Sunday, February 22, 2015

Chicken Wing Dissection Lab



 1.  Put on gloves.  Thoroughly rinse and dry chicken leg or wing.  Place it on a plate or tray.

 2.  Examine the outside skin tissue.  Record at least 4 observations of the chicken skin. 
      The skin was bumpy, with a pinkish/white coloring.  It was pretty thick and very loose.

 3.  Using scissors, knife, and tweezers, work slowly and carefully to cut the skin and peel it away  
      from the muscle below.  Notice the clear connective tissue that holds the skin to the muscles.  
      The probe may be the most effective tool.  As you peel off the skin, you may need to cut away  
      some of the connective tissue.

 4.  Record at least 4 observations of connective tissue.
      The connective tissue was clear, stretchy, very thin and very shiny.  It also adhered to the skin very
      well.

 5.  

 6.  What specific type of connective tissue is this?
      This is loose connective tissue.

 7.  Observe the yellowish clumps of fat tissue found outside the skin.  Record at least 2 
      observations of the fat.
      Fat was clumped together in little tiny pockets and was surrounded by loose connective tissue
      as well.

 8.  What is the biological term for the type of cells that store fat.
      Adipocytes

 9.  Name at least 2 functions of this fat.
      Fat protects and insulates.

10. Observe bundles of muscle tissue surrounding bones.  Separate the bundles of muscle by
      separating them out with your fingers.  Begin by inserting your thumb into the muscle by
      pushing though the connective tissue covering the muscle.  It will give way at the natural 
      separations between the muscle bundles.

11. Viewing through a magnifying too, if you have one, (but still do if you don't) describe 2
      characteristics of the arrangement of the muscle bundles as you see them here.
      All of the muscle fibers are going in the same direction and all the fibers were stacked in a layered
      fashion.

12. Using your textbook or another reference, sketch a representation of the muscles starting 
      with the muscle cell and ending with the whole muscle. Cite your source!
      
      Johnson, Michael D. (2014).  Human Biology Concepts and Current Issues (7th edition).  
                      Glenview, Il:  Pearson Education, Inc.


13. What type of muscle tissue are you viewing?
      Skeletal muscle tissue.

14. Name the function of this type of muscle tissue.
      The functions of skeletal tissue is movement.

15. Name 2 characteristics of the muscle tissue.
      Muscle tissue has long fibers and they are multi-nucleic.

16. Nerves are thin, threadlike, white strands found between the muscle and the nearest bone.
      Remove a single muscle by cutting the tendons and peeling the muscle away from the bone.
      Look for the nerve in your specimen.  The texture is much different from a tendon or bone.
      It is rather slippery.  Did you find one?
      Yes.

17.
Nerve (should be) on the far right side of the bone.

18. The strong, shiny, white cords of tendons hold the muscle to the bones.  Some of these 
      tendons pull away from the bone as you separated the muscle bundles.  Observe with a
      magnifying tool, if you have one, describe, and sketch.
      a.  The attachment of tendon to muscle.
      b.  The attachment of tendon to bone.

19.  
My sad little drawing. : ) Artist, I am not.

Tendon attached to muscle

20. Cut across the tendons at the elbow and peel back toward the carpal joint as if you were 
      peeling back a banana.  Observe the numerous tendons and pull the freed muscle down and
      away from the bone.  Don't cut any ligaments that attach bone to bone.

21. 
Ligament

22. Look closely at the ligaments with a magnifying tool.  Describe 2 differences in appearance 
      between tendons and ligaments.
      Ligaments are much stronger and harder than tendons and the attachment to the bone seems much
      stronger.

23. What type of connective tissue composes the ligaments?
      Ligaments are fibrous connective tissue.

24. Remove all remaining muscle to expose the bones of the chicken leg.

25. 



26. Bend the elbow.  Refer to pages 113-115 in your textbook and answer these questions.
      a.  What type of joint is this.
           This is a hinge joint.
      b.  What type of movement is being demonstrated?
           The bones can only move one way - open and closed.

27. Cut into the elbow joint and separate the ulna and radius from the metacarpals.  Observe
      the shiny white layer covering the ends of the bones.  Name this covering according to its
      primary tissue and specific type.
      The covering is a synovial membrane.

28. Describe the texture of the ends of the bones at the joint.
      The texture was extremely smooth.

29. Name three functions of bone.
      Three functions of bone are for strength, structure and protection.

30. If you could see inside the bone.  What soft material would you find?  Do not break the raw 
      chicken bone.  There is danger from bone fragments flying out.
      You would find bone marrow.

31. Name three specific types of cells present here.
      Stem cells, osteoblasts and osteocytes.

32. Explore and examine other parts.

33. Dispose of materials.  Using warm water and soap thoroughly wash all tools and materials,
      including your hands and the surface you worked upon.




Sunday, February 8, 2015

TISSUES, SKIN, MEMBRANES LAB

PART 1


Epithelial Tissue



Epithelial tissue offers protection and creates linings all over the body.  Their tightly packed cells are ideal for these functions.


Connective Tissue



Connective tissue has fat vacuoles for cushioning and strong matrixes that offer support, storage and strength to organs and other body parts.


Muscle Tissue



Muscle tissue consist of long (for the most part) and thin fibers that are excellent for contracting.


Nervous Tissue



Nervous tissue sends electric impulses to different regions of the body.  Their dendrites and long axons are like lighting rods accepting impulses and sending them on their way quickly.



PART 2


Serous Membrane




Mucous Membrane



Synovial Membrane



Cutaneous Membrane





PART 3

1. A friend tells you she has a blister on the inferior surface of her foot.  She adds that it is posterior, not anterior.  Where is her blister?

Her blister is on the bottom of her foot, towards her heel.

2.


PART 4

Visualizing changes in skin color.



What would happen if in this area the pressure continued for an extended period of time?

Since pressure slows down blood flow, if there was extended pressure the epidermis would eventually die from lack of blood delivery.


Testing tactile locations and adaptation.




Table 1

Palm          Fingertip          Forearm          Back of Hand

45mm        30mm              85mm              60mm


In the tactile location exercise, which area had the smallest error of localization?

For my subject the area of the smallest localization was the fingertip.  I think this was because the area was much smaller than the rest of the locations, so it was easier to pinpoint.

Coin experiment:

Do a bit of research to learn if the same receptors being stimulated when the four coins, rather than the one coin is used.  What is your conclusion?

The Meisner corpuscles are being stimulated when one quarter is placed on the forearm.  When the four quarters are placed on the forearm, the Pacinian corpuscle may be stimulated.  However in my experiment that didn't seem possible, since the weight of the four coins was not that great and it would likely require a deeper touch to stimulate the Pacinian.


Appendages of the skin.




The action of UV light.

What kind of sunscreen or sunblock do you use and how frequently?

I use UVA/UVB 30 sunblock everyday.  I am pretty light skinned.

What does the production of more melanin tanning mean?

It means that the skin is being exposed to the sun and the keratinocytes in the dermis is creating more melanin to protect it.

Saturday, January 31, 2015

THE MICROSCOPE, CELLS, AND ORGANELLES LAB




Microscope, Cells, and Organelles Lab

Part 1


Table 1.  Microscope magnification.

                                   Lens mag.      Ocular mag.       Total mag.

a. Scanning                 4x                  10x                  =40x

b. Low Power            10x                 10x                  =100x

c. High Power            40x                 10x                  =400x

d. Oil Immersion        100x               10x                  =1000x



Part 2





Cheek Smear

1.  Nucleus
2.  Cytoplasm
3.  Cell membrane




Onion Root

1.  Nucleus
2.  Nucleolus
3.  Cell membrane


1.   How might the thin, flat shape of cheek cells relate to their function?  
      Cheek cells are thin and flat so they can have many layers that protect the inside of the mouth.

2.   What structure separates the contents of the nucleus from the cytoplasm?
      The nuclear membrane separates the nucleus from the cytoplasm.

3.   What is the function of the nucleoli? Why is this important?
      The nucleoli houses the parts to synthesize ribosomes.  This is important because ribosomes create         
      specific proteins for the body.

4.   Other than the nucleoplasm and nucleoli, what are three other materials found in the nucleus?
      Three other materials found in the nucleus are DNA, RNA and small proteins.

5.   When you begin, in what position should the condenser be?
      The condenser should be kept in the highest position.

6.   What objective should be in place when you start?
      The objective should be placed on 4x.

7.   Which focusing knob do you first use when you begin looking at a slide?
      The focusing knob you first use when looking at a slide is the course adjustment.

8.   What do you adjust if you can see two overlapping circles with part of the object in each circle?
      You should adjust the oculars if you see two overlapping circles in the view.

9.   How do you move the slide on the stage?
      To move the slide on the stage use the adjustment knobs that are attached to the clips on the stage.

10. What device can be opened to increase light?
      The diaphragm can be opened to increase light to the slide.

11. What is the name of the highest magnifying objective?
      The highest magnifying objective is called oil immersion.

12.  What materials are used to clean slides?
       The materials used to clean slides are soap and water.

13.  What materials are used to clean objectives?
       The materials used to clean objectives are lens paper and cleaner.

14.  Explain the procedure for stowing the microscope.
       After cleaning the microscope the procedure for stowing is to center the stage, make sure all parts 
       tucked in, wrap the cord around the arm or head, then place on the shelf with its matching number.

15.  Describe two ways you can decrease light intensity?
       Two ways to decrease light intensity is by adjusting the diaphragm and the lamp.

16.  Which objective allows you to see the largest area of the object that you are viewing?
       The objective that allows the largest area for viewing is the 4x objective.


Part 3





Predictions:

I think that the carrot that is placed in the saltwater will expand, because salt will cross it's barrier membrane and move inside the carrot.  I think this will happen because there is not a lot of salt inside the carrot so the salt will move to where a lower concentration exists. 





Table 2. Starting and Ending Carrot Measurements.


                                 Start     End        Start    End
                                                     

Freshwater Carrot     8"L     7 1/2"L   1"W    1 1/8"W

Saltwater Carrot        8"L     7 1/4"L   1"W    7/8"W


Observations:

The string on the saltwater carrot was significantly looser than the string on the freshwater carrot.  The string on the fresh water carrot was also somewhat tighter than it was in the beginning of the experiment. The texture of the saltwater carrot was smoother, while the fresh water carrot had some splitting.

The saltwater carrot seemed to have a decrease in cell size.

The saltwater cell seemed to have lost water, while the freshwater cell seemed to have gained water.

The measurements showed that the saltwater carrot decreased in length by 3/4 of an inch and 1/8 of an inch in width, while the freshwater carrot decreased in length by 1/2 inch, but increased in size by 1/8 inch.  It seems that the freshwater carrot cell increased in size making the whole carrot swell.  The saltwater carrot cell actually decreased, shrinking the width and length of the cell.  The carrots actually did the opposite of what I thought they would do in my original predictions!

What is Osmosis?

Osmosis is the movement of substances from high concentration to low concentration through a selectively permeable membrane.  Small molecules, small substance, and water can pass through the membrane, however, larger substances and molecule cannot.  It largely depends on what the membrane will allow.  This is important for the health of cells, because if the membrane allowed everything through its barrier than the cell could rupture or get substances that prevent it from working properly.