Python shell.
Hope this helps!
-Payshence xoxo<span>
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<h2>Region between 2 and 3</h2>
Explanation:
Muscles consists of two protein filaments:a thick filament which is made up of protein myosin whereas a thin filament is made up of protein actin
- During contraction,thin filaments slide past the thick filament resulting in shortening of sarcomere 
- Myosin thick filaments grab on to the actin filaments by forming cross bridges 
- The thick filaments pull the thin filaments past them making the sarcomere shorter 
- The region between points 2 and 3 includes the area of overlap between thin and thick filaments 
 
        
        
        
The human body comprises of more than 600 muscles differentiated in three classifications, and all are under the control of the nervous system. The activities like picking up a dropped pen or leaning over incorporate the combined effort of various muscle groups.  
The alert mind relays this instruction to the central nervous system that conducts it in the form of electrical impulses. These are then mediated via the somatic segment of the peripheral nervous system to the nerves accountable for monitoring the essential muscles.  
When the signals arrive, a chemical known as acetylcholine gets discharged from the nerve terminals, activating the membranes of muscle fibers and making them to contract. The receptors present in the muscles provide the brain with the instruction regarding the movement and position of the body, the brain monitors the contraction of skeletal muscles.  
 
        
             
        
        
        
<span>B. HEMOGLOBIN. In sickle cell anemia, </span>the hemoglobin is mutated or abnormal and it gives the red blood cells a crescent shape. This abnormal hemoglobin is referred to as hemoglobin S.
        
             
        
        
        
When you breathe your diaphragm contracts and moves downwards. This increases the space in your chest cavity, and it allows your lungs to expand into it. This is beneficial because it decreases pressure and drives air into our lungs