All about the Cardiac Muscle Cell (2023)

All about the Cardiac Muscle Cell (2)

A little about where it is in the body and specifics:

Cell- Cardiac Muscle Cell (Cardiomyocytes)

Tissue- Cardiac muscle tissue

Organ- Heart

Organ System- Circulatory System

Organism- Me (mammals {animals with hearts})

Function of the Cell

The main point of the cardiomyocytes is to contract and help the person breath as that contraction helps deliver the oxygen to the entire body. It also plays a vital role in supplying blood to your entire body, which is very important. Cardiomyocytes within the heart are required to contract in unison in order to provide effective pump action that can ensure enough blood perfusion (which is when the blood is delivered to the tissue), to the various organs and tissues. The cardiomyocytes include receptors, pumps, and channels (used to transport calcium in this scenario). This is a specialized feature of the sarcolemma and is essential to the contractile process of the myocyte. As with most lipid bilayers, the fundamental function of the sarcolemma is to provide a barrier for diffusion and to site where calcium enters and leaves to go into the ion channels. The sarcolemma, the plasma membrane of the muscle cell, also contains membrane proteins. The cardiac muscle cells are called the cardiomyocytes and contain many mitochondria and are not under control by anything. The nucleus is inside the myocyte (smallest unit of muscular tissue) which is located right in the middle. The cardiomyocytes are surrounded with a membrane called the sarcolemma. The cells responsible for generating contractile (ability to contract) force in the heart.

Organelles inside the Cardiac Muscle cell:

All about the Cardiac Muscle Cell (3)
  1. nucleus
  2. Mitochondria
  3. Golgi apparatus
  4. t-tubule
  5. Sarcoplasmic reticulum
  6. Sarcolemma
  7. Sarcomere
  8. Z Disk
  9. Intercalated Disc
  10. Ribosomes
  11. Plasma membrane

What does Each part of the cell do? How do they support the function?

All about the Cardiac Muscle Cell (4)

Nucleus holds all the main genetic material, and gives instructions to every other organelle (parts of the cell) in the cardiomyocytes. This means that the nucleus gives the commands for the rhythmic contractions. This means it is giving directions to all the other organelles like the mitochondria to form the energy to help push out the oxygen and calcium to the heart and then the heart will get the calcium and distribute it to the rest of the body. With out this, the heart would not work. This means without a nucleus you won’t be living your happy life.

Mitochondria are the organelles in the cell that produce energy in the form of ATP (conversion into energy). When cells complete the process of cellular respiration (meaning u are able to breath) they produce oxygen, glucose (C6H12O6), and this form of energy. The mitochondria is the the (literal powerhouse of the place) because they produce the energy in the form of ATP and when the cardiomyocytes (cardiac muscle cells) contracts it collects all of the energy and then when the heart is ready then it pushes all the oxygen and glucose created internally and blows it out to the rest of the body to keep you body full with oxygen. Without the cardiomyocytes and without the mitochondria you’re dead…you should be able to see the pattern by now; each organelle is crucial to your body.

The Golgi Apparatus is like the “Loading dock” of the place as it delivers ion channels to specific sections on the plasma membrane. They are a section where the proteins are passed through. These ion channels help control how much calcium is inside of it. If there’s not enough calcium in the heart’s flow and the ions decrease then the heart will result in heart failure causing the person to be dead.

T-tubules are regions and are responsible for triggering and regulating the strength of each contraction, as the calcium enters through there and this causes the triggering larger calcium releases from the corresponding sarcoplasmic reticulum. The T tubules are rich in ion channels so this means that the calcium inside the ion channels will be regulated with the sarcoplasmic reticulum which will be holding the calcium. If the calcium intake (how much going in) is not regulated then the person could get hypercalcemia (excessive amount of calcium in your body) and this could make the heart beat irregularly and this could be bad for the person which could cause heart attacks. If the calcium flow is not regulated enough then the body will lose a lot of calcium or won’t get enough and that will cause your muscles many more problems.

The sarcoplasmic reticulum, that stores most of the calcium required for heart contraction. This is like the storage of calcium , this is usually located in the very middle of the cell with the Ryanodine receptor (which release the calcium from intracellular calcium channels which is both in the cardiac and skeletal cell) helping it bind with other machinery so it can be released and then help inside the contractions. The calcium release from that area inside the cell helps initiate the contraction, so the only way the contractions would even happen is only if the sarcoplasmic reticulum starts it. The sarcoplasmic reticulum is a type of endoplasmic reticulum and is mainly for the calcium ion and how it is handled inside the CM, and calcium ions are really needed for contraction and relaxation of the heart.

The sarcomere is the main unit or things that help within the cardiomyocytes driving heart muscle contractions. It is made of myosin (A fibrous protein) and is made of many subunits and the light chain subunits. This is the main reason the cardiomyocytes are able to contract is because of the sarcomere as it allows for the contractions and is in involuntary control. The sarcomeres also make up most of the cardiomyocytes. The function is to help contract and provide the oxygen and the sarcomere is the only reason it can do what it does.

The Z Disc are the lateral boundaries (horizontal boundaries) of the main contractile unit of the myocyte, the sarcomere. It borders the sarcomere together and connects them together and is a very good connection to the sarcomere. The Discs main point is stabilizing the F actin filament, and allowing transfer between the individual sarcolemma and acting like a signal center; it will be relaying information to the other sarcomeres. This is super crucial to the cardiomyocytes because the sarcomere needs to communicate to be able to contract. And the contractions are necessary as they keep you alive.

The intercalated discs are highly organized cell adhesion (stick to other things) structures and help it connect the cardiomyocytes to one another. They help create the 3 major complexes: the desmosomes, fascia adherens, and gap junctions (these are all parts of the intercalated discs) . The cardiomyocytes require the desmosomes (Adhesion structure in cardiomyocytes) and the fascia adherens junctions (Junctions of both the sarcolemma and the disc) as it is used for coupling and reinforcing the cardiomyocytes. The gap junctions (they help with the synchronous connection) are essential for the electrical transmissions and deficiencies in various ICD counts (ICD is a set of codes that are used by health care staff to communicate diseases) and can lead to many diseases or problems. This is the most important part of the cardiomyocytes as it helps hold everything together like glue, and is needed for the heart to be able to contract.

How do the cells communicate with each or other cells

All about the Cardiac Muscle Cell (5)

The sliding filament model is used to show the mechanism of the contractions of the cardiac muscles in the heart. The model is composed of actin and myosin filaments which overlap each other and result in very short muscle fibre length. The filaments conduct the cellular movements. The filaments also help conduct the movement on the surface, as the cardiac muscle helps form repetitive events that generate tension in the muscle. This is caused by the calcium as it goes and binds with them creating that electrical charge in the person’s heart which helps pump all the blood to their heart. The sliding filament contraction occurs in the sarcomere region, as the myosin filaments slide over the actin filaments. The actin filaments have myosin sites where the binding occurs and the troponin molecules start to bind with the calcium ion on the filaments, this causes a bridge to form between the 2 filaments. This whole process is fueled by ATP, acting as the cell’s energy source.

The pacemaker cells are specialized cells in the right atrium of the heart which is the upper chamber of the heart. The right atrium is where the heart receives blood low in oxygen and then empties it into the right ventricle which refills the oxygen. The pacemaker cells of the heart are called the sinus nodes. The sinus node responds to signals from the nervous system and then it tells the heart to speed up or slow down. The impulse from the cells runs in a random manner and in the tissue then into the heart and there are multiple intracellular events that take place involving calcium.

All about the Cardiac Muscle Cell (6)

The cells send each other cells messages through the release of neurotransmitter acetylcholine. In the myocardium the Cardiomyocytes communicate with each other through gap junctions, desmosomes, and adherent junctions. They also communicate through some physical contacts as when the electric current is being passed through each singular CM then they make some form of physical contact and they expand and contract.

Top Articles
Latest Posts
Article information

Author: Fredrick Kertzmann

Last Updated: 06/30/2023

Views: 6194

Rating: 4.6 / 5 (66 voted)

Reviews: 89% of readers found this page helpful

Author information

Name: Fredrick Kertzmann

Birthday: 2000-04-29

Address: Apt. 203 613 Huels Gateway, Ralphtown, LA 40204

Phone: +2135150832870

Job: Regional Design Producer

Hobby: Nordic skating, Lacemaking, Mountain biking, Rowing, Gardening, Water sports, role-playing games

Introduction: My name is Fredrick Kertzmann, I am a gleaming, encouraging, inexpensive, thankful, tender, quaint, precious person who loves writing and wants to share my knowledge and understanding with you.