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Head and Neck Muscles
Published in Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo, Handbook of Muscle Variations and Anomalies in Humans, 2022
Eve K. Boyle, Vondel S. E. Mahon, Rui Diogo, Warrenkevin Henderson, Hannah Jacobson, Noelle Purcell, Kylar Wiltz
Petropharyngeus may be present bilaterally (Shimada et al. 1991; Sakamoto 2009; Siddiqui et al. 2017). It may be divided into two bundles (Choi et al. 2020). It may present as a thin and small fascicle, a fibromuscular structure, or a well-developed muscular slip (Siddiqui et al. 2017; Choi et al. 2020).
Functional Anatomy
Published in James Crossley, Functional Exercise and Rehabilitation, 2021
Skeletal muscle is composed of many individual muscle fibers wrapped together in bundles. Connective tissue known as fascia covers each of these bundles. The outer layer that covers the whole muscle is called the epimysium. The epimysium runs into tendon of the muscle that attaches and transmits force to the bone. Muscles attach to bone proximally (origin) and distally (insertion). Origin – muscle attachment that is generally more proximal and moves the leastInsertion – muscle attachment that is generally more distal and moves the most Under the epimysium we see bundles of muscle fibers known as the fascicles, wrapped in fascia called the perimysium. Each muscle fiber is wrapped in a connective tissue called the endomysium. Each muscle fiber forms the building blocks of muscle called myofibrils.
Neuromuscular Final Report
Published in Maher Kurdi, Neuromuscular Pathology Made Easy, 2021
Frozen sections: H&E stained slides show a skeletal muscle in a cross-sectional array. The fascicles are well populated with muscle fibers. There is (minimal/moderate/marked) variation in muscle fiber caliber owing to the presence of (small round/atrophic/hypoplastic/hypertrophic) fibers that are thoroughly mixed in with fibers of (normal or slightly larger than normal caliber). There is (no/yes) evidence of inflammation. Scattered nuclear bags indicative of severe fiber atrophy are (present/not present). No ring or split fibers are identified. Regenerative and degenerative fibers are (occasionally seen/not seen). Fibers with internalized nuclei are (increased (>3%)/not increased in number) throughout the biopsy.
Hamstrings injury incidence, risk factors, and prevention in Rugby Union players: a systematic review
Published in The Physician and Sportsmedicine, 2023
Christian Chavarro-Nieto, Martyn Beaven, Nicholas Gill, Kim Hébert-Losier
Running training and high speed exposures have been postulated as an effective tool to reduce hamstring injuries [53]. One of the recommendations by Buckthorpe et al. [15] for preventing hamstring injuries involved incorporating high speed-running routines at least twice a week at 95% of maximum speed. Analysis of a player with a hamstring injury identified impaired sprint accelerations with a decrease in horizontal force production, potentially due to weak hamstring or gluteal muscles, before the injury and after return to play [33]. The authors highlighted the importance of running activities for preventing hamstring injuries, and suggested sprint time measurement to detect deficits during the initial acceleration phase. Magnetic resonant imaging of hamstring injuries in professional players showed the biceps femoris long head fascicle was the most injured muscle (73%), and that this injury occurred most frequently in running actions (77%) [45]. In contrast to football players who sustained more Proximal Myofascial junction intramuscular injuries [54], the Distal Myofascial junction site was more common in Rugby Union players, re-emphasizing the importance of Nordic exercises to target this portion of the muscle [55].
Chameleons, red herrings, and false localizing signs in neurocritical care
Published in British Journal of Neurosurgery, 2022
Boyi Li, Tolga Sursal, Christian Bowers, Chad Cole, Chirag Gandhi, Meic Schmidt, Stephan Mayer, Fawaz Al-Mufti
Superior divisional third nerve palsy, which presents as upper eyelid ptosis and limited supraduction without pupillary involvement, is typically associated with lesions localized to the anterior cavernous sinus and or superior orbital fissure compressing the superior division of the oculomotor nerve.17 However, other etiologies have been found to include those further from the expected sites, such as intrinsic brainstem disease, metastatic subarachnoid infiltration, and superior cerebellar–posterior cerebral artery junction and the basilar artery apex aneurysms.17–20 Despite similar clinical presentation, varying etiologies are a consequence of topographical arrangement of fascicles within the nerve, of which there can be anatomical variation.17,18 Clinicians should remain aware that superior divisional CN III may suggest a more distal intracranial lesion and perform appropriate diagnostic imaging studies.
Shoulder abduction reconstruction for C5–7 avulsion brachial plexus injury by dual nerve transfers: spinal accessory to suprascapular nerve and partial median or ulnar to axillary nerve
Published in Journal of Plastic Surgery and Hand Surgery, 2022
Gavrielle Hui-Ying Kang, Fok-Chuan Yong
The donor median or ulnar nerve and biceps branch of musculocutaneous nerve were identified via the same anterior axillary incision extended distally. (Figure 3) A partial longitudinal epineurotomy was made on the donor nerve for intra-operative nerve stimulation to identify suitable donor fascicles. For the median nerve, suitable donors include the fascicles to wrist or finger flexors (FCR or FDS), or forearm pronator (PT). The suitable donor fascicles for the ulnar nerve would be the fascicles to the FCU. The donor fascicles were identified when strong muscle contractions were observed with nerve stimulation and isolated to the expandable muscle. Fascicles that did not elicit a response to nerve stimulation were assumed to be sensory fascicles and were spared. Fascicles that elicited a motor response to any of the flexor digitorum profundus or flexor pollicis longus on stimulation were spared as well. The chosen fascicles were then isolated with a vessel loop. The nerve fascicle that elicited the stronger muscle contraction was chosen for neurotization to the nerve to the biceps muscle. If the ulnar nerve and median nerve fascicles elicited similarly strong muscle contractions, the ulnar nerve was chosen for neurotization to the nerve to the biceps muscle. The other donor nerve fascicle was then utilized for neurotization to the axillary nerve.