Tissue Blog 9

Hello Learner,

In the previous blog, we have discussed Connective Tissue. I hope you must have understood the chapter well. If you have any doubts, feel free to write in comment box. 

Today, we will be discussing more about Muscular Tissue in details

At the end to today's topic, you will be able to
1. Explain muscular tissue.
2. Describe different types of muscular tissue.
3. Tell the location and function of different type of muscular tissue.
4. Draw diagrams of different type of muscular tissue.

So, let us start the topic......

              Muscular Tissue

(i)          Muscular tissue consists of elongated cells called muscle fibres. This tissue is responsible for movement in out body.

(ii)         Muscles contain special proteins called contractile proteins which help in movement and locomotion.

(iii)        Some muscles fibres may be bounded by a specialized membrane called sarcolemma.

           https://www.youtube.com/watch?v=sfNBe9jCsT4

On the basis of structure, location and function, the muscles are grouped into three categories as described below:

           
           https://www.youtube.com/watch?v=CocaDUxW5G0

   A)  Striated muscles-

(i)          These muscles work according to our will and called as voluntary muscles. These muscles are also called as skeletal muscles as they are mostly attached to bones and help in body movement.

(ii)         Striated muscle cells are long cylindrical, unbranched and multinucleated and are present in general musculature of our body.

(iii)        Under the microscope, these muscles show alternate light and dark bands or striations when stained, hence called as striated muscles. The light (I-band) and dark (A-band) bands gives the characteristic striated appearance.

(iv)       Muscles present in our limbs move when we them to and stop when we so decide.

   B)  Unstriated muscles-

(i)          These fibres do not work according to our will and called as involuntary muscles. They work continuously without getting tired.

(ii)         Unstriated muscle cells are long spindle shaped (pointed ends) and uninucleate.

(iii)        These muscles do not show alternate light and dark bands or striation when stained.

(iv)       These muscles are found in the iris of eye, in ureters and in the bronchi of the lungs, in the alimentary canal and blood vessels.

  

     Difference between Striated and Un-striated Muscles

   C)  Cardiac muscles-

(i)          These muscles are cylindrical, branched and uninucleate.

(ii)         These fibres do not work according to our will and work continuously throughout life without getting tired.

(iii)        Since these muscles are present only in the heart region of the body hence they are called as heart muscles cells.

Recap:  https://www.youtube.com/watch?v=ySQgsGTTjqM
Home Assignment
1. Complete the notes in your biology note book.
2. Draw the fig 6.11 Pg 76.