Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10

Functionality of Cardiac and Skeletal Muscles

Extracts from this document...

Introduction

Functionality of Cardiac and Skeletal Muscles Sean Tavakoli April 14, 2010 Section: A020 Abstract: Lab exercises 8 and 9 were performed to learn about the physiological properties of skeletal and cardiac muscles. In lab exercise 8, the gastrocnemius muscle was isolated from a bullfrog and several experiments were performed with a kymograph to test the effect of stimulus intensity on a muscle, the timing of muscular contraction, and testing titanic contraction. In lab exercise 9, a bullfrog heart was used to understand the properties of cardiac muscle. Cardiac muscle is very unique, because it can only be found in the heart organ. Experiments in lab exercise 9 included controlling the heart rate with four different agents: adrenalin, cold ringer's solution, warm ringer's solution, and acetylcholine. Additionally, the initiation and transmission of cardiac contraction was tested by stopping the SA node and finally looking at the reaction properties of cardiac muscle with the assistance of a kymograph (Stefaniak pg 84). Introduction: Skeletal and Cardiac muscles can be very similar. They possess the ability to contract due to the actin and myosin sliding filaments, which is a trait in every type of muscle tissue. They are also both striated and when stimulated, can cause action potentials. ...read more.

Middle

A baseline heart rate should be recorded on to the kymograph paper that can be used as a comparison to the heart rates after adrenaline or acetylcholine has been added. The kymograph must be adjusted so that one full rotation will equal one minute. This is to measure the amount of heart beats per minute. Record the baseline heart rate and then add three drops of adrenalin to the sinus venosus area of the heart. After the data has been recorded wash off the adrenalin with room temperature ringer's solution. Then record another baseline tracing and afterward apply 20 drops of acetylcholine directly to the heart (Stefaniak pg 93). Hypothesis 4: The materials used to test this hypothesis are ring stand clamps, insect hook, a kymograph, kymograph paper, a ring stand, electrode and stimulator, a functional bullfrog heart, a heart lever, thread, and clay. These materials should have the same setup in hypothesis three, but no acetylcholine or adrenaline should be used. Instead hook an electrode that is connected to a stimulator to an isolated heart which is no longer beating. The settings for the stimulator are: the mode is set to off, the events/sec should not be used, and the duration set to .2 ms. ...read more.

Conclusion

During the lab, the heart rate increased instead of having an expected decrease. The results for hypothesis four show that as the stimuli intensity increased, the force of the cardiac contractions stayed the same. The kymograph paper showed that the amplitude, when the heart was stimulated with various amounts of volts, all measured out to 20 mm. The heart would not contract any harder or any lighter after it passed the subthreshold value. This can be explained by the fact that cardiac muscles have relatively long refractory periods that are much longer than that of skeletal muscles. In order for stronger contractions to occur, the intervals of time for the stimuli shocks have to be slightly greater than that of the refractory period. However, a situation like that to occur to cardiac muscle on a normal daily basis is highly unlikely (Johnson). Acknowledgements: I would like to thank my teaching assistant, Dean Able, for helping explain to me each of the lab procedures of how to dissect and isolate the frog calf muscle as well as explain about action potentials to me. My lab partners Scott Hoover, Alex Laffoon, and Christian Erickson, were also a great help to me and without them experiment exercises 8 and 9 would be of greater difficulty to complete. Together, all of us were able to actively engage in the labs and understand very important muscle and contraction concepts. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our University Degree Applied Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related University Degree Applied Biology essays

  1. Comparing and and contrasting the endocrine system with the nervous system in their control ...

    Some of them will be responsible for processing of sensory information and other handle motor functions (Bradley & Calvert 2011). The nervous system deals with coordination of movement, higher thinking processes, memory, emotions, sensory information and control essential functions such as breathing (Bradley & Calvert 2011).

  2. Lab report: food dehydration. This experiment focuses on the follow four questions: ...

    The low moisture level contributes to the low level of water activity. Based on Graph 1 and 2, it can be seen that moisture content on the dry basis of all carrot and potato samples has significantly declined after dehydration.

  1. SDS-PAGE and Western Blotting Lab report (extensive methods section)

    The butanol was then removed from the top of the pre-prepared resolving/separating gel and the gel sandwich was washed with water to remove the excess butanol. The stacking gel was then poured carefully on top of the resolving gel and the comb inserted.

  2. The functional part of the kidney are called the Nephrons, in each of the ...

    which it doesn't require, the basic is to create a strong salt concentration in the next part of the tubule; this will draw water out of the tube by osmosis, to be taken away from the blood this conserve water levels in the body.

  1. This experiment was carried out to separate and characterize the protein mixture which contained ...

    Before the absorbance of serum albumin was taken, the spectrophotometer was blank with a blank solution which contained every substance similar to the sample solution except for the particles needed to be determined.

  2. Effect of exercise on heart rate and arterial blood pressure in young healthy volunteers.

    The AV valve on the right is called the tricuspid valve as it has 3 flaps involved in its mechanism, and the AV valve on the left is called the bicuspid valve as it has 2 flaps [1]. The opening of these valves only occurs when the pressure in the atrium is greater than the ventricle pressure.

  1. Characterize of organic macromolecules, which are carbohydrates, protein, and lipid, that present food.

    As for the distilled water, it serves as a negative control of this experiment, so, it showed a negative result. While, for the food sample, only the potato juice and instant noodle showed positive result which indicates the presence of starch, the rest all showed a negative result.

  2. Isolation & Characterisation of Proteins. The purpose of conducting this experiment is to ...

    Determination of serum albumin i) DEAE column Table 5: Absorbance, A595 of Standard Solution for Serum Albumin in DEAE Column. Standard BSA solution, µg Absorbance, A595 0 0.000 10 0.231 20 0.405 30 0.571 Figure 5: Standard curve of absorbance against mass of BSA contained in the solution (µg)

  • Over 180,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work

Marked by a teacher

This essay has been marked by one of our great teachers. You can read the full teachers notes when you download the essay.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review on the essay page.

Peer reviewed

This essay has been reviewed by one of our specialist student essay reviewing squad. Read the full review under the essay preview on this page.