Hafiz Bilal

Movement is Life.
Hafiz Bilal

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  • August 01 2014
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  • August 01 2014
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Hafiz Bilal is following Physiology

  • August 01 2014
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Hafiz Bilal is following Biochemistry

  • July 31 2014
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Hafiz Bilal is following Sugandh Chadha and SHASHI KANT

  • July 31 2014
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  • July 16 2014

Chemoreceptor Trigger Zone : #HighYield

Emesis originates by several physiologic mechanisms that respond to stimulation of the central and peripheral nervous systems, the effect (vomiting) is the result of a series of motor activities in the chest and abdomen. The final motor co-ordination that results in vomiting occurs because of the stimulation of the emetic centre, an area of the brainstem, which is vested in two separate units of the medulla: the chemoreceptor trigger zone (CTZ) and the vomiting centre (VC).

Enterochromaffin cells in the gut are one of the body's largest reservoirs of the neurotransmitter serotonin. When enterochromaffin cells are damaged or destroyed they release serotonin (5-hydroxytryptamine or 5-HT), which then binds with serotonin type 3 (5-HT3) receptors located on vagal afferent nerves, causing stimulatory impulses to the emetic centre. As a secondary emetic pathway, serotonin released in the gastrointestinal tract may also travel via the bloodstream to the brain and activate central 5-HT3 receptors in the chemoreceptor trigger zone. Recent studies point to the importance of the exposure of the CTZ to a variety of neurotransmitters (i.e., neuroreceptors in the gastrointestinal tract which have afferents to the vomiting centre) that are known as mediators of nausea and vomiting, including serotonin, dopamine, histamine, prostaglandins, and gamma-aminobutyric acid. The vomiting centre receives many excitatory inputs from nerve endings of vagal sensory fibres in the gastrointestinal tract, from the labyrinths via the vestibular nuclei, from higher centres in the cortex, from the CTZ, and from intracranial pressure receptors.

Chemotherapeutic agents are toxins by their nature and mechanism of action; they can induce local cellular toxicity in the stomach cells, which stimulates the release of serotonin. Serotonin causes emesis by either stimulating afferent fibers directly or by passing into the circulation and stimulating the emetic centers. Chemotherapeutic agents vary significantly in their emetogenic potential (their ability to cause emesis) from low to high.

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  • July 16 2014

Megacolon {Volvulus} is an abnormal dilation of the colon (a part of the large intestine). The dilation is often accompanied by a paralysis of the peristaltic movements of the bowel. In more extreme cases, the feces consolidate into hard masses inside the colon, called fecalomas (literally, fecal tumor), which can require surgery to be removed.

A megacolon can be either acute or chronic. It can also be classified according to etiology.

Signs and symptoms

- Constipation of very long duration

- Abdominal bloating, abdominal tenderness and tympany, abdominal pain

- Palpation of hard fecal masses and, in toxic megacolon

- Fever, low blood potassium, tachycardia and shock

- Stercoral ulcers are sometimes observed in chronic megacolon


- Congenital or aganglionic megacolon

- Medication

- Acquired megacolon, of which there are several possible etiologies:

- Idiopathic megacolon

- Toxic megacolon

- Megacolon secondary to infection

- Clostridium difficile

- Other neurologic, systemic and metabolic diseases


- Radiographical and ultrasound imaging

- Colonic marker transit studies

- Colonoscopy.

- Anorectal manometry .

- Rectal biopsy is recommended to make a final diagnosis of Hirschsprung disease.



- In stable cases, use of laxatives and bulking agents, as well as modifications in diet and stool habits are effective.

- Corticosteroids and other anti-inflammatory medication is used in toxic megacolon.

- Antibiotics are used for bacterial infections such as oral vancomycin for Clostridium difficile

- Disimpaction of feces and decompression using anorectal and nasogastric tubes.

- When megacolon worsens and the conservative measures fail to restore transit, surgery may be necessary.

Alternative Treatment: Colon Hydrotherapy.

There are several surgical approaches to treat megacolon, such as a colectomy (removal of the entire colon) with ileorectal anastomosis (ligation of the remaining ileus and rectum segments), or a total proctocolectomy (removal of colon, sigmoid and rectum) followed by ileostomy or followed by ileoanal anastomosis.

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  • July 16 2014

Circumventricular organs #HighYield "SPASMO"

Circumventricular organs (CVOs) are structures in the brain that are characterized by their Extensive vasculature and lack of a Normal blood brain barrier (BBB). CVOs allow for the linkage between the central nervous system and peripheral blood flow; additionally they are an integral part of neuroendocrine function. The lack of a blood brain barrier allows the CVOs to act as an alternative route for peptides and hormones in the neural tissue to the peripheral blood stream, while still protecting it from toxic substances.

CVOs can be classified in two ways, the sensory and the secretory organs.

The sensory organs

include the area postrema (AP), the subfornical organ (SFO) and the organum vasculosum of lamina terminalis (OVLT). They have the ability to sense plasma molecules and then pass that information into other regions of the brain. Through this, they provide direct information to the autonomic nervous system from systemic circulation.

The secretory organs

include the subcommissural organ (SCO), the posterior pituitary (also known as the neurohypophysis), the pineal gland, the median eminence and the intermediate lobe of the pituitary.These organs are responsible for secreting hormones and glycoproteins into the peripheral vascular system using feedback from both the brain environment and external stimuli.

Circumventricular Organs “SPASMO”

S : Sub fronical Organ

P : Posterior Pituitary / Pineal Gland

A : Area Postrema

S : Sub commisural Organ

M : Median Eminence

O : Ovlt

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  • July 16 2014
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  • July 05 2014

Do u Know ?!!

what is the dieffer. bet. Cholelithiasis & choledocholithiasis ?!

Cholelithiasis refers to the presence of gallstones in the

Hafiz Bilal

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  • July 05 2014

Regulatory and catalytic subunits of cAMP-dependent protein kinase A (important concept)

Gs class of Ga subunits activate cAMP production.

Hafiz Bilal

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  • July 05 2014

Nystagmus with quick-phase correction - caloric testing - remember: COWS

Cold water

nystagmus toward lesion with quick phase to Opposite si

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  • July 05 2014

10 Tips To Be A Successful Doctor:

1- Read more : Every day there are new medical studies ,

new diseases , new drugs ... etc , if you want t

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Independent Medical College , Faisalabad Pakistan
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