Tag: muscles and their structure

• Myoglobin is an iron- and oxygen-binding protein found in the muscle tissue of vertebrates in general and in almost all mammals. 
• It is distantly related to haemoglobin which is the iron- and oxygen-binding protein in blood, specifically in the red blood cells. Hence, Muscles contain a red coloured oxygen-storing pigment called myoglobin.

• Muscle contains a red coloured oxygen-containing pigment called myoglobin. It is similar to hemoglobin pigment that stores oxygen in the blood cells. Myoglobin binds oxygen with its heme group.

1. sarcoplasmic reticulum is a specialized type of smooth ER that regulates the calcium ion concentration in the cytoplasm of striated muscle cells. 
   
3. sarcoplasmic reticulum  is a membrane-bound structure found within muscle is also known as endoplasmic reticulum of muscle. so option A is correct answer .

• The ‘A’ and ‘I’ bands are arranged alternately throughout the length of the myofibrils.
  
• In the centre of each ‘I’ band, there is an elastic fibre called ‘Z’ line which bisects it. The thin filaments are firmly attached to the ‘Z’ line. 
• The portion of the myofibril between two successive ‘Z’ lines is considered as the functional unit of contraction and is called sarcomere.
• Hence Sarcomere is the unit of contraction.
  

• Muscle is a  bundle of fibrous tissue in a body that has the ability to contract, producing movement in or maintaining the position of parts of the body.
  
• The total number of muscles in the human body comes in the range of 640-850.
  
• So,the correct answer is '640-850'

Movement is performed by muscular tissues. Every bone moves with the help of 2 muscles required to move it. 

•  Syncytial or syncytium is a multinucleated cell that can result from multiple cell fusions of uninuclear cells (i.e., cells with a single nucleus), which can result from multiple nuclear divisions without accompanying cytokinesis. 
• Syncytial is also referring to cells interconnected by the specialized membrane with gap junctions, as seen in the heart muscle cells and certain smooth muscle cells, which are synchronized electrically in an action potential. Hence, Condition of having a number of nuclei in a muscle fibre is syncytial.

• Cardiac muscle is specialized tissue that is found only in the heart.
•  It has characteristics similar to both smooth and skeletal muscle tissue, as well as specialized properties, that allow it to function with fast but sustained contractions, rapid conduction and coordinated movement. Hence,  the property of cardiac muscle is involuntary muscles, resistant to fatigue and striated muscle.