Use of skeletal musclesand transfer of energy

From the whole animal to the cellular level

Food energy Metabolic pool

in body

Energy storage

Internal work

External work

Thermal energy(heat)

Energy outputEnergy input

TRANSFER OF ENERGY

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.

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

Where does the ATP come from?

Explosive releaseof energy as heat

Food O 2

Energy harnessed as ATP,the common energy currencyfor the body

ATP

ATPATP

Partly used to maintainbody temperature inendotherms

Excess heateliminated to theenvironment

Muscle contraction

The body must regulate the level of ATP since you only want it around when you need it asit will break down and make heat.

Regulation of ATP production comes aboutby controlling production through graded reactionsinside cells.

The breaking of thesechemical bonds will produce heat.

The energy stored inthe chemical bonds istransferred to heat.

Glucose is broken downto make ATP

Most cells in your body.

Most ATP is produced here in the chemical reactions.

This ATP can be used to allow muscle cells to function.

Mitochondria are the power houseof the cell.

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 itemsfor the cell (Na+ sodium & K+ potassium).

*

Explosive releaseof energy as heat

Food O 2

Energy harnessed as ATP,the common energy currencyfor the body

ATP

ATPATP

Partly used to maintainbody temperature inendotherms

Excess heateliminated to theenvironment

Muscle contraction *

Getting rid of the heat from muscle contraction and breaking chemical bonds to make the ATP

is a problem in exercise.

Many chemical reaction in our body give off heat.

A + B C

Heat

A B + C

Heat

Building a compound:

Breaking down a compound:

Snowball

Direction of arrows denotes direction of heat transfer

Liquidconvertedto gaseousvaporConvection

current

Heating pad

1 2

3 4

RadiationConductionConvectionEvaporation

Transfer heat from the hot body to cool water

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)

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 andmuscles work for performing a task

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 andmuscles work for performing a task

nerve

muscle

Muscle fibers

Axon terminals

Terminal button

Chemically-gated ion channel forNa+, K+, or Cl2

Presynaptic axonterminal

Synaptic knob

Synaptic vesicle

Postsynaptic neuronReceptor for neurotransmitter

Synaptic cleft

Ca2+

Voltage-gatedCa2+ channel

Neurotransmitter molecule

Subsynaptic membrane

Muscle

muscle

Neurotransmitter

Na+

K+

Ion movement results in electrical change across cell membrane

Receptor on cell

Muscle cell

2 K+

3 Na+

ATP

Pump ions back acrossmembrane (needs ATP)

Action potentialpropagationin muscle fiber

Axon of motor neuronMyelin sheath

Terminal buttonAxon terminal

Vesicle of acetylcholine

Acetylcholine receptor site

Acetylcholinesterase

Plasma membraneof muscle fiber

Voltage-gated Na+ channel

Chemically gated cation channel

Contractile elements within muscle fiber

Motor end plate

K+

Na+

Ca2+

Na+

Voltage-gatedcalcium channel

Action potentialpropagationin motor neuron

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

Ca2+ is pumped backTakes ATP

To increase muscle contraction:1. Increase muscle cell activity

(increase nerve activityby # of electrical events)

2. Increase the # of muscle units(increase # of nerves used)

Need fine control:Pick up a piece of paper or a rock.

Muscle fatigue:

nerve

muscle

1. The nerve

2. At the nerve to muscle

3. At the muscle level

Muscle fatigue:

nerve

muscle

1. The nerve

2. At the nerve to muscle

3. At the muscle level

ATP needed here to keep ions (Na+ & K+) normal

ATP needed here to keep vesicles cycling

ATP needed here to keep muscle working

Note: ATP is made inside the cells that require it.

• 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)

Name Time to 50% Forearm (cm) Tired, food, etc Other factors

• Pinch strength– Same idea as the grip strength– Can graph on same graph (left and right

sides)

Name Right arm 50%

Left Arm 50%

RightFinger 50%

LeftFinger 50%

Tired, food, etc

Other factors

Heart rate changes:

Decrease HR- decrease breathing rate just sitting still (not to slow that you pass out)- cold rag on back of the neck (not on face - some people

have strong diving responses and can pass out. KIDS !!!) Increase HR

- increase breathing rate just sitting still (not to fast that you pass out)- measure before and after running in place (5 min)

Graph data with variable used. Compare with class and have discussion.

- Reasons for the changes.- Reasons for differences in students for same test.- List what other types of experiments could be done.

Why does HR go up or down?

• Oxygen to tissues for making ATP for the muscles to work.

• How does oxygen get to the tissues?

• Heart is a pump for blood. The blood carries the oxygen. So HR goes up to bring the blood with its oxygen to the muscle.

Heartpumpsthe blood

Acknowledgements

Robin Cooper(UK- Biology)

Terry Williams (UK- Biology, Secondary science Ed.)

Richard Cooper (6th- Morton Middle)

Ann Cooper (10th- Lafayette High, past Morton student)

Jan. 2007

Folder: Human Physiology with Vernier Inside folder find----

17a Grip Strength Fatigue

Note: do not hold on to hand grip place when conducting finger fatigue experiment.

Hand Grip

Finger Grip

Find program: 27 Heart Rate & Fitness

Note: Watch the direction of arrows on hand device and monitor.Need to be in the same direction and keep handsbetween the monitor.

1st page should look like this

NAME OF PROGRAM: 27 Heart Rate & Fitness

1sec hand grip contractionsDo it for 30 sec to match 50% fatigue

To copy pictures: Go to “select all” and then “copy” and “paste”

Can be put directly into ppt or any graphic program