Question 1 of 263 Next A 56 year old man is left impotent following an abdomino-perineal excision of the colon and rectum. What is the most likely explanation? A. Psychosexual issues related to an end colostomy B. Damage to the sacral venous plexus during total mesorectal excision C. Damage to the left ureter during sigmoid mobilisation D. Damage to the hypogastric plexus during mobilisation of the inferior mesenteric artery E. Damage to the internal iliac artery during total mesorectal excision Next question Autonomic nerve injury is the most common cause. Nerve lesions during surgery A variety of different procedures carry the risk of iatrogenic nerve injury. These are important not only from the patients perspective but also from a medicolegal standpoint. The following operations and their associated nerve lesions are listed here: • Posterior triangle lymph node biopsy and accessory nerve lesion. • Lloyd Davies stirrups and common peroneal nerve. • Thyroidectomy and laryngeal nerve. • Anterior resection of rectum and hypogastric autonomic nerves. • Axillary node clearance; long thoracic nerve, thoracodorsal nerve and intercostobrachial nerve. • Inguinal hernia surgery and ilioinguinal nerve. • Varicose vein surgery- sural and saphenous nerves. • Posterior approach to the hip and sciatic nerve. • Carotid endarterectomy and hypoglossal nerve. There are many more, with sound anatomical understanding of the commonly performed procedures the incidence of nerve lesions can be minimised. They commonly occur when surgeons operate in an unfamiliar tissue plane or by blind placement of haemostats (not recommended). Previous Question 2 of 263 Next A 73 year old man is due to undergo a radical prostatectomy for carcinoma of the prostate gland. To which of the following lymph nodes will the tumour drain primarily?
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Question 1 of 263
Next
A 56 year old man is left impotent following an abdomino-perineal excision of the colon and rectum. What is the most likely
explanation?
A. Psychosexual issues related to an end colostomy
B. Damage to the sacral venous plexus during total mesorectal excision
C. Damage to the left ureter during sigmoid mobilisation
D. Damage to the hypogastric plexus during mobilisation of the inferior
mesenteric artery
E. Damage to the internal iliac artery during total mesorectal excision
Next question
Autonomic nerve injury is the most common cause.
Nerve lesions during surgery
A variety of different procedures carry the risk of iatrogenic nerve injury. These are important not only from the patients
perspective but also from a medicolegal standpoint.
The following operations and their associated nerve lesions are listed here:
• Posterior triangle lymph node biopsy and accessory nerve lesion.
• Lloyd Davies stirrups and common peroneal nerve.
• Thyroidectomy and laryngeal nerve.
• Anterior resection of rectum and hypogastric autonomic nerves.
• Axillary node clearance; long thoracic nerve, thoracodorsal nerve and intercostobrachial nerve.
• Inguinal hernia surgery and ilioinguinal nerve.
• Varicose vein surgery- sural and saphenous nerves.
• Posterior approach to the hip and sciatic nerve.
• Carotid endarterectomy and hypoglossal nerve.
There are many more, with sound anatomical understanding of the commonly performed procedures the incidence of nerve
lesions can be minimised. They commonly occur when surgeons operate in an unfamiliar tissue plane or by blind placement of
haemostats (not recommended).
Previous
Question 2 of 263
Next
A 73 year old man is due to undergo a radical prostatectomy for carcinoma of the prostate gland. To which of the following lymph nodes will the tumour drain primarily?
A. Para aortic
B. Internal iliac
C. Superficial inguinal
D. Meso rectal
E. None of the above
Next question The prostate lymphatic drainage is primarily to the internal iliac nodes and also the sacral nodes. Although internal iliac is the first site.
Prostate gland The prostate gland is approximately the shape and size of a walnut and is located inferior to the bladder. It is separated from the rectum by Denonvilliers fascia and its blood supply is derived from the internal iliac vessels. The internal sphincter lies at the apex of the gland and may be damaged during prostatic surgery, affected individuals may complain of retrograde ejaculation. Summary of prostate gland
Venous drainage Superficial venous plexus to sub clavian, axillary and intercostal veins.
Lymphatic drainage • 70% Axillary nodes • Internal mammary chain • Other lymphatic sites such as deep cervical and supraclavicular fossa (later in disease)
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Question 15 of 263
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Which of the following muscles is supplied by the external laryngeal nerve?
A. Transverse arytenoid
B. Cricothyroid
C. Thyro-arytenoid
D. Posterior crico-arytenoid
E. Oblique arytenoid
Next question
The others are all supplied by the recurrent laryngeal nerve.
Larynx
The larynx lies in the anterior part of the neck at the levels of C3 to C6 vertebral bodies. The laryngeal skeleton consists of a
number of cartilagenous segments. Three of these are paired; arytenoid, corniculate and cuneiform. Three are single; thyroid,
cricoid and epiglottic. The cricoid cartilage forms a complete ring (the only one to do so).
The laryngeal cavity extends from the laryngeal inlet to the level of the inferior border of the cricoid cartilage.
Divisions of the laryngeal cavity
Laryngeal vestibule Superior to the vestibular folds
Laryngeal ventricle Lies between vestibular folds and superior to the vocal cords
Infraglottic cavity Extends from vocal cords to inferior border of the cricoid cartilage
The vocal folds (true vocal cords) control sound production. The apex of each fold projects medially into the laryngeal cavity.
Each vocal fold includes:
• Vocal ligament
• Vocalis muscle (most medial part of thyroarytenoid muscle)
The glottis is composed of the vocal folds, processes and rima glottidis. The rima glottidis is the narrowest potential site within
the larynx, as the vocal cords may be completely opposed, forming a complete barrier.
Muscles of the larynx
Muscle Origin Insertion Innervation Action
Posterior cricoarytenoid
Posterior aspect of lamina of cricoid
Muscular process of arytenoid
Recurrent Laryngeal
Abducts vocal fold
Lateral cricoarytenoid
Arch of cricoid Muscular process of arytenoid
Recurrent laryngeal
Adducts vocal fold
Thyroarytenoid Posterior aspect of thyroid cartilage
Anterior Hepatic flexure of colon Stomach, Pancreatic tail
Superior Liver, adrenal gland Spleen, adrenal gland
Fascial covering
Each kidney and suprarenal gland is enclosed within a common and layer of investing fascia that is derived from the
transversalis fascia into anterior and posterior layers (Gerotas fascia).
Renal structure
Kidneys are surrounded by an outer cortex and an inner medulla which usually contains between 6 and 10 pyramidal structures.
The papilla marks the innermost apex of these. They terminate at the renal pelvis, into the ureter.
Lying in a hollow within the kidney is the renal sinus. This contains:
1. Branches of the renal artery
2. Tributaries of the renal vein
3. Major and minor calyces's
4. Fat
Structures at the renal hilum
The renal vein lies most anteriorly, then renal artery (it is an end artery) and the ureter lies most posterior.
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Question 6 of 248
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A baby is found to have a Klumpke's palsy post delivery. Which of the following is most likely to be present?
A. Loss of flexors of the wrist
B. Weak elbow flexion
C. Pronation of the forearm
D. Adducted shoulder
E. Shoulder medially rotated
Next question
Features of Klumpkes Paralysis
• Claw hand (MCP joints extended and IP joints flexed)
• Loss of sensation over medial aspect of forearm and hand
• Horner's syndrome
• Loss of flexors of the wrist
A C8, T1 root lesion is called Klumpke's paralysis and is caused by delivery with the arm extended.
Brachial plexus
Origin Anterior rami of C5 to T1
Sections of the plexus • Roots, trunks, divisions, cords, branches
• Mnemonic:Real Teenagers Drink Cold Beer
Roots • Located in the posterior triangle • Pass between scalenus anterior and medius
Trunks • Located posterior to middle third of clavicle • Upper and middle trunks related superiorly to the subclavian artery • Lower trunk passes over 1st rib posterior to the subclavian artery
Divisions Apex of axilla
Cords Related to axillary artery
Diagram illustrating the branches of the brachial plexus
Image sourced from Wikipedia
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Question 7 of 248
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A 22 year old man undergoes a superficial parotidectomy for a pleomorphic adenoma. The operation does not proceed well and
a diathermy malfunction results in division of the buccal branch of the facial nerve. Which of the following muscles will not
demonstrate impaired function as a result?
A. Zygomaticus minor
B. Mentalis
C. Buccinator
D. Levator anguli oris
E. Risorius
Next question
Buccal branch supplies
Zygomaticus minor Elevates upper lip
Risorius Aids smile
Buccinator
Pulls corner of mouth backward and compresses cheek
Levator anguli oris Pulls angles of mouth upward and toward midline
Orbicularis Closes and tightens lips together
Nasalis Flares nostrils and compresses nostrils
Facial nerve
The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an
efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few
afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste.
Supply - 'face, ear, taste, tear'
• Face: muscles of facial expression
• Ear: nerve to stapedius
• Taste: supplies anterior two-thirds of tongue
• Tear: parasympathetic fibres to lacrimal glands, also salivary glands
Which of the following structures is not directly related to the right adrenal gland?
A. Diaphragm posteriorly
B. Bare area of the liver anteriorly
C. Right renal vein
D. Inferior vena cava
E. Hepato-renal pouch
Next question
The right renal vein is very short and lies more inferiorly.
Adrenal gland anatomy
Anatomy
Location Superomedially to the upper pole of each kidney
Relationships of the right adrenal
Diaphragm-Posteriorly, Kidney-Inferiorly, Vena Cava-Medially, Hepato-renal pouch and bare area of the liver-Anteriorly
Relationships of the left adrenal
Crus of the diaphragm-Postero- medially, Pancreas and splenic vessels-Inferiorly, Lesser sac and stomach-Anteriorly
Arterial supply
Superior adrenal arteries- from inferior phrenic artery, Middle adrenal arteries - from aorta, Inferior adrenal arteries -from renal arteries
Venous drainage of the right adrenal
Via one central vein directly into the IVC
Venous drainage of the left adrenal
Via one central vein into the left renal vein
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Question 14 of 248
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With respect to the basilic vein, which statement is false?
A. Its deep anatomical location makes it unsuitable for use as an arteriovenous
access site in fistula surgery
B. It originates from the dorsal venous network on the hand
C. It travels up the medial aspect of the forearm
D. Halfway between the shoulder and the elbow it lies deep to muscle
E. It joins the brachial vein to form the axillary vein
Next question
It is used in arteriovenous fistula surgery during a procedure known as a basilic vein transposition.
Basilic vein
The basilic and cephalic veins both provide the main pathways of venous drainage for the arm and hand. It is continuous with
the palmar venous arch distally and the axillary vein proximally.
Path
• Originates on the medial side of the dorsal venous network of the hand, and passes up the forearm and arm.
• Most of its course is superficial.
• Near the region anterior to the cubital fossa the vein joins the cephalic vein.
• Midway up the humerus the basilic vein passes deep under the muscles.
• At the lower border of the teres major muscle, the anterior and posterior circumflex humeral veins feed into it.
• Joins the brachial veins to form the axillary vein.
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Question 15 of 248
Next
Mobilisation of the left lobe of the liver will facilitate surgical access to which of the following?
A. Abdominal oesophagus
B. Duodenum
C. Right colic flexure
D. Right kidney
E. Pylorus of stomach
Next question
The fundus of the stomach is a posterior relation. The pylorus lies more inferolaterally. During a total gastrectomy division of
the ligaments holding the left lobe of the liver will facilitate access to the proximal stomach and abdominal oesophagus. This
manoeuvre is seldom beneficial during a distal gastrectomy.
Liver
Structure of the liver
Right lobe • Supplied by right hepatic artery • Contains Couinard segments V to VIII (-/+Sg I)
Left lobe • Supplied by the left hepatic artery • Contains Couinard segments II to IV (+/- Sg1)
Quadrate lobe • Part of the right lobe anatomically, functionally is part of the left • Couinard segment IV • Porta hepatis lies behind • On the right lies the gallbladder fossa • On the left lies the fossa for the umbilical vein
Caudate lobe • Supplied by both right and left hepatic arteries • Couinard segment I • Lies behind the plane of the porta hepatis • Anterior and lateral to the inferior vena cava • Bile from the caudate lobe drains into both right and left hepatic ducts
Detailed knowledge of Couinard segments is not required for MRCS Part A
• Between the liver lobules are portal canals which contain the portal triad: Hepatic Artery, Portal Vein, tributary of Bile
Duct.
Relations of the liver
Anterior Postero inferiorly
Diaphragm Oesophagus
Xiphoid process Stomach
Duodenum
Hepatic flexure of colon
Right kidney
Gallbladder
Inferior vena cava
Porta hepatis
Location Postero inferior surface, it joins nearly at right angles with the left sagittal fossa, and separates the caudate lobe behind from the quadrate lobe in front
Transmits • Common hepatic duct • Hepatic artery • Portal vein • Sympathetic and parasympathetic nerve fibres • Lymphatic drainage of the liver (and nodes)
Ligaments
Falciform ligament • 2 layer fold peritoneum from the umbilicus to anterior liver surface • Contains ligamentum teres (remnant umbilical vein) • On superior liver surface it splits into the coronary and left triangular ligaments
Ligamentum teres Joins the left branch of the portal vein in the porta hepatis
Ligamentum venosum Remnant of ductus venosus
Arterial supply
• Hepatic artery
Venous
• Hepatic veins
• Portal vein
Nervous supply
• Sympathetic and parasympathetic trunks of coeliac plexus
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Question 16 of 248
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The following statements relating to the ankle joint are true except?
A. Three groups of ligaments provide mechanical stability
B. The sural nerve lies medial to the Achilles tendon at its point of insertion
C. Eversion of the foot occurs at the sub talar joint
D. The flexor hallucis longus tendon is the most posterior structure at the medial malleolus
E. The saphenous nerve crosses the ankle joint.
Next question
The sural nerve lies behind the distal fibula. Inversion and eversion are sub talar movements. The structures passing behind the
medial malleolus from anterior to posterior include: tibialis posterior, flexor digitorum longus, posterior tibia vein, posterior
tibial artery, nerve, flexor hallucis longus.
Ankle joint
The ankle joint is a synovial joint composed of the tibia and fibula superiorly and the talus inferiorly.
Ligaments of the ankle joint
• Deltoid ligament (medially)
• Lateral collateral ligament
• Talofibular ligaments (both anteriorly and posteriorly)
The calcaneofibular ligament is separate from the fibrous capsule of the joint. The two talofibular ligaments are fused with it.
The components of the syndesmosis are
• Antero-inferior talofibular ligament
• Postero-inferior talofibular ligament
• Inferior transverse talofibular ligament
• Interosseous ligament
Movements at the ankle joint
• Plantar flexion (55 degrees)
• Dorsiflexion (35 degrees)
• Inversion and eversion movements occur at the level of the sub talar joint
Nerve supply
Branches of deep peroneal and tibial nerves.
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Question 17 of 248
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A 78 year old man is lifting a heavy object when a feels a pain in his forearm and is unable to continue. He has a swelling over
his upper forearm. An MRI scan shows a small cuff of tendon still attached to the radial tuberosity consistent with a recent tear.
Which of the following muscles has been injured?
A. Pronator teres
B. Supinator
C. Aconeus
D. Brachioradialis
E. Biceps brachii
Next question
Biceps inserts into the radial tuberosity. Distal injuries of this muscle are rare but are reported and are clinically more important
than more proximal ruptures.
Radius
• Bone of the forearm extending from the lateral side of the elbow to the thumb side of the wrist
Upper end
• Articular cartilage- covers medial > lateral side
• Articulates with radial notch of the ulna by the annular ligament
• Muscle attachment- biceps brachii at the tuberosity
Shaft
• Muscle attachment-
Upper third of the body Supinator, Flexor digitorum superficialis, Flexor pollicis longus
Middle third of the body Pronator teres
Lower quarter of the body Pronator quadratus , tendon of supinator longus
Lower end
• Quadrilateral
• Anterior surface- capsule of wrist joint
• Medial surface- head of ulna
• Lateral surface- ends in the styloid process
• Posterior surface: 3 grooves containing:
1. Tendons of extensor carpi radialis longus and brevis
2. Tendon of extensor pollicis longus
3. Tendon of extensor indicis
Image sourced from Wikipedia
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Question 18 of 248
Next
The oesophagus is constricted at the following levels apart from:
A. Cricoid cartilage
B. Arch of the aorta
C. Lower oesophageal sphincter
D. Left main stem bronchus
E. Diaphragmatic hiatus
Next question
The oesophagus is not constricted at the level of the lower oesophageal sphincter.
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Question 19 of 248
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A 19 year old man is playing rugby when he suddenly notices a severe pain at the posterolateral aspect of his right thigh. Which of the following muscle groups is most likely to have been injured?
A. Semimembranosus
B. Semitendinosus
C. Long head of biceps femoris
D. Gastrocnemius
E. Soleus
Next question Theme from April 2012 Exam The biceps femoris is the laterally located hamstring muscle. The semitendinosus and semimembranosus are located medially. Rupture of gastrocnemius and soleus may occur but is less common.
Biceps femoris The biceps femoris is one of the hamstring group of muscles located in the posterior upper thigh. It has two heads. Long head
Origin Ischial tuberosity
Insertion Fibular head
Action Knee flexion, lateral rotation tibia, extension hip
Innervation Tibial nerve (L5, S1, S2)
Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery
Image demonstrating the biceps femoris muscle, with the long head outlined
Image sourced from Wikipedia
Short head
Origin Lateral lip of linea aspera, lateral supracondylar ridge of femur
Insertion Fibular head
Action Knee flexion, lateral rotation tibia
Innervation Common peroneal nerve (L5, S1, S2)
Arterial supply Profunda femoris artery, inferior gluteal artery, and the superior muscular branches of popliteal artery
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Question 20 of 248
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Which of the following is a branch of the third part of the axillary artery?
A. Superior thoracic
B. Lateral thoracic
C. Dorsal scapular
D. Thoracoacromial
E. Posterior circumflex humeral
Next question
The other branches include:
• Subscapular
• Anterior circumflex humeral
Axilla
Boundaries of the axilla
Medially Chest wall and Serratus anterior
Laterally Humeral head
Floor Subscapularis
Anterior aspect Lateral border of Pectoralis major
Fascia Clavipectoral fascia
Content:
Long thoracic nerve (of Bell)
Derived from C5-C7 and passes behind the brachial plexus to enter the axilla. It lies on the medial chest wall and supplies serratus anterior. Its location puts it at risk during axillary surgery and damage will lead to winging of the scapula.
Thoracodorsal nerve and thoracodorsal trunk
Innervate and vascularise latissimus dorsi.
Axillary vein Lies at the apex of the axilla, it is the continuation of the basilic vein. Becomes the subclavian vein at the outer border of the first rib.
Intercostobrachial nerves Traverse the axillary lymph nodes and are often divided during axillary surgery. They provide cutaneous sensation to the axillary skin.
Lymph nodes The axilla is the main site of lymphatic drainage for the breast.
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Question 21 of 248
Next
Which of the following structures separates the intervertebral disks from the spinal cord?
A. Anterior longitudinal ligament
B. Posterior longitudinal ligament
C. Supraspinous ligament
D. Interspinous ligament
E. Ligamentum flavum
Next question
The posterior longitudinal ligament overlies the posterior aspect of the vertebral bodies. It also overlies the posterior aspect of
the intervertebral disks.
Intervertebral discs
• Consist of an outer annulus fibrosus and an inner nucleus pulposus.
• The anulus fibrosus consists of several layers of fibrocartilage.
• The nucleus pulposus contains loose fibres suspended in a mucoprotein gel with the consistency of jelly. The nucleus
of the disc acts as a shock absorber.
• Pressure on the disc causes posterior protrusion of the nucleus pulposus. Most commonly in the lumbrosacral and lower
cervical areas.
• The discs are separated by hyaline cartilage.
• There is one disc between each pair of vertebrae, except for C1/2 and the sacrococcygeal vertebrae.
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Question 22 of 248
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At what level does the aorta bifurcate into the left and right common iliac arteries?
A. L1
B. L2
C. L3
D. L4
E. L5
Next question
The aorta typically bifurcates at L4. This level is usually fairly constant and is often tested in the exam.
Levels
Transpyloric plane
Level of the body of L1
• Pylorus stomach
• Left kidney hilum (L1- left one!)
• Right hilum of the kidney (1.5cm lower than the left)
• Fundus of the gallbladder
• Neck of pancreas
• Duodenojejunal flexure
• Superior mesenteric artery
• Portal vein
• Left and right colic flexure
• Root of the transverse mesocolon
• 2nd part of the duodenum
• Upper part of conus medullaris
• Spleen
Can be identified by asking the supine patient to sit up without using their arms. The plane is located where the lateral border of
the rectus muscle crosses the costal margin.
Anatomical planes
Subcostal plane Lowest margin of 10th costal cartilage
Intercristal plane Level of body L4 (highest point of iliac crest)
Intertubercular plane Level of body L5
Common level landmarks
Inferior mesenteric artery L3
Bifurcation of aorta into common iliac arteries L4
Attached to chordae tendinae No chordae No chordae Attached to chordae tendinae
Previous 2 / 3 Question 24-26 of 248
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Theme: Nerve lesions
A. Intercostobrachial
B. Median
C. Axillary
D. Radial
E. Ulnar
F. Musculocutaneous
G. Brachial plexus upper cord
H. Brachial plexus lower cord
Please select the most likely nerve injury for the scenarios given. Each option may be used once, more than once or not at all.
24. A 23 year old rugby player sustains a Smiths Fracture. On examination opposition of the thumb is markedly weakened.
Median This high velocity injury can often produce significant angulation and displacement. Both of these may impair the function of the median nerve with loss of function of the muscles of the thenar eminence
25. A 45 year old lady recovering from a mastectomy and axillary node clearance notices that sensation in her armpit is impaired.
Intercostobrachial The intercostobrachial nerves are frequently injured during axillary dissection. These nerves traverse the axilla and supply cutaneous sensation.
26. An 8 year old boy falls onto an outstretched hand and sustains a supracondylar fracture. In addition to a weak radial pulse the child is noted to have loss of pronation of the affected hand.
You answered Ulnar The correct answer is Median This is a common injury in children. In this case the angulation and displacement have resulted in median nerve injury.
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Question 27 of 248
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A 23 year old lady with sialolithiasis of the submandibular gland is undergoing excision of the gland. Which of the following
nerves is at risk as the duct is mobilised?
A. Lingual nerve
B. Buccal nerve
C. Facial nerve
D. Glossopharyngeal
E. Vagus
Next question
The lingual nerve wraps around Whartons duct. The lingual nerve provides sensory supply to the anterior 2/3 of the tongue.
Submandibular gland
Relations of the submandibular gland
Superficial Platysma, deep fascia and mandible Submandibular lymph nodes Facial vein (facial artery near mandible) Marginal mandibular nerve Cervical branch of the facial nerve
Deep Facial artery (inferior to the mandible) Mylohoid muscle Sub mandibular duct Hyoglossus muscle Lingual nerve Submandibular ganglion Hypoglossal nerve
Submandibular duct (Wharton's duct)
• Opens lateral to the lingual frenulum on the anterior floor of mouth.
• 5 cm length
• Lingual nerve wraps around Wharton's duct. As the duct passes forwards it crosses medial to the nerve to lie above it
and then crosses back, lateral to it, to reach a position below the nerve.
Innervation
• Sympathetic innervation- Superior Cervical ganglion via the Lingual nerve