Definitions:

 

Physiology:

 

1. A band: the region on a sarcomere from the beginning of myosin, past the midline, and to the other end of the next myosin filament.

2. Actin: a protein that interacts with myosin in order to produce muscle contraction.

3. Action potential- a change in electrical potential that results in an impulse travelling along the membrane of a nerve or muscle cell.

4. Aerobic: requiring oxygen

5. Affinity: fondness or attraction for something

6. Anaerobic: without oxygen

7. Creatine phosphokinase: an enzyme that generates ATP and creatine from ADP and phosphocreatine.

8. Cross bridge cycling: the process of a myosin head group binding to actin to produce skeletal muscle contraction.

9. Depolarization: positively increase a membrane potential in a nerve or muscle cell

10. Exocytosis: process in which a vacuole membrane fuses with the cell membrane and releases its contents.

11. Fick’s Law of diffusion: a law relating flux to the diffusion coefficient D and concentration.

12. Flux: the rate of flow

13. Force: a vector measured in Newtons representing an applied pressure

14. Glycolysis: the process of breaking down glucose, yielding energy in the form of ATP and pyruvic acid.

15. H zone: the region around the M-line where myosin filaments do not overlap.

16. I band: the portion of a sarcomere containing only actin filaments

17. Involuntary muscle: muscle that cannot be electively or consciously controlled.

18. M line: the sarcomere midline

19. Myofibril: the individual unit within a muscle fiber. Is composed of bundles of myofilaments

20. Myofilament: an individual muscle unit within a myofibril.

21. Myosin: a protein that interacts with actin in order to produce muscle contraction.

22. Oxidative Phosphorylation: the process by which mitochondria oxidize nutrients, yielding ATP.

23. Oxygen saturation curve: a graph of % O2 bound to hemoglobin as a function of the partial pressure of oxygen.

24. Power: energy divided by time

25. Sarcomere: the repeating unit within a myofilament.

26. SERCA protein: sarco/endoplasmic reticulum calcium ATP-ase. An enzyme that utilizes ATP to shuttle calcium from the cytosol to the lumen of the cell.

27. Smooth muscle: muscle containing no striations.

28. Striated muscle: muscle containing repeated sarcomeres

29. Tropomyosin: blocks the myosin-binding sites on actin

30. Troponin: a complex of three proteins attached to the end of the tropomyosin molecule. When calcium binds to troponin, it causes tropomyosin to move, unblocking the myosin binding sites.

31. VDCC: voltage dependent calcium channels

32. Velocity: distance divided by time

33. Voluntary muscle: muscle that can be electively and consciously controlled, such as skeletal muscle.

34. Z disk: a line within the I band that represents the end-to-end contact between two neighboring actin filaments.

 

Pathophysiology:

 

1. Rhabdomyolysis: The release of the intracellular contents of striated myocytes into the circulatory system due to cell death.

2. ATP: Adenosine triphosphate is the energy source for cells.

3. Pathophysiology: A condition that causes a disruption to normal homeostatic physiology.

4. Creatine Kinase: Enzyme that is utilized to increase phosphorylation of ATP and is found in high amounts in the urine during rhabdomyolysis.

5. Cross bridge cycle: The cycle by which actin and myosin interaction occurs to cause muscle contraction or relaxation.

6. Hydrolysis:  The use of water to destroy bonds between molecules.

7. Sarcoplasmic reticulum: Endoplasmic reticulum that stores and releases calcium.

8. Mitochondria: Power house of the cell.

9. Sodium Calcium Exchanger: Cellular ion channel that transfers calcium out and sodium into the cell.

10. Proteolytic Enzymes: Enzymes designed to breakdown proteins.

11. Necrotic: Unprogrammed cell death.

12. Myoglobin: Heme protein that contains one heme group capable of binding one oxygen molecule.

13. Heme: Group within myoglobin and hemoglobin that contains the iron needed to bond oxygen.

 

Clinical Repercussions:

 

1. Glomerular Filtration Rate (GFR): The rate at which the glomeruli filter blood. It can be estimated (eGFR) with the Chronic Kidney Disease Epidemiology Collaboration equation (CDK-EPI). For females, this states: eGFR=144x(0.993)^Age  x  (Serum Creatinine/0.7)^(-0.329). For males, it states: eGFR=141x(0.993)^Age  x  (Serum Creatinine/0.9)^(-0.411)

2. Tamm-Horsfall Protein: Renal glycoprotein present in normal urine; the main component of casts [1]

3. Hyperkalemia: elevated potassium levels

4. Disseminated Intravascular Coagulation: Condition that causes blood clotting throughout the body

5. Compartment syndrome: Condition resulting from increased pressure in body cavity

6. CPK elevation: elevated creatine phosphokinase

7. Sickle cell: Disorder with abnormally shaped blood cells

8. Hemoprotein: A protein with a heme group.

9. Nitric oxide (NO): For one pathway involving myoglobin and NO metabolism, see the supplemental information at the bottom of the page

10. Nitrate (NO3-): An inorganic anion that is a product of NO metabolism. For one pathway involving myoglobin, see the supplemental information at the bottom of the page

11. Adenosine Triphosphate (ATP): The energy source for the cells.

12. Endothelin Receptors: The two types of endothelin receptors that we are concerned about are ETa and ETb. See the supplemental information section to see how they play a part in vascular volume.

13. Vasodilation: Dilation of the blood vessels (results in a larger diameter).

14. Vasoconstriction: Constriction of the blood vessels (results in a smaller diameter).

15. Ischemia: Lack of appropriate blood flow. It can result in cell death.

16. Hypocalcemia: Low calcium levels.

17. Casts: Small particles that are produced in the kidney and expelled with the urine.

18. Creatinine: See the supplemental information section to see the balance between phosphocreatine, creatine, and creatinine.

 

Supplemental Information

 

Nitric Oxide and Nitrate