Skip to main content

cardiac muscles properties - morphology

Cardiac muscle is striated same as a typical skeletal muscle. The muscle fibrils are surrounded by numerous and elongated mitochondria since the heart needs energy supply continously. The muscle fibres branch and interdigitate. They lie parallel to one another but at the end of each muscle fibres there are extensive folds of the cell membrane that are called as intercalated disks/discs.

The intercalated discs act as gap junctions that is very permeable and allow almost free diffusion of ions. They always occur at the Z lines i.e. the dark middle section of the light (I) band of the muscle. They provide a strong union between fibers, maintaining cell-to-cell cohesion, so that the pull of one contractile cell can be transmitted along its axis to the next.

The heart muscle thus acts as a syncytium. i.e. a multinucleated mass. Therefore when one of the cells is excited, the action potential spreads from cell to cell through the latticework interconnections fast and the syncytium as a whole contracts.

The heart is divided into the atrial and ventricular syncytium separated by the fibrous annulus at the A-V juntion. The action potential has to travel through the specialised conducting system that pierces the fibrous tissue. This division of the heart into 2 functional syncytiums allow the atria to contract a short time before the ventricles, which is important for the effectiveness of the heart as a pump.

The T system in cardiac muscle is located at the Z lines rather than at the A–I junction, where it is located in mammalian skeletal muscle. The T system of transverse tubules, which is continuous with the sarcolemma of the muscle fiber, forms a grid perforated by the individual muscle fibrils. It provides a path for the rapid transmission of the action potential from the cell membrane to all the fibrils in the muscle. The sarcoplasmic reticulum is an important store of Ca2+ and also participates in muscle metabolism.

Comments

  1. post on the different time intervals when cardiac markers start to rise and till when they remain detectable in the setting up of an acute Myocardial infarction

    ReplyDelete

  2. Competitor ought to considered that with the C17-AA modification to sidestep the livers first pass it will bring about weight on the liver with the oral planning (It could occur with the injectable too.) http://www.roidsupport.biz

    ReplyDelete
  3. To work brilliant, at that point you should know the art of lifting weights and not simply to lift weights haphazardly. You should likewise know how to eat effectively to encourage and support muscle development.
    All Vibration plates

    ReplyDelete
  4. Secure your cooler with a youngster wellbeing bodypiercingsavedmylife lock if medicines are put away in there.

    ReplyDelete
  5. Such practices incorporate naturopathy, sterile practices, herbalism, support of self-mind sources like books, ebooks and diaries, healthy eating less junk food and vitamin and supplement supplements.buy wartrol

    ReplyDelete
  6. Tailored treatment protocol following the most recent detox methods Neworld Detox.

    ReplyDelete
  7. In this article, I will show you some health and fitness tips that you can use to lose weight in no time at all. I have personally been using these health and fitness tips myself to lose weight, so you should stand to benefit from these tips.http://www.gohealthing.com/2018/08/06/everything-you-wanted-to-know-about-gout/

    ReplyDelete
  8. Nonetheless, you may have some genuine medical issues, and are discovering it a test to find an organization who will offer you an arrangement.https://mevolv.com

    ReplyDelete
  9. These drug stores principally care for patients that require some type of IV or other non oral medicine, and need to get the treatment at home (thus the name home-implantation).Асhеtеr médiсаmеnts

    ReplyDelete
  10. Pharmaceuticals burn through a large number of dollars for research and printed material for another helpful case of a set up tranquilize all to fulfill Food And Drugs Administration prerequisites. Turmeric plus

    ReplyDelete
  11. This comment has been removed by the author.

    ReplyDelete
  12. When you shop at a Pharmacy Online, you can take as much time as necessary choosing the things that you truly need and need.online pills

    ReplyDelete
  13. What this will involve is distinctive for every individual. The most ideal approach to boost your chance and endeavors is to work with a fitness coach. essential oil

    ReplyDelete
  14. In the event that you've been perusing BIOM's Seasonal Health Tips, you've perceived that the impact Spring has on your body has been very solid this year, in light of whichever of the basic Spring health issues you might understanding. dianabol steroids for sale

    ReplyDelete
  15. Some of the online pharmacy stores are providing prescribed drugs at discounted prices as part of increasing business. buy arimidex

    ReplyDelete
  16. Extraordinary detox programs alongside awesome help can spell the distinction between progress and additionally disappointment. detox center in

    ReplyDelete
  17. Not exclusively does weight preparing speed the body's digestion, it consumes fat and fabricates muscle.here

    ReplyDelete
  18. The secret to let the sexiness out is fitness workouts. Fitness workouts are designed to create total fitness in the body. pre workout for women

    ReplyDelete
  19. Buyers seem to be lapping up these drugs irrespective of the general feeling that there may be safety and other issues in purchasing them online.

    dianabol 20 mg

    ReplyDelete
  20. In these innovation days, the online pharmacy business is developing quick since from the previous three years and soon the business will reach up to two billion dollar industry. www.acheter-levitra.net/levitra-instructions.html

    ReplyDelete
  21. Additionally center around remaining dynamic for the duration of the day-not simply amid your activity time. This is especially essential in the event that you sit a great deal for work.
    My about.me profile

    ReplyDelete
  22. The main infringement of the laws of nature on Earth made the requirement for a characteristic arrangement of mending, one that would give us access to those optional laws that would lessen the harm caused by infringement of the essential laws. order australia

    ReplyDelete
  23. The most effective method to spare many dollars every year on health care at your specialist's office: The most effective method to spare many dollars every year on health care at your specialist's office: clenbuterol for sale

    ReplyDelete
  24. Pharmaceuticals need medicine from an affirmed specialist for procurement. The decision of a health supplements is up to the person. Detox

    ReplyDelete
  25. You never really understand a person until you consider things from his point of view... Until you climb inside of his skin and walk around in it. Obat Alami Ngilu2 di Pergelangan Tangan

    ReplyDelete
  26. Avoiding medical errors in the interpretation process is partly the role of the patient, a patient is supposed to present all the previous medical reports, including all the drugs that were used, this can help the doctor to know what next step to opted if a particular medicine didn't work.Joint health ingredient

    ReplyDelete
  27. So you've heard a lot of talk about my health and living as well as the seven principles of health. There are a lot of different thoughts about these principles. In general, we are talking about the health principles that really matter.Health

    ReplyDelete

Post a Comment

Popular posts from this blog

Hypokalemia - Potassium replacement calculation

 DEFINITION  Hypokalemia is defined as a serum potassium level of less than 3.5 mmol/L. Normal level= 3.5-5.5 mmol/L. It is encountered in >20% of patients. Patients are usually asymptomatic but severe arrhythmias and rhabdomyolysis can occur. Non-specific complaints include easy fatiguability and skeletal muscle weakness. The preferred method of replacement is via the oral route but at times this is not possible. The article below will give you an idea about how to calculate the amount of KCl to be given I.V. 1) Potassium deficit in mmol is calculated as given below: K deficit  (mmol) = (K normal lower limit  - K measured ) x kg body weight x 0.4 2) Daily potassium requirement is around 1 mmol/Kg body weight. 3) 13.4 mmol of potassium found in 1 g KCl . ( molecular weight KCl = 39.1 + 35.5 = 74.6) Suppose we get an asymptomatic patient of  70 Kg with a serum potassium level of 3.0 mmol/L and he is on nil by mouth but having an adequate diuresis, w

The plantar reflex - Babinski's sign

The plantar response is an important test to identify an upper motor neuron lesion.  PROCEDURE  To elicit it, the muscles of the lower limbs must be relaxed. The outer edge of the sole of the foot is stimulated by firmly scratching a blunt object like a key or a stick along it from the heel towards the little toe. This is what  Joseph Babinski did in the year 1896. He described the 'great toe sign' that year and then in 1903 the 'toe abduction or fan sign'. Nowadays, a final medial movement across the sole of the metatarsus is also done. i.e. we start at the heel to the little toe and finally arcing to the big toe. The final arcing movement is absent in the original Babinski plantar response test. Babinski sign refers to a combination of 'the great toe sign' and the 'fan sign'.  SIGNIFICANCE  The normal response is plantar flexion of the toes (down going) and they are drawn together. More precisely, there is flexion of the big toe and addu

Differences between hyperemia and congestion

Hyperemia and congestion both indicate a local increased volume of blood in a particular tissue. Hyperemia is an active process that result from augmented blood flow due to arteriolar dilation (e.g. at sites of inflammation or in skeletal muscle during exercise). The affected tissue is redder than normal because of engorgement with oxygenated blood. Congestion, on the other hand, is a passive process resulting from impaired venous return out of a tissue. It may occur due to systemic causes like cardiac failure or a local cause like isolated venous obstruction. The tissue is cyanosed because the worsening congestion leads to accumulation of deoxygenated hemoglobin in the affected tissues. 

Apgar scoring - table, mnemonic

 INTRODUCTION  The  Apgar score  was devised in 1952 by Dr Virginia Apgar (anesthesiologist) as a simple and repeatable method to quickly and summarily assess the health of newborn children immediately after birth.  This helps to identify those requiring resuscitation and can also be used to predict survival in the neonatal period.   MNEMONIC  A mnemonic for learning purposes includes: A - Appearance (skin colour) P - Pulse (heart rate) G - Grimace (reflex irritability) A - Activity (muscle tone) R - Respiration  Another mnemonic is also useful:  How -   Heart rate Ready - Respiration Is -        Irritability This -    Tone Child -   Colour Apgar scoring is divided into 1 and 5-min scores.  1-MIN SCORE    Sixty seconds after complete birth, the five parameters specified in the table above must be evaluated and scored. A total score of 10 indicates that the baby is in the best possible condition. A score between 0-3 me

Chickenpox - dew on rose petal appearance

Definition: Chickenpox is a benign viral disease of childhood, characterized by an exanthematous vesicular rash. It is an extremely common and contagious condition. It is caused by the varicella-zoster virus which is a herpes virus and contains a double stranded DNA in its center. Epidemiology: Age group affected- 5 to 9 years. The infection can be there at other ages too but it is less frequent. It is highly contagious and it affects all races and both sexes equally. The attack rate is around 90% among seronegative persons. Pathogenesis: Incubation period- 10 to 21 days but is usually 14 to 17 days. Patients are infectious around 48 hours from onset of vesicular rash, during the period of vesicular formation (around 4-5 days) and until all vesicles are crusted. Transmission occurs by respiratory route. The virus is believed to be localized in the nasopharynx, in the reticulo-endothelial system. It then enters the blood. This stage of viremia is characterized by diffused ski