MUSCLE PHYSIOLOGY

MUSCLE PHYSIOLOGY

- There is about 629 muscle in the human body
- These muscle are denoted as "engines of the body"
- These muscle are mesodermal in nature
- These muscle help us to maintain of our equillibrium towards any state
- Study of muscle called "myology"

@ Muscle Properties and defination :-

* Threshold stimulus :-

         minimum strength of stimulus required to excite a muscle

* Sub-threshold Stimulus :-

            Stimulus below threshold stimulus

* Single Muscle twitch :-

            single response of muscle to single stimuli given, it can be varies according to external temperature difference

* Muscular tetany :-

             state of sustained contraction

* Muscle fatique :-

          Working muscle leads to formation of lactic acids which cause in feels fatiqueness

* Oxygen- debt :-

             amount of excess oxygen consumed during the recovery after an exercise

* Neuro-muscular junction :-

          junction where motor nerve fibre attach to muscle

* Muscle tone :-

              when a muscle in partial contraction state

* Contractibility :-

         muscle have character to contract and relax according to stimulus type

* Conductivity :-

            muscle can also conduct waves of stimulus through their network

* Refractory Period :-

              time between in which muscle can't show response to other stimuli

* Motor nerve :-

         these are those nerve which take stimuli signal to effect site from spinal cord or brain

@ Type of muscle :-

1.) Striated or skeletal muscle :-

- These muscle denoted by "sarco" word
- These muscle constituet 40% of body weight
          - these muscle are also called skeletal muscle beacuse these muscle directly attach to bone by tendons
- These muscle are highly vascular muscle
- these muscle are voluntary in nature because they are work according to our will
- High number of mitochondria present in these muscle for more activity

# Character :-

* These muscle are long, striaght, unbranched shape
* Shape of this muscle are fussiform shape
 * These muscle arranged in bundle called fasciculi
* Mesodermal in origin
* These muscle are present at biceps, triceps like areas of body
* Each muscle fibre covered by sheath called endomysium
* Each bundle muscle covered by sheath called perimysium
* Whole muscle covered with sheath called epimysium
* Externally these muscle are covered by membrane called sarcolemma
* These muscle ER called sarcoplasmic reticulum
* Multinucleate condition found in these in these muscle
* These muscle cytoplasm called sarcoplasm
* These muscle go in rapid and powerful contraction on stimuli
* Readily get fatique after some heavy work load

@ Structure :-

   ~ In Striated muscle there is a dark band present called anisotropic or A-band
~ In Dark band there is light line present in middle called H-line (Hensen's line)
~ In Striated muscle there is a light band present called Isotropic or I-band
~ In light band there is dark line present in middle called Z-line (Zwischenscheibe's line)
~ A part of myofibril between two adjacent Z-line is known as sarcomere

~ Sarcomere :-

         indivisual unit of muscle which are capable for contraction itself on giving stimulus
~ The A-band have a myosin protein which are connected by 6 actin protein surroundingly by cross bridge

2. Smooth Muscle Fibre :-

- These muscle are muscle of visceral organ like alimentary canal, intestine and etc
- Due to their high power of attaining load these play major role in urinary bladder ,which increased more than 3 time at actual
- these muscle are single, found in layer and spindle shaped  (Thick in mid and Thin in ends)
- These muscle are covered by plasma membrane
- These muscle are less vascular in nature
- These muscle are involuntary in nature
- Uninucleate condition found in this muscle
- These muscle show less or slowly reaction on giving stimulus
- Special character of these muscle are that they are have some non -fatique character

3. Cardiac muscle :-

      * As there name suggest there muscle are related to heart
* These musce are generally found on heart region
* these muscle are involuntary in nature
* Non-fatique in nature
* These muscle form continuiously network because these muscle have branched structure
* These muscle are short, cylindrical with flat ends
* Highly vascular in nature
* These muscle have rapid contraction ability
* Uninucleate in nature
* Line divide two cell of these muscle are called Intercalary disc
* these muscle also have light and dark bands
* These muscle are controlled by both CNS or ANS system