Question 1 – Circle of Willis
Write short notes on the anatomy of the anatomy of the circle of Willis (under the following headings: Origin and components, Position and relations, Branches and distribution, Development and variations)
An arterial ring structure formed as the internal carotid artery and vertebrobasilar system anastomoses in the suprasellar cistern. The communicating pathways allow for anastomotic circulation and equalisations of blow flow between hemispheres
ORIGIN
– Internal carotid arteries – branch from the common carotid arteries at the level of the upper border of thyroid cartilage (C4). Ascends up the neck entering the skull base via the petrous temporal bone.
– Vertebrobasilar arteries – vertebral arteries arise as the first branch of the subclavian arteries bilaterally, ascending through the transverse foramen of C6 to C1, entering the skull base via the foramen magnum.
COMPONENTS
Anterior circulation: internal carotid arteries, anterior cerebral arteries, anterior communicating artery and middle cerebral arteries
Posterior circulation: vertebral arteries, basilar artery, posterior cerebral arteries and posterior communicating arteries
POSITION
Suprasellar cistern
RELATIONS
Surrounds optic chiasm, pituitary infundibulum and mammillary bodies
Inferiorly: pituitary gland
Inferolateral to the hypothalamus
Horizontal (A1) ACA segments normally course above optic nerves
• Inferior: Sella turcia
• Superior: Ventral surface of brain, corpus callosum, ventricles
• Medial: hypothalamus, infundibulum
• Lateral: temporal lobes
BRANCHES
ACOM: Perforators to optic chiasm, hypothalamus, cingulate gyrus, corpus callosum
• P1:
o Thalamoperforating arteries – to thalamus
o Branches to midbrain
• PCOM:
o Perforators to optic tract, hypothalamus, mammillary body, pituitary gland
o Polar branches – to thalamus
• Basilar Artery:
o Thalamoperforating arteries
o Thalamogeniculate arteries
• Anterior choroidal artery – branch of terminal ICA to optic tract, thalamus, LGN, posterior limb of internal capsule and choroid plexus of lateral ventricles
VARIANTS
Duplicated, hypoplastic, fenestrated or absent ACOM
Hypoplastic or absent A1 – two ACAs supplied by one ICA trunk
Azygos anterior cerebral artery – both A1 segments of the anterior cerebral arteries unite to form a single midline A2 trunk, resulting in no anterior communicating artery.
Trifurcation of ACA
Hypoplastic or absent PCOM
Fetal origin of PCA – where PCOM is larger than P1 segment of ipsilateral PCA
Question 2 – Sphenoid bone
Write short notes on the anatomy of the sphenoid bone (under the following headings: Bony features, Apertures, Articulations, Relations and Ossification)
BONY FEATURES
– butterfly-shaped bone
– body: centre of sphenoid bone, cubical in shape. contains the sphenoidal sinuses separated by a septum.
– sella turcica – saddle-shaped depression (tubuerculum sellar anterior wall, hypophyseal fossa where the pituitary gland sits, dorsum sellae posterior wall)
– chiasmatic groove – anterior to sella turcica, sulcus formed by optic chiasm
– greater wings – forms floor of middle cranial fossa, lateral wall of skull, posterolateral wall of orbit. contains three apertures: foramen rotundum/ovale/spinosum
– lesser wings: separates anterior cranial fossa from middle cranial fossa. forms lateral border of optic canal
– two pterygoid processes, medial: supports posterior opening of nasal cavity, lateral: origin of medial lateral pterygoid muscles
APERTURES
– Superior orbital fissure: CN III (oculomotor), IV (trochlear), V1 (ophthalmic branch of trigeminal), VI (abducens), ophthalmic vein
– Foramen rotundum: V2 (maxillary branch of trigeminal)
– Foramen ovale: V3 (mandibular branch of trigeminal), accessory meningeal (branch of maxillary artery), lesser petrosal nerve
– Foramen spinosum: middle meningeal artery and vein
ARTICULATIONS
It has articulations with twelve other bones:
Unpaired bones – Occipital, vomer, ethmoid and frontal bones.
Paired bones – Temporal, parietal, zygomatic and palatine bones.
RELATIONS
OSSIFICATION
Question 3 – Mandibular nerve
Write short notes on the anatomy of the mandibular division of the trigeminal nerve (CN Vc) (under the following headings: General description, Branches, Distribution and Relations).
GENERAL DESCRIPTION
A terminal branch of the trigeminal nerve.
BRANCHES & DISTRIBUTION
The mandibular nerve (V3) exits the cranium through the foramen ovale (Figures 2.2 and 2.3). On its extracranial course, it divides into three main branches: the buccal, mental, and auriculotemporal nerves
The buccal nerve pierces the skin on the face behind the ramus of the mandible, passes in front of the masseter, and innervates the skin anteriorly of the buccinator muscle.
As the terminal branch of the inferior alveolar nerve, the mental nerve enters the face through the mental foramen and supplies the skin of the lower lip.
The auriculotemporal nerve innervates the skin behind the temporomandibular joint and within the superior surface of the parotid gland. It has a course along a temporalis superficialis and innervates the tragus and part of the adjoining auricle of the ear and the posterior part of the temple.36
In sum, the mandibular nerve supplies the skin over the mandible, the lower lip, the fleshy part of the cheek, part of the auricle of the ear, and part of the temple36 (Figures 2.2 and 2.3).
It also supplies the muscles of mastication which are the medial and lateral pterygoids, temporalis, and masseter. It also supplies some smaller muscles namely the tensor veli tympani, tensor veli palatini, mylohyoid, and the anterior belly of digastric
Auriculotemporal nerve
– superior root – sensory fibres
– inferior root – carries secretory-motor parasympathetic from CN IX to parotid gland
– supplies anterior part of the auricle, lateral part of the temple, anterior external meatus, anterior tympanic membrane
Buccal Nerve
– carries sensory fibres, passing between the two heads of the lateral pterygoid muscle to the buccal membranes of the mouth. Also supplies 2nd and 3rd molar teeth
Inferior alveolar nerve
– carries sensory and motor
– gives rise to the mylohyoid nerve (innervates mylohyoid and anterior digastric muscles)
– enters mandibular canal, providing branches to mandibular teeth
– emerges throught mental foramen as mental nerve, innervating lower lip and chin
Lingual nerve
– sensory
– innervates anterior two-thirds of tongue (taste and general sensation)
– innervates submandibular and sublingual glands
Motor innervation
Mylohyoid
Anterior belly of the digastric muscle
Tensor veli palatini
Masticatory muscles
Tensor tympani
RELATIONS
Question 4 – Lumbosacral articulations
Write short notes on the anatomy of the lumbosacral articulations (under the following headings: General description, Articulations, Attachments, Relations, and Development and Variations)
GENERAL
The lumbosacral joint/symphysis is an articulation between the 5th lumbar vertebra L5 and first sacral vertebrae S1
ARTICULATIONS
– Anterior intervertebral joint – symphysis joint between vertebral bodies of L5 and S1, separated by a large invertebral disc and connected by verebtral ligaments. They articulate at an approximate angle of 140 degrees.
– Facet joints – two zygapophysial joints formed between the inferior articular process of L5 and superior articular S1 vertebrae
ATTACHMENTS
– iliolumbar ligament – arise from apex of transverse process of L5 vertebra and radiates inferolaterally across sacroiliac ligament to attach on inner lip of the iliac crest. Continuous with the anterior and middle layers of thoracolumbar fascia.
– lateral lumbosacral ligament – arises from the lower margin of the transverse process of L5 vertebra and passes obliquely inferiorly to attach to the ala of the sacrum. Partially continuous with iliolumbar ligament at origin and blends with anterior sacroiliac ligament at insertion
RELATIONS
Lateral: psoas major, iliacus, ascending (right) and descending colons (left)
Anterior: common iliac vein, internal arteries, ureters,
Posterior: sacral nerves, coccygeal nerve, vertebral canal
DEVELOPMENT AND VARIATIONS
– Sacralisation of the 5th lumbar vertebra
– Lumbarisation of the 1st sacral vertebra – nonfusion of 1st and 2nd sacral segments
– Imperfect fusion of the sacral lateral masses
Question 5 – Lymphatic drainage of breast
Write short notes on the anatomy of the lymphatic drainage of the breast (under the following headings: Lateral quadrants, Medial quadrants, Path to venous system and other routes, Structure and Variations)
OVERVIEW
Lymphatic drainage originates from breast lobules and flows into a subareolar plexus (Sappey plexus), then drains via 3 main routes: axillary, internal thoracic, thoracic duct.
LATERAL QUADRANTS
– from Sappey’s plexus, the satellite and parenchymal lymph runs around the inferior edge of pectoralis major and drains to the anterior/pectoral group of lymph nodes in the axilla
– this pathway receives 75% of lymph drained from the breast
– lymph from anterior group drain via central group into apical group of axillary nodes
– lymph from superior regions of breast may drain directly into apical nodes
MEDIAL QUADRANTS
– drains to the internal thoracic group of nodes drain medially into parasternal nodes in the intercostal
spaces just lateral to sternum
– Connects with contralateral parasternal nodes across the midline
PATH TO VENOUS SYSTEM
Axillary pathway
– Lymph from axillary nodes ultimately drain superomedially via subclavian trunk into subclavian vein immediately before its union with internal jugular vein
– may unite with thoracic duct on the left before entering subclavian vein
Internal thoracic pathway
– Lymph from parasternal nodes enter subclavian vein via bronchomediastinal trunks
STRUCTURE AND VARIATIONS
– Breast hypoplasia
– Amastia (absent breast and nipple)
– Amazia (absent breast, present nipple)
– Supernumerary nipples
– Polymastia
– Inverted nipple
– Size and shape
– Size of areola
This answer needs improvement.
Questions 6 – Azygos Venous System
Write short notes on the anatomy of the azygos venous system (under the following headings: General description, Tributaries and communications, Course and relations, and Variations).
GENERAL DESCRIPTION
A venous system found in the posterior mediastinum consisting of azygos vein on right and hemiazygos and accessory hemiazygos vein on left. Drains thorcaic wall and viscera within the mediastinum.
TRIBUTARIES & COMMUNICATIONS
Receives all but the first intercostal vein on the right.
Second, third and fourth intercostal vein drain via the right superior intercostal vein.
hemiazygos and accessory azygos vein drain into azygos vein at mid thoracic level.
Right bronchial veins drain into azygos vein near its termination
Other tributaries: oesophagus, pericardium, mediastinum
COURSE & RELATIONS
Enters thoracic cavity passing behind right crus of the diaphragm
Ascends within the posterior mediastinum on the anterolateral surface of the vertebral column (T12 → T5), right of the midline, aorta and thoracic duct
At level of T4, it arches anteriorly over hilum of right lung
Terminates as it drains into the superior vena cava at upper limit of pericardium
posterior
Anterior longitudinal ligament
Right posterior inercostal arteries
vertebral bodies of T4 – T12
Medial
thoracic duct
aorta
oesophagus
trachea
right vagus nerve
Laterally
the right greater splanchnic nerve
right lung and pleura
VARIATIONS
Question 7 – Vermiform appendix
Write short notes on the anatomy of the vermiform appendix (under the following headings: Structure, Position and relations, Neurovascular supply and lymphatics, Development and Variations).
Narrow, hollow and blind-ended muscular tube attached to caecum
STRUCTURE
Arises from posteromedial (most commonly) surface of cecum, at the origin of the taenia coli
POSITION
– Retrocecal (most common)
– Pelvic
– Pre or post ileal
– Promontory
– Paracecal
– Subcecal
RELATIONS
relation to terminal ileum and caecum is dependent on the position
posterior
NEUROVASCULAR SUPPLY
Appendicular artery, branch of ileocaecal artery (of superior mesenteric artery), descends posterior to terminal ileum to enter mesoappendix and runs to appendix tip
LYMPHATICS
– Contains lymphatic tissue within its walls
– Drains along vessels associated with ileocolic artery to superior mesenteric nodes
DEVELOPMENT AND VARIATIONS
– Subhepatic cecum
– Orientation
Question 8 – Inguinal canal
Write short notes on the anatomy of the inguinal canal (under the following headings: Position and apertures, Walls, Coverings and Contents)
POSITION
A short passage extending inferomedially through the inferior part of the abdominal wall.
APERTURE
Deep internal ring – midpoint of the inguinal ligament. which is lateral to the inferior epigastric artery and vein. The ring is created by the transversalis fascia, which invaginates to form a covering of the contents of the inguinal canal.
Superficial (external) ring marks the end of the inguinal canal, and lies just superior to the pubic tubercle. It is a triangle shaped opening, formed by the evagination of the external oblique, which forms another covering of the inguinal canal contents.
WALL
Anterior wall – aponeurosis of the external oblique, reinforced by the internal oblique muscle laterally.
Posterior wall – transversalis fascia.
Roof – transversalis fascia, internal oblique, and transversus abdominis.
Floor – inguinal ligament (a ‘rolled up’ portion of the external oblique aponeurosis), thickened medially by the lacunar ligament.
COVERING
– Transversalis fascia invaginates to cover the contents of the inguinal canal
– External oblique evaginates at the superficial ring forming another covering of the inguinal canal
CONTENTS
– Spermatic cord (males): pampiniform plexus, ductus deferens, cremasteric artery, testicular artery, artery of the ductus deferens, genital branch of genitofemoral nerve (L1-L2, lumbar plexus), sympathetic nerve fibres, lymphatic vessels
– Round ligament (females) – originates from the uterine horn and travels through the inguinal canal to attach at the labia majora.
– Ilioinguinal nerve (L1) – contributes towards the sensory innervation of the genitalia Note: only travels through part of the inguinal canal, exiting via the superficial inguinal ring (it does not pass through the deep inguinal ring)
– Genital branch of the genitofemoral nerve – supplies the cremaster muscle and anterior scrotal skin in males, and the skin of the mons pubis and labia majora in females.
Question 9 – Levator ani
Write short notes on the anatomy of the levator ani (under the following headings: General description, Attachments, Surfaces and relations, Neurovascular supply and Actions)
GENERAL DESCRIPTION
The levator ani is a broad, thin muscle group situated on either side of the pelvis. Formed by three paired muscles: pubococcygeus, iliococcygeus, puborectalis.
ATTACHMENTS
Puborectalis
– Originates from both sides of the body of the pubis, and passes posteriorly to encircle the rectum and form a U-shaped sling around the anorectal junction
Pubococcygeus
– Main component of levator ani
– Originates from the body of pubis, lateral to the origin of the puborectalis muscle
– The fibres course around margin of urogenital hiatus posteriorly to attach to the tendinous centre of the perineum, anococcygeal body and coccyx.
Iliococcygeus
-Originates from the inner surface of the ischial spine and along tendinous arch (a thickened band of fascia covering the inner aspect of obturator internus muscle)
Posteriorly attaches to iliococcygeus of the opposite side in the midline to form anococcygeal raphe extending from anal aperture to coccyx.
SURFACE AND RELATIONS
NEUROVASCULAR SUPPLY
Blood supply
– Inferior gluteal artery
– Inferior vesical
– Pudendal
Innervation
– Innervated by nerve to levator ani, branches from ventral ramus of S4,
Also contributions from inferior rectal branch of pudendal nerve (S2-4)
ACTIONS
Puborectalis
Tonic contraction bends the canal anteriorly and forms a 90-degree anorectal angle at the anorectal junction to maintain faecal continence
Question 10 – Urinary Bladder
Write short notes on the anatomy of the urinary bladder in the female (under the following headings: General description, Structure, Ligaments and folds, Neurovascular supply and lymphatics, Relations and Variants)
GENERAL DESCRIPTION
A hollow, distensible muscular organ in the anterior, midline, lesser pelvis extraperitoneal cavity, serves as a reservoir for urine and assists with micturition.
STRUCTURE
– shaped as an inverted pyramid, triangular in shape when empty
– apex directed towards pubic symphysis, connected to umbilicus by the median umbilical ligament (urachal remnant)
– base traingular, facing posteroinferiorly
– trigone – smooth triangular region on the internal surface of the bladder. formed by two ureteric orifices and internal urethral orifice.
LIGAMENTS AND FOLDS
– Median umbilical ligament: remnants of the embryonic communication between cloaca and allantois, runs from apex to umbilical ring of the anterior abdominal wall
– Medial umbilical ligament – obliterated part of the umbilical artery, pair structure extends from the origin of the superior vesical artery to umbilical ring on the anterior abdominal wall. Gives rise to 2 – 5 folds of parietal peritoneum on the anterior abdominal wall
– Pubovesical ligament: a continuation of the detrusor muscle and adventitia surround the bladder, connecting the bladder to the pubis and to the tendinous arch of pelvic fascia. May have lateral and medial branches in females.
– Puboprostatic ligament: thickening of the superior fascia of the pelvis diaphragm, extends laterally from prostate to the tendinous arch of pelvic fascia and continues forward and medially from the tendinous arch to the pubis
– Pubourethral ligament: paired ligaments inserted on the posterior surface of the pubis and inserted to the dorsal aspect of urethra and neck of the bladder.
NEUROVASCULAR SUPPLY AND LYMPHATICS
Innervation
Sympathetic – hypogastric nerve (T12 – L2) causes relaxation of the detrusor muscle for urine retention
Parasympathetic – pelvic nerve (S2-S4) causes contraction of the detrusor muscle to assist with micturition
Somatic – pudendal nerve (S2-4) provides voluntary control of external urethral sphincter
Inferior vesical artery (branch of internal iliac artery)
Internal pudendal artery (branch of internal iliac artery)
Obturator artery (branch of internal iliac artery)
RELATIONS
Superior: peritoneum, small intestinal loops, uterus (depending on version)
Anterior: pubic symphysis, peritoneum, anterior abdominal wall (when full)
Inferior:
– females: uterine cervix, vagina, urethra, pelvic floor (levator ani), obturator internus
– males: prostate gland
Posterior:
– females: urterine cervix and isthmus, vagina, ureter
– males: vas deferens, seminal vesicles, rectum, ureter, peritoneum, small bowel
Lateral: peritoneum, runs into broad ligament of the uterus
VARIANTS
– double bladder: receives ipsilateral ureter and has a separate urethra
– septation: septum may divide the bladder internally into two or more compartments
– agenesis: persistence of the cloaca
– ureterocele: dilation of the intravesical part of the ureter
Question 11 – Ulna
Write short notes on the anatomy of the ulna (under the following headings: General description, Bony features, Muscle attachments, Ligament attachments and Ossification)
GENERAL DESCRIPTION
Medial long bone of the forearm
BONY FEATURES
Broad proximally, narrow distally
Proximal end
– Olecranon – projects proximally, attaches triceps brachii, anterior surface articular
– Coronoid process – bony ridge projecting anteriorly, superior surface articular
– Trochlear notch – wrench shaped articular surface for trochlea of humerus, formed by olecranon and coronoid process
– Radial notch – lateral surface, at the inferior margin of the trochlear notch, articulates with radial head
– Tuberosity – anterior surface, for brachialis attachment
Shaft
3 borders (anterior, posterior, interosseous)
– Interosseous border attaches interosseous membrane
– Posterior border subcutaneous
3 surfaces (anterior, posterior, medial)
Distal
– Round head
– Distally and anterolaterally covered by hyaline cartilage
– Ulnar styloid originates posteromedially, projects distally
MUSCLE ATTACHMENTS
Anterior compartment
– Brachialis
– Flexor carpi ulnaris
– Pronator teres
– Flexor digitorumsuperficialis
– Flexor digitorumprofundus
– Pronator quadratus
Posterior compartment
– Anconeus
– Supinator
– Abductor pollicis longus
– Extensor pollicis longus
– Extensor indicis
LIGAMENT ATTACHMENTS
Anular ligament
Ulnar collateral of the elbow
Portion of radial collateral of the elbow
Quadrate ligament
Oblique cord
Interosseous membrane
Dorsal and palmar radioulnar ligaments
Ulnar collateral of the wrist
Palmar ulnocarpal ligaments (ulnotriquetral, ulnolunate, ulnocapitate)
OSSIFICATION
Shaft (8 weeks gestation)
Distal (6 years → 16 years)
Proximal (10 years → 15 years)
Question 12 – Axillary nerve
Write short notes on the anatomy of the axillary nerve (under the following headings: Origin and termination, Branches and supply, Course, Relations and Variants)
ORIGIN
Terminal nerve branch of posterior cord of brachial plexus in axilla, posterior to axillary artery
TERMINATION
As muscular and cutaneous branches
BRANCHES & SUPPLY
– Muscular branch supplies deltoid and teres minor muscles
– Cutaneous branch supplies skin overlying inferior part of deltoid muscle (regimental badge
area)
COURSE
– Exits posterior wall of axilla via quadrangular space (formed superiorly by inferior border of teres
minor, inferiorly by the superior border of teres major, medially by the lateral border of long head of triceps and medial border of humerus) accompanied by posterior circumflex humeral artery and vein
– Passes laterally, directly related to posterior surface of surgical neck of humerus
RELATIONS
posterior to axillary artery
VARIANTS
Forms from C4 nerve root (pre-fixed brachial plexus)
Supply infraspinatus and/or long head of triceps
may only have C5 fibres
may supply subscapularis
branches to the long head of the triceps
branches to the infraspinatus
may supply teres major
Question 13 – Menisci of the knee
Write short notes on the anatomy of the menisci of the knee (under the following headings: General description, Attachments, Relations and Variations).
GENERAL DESCRIPTION
Two (medial and lateral) crescent-shaped fibrocartilaginous structures within the knee joint, which deepen the tibiofemoral articulation. Provides shock absorption, knee joint stability and load transmission.
ATTACHMENTS
Medial meniscus
– Both horns attached at intercondylar area
– Anterior horn attaches, anterior to attachment of ACL
– Posterior horn attaches anterior to PCL insertion, posterior to posterior horn of lateral meniscus
– Margins attached to joint capsule, therefore less mobile
Lateral meniscus
– Both horns attached at intercondylar area
– Anterior horn immediately lateral to tibial attachment of ACL
– Posterior horn attached anterior to medial meniscus and PCL
– No lateral attachments due to intracapsular popliteal tendon
Ligaments
– Meniscofemoral ligaments – from posterior horn of lateral meniscus to lateral aspect of medial
femoral condyle, posterior ligament behind PCL, anterior ligament in front of PCL
– Transverse ligament – between anterior horns
RELATIONS
VARIATIONS
– Absent menisci
– Hypoplasia of menisci
– Discoid meniscus (body too wide)
– Aberrant insertion of anterior horn of medial meniscus (into ACL or intercondylar notch, anterior margin
of tibia, no attachment)
– Speckled anterior horn (fibers of ACL insertion into meniscus)
– Meniscal ossicles
Question 14 – Arterial supply of the foot
Write short notes on the anatomy of the arterial supply of the foot (under the following headings: Arteries, Course, relations and branches of major vessels, and Development and Variations)
DESCRIPTION
The foot is supplied by three main vessels
1. Anterior tibial (terminal branch of popliteal)
Descends from the knee joint, anterior to the interosseous membrane supplying anterior compartment of lower leg. Gives off anterior medial and lateral malleolar arteries at the ankle before continuing as the dorsalis pedis artery
2. Posterior tibial (largest terminal branch of popliteal)
Descends between the superificial and deep muscles of posterior compartment of lower leg. Distally becomes courses medially, passing behind the medial malleolus. Gives of posterior medial malleolar artery at ankle, communicating branch and artery of tarsal canal.
3. Peroneal (fibular) (branch of the tibiofibular trunk)
Originates from posterior tibial artery (2.5 cm from origin) and pierces interosseous membrane. Gives off posterior lateral malleolar artery at ankle and communicating branch. Terminates as the lateral calcaneal branch in the foot.
DORSAL SUPPLY
1. Dorsalis pedis
Description: Supplies dorsum of foot
Origin: continuation of anterior tibial artery across ankle joint
Course: passes distally over dorsal aspect of talus, navicular and intermediate cuneiform
Termination: passes between two heads of first dorsal interosseous muscle to join deep plantar arch in the
sole
Branches:
– tarsal arteries: pass medially and laterally over tarsal bones, forming anastomoses
– arcuate artery: arches laterally at bases of metatarsals deep to extensor tendons, gives 3 dorsal metatarsal arteries which supply dorsal digital branches to digits 2-5
– first dorsal metatarsal artery: supplies dorsal digital branches to great toe and medial side of 2nd toe
– dorsal metatarsal arteries: receive perforating branches from deep plantar arch
PLANTAR SUPPLY
1. Lateral plantar artery
Origin: Posterior tibial enters foot through tarsal tunnel behind medial malleolus, terminal bifurcation into medial and lateral plantar arteries
Course:
– Passes obliquely lateral toward base of 5th metatarsal
– Curves medially at bases of metatarsals to form deep plantar arch
– Joined by deep plantar artery (terminal branch of dorsalis pedis) which enters from dorsum between metatarsals 1 and 2
Branches:
– Digital branch to lateral side of little toe
– Four plantar metatarsal arteries to interspaces (between metatarsals), supplies digital branches to adjacent sides of the toes, and medial great toe
– Three perforating arteries which pass between bases of metatarsals 2-5 to anastomose with vessels on dorsum
– Digital branch to medial great toe
2. Medial plantar artery
– Passes distally into sole, deep to first layer of muscle
– Joined by digital branch of deep plantar arch to supply medial side of great toe
– Gives branches that anastomose with plantar metatarsal arteries of deep arch
VARIATIONS
– Absent dorsalis pedis, dorsal supply from plantar arteries
– Dorsalispedis supplied by fibular artery
– Plantar arch supplied by fibular artery
– Absent arcuate artery
– Arcuate artery from lateral tarsal artery
– No communication between plantar and dorsal arch