A previously healthy 20-year-old man comes to the physician because of a 1-week history of progressive weakness in his arms and legs and tingling in his toes and fingertips. He also has difficulty drinking with a straw. Mental status examination shows no abnormalities. Physical examination shows prominent facial weakness. He unable to puff out his cheeks. Ocular motions are normal. He is barely able to lift his arms above his head and is unable to rise from a chair without pushing with his arms on the armrests. Vibratory perception in his feet is decreased. Muscle stretch reflexes are absent. Plantar responses are flexor bilaterally. Which of the following portions of the motor system is most likely damaged in this patient? A) Lower motoneurons B) Neuromuscular junctions C) Peripheral nerves D) Skeletal muscles E) Upper motoneurons

Human Anatomy & Physiology (11th Edition)
11th Edition
ISBN:9780134580999
Author:Elaine N. Marieb, Katja N. Hoehn
Publisher:Elaine N. Marieb, Katja N. Hoehn
Chapter1: The Human Body: An Orientation
Section: Chapter Questions
Problem 1RQ: The correct sequence of levels forming the structural hierarchy is A. (a) organ, organ system,...
icon
Related questions
Question
100%
46. A previously healthy 20-year-old man comes to the physician because of a 1-week history of progressive weakness in his arms and legs and tingling in his toes and
fingertips. He also has difficulty drinking with a straw. Mental status examination shows no abnormalities. Physical examination shows prominent facial weakness. He is
unable to puff out his cheeks. Ocular motions are normal. He is barely able to lift his arms above his head and is unable to rise from a chair without pushing with his
arms on the armrests. Vibratory perception in his feet is decreased. Muscle stretch reflexes are absent. Plantar responses are flexor bilaterally. Which of the following
portions of the motor system is most likely damaged in this patient?
A) Lower motoneurons
B) Neuromuscular junctions
C) Peripheral nerves
D) Skeletal muscles
E) Upper motoneurons
Transcribed Image Text:46. A previously healthy 20-year-old man comes to the physician because of a 1-week history of progressive weakness in his arms and legs and tingling in his toes and fingertips. He also has difficulty drinking with a straw. Mental status examination shows no abnormalities. Physical examination shows prominent facial weakness. He is unable to puff out his cheeks. Ocular motions are normal. He is barely able to lift his arms above his head and is unable to rise from a chair without pushing with his arms on the armrests. Vibratory perception in his feet is decreased. Muscle stretch reflexes are absent. Plantar responses are flexor bilaterally. Which of the following portions of the motor system is most likely damaged in this patient? A) Lower motoneurons B) Neuromuscular junctions C) Peripheral nerves D) Skeletal muscles E) Upper motoneurons
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps

Blurred answer
Recommended textbooks for you
Human Anatomy & Physiology (11th Edition)
Human Anatomy & Physiology (11th Edition)
Anatomy and Physiology
ISBN:
9780134580999
Author:
Elaine N. Marieb, Katja N. Hoehn
Publisher:
PEARSON
Anatomy & Physiology
Anatomy & Physiology
Anatomy and Physiology
ISBN:
9781259398629
Author:
McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa Stouter
Publisher:
Mcgraw Hill Education,
Human Anatomy
Human Anatomy
Anatomy and Physiology
ISBN:
9780135168059
Author:
Marieb, Elaine Nicpon, Brady, Patricia, Mallatt, Jon
Publisher:
Pearson Education, Inc.,
Anatomy & Physiology: An Integrative Approach
Anatomy & Physiology: An Integrative Approach
Anatomy and Physiology
ISBN:
9780078024283
Author:
Michael McKinley Dr., Valerie O'Loughlin, Theresa Bidle
Publisher:
McGraw-Hill Education
Human Anatomy & Physiology (Marieb, Human Anatomy…
Human Anatomy & Physiology (Marieb, Human Anatomy…
Anatomy and Physiology
ISBN:
9780321927040
Author:
Elaine N. Marieb, Katja Hoehn
Publisher:
PEARSON