Use of skeletal muscles and transfer of energy From the whole animal to the cellular level

1. Use of skeletal musclesand transfer of energyFrom the whole animal to the cellular level

4. TRANSFER OF ENERGY Energy input Energy output Food energy Metabolic pool in body Internal work Thermal energy (heat) External work Energy storage

6. Calorie: The amount of heat required to raise the temperature of one gram of water from 14.5°C to 15.5°C. 1 calorie = 4.184 joules.

7. A good example of a structure and function relationship is skeletal muscle

15. Where does the ATP come from?

16. Food O 2 Energy harnessed as ATP, the common energy currency for the body Explosive release of energy as heat Partly used to maintain body temperature in endotherms Excess heat eliminated to the environment Muscle contraction

17. The body must regulate the level of ATP since you only want it around when you need it as it will break down and make heat. Regulation of ATP production comes about by controlling production through graded reactions inside cells.

18. The breaking of these chemical bonds will produce heat. The energy stored in the chemical bonds is transferred to heat. Glucose is broken down to make ATP

20. Most cells in your body.

21. Most ATP is produced here in the chemical reactions. This ATP can be used to allow muscle cells to function. Mitochondria are the power house of the cell.

22. Energy within the cells used to drive the tissue- to organ- to system. Energy transfer from food (fuel) to ATP in cells that can then be used to make proteins or used to contract muscles or to keep cells working properly by transporting items for the cell (Na+ sodium & K+ potassium). *

23. Food O 2 Energy harnessed as ATP, the common energy currency for the body Explosive release of energy as heat Partly used to maintain body temperature in endotherms Excess heat eliminated to the environment * Muscle contraction

24. Getting rid of the heat from muscle contraction and breaking chemical bonds to make the ATP is a problem in exercise.

25. Many chemical reaction in our body give off heat. Heat Building a compound: A + B C Heat Breaking down a compound: A B + C

26. Direction of arrows denotes direction of heat transfer Snowball Heating pad 1 2 Radiation Conduction Convection Evaporation Liquid converted to gaseous vapor Convection current 3 4

28. Transfer heat from the hot body to cool water

29. For work from muscles: Energy comes from food or body reserves (fat, protein, glycogen). Food or body reserves provides ATP through a series of chemical reactions inside cells. (Energy transfer from chemical bonds to ATP + heat) ATP used for muscles to function. Sliding units of muscle. (Energy transfer from muscles to external work + heat)

30. Muscle fatigue: This is a study of human performance. Task dependant (type of muscle) Before we can study this one has to know how nerves and muscles work for performing a task

31. Muscle fatigue: This is a study of human performance. Task dependant (type of muscle) Before we can study this one has to know how nerves and muscles work for performing a task nerve muscle

32. Terminal button Muscle fibers Axon terminals

33. Presynaptic axon terminal Voltage-gated Ca2+ channel Synaptic knob Ca2+ Neurotransmitter molecule Synaptic vesicle Synaptic cleft Subsynaptic membrane Chemically-gated ion channel for Na+, K+, or Cl2 Receptor for neurotransmitter Postsynaptic neuron Muscle

34. muscle

35. Neurotransmitter Ion movement results in electrical change across cell membrane Na+ Receptor on cell K+ Muscle cell 3 Na+ ATP Pump ions back across membrane (needs ATP) 2 K+

36. Axon of motor neuron Action potential propagation in motor neuron Myelin sheath Axon terminal Terminal button Vesicle of acetylcholine Acetylcholine receptor site Voltage-gated calcium channel Acetylcholinesterase Action potential propagation in muscle fiber Plasma membrane of muscle fiber Ca2+ Na+ Voltage-gated Na+ channel K+ Na+ Motor end plate Chemically gated cation channel Contractile elements within muscle fiber

38. Electrical change results in a process within the cell to cause the muscle to contract. (calcium ion movement)

40. Ca2+ is pumped back Takes ATP

41. Need fine control: Pick up a piece of paper or a rock. • To increase muscle contraction: • Increase muscle cell activity • (increase nerve activity • by # of electrical events) • Increase the # of muscle units • (increase # of nerves used)

42. Muscle fatigue: 1. The nerve nerve 2. At the nerve to muscle muscle 3. At the muscle level

43. Muscle fatigue: 1. The nerve ATP needed here to keep ions (Na+ & K+) normal nerve 2. At the nerve to muscle ATP needed here to keep vesicles cycling muscle 3. At the muscle level ATP needed here to keep muscle working Note: ATP is made inside the cells that require it.

46. Grip strength 1st -1 second series of contractions - measure the time it takes to fatigue 50% - graph each others data - discussion of results 1. measures of forearm circumference and relate to time (muscle mass, bone thickness- distorts results) 2. did they just eat, tired, sleep, etc.. (could have a box to check off on chart)

48. Pinch strength • Same idea as the grip strength • Can graph on same graph (left and right sides)