Abdominal and pelvic anatomy encompasses the anatomy of all structures of the abdominal and pelvic cavities.
This anatomy section promotes the use of the Terminologia Anatomica, the international standard of anatomical nomenclature.
The abdominal aorta (plural: aortas or aortae 4) is the main blood vessel in the abdominal cavity that transmits oxygenated blood from the thoracic cavity to the organs within the abdomen and to the lower limbs.
origin: continuation of descending thoracic aorta at T12
Aberrant internal carotid artery is a variant of the internal carotid artery and represents a collateral pathway resulting from involution of the normal cervical portion (first embryonic segment) of the internal carotid artery 5.
There is consequent enlargement of the usually sma...
Aberrant left pulmonary artery, also known as pulmonary sling, represents an anatomical variant characterised by the left pulmonary artery arising from the right pulmonary artery and passing above the right main bronchus and in between the trachea and oesophagus to reach the left lung. It may le...
Aberrant right subclavian arteries (ARSA), also known as arteria lusoria, are one of the commonest of the aortic arch anomalies.
The estimated incidence is 0.5-2%.
They are often asymptomatic, but around 10% of people may complain of tracheo-oesophageal sy...
The accessory appendicular artery, also known as the artery of Seshachalam, is a branch of the posterior caecal artery. It arises from the ileocolic artery, and runs in the mesoappendix.
The exact prevalence of this accessory artery and its impact upon the risk of appendicitis varies among stud...
The accessory (or superior) hemiazygos vein forms part of the azygos system and along with the hemiazygos vein, it is partially analogous to the right-sided azygos vein. It drains the left superior hemithorax.
Spelling it "hemiazygous" when referring to the vein is incorrect, rega...
The accessory meningeal artery is a branch of the maxillary artery but can also branch from the middle meningeal artery.
The artery passes upwards through the foramen ovale to supply the trigeminal ganglion and the dura mater of Meckel cave and the middle cranial fossa. It also usually supplies...
The accessory middle cerebral artery is a variant of the middle cerebral artery (MCA) that arises from the anterior cerebral artery (ACA). It is different from a duplicated middle cerebral artery, in which the duplicated vessel originates also from the distal end of the internal carotid artery (...
Accessory renal arteries are a common variant and are present in ~25% (range 20-30%) and are bilateral in ~10% of the population 7. Their proper identification is of utmost importance for surgical planning prior to live donor transplantation 2,3 and renal artery embolisation for various reasons ...
An accessory right inferior hepatic vein is the most common variation of the hepatic veins. It is present in up to 48% of the population and drains the posterior part of the right lobe (mainly segments 6 and 7) directly into the inferior vena cava.
Variations in hepatic vascular anatomy are pa...
The adrenal glands are supplied by three adrenal (suprarenal) arteries:
superior adrenal artery: arises from ipsilateral inferior phrenic artery
middle adrenal artery: arises from lateral side of abdominal aorta
inferior adrenal artery: arises from the ipsilateral renal artery
The venous drainage of the adrenal (suprarenal) glands is typically comprised of a single vein draining each adrenal gland. Like the gonadal veins each side drains differently:
left suprarenal vein drains into the left renal vein 1.
right suprarenal vein drains directly into the inferior vena ...
AICA-PICA dominance refers to the principle that the cerebellar vascular territory supplied by the anterior inferior cerebellar artery and posterior inferior cerebellar artery have a reciprocal arrangement. That is the size of the AICA and the subsequent territory it supplies is inversely propor...
The alar thoracic artery is a rare variant arterial glandular branch of the axillary artery (usually the second part) that supplies the axillary fat, lymph nodes and skin of the axilla.
The anatomy curriculum is one of our curriculum articles and aims to be a collection of articles that represent the core anatomy knowledge for radiologists and imaging specialists.
Head and neck anatomy
Abdominal and pelvic anatomy
The angular artery is the terminal branch of the facial artery.
It becomes the angular artery after the lateral nasal artery branch from the facial artery. It courses superiorly along the lateral border of the external nose to the medial canthus. It is accompanied by the angular vein which drai...
The angular vein drains the anterior region of the scalp 1. It is formed by the union of the supratrochlear and supraorbital veins and becomes the facial vein 1,2,3.
The angular vein is formed at the medial canthus as the supratrochlear vein and supraorbital vein unite 1,2. The a...
Anomalous course of a coronary artery is a type of congenital coronary artery anomaly. It may represent a benign and incidental finding, but can also be a malignant course predisposing patients to life-threatening myocardial ischaemia or arrhythmias, depending on where the artery runs.
The anterior cardiac veins are a group of parallel coronary veins that course over the anterior surface of the right ventricle, draining it and entering directly into the right atrium. They may occasionally drain into the small cardiac vein.
The anterior cardinal veins are paired transient embryologic venous vessels which deliver venous return to the heart starting at about 4 weeks of gestation 1.
The anterior cardinal veins begin their embryological development as symmetric venous channels draining blood from the cr...
The anterior cerebral artery along with the middle cerebral artery forms at the termination of the internal carotid artery. It is the smaller of the two, and arches anteromedially to pass anterior to the genu of the corpus callosum, dividing as it does so into its two major branches; pericallosa...
The anterior choroidal artery (AChA) supplies several crucial anatomical structures of the brain important for vision and motor control. Identification of AChA is important because of its strategic and extensive area of supply as well as large variations in the territorial distribution.
The anterior circulation is the blood supply to the anterior portion of the brain, including most of the supratentorial structures excluding the occipital lobes.
The anterior circulation is supplied by the internal carotid arteries which each divide into two the large terminal branches, the ant...
The anterior communicating artery (ACOM) arises from the anterior cerebral artery and acts as an anastomosis between the left and right anterior cerebral circulation. Approximately 4 mm in length, it demarcates the junction between the A1 and A2 segments of the anterior cerebral artery.
The anterior ethmoid artery is a branch of the ophthalmic artery. It supplies the anterior and middle ethmoidal sinuses, frontal sinus, the lateral nasal wall and the nasal septum (see nasal cavity).
It traverses the anterior ethmoidal foramen with the anterior ethmoidal nerve (w...
The anterior humeral circumflex artery is a vessel arising from the axillary artery at the proximal part of the arm. It is smaller in size relative to the posterior humeral circumflex artery.
origin: branch of the axillary artery at the proximal part of the arm
location: proximal arm...
The anterior inferior cerebellar artery (AICA) is one of three vessels that provides arterial blood supply to the cerebellum. It has a variable origin, course and supply, with up to 40% of specimens not having an identifiable standard AICA. The amount of tissue supplied by the AICA is variable (...
The intercostal spaces are supplied by pairs of posterior and anterior intercostal arteries.
The 1st to 6th anterior intercostal arteries arise directly from the lateral aspect of the internal thoracic artery. The 7th to 9th arise from the musculophrenic artery, a branch of the i...
The anterior interosseous artery is one of the two branches of the short common interosseous artery (from the ulnar artery). The artery courses deep in the anterior compartment of the forearm on the anterior surface of the interosseous membrane along with the anterior interosseous nerve (from th...
The anterior jugular vein is a paired tributary of the external jugular vein.
It arises beneath the chin in the region of the hyoid bone or suprahyoid neck.
Origin and course
The anterior jugular vein has its origin as the confluence of several small superficial subma...
The anterior lateral malleolar artery is the counterpart to the anterior medial malleolar artery, supplies the lateral aspect of the ankle.
Origin and course
branch of anterior tibial artery
runs posterior to the tendons of extensor digitorum longus and fibularis tertius to th...
Anterior medial malleolar artery is the counterpart to the anterior lateral malleolar artery, and supplies the medial aspect of the ankle.
Origin and course
branch of anterior tibial artery
arises approximately 5 cm proximal to the ankle
passes posterior to the tendons of exte...
The anterior spinal artery supplies the anterior portion of the spinal cord and arises from the vertebral artery in the region of the medulla oblongata. The two vertebral arteries (one of which is usually bigger than the other) anastamose in the midline to form a single anterior spinal artery at...
The anterior superior iliac spine is an important bony surface landmark and is the prominence is the most anterior part of the ilium. It can be palpated at the lateral end of the inguinal fold. Attachments include the inguinal ligament, sartorius and depending on which resource you read, the ten...
The anterior temporal artery is usually a branch of the M1 segment of the middle cerebral artery (MCA) that curves out of the Sylvian fissure and runs over the temporal lobe to supply the anterior third of the superior, middle and inferior temporal gyri.
The temporopolar arter...
The anterior tibial artery is the main arterial supply of the anterior compartment of the leg.
The anterior tibial artery arises from the popliteal artery in the popliteal fossa and continues distally as the dorsalis pedis artery.
The popliteal artery usually divides at...
The anterior tibial veins, continuations of the venae comitantes of the dorsalis pedis artery, leave the anterior compartment of the leg between the tibia and fibula and pass through the proximal end of the interosseous membrane. They unite with the posterior tibial veins to form the popliteal v...
The anterior ulnar recurrent artery is a recurrent branch of the proximal ulnar artery that ascends in the anterior medial aspect of the elbow, anterior to the medial epicondyle of the humerus to anastomose with the inferior ulnar collateral artery (from the brachial artery) and contribute to th...
The aorta, the great artery, is the largest artery of the human body and carries oxygenated blood ejected from the left ventricle to the systemic circulation. It is divided into:
It has branches from each section a...
The aortic annulus is a fibrous ring at the aortic orifice to the front and right of the atrioventricular aortic valve and is considered the transition point between the left ventricle and aortic root. The annulus is part of the fibrous skeleton of the heart. It is at the level of the sinus of V...
The aortic arch represents the direct continuation of the ascending aorta and represents a key area for a review of normal variant anatomy and a wide range of pathological processes that range from congenital anomalies to traumatic injury.
origin: continuation of the ascending aorta at...
A useful mnemonic to remember the major branches of the aortic arch is:
A: arch of aorta
B: brachiocephalic trunk
C: left common carotid artery
S: left subclavian artery
The aortic hiatus is one of the three major apertures through the diaphragm and lies at the level of T12. Strictly speaking, it is not a real aperture in the diaphragm, but an osseoaponeurotic opening between it and the vertebral column.
The hiatus is situated slightly to the left of the midli...
The aortic isthmus is the part of the aorta just distal to the origin of the left subclavian artery at the site of the ductus arteriosus.
This portion of the aorta is partly constricted in the fetus because of the lack of flow within the aortic sac and ascending aorta. It marks the partial sepa...
The aortic root is the first part of the aorta and connects the heart to the systemic circulation.
The aortic root lies between the junction of the aortic valve and ascending aorta. It has several subparts 1:
three aortic valve leaflets and leaflet attachments
three aortic sin...
Aortic spindles are an anatomical variant of the proximal descending thoracic aorta. It occurs just distal to the aortic isthmus and has a circumferential smooth bulging appearance.
ductus diverticulum: not circumferential
thoracic aortic aneurysm
The appendicular artery is a branch of the ileal or posterior caecal branch of the ileocolic artery, which is from the superior mesenteric artery.
It courses posteriorly to the terminal ileum in the free wall of the mesoappendix to supply the appendix.
The arc of Barkow is formed by the anastomosis of the right gastroepiploic (a branch of the gastroduodenal artery) and left gastroepiploic (a branch of the splenic artery) arteries.
The arc of Barkow supplies the transverse colon via multiple ascending branches.
The arc of Riolan, also known as the mesenteric meandering artery (of Moskowitz) or central anastomotic mesenteric artery, is an arterioarterial anastomosis between the superior and inferior mesenteric arteries.
It is an inconstant artery that connects the proximal superior mesen...
The periarticular arterial anastomosis of the elbow consists of several arteries that supply the elbow joint and its supporting structures. It functions to allow blood to flow around the elbow joint no matter which position the joint is in. The arteries that contribute include:
from the brachi...
The arteries of the head and neck are branches of the common carotid and subclavian arteries.
common carotid artery
internal carotid artery (segments)
persistent stapedial artery
The arterial supply of the lower limbs originates from the external iliac artery.
The common femoral artery is the direct continuation of the external iliac artery, beginning at the level of the inguinal ligament. The common femoral artery becomes the superficial femoral artery at the point wh...
The arterial supply of the upper limb is derived from the subclavian artery. The right subclavian artery originates from the brachiocephalic artery, which is the first branch of the aortic arch. The left subclavian artery originates directly from the aortic arch, being the third branch.
Arterial supply to the foot can be divided into plantar and dorsal components.
Plantar arterial supply
Posterior tibial artery
gives off its calcaneal branch
then divides into the medial and lateral plantar arteries
Medial plantar artery
branch of the posterior tibial artery
The arterial supply to the hand is comprised of a complex vascular network formed from the branches and distal continuations of the radial and ulnar arteries. This rich vascular network can be divided into palmar and dorsal components.
Palmar arterial supply
The palmar arterial supply can be d...
The arterial vasocorona is part of the spinal cord blood supply and is formed by pial anastomoses between the anterior and posterior spinal arteries on the surface of the spinal cord. It encircles the cord and supplies the peripheral lateral aspect of the spinal cord.
The artery of Adamkiewicz, also known as the great anterior radiculomedullary artery or arteria radicularis anterior magna, is the name given to the dominant thoracolumbar segmental artery that supplies the spinal cord.
The artery of Adamkiewicz has a variable origin but ...
The artery of Bernasconi and Cassinari, also known as medial or marginal tentorial artery (of Bernasconi–Cassinari), commonly arises from the cavernous segment of the internal carotid artery.
The artery of Bernasconi and Cassinari is ~2 cm long and is an important branch of the m...
The artery of Percheron is a rare variant of the posterior cerebral circulation characterised by a solitary arterial trunk that supplies blood to the paramedian thalami and the rostral midbrain bilaterally. From the original classification of arterial patterns at the origin of the paramedian art...
The artery to the ductus deferens (deferential or vesiculodeferential artery) is a branch of the superior vesical artery, which in turns arises from the internal iliac artery via the umbilical artery.
origin: superior vesical artery
main branch: no named branches
The ascending aorta is the first part of the aorta, and begins at the aortic valve, located obliquely just to the left of the midline at the level of the third intercostal space. It terminates as it exits the fibrous pericardium where it becomes the aortic arch, in the plane of Ludwig, a horizon...
The ascending cervical artery is 1 of the 4 branches of the thyrocervical trunk (off the first part of the subclavian artery).
It is a small artery that ascends medial to the phrenic nerve on the prevertebral fascia. It contributes many small spinal branches into the intervertebral foramina of ...
The ascending lumbar communicant vein is a communication between the left ascending lumbar vein and the left renal vein. Because of its retroperitoneal location, when dilated, it may be mistaken for a lymph node on non-contrast studies with thick collimation.
The image shows the left renal vein...
The ascending lumbar vein is a paired structure which forms a part of the venous drainage of the lumbar vertebral column.
location: near midline on the side of the vertebral column in the lumbar region
origin and termination: continuation of the lateral sacral veins; joins the subcost...
The ascending pharyngeal artery, the smallest branch of the external carotid artery, is a long, slender vessel, deeply seated in the neck, beneath the other branches of the external carotid and under the stylopharyngeus.
origin: a branch of the external carotid artery
The axillary artery represents the continuation of the subclavian artery and is a major artery of the upper limb.
origin: continuation of the subclavian artery as it passes under the midpoint of the clavicle on the outer edge of the first rib
termination: continues as the brachial ar...
Useful mnemonics to remember the branches of the axillary artery are:
S AL SAP
Screw the lawyer, save a patient!
S AL SAP
The gap between the 'S' and the 'AL' to emphasise that 'S' is 1st part and 'AL' are 2nd part
S: superior thoracic artery (from 1st part)
A: acromiothoracic (...
The axillary vein is one of the major veins of the upper limb. It is formed by the union of the paired brachial veins and the basilic vein and contributes to the drainage of the axilla, arm and superolateral chest wall.
origin: formed by the union of the paired brachial veins and the b...
An azygos anterior cerebral artery is an uncommon to rare variant of the circle of Willis where the two A1 segments of the anterior cerebral artery (ACA) join to form a single trunk. As a result, there is no anterior communicating artery. This organisation is similar to that seen in lower primat...
Azygos continuation of the inferior vena cava (also known as the absence of the hepatic segment of the IVC with azygos continuation) is an uncommon vascular anomaly and is a cause of a dilated azygos vein.
Spelling it "azygous" when referring to the vein is incorrect, regardless of...
The azygos vein is a unilateral vessel that ascends in the thorax to the right side of the vertebral column, carrying deoxygenated blood from the posterior chest and abdominal walls. It forms part of the azygos venous system.
Spelling it "azygous" when referring to the vein is inco...
The azygos (venous) system is a collective term given to the H-shaped configuration of the azygos, hemiazygos, accessory hemiazygos veins and left superior intercostal vein.
It is responsible for draining the thoracic wall and upper lumbar region via the lumbar veins and posterior intercostal v...
Barrow caroticocavernous fistula classification divides caroticocavernous fistulas into direct (type A) or indirect (types B-D). This classification was proposed by Barrow et al. in 1985 1 and at the time of writing (mid-2016) remains the most widely used system for describing caroticocavernous ...
The basal veins, also known as the veins of Rosenthal, are paired, paramedian veins which originate on the medial surface of the temporal lobe and run posteriorly and medially. Each vein passes lateral to the midbrain through the ambient cistern to drain into the vein of Galen with the internal ...
Basilar artery fenestration (or more simply, basilar fenestration) is the most common intracranial arterial fenestration. It refers to duplication of a portion of the artery, thought to occur due to failed fusion of plexiform primitive longitudinal neural arteries 4. Its reported prevalence is h...
The basilar venous plexus lies between the endosteal and visceral layers of the dura on the inner surface of the clivus. It connects the:
inferior petrosal sinuses
superior petrosal sinuses
internal vertebral venous plexus
marginal sinus (around the...
The basilic vein, along with the cephalic vein, is one of the primary superficial veins that drain the upper limb 1. It courses through both the forearm and arm, and contributes to the formation of the axillary vein.
origin: ulnar aspect of the superficial venous network of the dorsum ...
Batson venous plexus, also known as Batson veins, are a network of veins with no valves that connect deep pelvic veins draining the bladder, prostate, and rectum to the internal vertebral venous plexus 1. These veins are important because they are believed to provide a route for spread of pelvic...
Bouthillier et al. described (in 1996) 1 a seven segment internal carotid artery (ICA) classification system. It remains the most widely used system for describing ICA segments at the time of writing (mid-2016).
There are a few other classifications systems including those proposed by Fisher (1...
Bovine arch is the most common variant of the aortic arch and occurs when the brachiocephalic (innominate) artery shares a common origin with the left common carotid artery.
A bovine arch is apparent in ~15% (range 8-25%) of the population and is more common in individuals of African descent. ...
The brachial artery is the main supply of arterial blood to the arm, forearm, and hand.
origin: continuation of the axillary artery distal to teres major
location: medial upper arm
supply: muscles of the arm, forearm, and hand
main branches: profunda brachii
terminal branches: rad...
The brachial vein is a component of the deep venous system of the upper limb. After forming from the radial and ulnar veins1, the brachial vein travels from the cubital fossa superiorly to become the axillary vein.
origin: union of the ulnar and radial veins in the cubital fossa1
The brachiocephalic trunk (BCT) (also known as the brachiocephalic artery, and previously as the innominate artery) is a major vessel that supplies the head, neck and right arm.
The brachiocephalic trunk is the first of the three main branches of the aortic arch, which originates...
The brachiocephalic veins, previously known as the innominate veins, are large paired valveless asymmetric veins that drain the head, neck, upper limbs and part of the thorax and mediastinum.
In the root of the neck, the internal jugular (IJV) and subclavian veins unite t...
The brachioradial artery, also know as a high origin of the radial artery, represents an anatomical variant of the arterial branching pattern of the upper limb 1,2. It represents an artery originating proximal to the cubital fossa that will go on to form the radial artery. The brachioradial arte...
Useful mnemonics to remember the branches of the internal carotid artery is:
A VIP'S COMMA
calming voices make intra-operative surgery pleasurable and almost memorable
A VIP'S COMMA
A: anterior choroidal artery (C7)
V: Vidian artery (C2)
I: inferolateral trunk (C4)
A useful mnemonic to remember the branches of the internal iliac artery is:
I Love Going Places In My Very Own Underwear!
I: iliolumbar artery
L: lateral sacral artery
G: gluteal (superior and inferior) arteries
P: (internal) pudendal artery
I: inferior vesical (vaginal in female...
A mnemonic for remembering the branches of the maxillary artery is:
DAM I AM Piss Drunk But Stupid Drunk I Prefer, Must Phone Alcoholics Anonymous
D: deep auricular artery
A: anterior tympanic artery
M: middle meningeal artery
I: inferior alveolar artery
A: accessory meningeal ar...
A useful mnemonic to remember the branches of the ophthalmic artery is:
D: dorsal nasal artery
R: (central) retinal artery
M: muscular artery
C: ciliary arteries (long, short and anterior)
L: lacrimal artery
E: ethmoidal arteries (anterior and posterior)
Mnemonics to remember the branches of the anterior division of the internal iliac artery are:
SOI VU MR PIG (it can be remembered as SO fourth (IV) U MR PIG)
Oranges Under Some Ice Might Peel Instantly
SOI VU MR PIG
S: superior vesical artery
O: obturator artery
IV: inferior ves...
Useful mnemonics to remember the four branches of the thoracoacromial artery are:
CAlifornia Police Department
Cadavers Are Dead People
B: breast (pectoral)
CAlifornia Police Department
The bronchial arteries are the major supply of high-pressure oxygenated blood to the supporting structures of the lung, including the pulmonary arteries, yet they are responsible for only 1% of the lung blood flow overall.
Bronchial artery anatomy is variable, most commonly classified according...