Friday, April 29, 2011

Morula - mulberry

Following fertilisation – the fusion of the ovum and sperm – the fertilised ovum begins to divide into progressively smaller cells (blastomeres); first into two cells, then four cells, eight cells and so on. At a particular stage of division - 16 to 32 cell stage in humans - the ball of dividing cells resembles a mulberry and is called the morula from the Latin term morus meaning mulberry.
The blastomeres of the morula adopt a more flattened shape; the inner side (basolateral region) and outer side (apical region) of these cells begin to differ in appearance. Flattening of blastomeres occurs during the process of compaction and the development of differences between the basolateral and apical regions of blastomeres takes place during the process of polarisation.
Nikas G, Ao A, Winston RM, Handyside AH: Compaction and Surface Polarity in the Human Embryo In Vitro. Biol Reprod, 1996 55(1):32-7. Go to reference

Morula - Mulberry

Friday, April 22, 2011

Eggplant deformity

Although the penis does not contain bone (or cartilage), it can be fractured when subjected to trauma, for example, during sexual activity. The fracture/tear occurs in the tunica albuginea, a thin envelope surrounding the corpora carvenosa. During penile erection, blood engorges the corpora cavernosa which are cylindrical pairs of erectile tissue. A tear of the tunica albuginea may be accompanied by a cracking/popping/snapping sound, pain, immediate loss of the erection, penile swelling and reddening – the fractured penis resembles an eggplant in appearance – eggplant deformity. Though penile fracture is rare, it is a medical emergency requiring surgery.
Tiwary SK, Singh MK, Khanna R, Khanna AK: Penile fracture presenting as eggplant deformity. Kathmandu Univ Med J (KUMJ), 2006 4(2):249-50. Go to reference
Ozcan S, Akpinar E. Diagnosis of penile fracture in primary care: a case report. Cases J, 2009 30;2:8065. Go to reference

Penile fracture, human penis

Tuesday, April 19, 2011

Honeycomb lung

Lung scarring (fibrosis) with irregular air spaces interspersed between the areas of scarring gives the lung a look akin to a honeycomb – honeycomb lung.
Lung (pulmonary) fibrosis is the final consequence of a different group of diseases caused for example by infections, inhaled mineral dusts, drugs, etc. Sometimes, the cause of lung fibrosis is not known and this situation is known as idiopathic (cryptogenic) lung fibrosis.
In pulmonary fibrosis, the lung becomes less distensible due to scar tissue and its space for air becomes reduced.
The affected individual generally develops progressive shortness of breath.
Heppleston AG: The Pathology of Honeycomb Lung. Thorax, 1956 11(2):77–93. Go to reference 

Honeycomb lung

Wednesday, April 13, 2011

Strawberry cervix

Trichomoniasis is a sexually transmitted infection caused by the uni-cellular organism Trichomonas vaginalis. Infection with this organism may result in bleeding of the cervix (neck of the uterus), which occurs in a spotted pattern, leading to the cervix looking like a strawberry – strawberry cervix.
Mechanical cervical irritation from a tampon, an intrauterine contraceptive device, a pessary as well as chemical cervical irritation from a spemicide, douching can at times also result in a strawberry cervix.
Swygard H, Seña AC, Hobbs MM, Cohen MS: Trichomoniasis: clinical manifestations, diagnosis and management. Sex Transm Infect, 2004 80(2):91–95. Go to reference

Cervix, Trichomonas vaginalis life cycle 

Saturday, April 9, 2011

Cherry-red discoloration

Carbon monoxide is a toxic, colorless, odourless, tasteless and non-irritant gas that is produced during incomplete combustion, for example, in burning a fuel (e.g. wood) within an enclosed space that has a limited amount of oxygen. Carbon monoxide binds to hemoglobin - the oxygen-transporting protein found in red blood cells - with an affinity of about 230 times that of oxygen forming carboxyhemoglobin, thereby reducing oxygen supply to tissues.

The bright cherry red carboxyhemoglobin discolours the skin and mucous membranes – cherry-red discoloration. However, this discoloration is rare in carbon monoxide poisoning – in one study, 1 of 100 patients with carbon monoxide poisoning had the discoloration; there is also disagreement regarding which color exactly constitutes cherry-red.
Sources of carbon monoxide include fires, furnaces, vehicle exhausts, lawn mowers, etc.; carbon monoxide poisoning is one of the commonest forms of poisoning worldwide.
Simini B: Cherry-red discolouration in carbon monoxide poisoning. Lancet, 1998 352(9134):1154 Go to reference

Carbon monoxide

Wednesday, April 6, 2011

Red currant jelly stool

In intussusception, a condition more common in children, a proximal segment of intestine (the intussusceptum) prolapses abnormally into the lumen of the adjacent distal intestine (the intussuscipiens) in a manner akin to a segment of a telescope prolapsing into another segment. This prolapse of the intestine may result in bleeding and discharge of mucus into the bowel. The stool passed may consist of blood admixed with mucus, which resembles red currant jelly in appearance – red currant jelly stool.
Caution is advised because red currant jelly stool may also be a manifestation of dysentery, an intestinal disorder that at times involves passing bloody mucoid diarrhea.
Toso C et al: Intussusception as a cause of bowel obstruction in adults. Swiss Med Wkly, 2005 135(5-6):87–90. Go to reference


Sunday, April 3, 2011

Fourchette – little fork

The labia minora – small lips – are paired soft erectile folds of hairless skin that are part of the vulva (the external female genitals/sex or reproductive organs). The labia minora also known as nymphae are located between the labia majora – large lips – which unlike the labia minora are hair bearing skin folds.
Posteriorly, the right lip of the labia minora unites with the left lip of the labia minora to form a fork-shaped structure the fourchette (frenulum of the labia minora/frenulum labiorum pudendi). Fourchette is French for little fork.
Between the labia minora is the vestibule which contains the vaginal orifice, urethral opening and the ducts of various glands involved in sexual function; it is not unusual for the labia minora to protrude through the labia majora.
Rogers AW, 1992, Textbook of Anatomy, Churchill Livingstone, Edinburgh, page 668. Go to reference
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Fourchette – little fork, vulva