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Moves blood from the heart to the lungs.



in the pulmonary loop, the heart pumps blood from the heart through pulmonary artery that is low in oxygen and high in carbon dioxide concentration, to the lungs. Gas exchange occurs around alveoli of lungs and oxygenated blood returns to the heart via the pulmonary veins.

Pulmonary artery arises from right ventricle, divides in two branches to send blood in lungs of both sides.

arteries are generally thicker walled an able to withstand greater pressure (coming out of ventricles), whereas veins are typically thinner walled and don't experience as much pressure as it returns to atrium.


That doctor must have studied about diseases of the ear, nose, and throat (E,N,T).


According to medical-dictionary.thefreedictionary.com, the definition of otorhinolaryngology is,

"The combined specialties of diseases of the ear, nose, pharynx, and larynx; including diseases of the head and neck, tracheobronchial tree, and esophagus."

Please note that all these organs of our body remain interconnected through openings present in pharynx.

Middle ear opens in pharynx through Eustachian tube.

Nasal passage opens in pharynx by internal nare.

Glottis is the opening of wind pipe in throat, guarded by epiglottis.

Lastly pharynx opens in oesophagus through gullet.

Why is this important?

ENT specialists are also trained as surgeons. They are able to diagnose, treat and manage diseases affecting all these vital areas of our body.



HIV can lodge itself on membrane receptor of T lymphocyte and then injects viral RNA and viral enzymes in host cell.


Human immunodeficiency virus abbreviated as #HIV# is a host-specific retrovirus that targets the major components of human immune system i.e #T#-#lymphocytes# or #T#-#cells#.

Infection cycle of HIV:

  • Attachment:
    Firstly the HIV virus attaches to the #Cd4# receptor site on the T-cells. These fuse with the t-cell membrane and get entry into the cell's cytoplasm where they are uncoated.
  • Reverse transcription and Integration:
    HIV virus being a retrovirus has a special enzyme known as reverse trancriptase on the #RNA# #"genome"#. This enzyme uses the #"viral RNA"# as a template to make a strand of #DNA# and then uses the DNA strand as a template to make a DNA double helix. Original viral RNA gets degraded.
    The viral DNA integrates into the chromosomal DNA of T-cell of the host, now becoming a provirus.
  • Translation:
    The proviral DNA is transcribed into RNA which uses host cell's machinery to translate viral proteins to encase newly generated viral genome.
  • Assembly and Release:
    So, new capsids assemble around #"viral RNA"# and reverse transcriptase molecules. And they bud off from plasma membrane of T-cell as mature HIV viruses, ready to attack more T cells.

Increasing number of Cd4 cells start to die due to HIV infection.


The Appendicular Skeleton in composed of all of the bones of the Arms and Legs and Girdles.


The Skeleton in vertebrates is divided into two parts: axial and appendicular. In human, there are 126 bones in appendicular skeleton.

The Appendicular Skeleton is composed of all of the bones of the arms (=fore limb), legs (=hind limb) and girdles to which limbs are attached. Girdle for attachment of arm is pectoral and that for leg is pelvic.

The Axial Skeleton is composed of the bones of the head, spinal column and thorax (=rib cage).

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Leukocyte is just another name for white blood cells. On the other , lymphocytes are one of the types of white blood cells or leukocytes.


Leukocytes or white blood cells are divided into two groups on the basis of presences of granules in their cytoplasm.

  1. Granulocytes #to# neutrophils, basophils and eosinophils.
  2. Agranulocytes #to# monocytes and lymphocytes.

So, lymphocytes are one of the five types of WBCs and belong to granular leukocytes.
Lymphocytes mainly constitute T cells, B cells, and natural killer (NK) cells. Their most salient role is in immune system.

Thus we can say: All lymphocytes are leukocytes but all leukocytes are not lymphocytes.

are the T cells, B cells, and natural killer (NK) cells.

Hope it helps...


Open-heart surgery is any type of surgery where the chest is cut open and surgery is performed on the muscles, valves, or arteries of the heart.


Yes, doctors temporarily stop the heart to perform surgery on it. They place the patient on a heart-lung bypass machine, to stop the blood from flowing to the heart. This automatically stops pumping action of heart muscles.

How is open-heart surgery performed?

  1. The patient is given general anesthesia. This will make sure the patient is asleep and pain-free.

  2. The surgeon makes an 8- to 10-inch cut in the chest.

  3. The surgeon cuts through all or part of the patient’s breastbone to expose the heart.

  4. Once the heart is visible, the patient may be connected to a heart-lung bypass machine. The machine moves blood away from the heart so that the surgeon can operate.

  5. The surgeon performs the required procedure like attaching a graft vessel to bypass a blocked artery in heart wall, or replacing a heart valve, etc.

  6. The surgeon allows blood to flow back in heart after the procedure; closes the breastbone with wire.

  7. The cut is stitched up.

What are some of the risks to open heart surgery?

There are a lot of risks in a open heart surgery. Making it one of the most deadliest surgerys to perform.

Some common risks are,

  • Heart Attack/ Stroke
  • Chest Pain or low fever
  • Chest wound infection


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