this is a congenital abnormality which may not be noticed until the onset of mentruation.when complete(imperforate), the hymen forms a barriers in the vagina.blood accumulate in the vagina,uterus and uterine tubes wityh each menstural cycle,and its may enter the periotoneal cavity and cause peritonitis.the uterine tubes may becomes obstructed by coagulated blood,leading to infertility.
Author:someswara
shocks occurs when the metabolic needs of the cells are not being met because of inadequate blood flow.in effects,there is a reducation in circulating blood volume,in blood pressure and n cardiac tisue hypoxia,an inadequate supply of the nutrients and the accumulation of waste products.A number of different types of shock are described:
· hypovolaemic
· cardiogenic
· septic
· neurogenic
· anaphylactic
Hypovolaemic shocks:
this oocurs when the blood volume is reduced by 15 to 25%.reduced venous return and in turn cardiac output may occur following:
· serve haemorrhage whole blood lost
· extensive superficial burns serum is lost and blood cells at the site of the burns are destroyed
· serve vomiting and diarrhoea water and electrolytes are lost
· perforation of an organ allowing its conent to enters the peritoneal cavity(peritonitis)
Cardiogenic shocks:
this occurs in accute heart diseases when the damaged heart muscle cannot maintain an adequate cardiac output,e.g. in myocardial infractionSeptic shocks(bacteraemic,endotoxic)this is caused by severe infections in which endotoxins are released into the circulation from dead gram-negative bacteria,e.g. enterobactreia,pseudomonas. the mode of action of the toxins is not clearly understood.it may be that they cause an apparent reducation in the blood volume because of vasodilation and pooling of the blood in the large veins.this reduces the venous return to the heart and the cardiac output.
Neurogenic shocks(vasovagal attack,fainting):
the cause include sudden acute pain,severe emotional experince,spinal anaesthesia and spinal cord damage.parasympathetic nerve impluse reduce the heart rate,and in turn,the cardiac output.the venous return may also be reduced by the pooling of blood in dilated veins.these changes effectively reduce the blood supply to the brain,causing fainting.the period of unconsciousness is usually of short duration.
Anaphylactic shock:
in the allergy reaction an antigens interacts with an antibody and a variety of response can occurs .in severe cases,the chemicals released,e.g.histamine,bradykinin,produce widespread vasodilation and constriction of bronchiolar smooth muscle(bronchospam).the vasodilation profoundly reduces the venous return and the cardiac output resulting in the tissue hypoxia.bronchospasm reduces the amount of the air entering the lungs,increasing the tissue hypoxia.
author:someswara.
Respiratory allergies are one of the most common afflication of childhood in fact many allergies are more prevalent in childhood often abating with age. As with adults ,respiration allergies in children are most likely to appear in the form of allergic rhinitis and asthma.
Asthma symptoms in children can be varied and subtle. It is vital that parents learn how to describe them. Look for coughing episodes,especially at night or during exercising (children will also often complain of a sore throat after exercise).
this term suggests inflammatory conditions of the glomerulus, but there are several types of GN and inflammatory changes are not always present. in many cases immune complexes damage the glomerulli.these are formed when antigens combine either within the kidney or elsewhere in the body ,and they circulate in the blood.when immune complexes lodges in the walls of the glomeruli they often cause an inflammatory response that impairs glomerular function.other immune mechanisms are also implicated in GN.
classification of GN is complex and based on a number of features :the cause,immunological characteristics and finding on microscopy.microscopic distinction is based on:
the extent of damage:
diffuse:affecting all glomeruli
focal:affecting some glomeruli
appearence:
proliferative: increased number of the cells in the glomeruli .
membranous:thickening of the glomerular basement membrane.
Inflammation of the meninges may occur following a compound fracture of the skull that is accompained by leakage of CSF and blood from the site,providing a route of entry for microbes.the escape of CSF and blood may be through: 1)skin in compound fractures me the skull 2)middle ear, in fracture of the temporal bone(CSF otorrhoea) 3)nose, in the fracture me sphenoid,ethmoid or frontal bones when the air sinuses are involved (CSF rhinorrhoea).
If you are banking on a vitamin supplement daily to make up for any deficiencies in your diet,you bargained for,
researchers in europe have carried out a study and found that people who rely on vitamin pills, instead of eating a healthy diet of fresh fruits and vegetables,are doing more harm than good.
According to them,three supplements,vitamin A,vitamin E and beta carotene,can increase mortality rates among those taking them.however,vitamin C and selenium pills have no effects as such.
“our finding contradict the findings of observational studies claiming that antioxidants(commonly found in vitamin supplements) improve health,”british media quoted lead researcher goran bjelakovic of copenhagen universisty hospital in denmark as saying.
The researchers combined results of a number of clinical trials to judge the overall effects of vitamin pills.they analysed 47 low-bias trials,involving 180,938 people and found that vitamin supplements as a whole increased their death rate by five percent. When the supplements were taken seperately, beta carotene increased death rates by seven per cent, vitamin A by 16 per cent, and vitamin E by four per cent . Vitamin C gave contradictory results, but when given singly or in combination with other vitamins in good quality trails, increased the death rate by six per cent, the researchers found. They, however, noticed that selenium was the only supplement to emerge with any credit, it can cut death rates by ten per cent when given on its own or as supplements, but’ the result is not statisitically significant.’
Rickets occurs in children and osteomalacia in adults after ossification is complete.they are caused by deficiency of vitamin D which promotes calcification of bone and absorption of calcium in the small intestine
deficiency may be due to:
1)dietary deficiency of vitamin D
2)malabsorption,e.g.coelic disease or following gastrointestinal surgery
3)lack of exposure to sunlight,e.g.pigmented skin,housebound people
4)excessive loss of vitamin D or its precursors,e.g.in choronic renal failure,haemodialysis
5)drugs that result in breakdown of vitamin D,e.g.anticonvulsants,including phenytoin.
In rickets,osteoid is deposited but calcification is incomplete although growth of the epiphyseal cartilage continues,growth is stunied.the bones remain soft and those of the lower limbs become bowed by the weight of the body.
In oesteomalacia there is increased and abnormal turnover of bone.as in rickets,osteoid is not calcified and the bones become soft,bowed and prone to fractures.
Heart block occurs when impluse formation is impaired or conduction is prevented,and the delay between atrial and ventricular contraction is increased.the severity depends on the extent of loss of stimulation of the AV node.
In complete heart block, ventricular contraction is entrirely independent of impluses initiated by the SA node.impluses generated by the AV node result in slow,regular ventricular contractions and a heart rate of about 30 to 40 beats per minute.in this state the heart is enable to respond quickly to a sudden increase in demand by,e.g., muscular exercise. The most common causes are:
1)acute ischaemic heart disease
2)myocardial fibrosis following repeated infarctions or myocarditis
3)drugs used to treat heart disease,e.g.digitalis,propranolol.
When heart block develops gradually there is some degree of adjustment in the body to reduced cardiac output but,if progressive,it eventually leads to death from cardiac failure and cerebral anoxia.
This is opacity of the lens which may be age-related or congenital,bilateral or unilateral.
In age-related catarct there is gradual development of lens opacity that usually develops during older age as the result of exposure to a variety of predisposing factors including:uv light,x-rays,cigarette smoke,diabetes mellitus,ocular trauma, uveitis, systemic drug therapy,e.g. Corticosteriods,chlorpromazine.
Congenital catarct may be due to genetic abnormality,e.g.downs syndrome,or maternal infection in early pregnancy,e.g.rubella.early treatment is required to prevent permanent blindness.
The extent of visual impairment depends on the location and extent of the opacicty.
This is the inability of the eyes to move together so that the same image falls on the corresponding parts of the retina in both eyes.the result is that two images are sent to the brain,one from each eye,instead of one intergrated image.it is caused by extraoculart muscles weakness or defective nerve supply to the muscle, i.e. defective cranial nerves 3,4 or 5.in most cases the images falling on the squiting eye is suppressed by the brain, otherwise there is double vision(diplopia).
