1. A 19 year old female is admitted with suspected meningitis. The House Officer is due to perform a lumbar puncture. What is the most likely structure first encountered when the needle is inserted? A. Ligamentum flavum B. Denticulate ligament C. Dural sheath D. Pia Mater E. Supraspinous ligament Theme from September 2012 exam Lumbar puncture Lumbar punctures are performed to obtain cerebrospinal fluid. In adults, the procedure is best performed at the level of L3/L4 or L4/5 interspace. These regions are below the termination of the spinal cord at L1. During the procedure the needle passes through: • The supraspinous ligament which connects the tips of spinous processes and the interspinous ligaments between adjacent borders of spinous processes • Then the needle passes through the ligamentum flavum, which may cause a give as it is penetrated • A second give represents penetration of the needle through the dura mater into the subarachnoid space. Clear CSF should be obtained at this point 2. A 34 year old male is being examined in the pre-operative assessment clinic. A murmur is identified in the 5th intercostal space just next to the left side of the sternum. From where is it most likely to have originated? A. Mitral valve B. Aortic valve C. Pulmonary valve D. Right ventricular aneurysm E. Tricuspid valve Theme from September 2012 Exam • Heart sounds Sites of auscultation Valve Site Pulmonary valve Left second intercostal space, at the upper sternal border Aortic valve Right second intercostal space, at the upper sternal border Mitral valve Left fifth intercostal space, just medial to mid clavicular line Tricuspid valve Left fifth intercostal space, at the lower left sternal border The diagram below demonstrates where the various cardiac valves are best heard. 3. What is the correct embryological origin of the stapes? A. First pharyngeal arch B. Second pharyngeal arch C. Third pharyngeal arch D. Fourth pharyngeal arch E. Fifth pharyngeal arch Embryological origin stapes = 2nd pharyngeal arch Theme from April 2012 Exam The dorsal ends of the cartilages of the first and second pharyngeal arches articulate superior to the tubotympanic recess. These cartilages form the malleus incus and stapes. At least part of the malleus is formed from the first arch and the stapes from the second arch. The incus is most likely to arise from the first arch. Pharyngeal arches These develop during the fourth week of embryonic growth from a series of mesodermal outpouchings of the developing pharynx. They develop and fuse in the ventral midline. Pharyngeal pouches form on the endodermal side between the arches. There are 6 pharyngeal arches, the fifth does not contribute any useful structures and often fuses with the sixth arch. Pharyngeal arches Pharyngeal Muscular Skeletal Endocrine Artery Nerve arch contributions contributions First Muscles of Maxilla n/a Maxillary Mandibular mastication Meckels External Anterior belly of cartilage carotid digastric Incus Mylohyoid Malleus Tensor tympanic Tensor veli palatini Second Buccinator Stapes n/a Inferior Facial Platysma Styloid branch of Muscles of facial process superior expression Lesser corn thyroid artery Stylohyoid and upper Stapedial Posterior belly of body of hyoid artery digastric Stapedius Third Stylopharyngeus Greater horn Thymus Common and Glossopharyngeal and lower part Inferior internal of hyoid parathyroids carotid Fourth Cricothyroid Thyroid and Superior Right- Vagus All intrinsic epiglottic parathyroids subclavian muscles of the cartilages artery, Left- soft palate aortic arch Sixth All intrinsic Cricoid, n/a Right - Vagus and muscles of the arytenoid and Pulmonary recurrent larynx (except corniculate artery, Left- laryngeal nerve cricothyroid) cartilages Pulmonary artery and ductus arteriosus 4. Which muscle initiates abduction of the shoulder? A. Infraspinatus B. Latissimus dorsi C. Supraspinatus D. Deltoid E. Teres major Theme from September 2012 exam The intermediate portion of the deltoid muscle is the chief abductor of the humerus. However, it can only do this after the movement has been initiated by supraspinatus. Damage to the tendon of supraspinatus is a common form of rotator cuff disease. Shoulder joint • Shallow synovial ball and socket type of joint. • It is an inherently unstable joint, but is capable to a wide range of movement. • Stability is provided by muscles of the rotator cuff that pass from the scapula to insert in the greater tuberosity (all except sub scapularis-lesser tuberosity). Glenoid labrum • Fibrocartilaginous rim attached to the free edge of the glenoid cavity • Tendon of the long head of biceps arises from within the joint from the supraglenoid tubercle, and is fused at this point to the labrum. • The long head of triceps attaches to the infraglenoid tubercle Fibrous capsule • Attaches to the scapula external to the glenoid labrum and to the labrum itself (postero-superiorly) • Attaches to the humerus at the level of the anatomical neck superiorly and the surgical neck inferiorly • Anteriorly the capsule is in contact with the tendon of subscapularis, superiorly with the supraspinatus tendon, and posteriorly with the tendons of infraspinatus and teres minor. All these blend with the capsule towards their insertion. • Two defects in the fibrous capsule; superiorly for the tendon of biceps. Anteriorly there is a defect beneath the subscapularis tendon. • The inferior extension of the capsule is closely related to the axillary nerve at the surgical neck and this nerve is at risk in anteroinferior dislocations. It also means that proximally sited osteomyelitis may progress to septic arthritis. Movements and muscles Flexion Anterior part of deltoid Pectoralis major Biceps Coracobrachialis Extension Posterior deltoid Teres major Latissimus dorsi Adduction Pectoralis major Latissimus dorsi Teres major Coracobrachialis Abduction Mid deltoid Supraspinatus Medial rotation Subscapularis Anterior deltoid Teres major Latissimus dorsi Lateral rotation Posterior deltoid Infraspinatus Teres minor Important anatomical relations Anteriorly Brachial plexus Axillary artery and vein Posterior Suprascapular nerve Suprascapular vessels Inferior Axillary nerve Circumflex humeral vessels 5. What is the most important structure involved in supporting the uterus? A. Round ligament B. Broad ligament C. Uterosacral ligaments D. Cardinal ligaments E. Central perineal tendon Theme from September 2012 Exam The central perineal tendon provides the main structural support to the uterus. Damage to this structure is commonly associated with the development of pelvic organ prolapse, even when other structures are intact. Uterus The non pregnant uterus resides entirely within the pelvis. The peritoneum invests the uterus and the structure is contained within the peritoneal cavity. The blood supply to the uterine body is via the uterine artery (branch of the internal iliac). The uterine artery passes from the inferior aspect of the uterus (lateral to the cervix) and runs alongside the uterus. It frequently anastomoses with the ovarian artery superiorly. Inferolaterally the ureter is a close relation and ureteric injuries are a recognised complication when pathology brings these structures into close proximity. The supports of the uterus include the central perineal tendon (the most important). The lateral cervical, round and uterosacral ligaments are condensations of the endopelvic fascia and provide additional structural support. Topography of the uterus 6. A 22 year old man suffers a compound fracture of the tibia. During attempted surgical repair the deep peroneal nerve is divided. Which of the following muscles will not be affected as a result? A. Tibialis anterior B. Peroneus longus C. Extensor hallucis longus D. Extensor digitorum longus E. Peroneus tertius Peroneus longus is innervated by the superficial peroneal nerve (L4, L5, S1). Image sourced from Wikipedia Deep peroneal nerve Origin From the common peroneal nerve, at the lateral aspect of the fibula, deep to peroneus longus Nerve root values L4, L5, S1, S2 Course and relation • Pierces the anterior intermuscular septum to enter the anterior compartment of the lower leg • Passes anteriorly down to the ankle joint, midway between the two malleoli Terminates In the dorsum of the foot Muscles innervated • Tibialis anterior • Extensor hallucis longus • Extensor digitorum longus • Peroneus tertius • Extensor digitorum brevis Cutaneous Web space of the first and second toes innervation Actions • Dorsiflexion of ankle joint • Extension of all toes (extensor hallucis longus and extensor digitorum longus) • Eversion of the foot After its bifurcation past the ankle joint, the lateral branch of the deep peroneal nerve innervates the extensor digitorum brevis and the extensor hallucis brevis The medial branch supplies the web space between the first and second digits. 7. A 56 year old man is undergoing a superficial parotidectomy for a pleomorphic adenoma. During the dissection of the parotid, which of the following structures will be encountered lying most superficially? A. Facial nerve B. External carotid artery C. Occipital artery D. Maxillary artery E. Retromandibular vein Most superficial structure on the parotid gland = facial nerve The facial nerve is the most superficial structure in the parotid gland. Slightly deeper to this lies the retromandibular vein, with the arterial layer lying most deeply. Parotid gland Anatomy of the parotid gland Location Overlying the mandibular ramus; anterior and inferior to the ear. Salivary duct