Physiology of Action Potentials and Muscle Atrophy

Course Information

• Fall 2024 course offerings include Physiology for Dental Students (DENT 625) and Fundamentals of Physiology (PHYSIOL 725).
• Course Director: Tom Adair, PhD, [email protected]
• Course Coordinator: Jennifer Duckworth, G251, [email protected]
• Contact hours: ~17 hours testing, ~80 hours lecture.
• Clinical correlation hours: 6 (online).
• Credit hours: DENT 625 – 7 Credit hours, PHYSIOL 725 – 7 Credit hours.
• Required Text: Hall JE and Hall ME. Guyton and Hall Textbook of Medical Physiology. 14th ed. Philadelphia, PA: Elsevier, 2021.

What is Physiology?

• Physiology studies the normal function of living organisms and their parts, including physical and chemical processes involved in maintaining life.
• Human physiology focuses on how the human body functions.

Physiology Links Basic Sciences and Medicine

• Physiology relates to various fields like:
  • Genes
  • Gene Expression
  • Cell Function
  • Biochemistry
  • Proteomics
  • Bioinformatics
  • Clinical Medicine
  • Integrative Physiology

Course Information (continued)

• Class meeting times: Monday/Wednesday/Friday, 10:00-11:50 AM, Upper Amphitheater, R354.
• Additional Resources:
  • Pocket Companion to Guyton and Hall Textbook
  • Guyton and Hall Physiology Review

Assessment Method

• Grades based on daily quizzes, block exams (7 total, ~312 points), and a final exam (100 points).
• Quizzes: ~0.5 points per hour of lecture
• Block exams: approximately four questions per hour of lecture

Course Information (continued)

• Online testing software (ExamSoft) used for block exams and the final exam.
• Daily quizzes are administered using Nearpod.
• Nearpod quiz access instructions provided at the start of the course.
• Students may submit quiz answers on paper but no more than 3 times per quiz.
• Grading scale: A=90%-100%, B=80%-90%, C=70%-80%, F=<70%

Dental School Attendance Policy

• Adherence to the dental school attendance policy is essential.
• Course coordinators may require in-person attendance for lectures or topics.
• Arriving late or leaving early considered an absence.
• Students required to contact course coordinator promptly, prior to next class, to make up missed class via UMMC email.
• Missed class assignments incur a 3-point penalty on the final course grade for each case.
• Failure to complete a missed-class assignment results in a failing grade (50).
• No make-up tests or daily quizzes offered regardless of whether an absence is excused.

Graduate Student Attendance Policy

• Dr. Casey Boothe ([email protected]) manages excused absences for Graduate students.
• Graduate students must inform course coordinator, Jennifer Duckworth, of any absence or query, copying the communication to Dr. Boothe.

Testing Policies

• All students required to study and agree with the Examination Honor Code before testing.
• ExamSoft practice testing of honor code provided.
• Specific procedures and seating arrangements applied on exam days.
• Students given personalized scratch paper which includes seat number.
• Students required to present student ID to proctors for bar code reading.
• Designated seating locations provided.
• All electronic devices stored at the front/back of the room (not aisles or seating rows).
• Proctors randomly check assigned seating during exams.
• Test question challenges accepted within one week of each test by contacting the course coordinator.
• Students may make appointments to review missed questions in the same time frame.

Course and Instructor Evaluations

• Opportunity to evaluate instructors (including pre and post block exams).
• Course evaluation after final exam.
• A cash award and plaque given to the student with the highest grade in dental and graduate classes.
• Absence from any test (excused or unexcused) disqualifies from receiving an award.

Physiology Course Schedule (partial)

• Course schedule included with specifics regarding days, time, session topics, and faculty.

Course Coordinator

• Jennifer Duckworth, [email protected], 601-984-1810

Instructors (partial)

• Several instructors presented: Tom Adair, PhD, and others
• Instructor responsibilities outlined for each block covering different physiology topics.

Unit 2 (Chapters 4-6)

• Topics specific to the chapters in unit 2

Unit 2 (Chapter 4)

• Transport of Substances through cell membranes discussed
• Includes discussion on the fluid-mosaic model, lipid bilayer, cell membrane, permeability coefficients (cm/sec), Molecular Gradients across cell membrane, Simple diffusion, Active Transport, Facilitated diffusion, diffusion of a molecule in water, facilitated diffusion of water through cell membranes, ion channels, Selectivity of potassium channel, Selectivity of sodium channel, How to study ion channels (Patch Clamp Method), Operation of Voltage-gated sodium channel, Simple vs. Facilitated Diffusion, what limits maximum rate of facilitated diffusion(Vmax), what is net diffusion, Electrical potential(EMF).

Unit 2 (Chapter 5)

• Membrane potentials and action potentials, active transport of Na+ and K+, simple diffusion of Na+ and K+, membrane potential(Vm), simplest case scenario for K+, simplest case scenario for Na+, The Sodium Nernst Potential, Resting Membrane Potential, Why is the cell membrane so permeable to K+, The Goldman-Hodgkin-Katz Equation, The effect of changing permeability of Na+ and K+ on membrane potential, functions of action potentials, resting and action potentials.

Unit 2 (Chapter 6)

• Contraction of skeletal muscle. includes: physiological anatomy of skeletal muscle, cellular organization, physiological anatomy of skeletal muscle detailed organization - molecular organization - Dystrophin, physiological anatomy of skeletal muscle—molecular organization—sarcomere, The Sarcomere, Titin, Function of Titin, what are the striations?, relaxed and contracted states - Which band shortens?, which band shortens - I or A?, Overall mechanisms of muscle contractions, the actin filament, Calcium triggers contraction by exposing active sights on actin filaments, The myosin filament, 'Walk-Along Theory of Muscle Contraction', Myosin-Actin Cycling in the presence of Ca2+, and ATP, Muscle Mechanics, Tension as a function of sarcomere length, Relationship of Contraction Velocity to Load, Isometric and isotonic contractions, muscle lever system, a single muscle twitch.

Unit 3 (Chapters 7-10)

• Topics related to unit 3, including specialized sections for chapters 7-10

Study Questions (partial)

• Study questions related to the physiology course content presented.

This quiz explores key concepts in physiology related to action potentials and muscle function, focusing on mechanisms of analgesia, the effects of K+ permeability, and implications of muscle atrophy. It also examines the role of the neuromuscular junction and factors influencing muscle hypertrophy and hyperplasia.