- Renal
- Gonadal
- Inferior phrenic
- Lumbar
What do inferior phrenic supply?
Underside of the diaphragm
What do lumbar arteries supply?
Muscles of back, vertebrae and intervertebral discs
Discuss levels at which branches from the abdominal aorta exit
T12
- Inferior phrenic
- Coeliac
L1
- Middle adrenal
- 1st lumbar
- Renal
- Superior mesenteric
L2
- Gonadal
- 2nd lumbar
L3
- 3rd lumbar
- Inferior mesenteric
L4
- 4th lumbar
Where does abdominal aorta bifurcate?
L4
What is the most common place in aortic aneurysm?
Abdominal aorta
Compressed nerve roots - numbness in lower limbs
Hoarse voice due to stretch of recurrent laryngeal
What is the pulmonary trunk? At what level does it split?
Pulmonary arteries before they branch
T5-6
Discuss pulmonary arteries
Left - bifurcates into two to supply each lobe of the lung
Bifurcates at about T5
Right - thicker and longer, also divides into 2
How many pulmonary veins are there? Describe
4 - one superior and one inferior for each lung
Enter left atrium on the posterior surface
Make the oblique pericardial sinus
The inferior left pulmonary vein is found at the hilum of the lung, while the right inferior pulmonary vein runs posteriorly to the superior vena cava and the right atrium.
Discuss superior vena cava
Deoxy from upper body -> right atrium
Formed by merging of brachiocephalic veins (subclavian + internal, external jugular + vertebral before this)
Union is behind sternoclavicular joints
Discuss inferior vena cava
Deoxy from lower body
Initially formed in pelvis by common iliac veins joining
Collects blood from hepatic, lumbar, gonadal, renal and phrenic veins
Enters pericardium at T8
Drains into inferior right atrium
Discuss drainage of the of chest wall
Key is that there are 11 pairs of posterior intercostal veins, 9 pairs of anterior and one pair of subcostal
Anterior wall
- 1-6 anterior intercostals -> internal thoracic veins
- 7-9 -> musculophrenic vein -> internal thoracic -> brachiocephalic vein -> unite to form the superior vena cava
Posterior wall -
- The 1st posterior intercostal -> brachiocephalic vein of the same side
- 2nd and 3rd posterior -> superior intercostal. Left superior intercostal -> left brachiocephalic. Right superior intercostal -> azygos -> superior vena cava
- Right - posterior intercostal veins -> azygos vein -> superior vena cava (looping over the right main bronchus)
- Azygous is formed from right subcostal and right ascending lumbar veins
- Left 4-7 posterior intercostal veins -> accessory hemiazygos
- Left 8-11th posterior intercostal -> hemiazygos
- Hemiazygos from left subcostal and left ascending lumbar
Hemiazygos and accessory hemiazyos corss and join the azygos
Discuss the two venous systems of abdomen
Portal venous and systemic venous
The portal system transports venous blood to the liver for processing, whilst the systemic venous system returns blood to the right atrium of the heart.
Where is the IVC in relation to the abdominal aorta?
To the right of it
What is the IVC formed by? At what level? At what level does it leave?
Union of common iliac veins
L5
Pieces the central tendon of the diaphragm at T8
Discuss the systemic venous system
Follows similar pattern to arteries but no tributaries from spleen, pancreas, gallbladder and abdominal part of GI tract (these go into the portal system first)
The left gonadal and left adrenal drain into left renal and then into the vena cava
The right gonadal and adrenal drain straight into the vena cava
Discuss hepatic portal system
The major vessel of the portal system is the portal vein. It is the point of convergence for the venous drainage of the spleen, pancreas, gallbladder and the abdominal part of the gastrointestinal tract. The portal vein is formed by the union of the splenic vein and the superior mesenteric vein, posterior to the neck of the pancreas, at the level of L2.
The inferior mesenteric usually drains into the splenic vein
Sinusoids
Then hepatic vein –> inferior vena cava
Discuss anterior trunk of internal iliac
Will go on to supply pelvic viscera:
Obturator - supplies adductors of thigh, iliac, iliacus, bladder (obturator foramen)
Umbilical (has a pelvic and distal which becomes obliterated in adults) - main branch is superior vesicle which goes on to supply superior bladder
Inferior vesical – supplies bladder
Middle rectal – supplies the distal rectum above pectinate line
Internal pudendal – supplies perineum (leaves via greater sciatic foramen) and external genitalia
Inferior gluteal – supplies gluteus medius & minimus and the acetabulofemoral joint.
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Difference between internal iliac in males and females
Females:
- uterine artery - uterine cervix and vaginal branches to vagina
- arises just below to obturator
- This forms anastomosis with ovarian artery
Males:
- The inferior vesicle also supplies prostate and seminal vesicles
- Superior vesicle (proximal part of umbilical) gives direct branch to ductus deferens
Discuss posterior trunk of internal iliac
Iliolumbar – quadratus lumborum, psoas major, iliacus, cauda equina
Lateral sacral – erector spinae, piriformis, skin of lower back
Superior gluteal – piriformis, gluteus maximus, obturator internus
Discuss blood supply to perineum
- Internal pudendal – terminal branch of anterior trunk of internal iliac artery
- Supplies external genitalia and Dorsal artery of penis
Discuss lymphatics generally (thoracic duct stuff)
Thoracic duct drains abdomen, pelvis, lower limbs as well as left thoax, arm, head and neck
- Doesnt drain right side of head and neck, right side of chest wall, right lung, right heart and right liver
- These are drained by the right lymphatic duct
The lower end of the thoracic duct = cisterna chyli = where lymph from intestinal trunk and two lumbar lymphatic trunks flow
Drains into the junction of left internal jugular and left subclavian vein
Discuss lymphatics at hilus of lung
Bronchopulmonary nodes -> tracheobronchial nodes -> paratracheal nodes -> bronchomediastinal -> thoracic duct/right lymphatic duct
Discuss abdominal lymph nodes
Converge around the aorta
3 main types:
- Preaortic. - in front - coeliac, superior and inferior mesenteric
- Para-aortic/lumbar - lateral to aorta
- Retro-aortic - behind
Discuss spleen
- Posterior to the stomach
- Upper border – superior surface of 9th rib.
- Lower border – inferior border of 11th rib.
- Trauma to this region could easily rupture the spleen.
- Pain felt in epigastrium and left flank.
- Excessive bleeding
- Supplied by splenic artery arising from coelic trunk
- Drained by splenic vein
Discuss pelvic lymphatics (draw)
Deep inguinal -> external (clitoris, penis, labia minora)
Superficial inguinal -> internal iliac (scrotum/labia majora)
Because of this connection with abdominal lympathics = easy spread of cancer
Discuss inferior epigastric vessels
The inferior epigastric artery, arising from the external iliac artery, supplies the and is an important anatomical landmark.
Direct inguinal hernias, protrusions of bowel through a weakening within the abdominal wall, usually occur within the inguinal triangle, created by the inferior epigastric vessels laterally, inguinal ligament inferiorly and the lateral border of the rectus sheath medially. Conversely, protrusions of bowel through a patent deep inguinal ring (indirect inguinal hernia) occur lateral to the inferior epigastric vessels.
All superior mesenteric = patent. Which region ischaemia?
Descending colon
Which tonsils are found between the palatoglossal and palatopharyngeal arches?
Palatine
The veins that directly connect the veins of the scalp to the dural venous sinuses are called the…
Emissary veins
A stroke involving the right anterior cerebral artery would have the most significant effect on which region of the body?
Left leg
