Diagram of Cardiac Muscles

The diagram of cardiac muscle shows the thick middle layer (myocardium) between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium). The diagram of cardiac muscle class 9 is often asked in the examinations. This muscle is crucial for pumping blood throughout the body and ensures oxygen and nutrients reach all the tissues and organs.

The diagram of cardiac muscle labeled is given below:

Structure of Cardiac Muscle

The labeled diagram of cardiac muscles shows its structure consisting of following points:

• Cardiac muscle fibers are connected by intercalated discs, acting like junctions. They allow for adhesion between cells and the passage of electrical impulses through structures like fascia adherens, desmosomes, and gap junctions.
• Fascia Adherens plays a very important role in the attachment of heart cells together .
• A gap junction forms channels between adjacent cardiac muscle fibers that allow the muscle cells to be electrically coupled, so that they beat in synchrony. The network of electrically connected cardiac muscle cells called a syncytium that enable the rapid transmission of electrical impulses through the network.
• Desmosomes (macula adherens) provide strong attachment by binding to the intracellular intermediate filaments/cytoskeleton during contraction.
• In the cardiac muscle there is also a sarcoplasmic reticulum ( store house of calcium), which is important for muscle contraction and relaxation.
• For the generation of impulses in the heart, pacemaker/ sinus node is present which causes the heart's chamber to contract.
• From SA node , the impulses are transfers to the AV node and then conducted to the bundle of his , Purkinje fiber which spreads the impulses along the ventricles, causing them to contract.

Properties of Cardiac Muscle

• Automaticity: The main property of the cardiac muscle is to produce impulses which gives the rhythmicity in the heart.
• Contractility: The cardiac muscle posses contraction and relaxation which helps in the regular pumping of blood across the heart.
• Excitability: It is the ability of a cell to respond to certain stimulus.
• Conductivity: The cardiac muscle fiber serves the function of transmission of electrical currents from one cell to another cell.

Conclusion - Diagram of Cardiac Muscle

Cardiac muscle tissue is a specialized, that only exist in the heart. It is responsible for pumping and circulating the blood around the body. The diagram of cardiac tissue shows the presence of a single nucleus along with the sarcomere which contains the contractile proteins (actin, myosin, tropomyosin and troponin). These proteins help in the contraction and relaxation. Cardiac muscle tissue contains cells that expand and contracts in response to electrical impulses from the nervous system. These cells work together to produce the rhythmic, wave like contractions.

Also Read:

• Difference Between Cardiac Muscle And Skeletal Muscle
• Definition, Types, Structure, and Functions of Muscles
• Diagram of Heart
• Anatomy and Functions of Heart’s Electrical System
• Cardiac Cycle | Class 11 Biology