2022 MEDI7112 Formative Quiz - Week 05 PDF

Strengths and Improvement Opportunities 2022 MEDI7112 Formative Quiz - Week 05 Course: [MEDI7112] Clinical Science 2 (St Lucia). Semester 2, 2022 ‡ Instructor: Ben Barry ‡ Questions: 10 50.00% My Score...

Strengths and Improvement Opportunities 2022 MEDI7112 Formative Quiz - Week 05 Course: [MEDI7112] Clinical Science 2 (St Lucia). Semester 2, 2022 ‡ Instructor: Ben Barry ‡ Questions: 10 50.00% My Score (5/10) CATEGORY MY SCORE 1 Knowledge (Remembering) 50.00% 2 Comprehension (Understanding) 100.00% Formative 50.00% David Amirtharajan, Sophia 0.00% 2017 50.00% 2019 0.00% 2019 Reviewed MEDI7211 Course Team 0.00% To be reviewed MEDI7112 0.00% Anatomy 75.00% Physiology 50.00% MEDI7112 Clinical Science 2 0.00% Nervous System and Special Senses 66.67% Physiology 50.00% Emergency Medicine discipline 0.00% Neuroanatomy 66.67% Neurological conditions 80.00% Nervous system 100.00% 2018 MEDI7112 Formative 66.67% 2019 MEDI7112 Formative 71.43% 2019 MEDI7112 MSE Def 0.00% LO1: Describe normal human structure, function and development at a molecular, cellular, organ, and systems level, with particular emphasis on the musculoskeletal, nervous systems, nutrition and metabolism, and gastrointestinal 0.00% Nervous System Module 50.00% 2021 MEDI7112 Formative 50.00% Nerve Entrapment Syndromes 100.00% Peripheral Neuropathy 66.67% QUESTION POINTS CORRECT NCORRECT PART AL CRED T Neurotransmitter release 1 At the neuromuscular junction, influx of which following cation at the pre-synaptic terminal button leads to 1/1 neurotransmitter release? > A: Calcium X B: Chloride X C: Magnesium X D: Potassium X E: Sodium Rationale: The correct response is Ca2+ In the resting state, neurotransmitters are stored in vesicles at the pre-synaptic terminal. Most neurons contain at least two types of synaptic vesicles, small (about 50 nm diameter) and large (70-200 nm diameter). Calcium (Ca2+) is plays a vital role in the process of neurotransmitter release; when Ca2+ channels are blocked, neurotransmitter release is inhibited. Nociceptors 2 Which of the following statements regarding polymodal nociceptors is MOST CORRECT? 0/1 > A: They respond equally to all mechanical, temperature and chemical noxious stimuli X B: They respond only when temperature is > 45°C X C: They respond only with strong mechanical stimulation and most effectively with sharp objects X D: They are normally unresponsive unless tissue is inflamed or injured X E: They respond only when temperature is < 4°C Rationale: The correct response is they respond equally to all mechanical, temperature and chemical noxious stimuli. (Dr. Bellingham's Lecture) Polymodal nociceptors are capable of mechanical, temperature and chemical noxious stimuli. Since many neurons can perform multiple functions they are often classified as polymodal.  Blood brain barrier- cell type 3 What cell type in the CNS is responsible for forming the blood brain barrier? 1/1 > A: Astrocytes X B: Ependymal cells X C: Microglia X D: Oligodendrocytes X E: Schwann cells Rationale: CNS comprises of neuroglial cells. Following is the cell types and their functions: Microglia- Phagocytic cells Astrocytes- Generate scar tissue, induce synapse formation, part of the BBB Oligodendrocytes- Myelinating cells Ependymal cells- Generate CSF Schwann cells are found in the peripheral nervous system and they help regeneration of the peripheral nerves. Peripheral neuropathy 4 A 36-year-old man presents with a six-month history of progressive numbness and weakness in his toes and feet 0/1 with some similar but milder symptoms in his hands. His cranial nerve examination is normal. In the upper limbs he has weakness of finger abduction, extension and absent reflexes with loss of light touch and pin prick to the wrist. In the lower limbs he has a high stepping gait with bilateral foot drop and sensory loss to the mid shin. There is wasting and absent reflexes in his legs. A pathology in which following regions BEST EXPLAINS his symptoms and signs? X A: Cortex X B: Midbrain X C: Neuromuscular junction > D: Peripheral nerve X E: Spinal cord Rationale: Characteristic symptoms of Peripheral neuropathy discussed in Dr. Walsh's Lecture. When a patient presents with symptoms of distal numbness, tingling and pain, or weakness, the first step is to determine whether the symptoms are the result of peripheral neuropathy or of a lesion in the CNS, and whether a single nerve root, multiple nerve roots, or a peripheral nerve plexus is involved. CNS lesions may be associated with other features, such as speech difficulty, double vision, ataxia, cranial nerve involvement, or, in cases of myelopathy, impairment of bowel and bladder functions. Deep tendon reflexes are usually brisk, and muscle tone is spastic. Lesions of the peripheral nerve roots are typically asymmetric, follow a dermatomal pattern of sensory symptoms, and may have associated neck and low back pain. Lesions of the plexus are asymmetric with sensorimotor involvement of multiple nerves in one extremity. Loss of sensation (including vibration, proprioception, temperature, and pinprick sensations) in distal extremities suggests peripheral neuropathy, as does a distal-to-proximal gradient of reflex elicitation. ( Source: https://www.aafp.org/afp/2010/0401/p887.html) Nerve supply to lower leg 5 A 43-year-old man who has recently had a plaster cast (encasing the foot, ankle and leg below the knee) removed 1/1 is noticed to have a foot drop, weakened ankle eversion and numbness over the dorsum of the foot. Which of the following nerves is MOST LIKELY affected in this man? > A: Common fibular X B: Medial tarsal X C: Saphenous X D: Superficial fibular X E: Sural Rationale: Plaster casts on the lower leg are likely to damage the common fibular nerve at the fibular neck. Compression neuropathy of the nerve will cause foot drop. Sural nerve is a cutaneous nerve as is the saphenous. Medial plantar nerve supplies the small muscles of the foot. Injury to the superficial fibular nerve will cause an inability to evert the foot and loss of sensation over the dorsum of the foot (with the exception of the first web space between the great toe and the second toe. Shoulder dysfunction 6 A 60-year-old man describes chronic weakness in abducting the left shoulder as well as left shoulder numbness. 1/1 He does not have shoulder or back pain. The left deltoid appears wasted on examination, and sensation to pinprick of the left shoulder is decreased. He thinks that these problems began after he dislocated his shoulder four years ago. What is the MOST LIKELY explanation of his condition? > A: Axillary nerve injury X B: C4 radiculopathy X C: C6 radiculopathy X D: Musculocutaneous nerve injury X E: Radial nerve injury Rationale: The axillary nerve or the circumflex nerve originates from the brachial plexus (upper trunk, posterior division, posterior cord) at the level of the axilla (armpit) and carries nerve fibers from C5 and C6 spinal nerve roots. The axillary nerve supplies three muscles in the arm: deltoid (a muscle of the shoulder), triceps (long head) and teres minor (one of the rotator cuff muscles). The axillary nerve also carries sensory information from the shoulder joint, as well as the skin covering the inferior region of the deltoid muscle. The inability to abduct the shoulder and wasting of the deltoid is a characteristic feature of axillary nerve damage.  Brachial Plexus 7 A 43-year-old patient presents to the Emergency Department after sustaining a fall onto his left shoulder. 0/1 Clinically, his left arm appears adducted and internally rotated at the shoulder and pronated and extended at the elbow. Which of the following nerve roots have MOST LIKELY been injured? > A: C5, 6 X B: C6, 7 X C: C7, C8 X D: C8, T1 X E: T1,T2 Rationale: The patient has Erbs palsy which is the injury to C5,C6 nerve root. This type of injury results from a fall onto the shoulder which results in waiter's tip presentation. It can also commonly occur in neonates during birth as a result of difficult delivery. Nerve fibres 8 Which of the following nerve fibres carry nociceptive signals associated with pain that is fast and sharp? 0/1 X A: A˞ fibers X B: A˟ fibers > C: Aˡ fibers X D: B fibers X E: C fibers Rationale: The correct answer is Aˡ A delta (Aˡ fibres carry pain that is fast and sharp. A˞ carry sensations such as touch, pressure vibration. A˟ carries muscle spindle sensory and nociceptive only after sensation. C fibres carry deep,dull, slow type of pain. (Dr. Mark Bellingham's lecture on Pain Processing) 9 0/1 Femoral triangle muscle innervation Which nerve innervates the muscle indicated by the white arrow? > A: Femoral X B: Inferior gluteal X C: Obturator X D: Pudendal X E: Sciatic Rationale: A muscle of the thigh has to be identified in an image of a prosected specimen and then knowledge recalled of that muscle's innervation. Spinal Cord Anatomy 10 Anatomically, the spinal cord terminates at the conus medullaris, after which the lumbar and sacral nerve roots 1/1 descend as the cauda equina. The terminal end of the spinal cord is typically at which level of the vertebral column? X A: T9-T10 X B: T10-T11 > C: L1-L2 X D: L5-S1 X E: S1-S2 Rationale: The spinal cord ends at approx. L3 in infants, and approx. L1-L2 in adult males and females. Refer : Claire Aland's lecture on spinal cord anatomy (Source: Last's Clinical Anatomy, ASIA and Dr. Laherty's lecture) ©2022 ExamSoft Worldwide nc All Rights Reserved