Human Health & Disease Test - 2

Plasmodium completes their life cycle in two hosts, female anopheles and human beings. The motile zygote of plasmodium occurs in gut of female anopheles, which get transferred to human being during mosquito bite.

• Typhoid fever in the human being is caused by Salmonella typhi .
• The pathogen enters the small intestine through food and contaminated water and migrates to other organs through blood

This illustration depicts a photomicrograph of  Salmonella typhi  bacteria:

Alzheimer disease is a neurological disorder in which the death of brain cells causes memory loss and cognitive decline. It is caused in human due to deficiency of acetylcholine.

The gut microbiota can influence the central nervous system through the synthesis of ACh and other neuroactive molecules:

Plasmodium vivax protozoa cause malaria in human beings having high fever and chill effect at the regular interval of time.
Hemozoin is released in the bloodstream by plasmodium that causes a high fever at the interval of 48 hours.

• Entamoeba histolytica causes Amoebic Dysentery or Amoebiasis in the large intestine of humans.
• Its symptoms include constipation, abdominal pain, cramps and stools with excess mucus and blood clots.

• Goitre is the enlargement of the thyroid gland which occurs due to deficiency of iodine in the body. Iodine is needed for the synthesis of thyroid hormone. When the iodine levels are low, the thyroid gland becomes hyperactive and enlarged to compensate for the deficiency of thyroid hormone in the body. The enlarged thyroid gland is visible as a swelling in the throat known as goitre.
• Grave 's disease or  exophthalmic goitre occurs due to over secretion of thyroid hormone as the thyroid gland becomes hyperactive. In exophthalmic goitre, protrusion of eyeballs occurs due to the deposition of excess fat behind the eyes. 
• The thyroid gland may also become hyperactive due to hypersecretion of TSH (Thyroid-stimulating hormone) from the anterior pituitary and this can occur due to pituitary adenoma (benign tumours of the pituitary gland).

Excessive intake of exogenous thyroxine can 't cause goitre.

The first antibiotic was discovered by Alexander Fleming from the fungus Penicilliumnotatum in 1928.

Antibodies in our body are present in the blood in form of glycoproteins. They produce antigens in response to foreign particles to provide immunity against the pathogen.

Memory cells are formed in lymphocytes of WBC. Immunization against the particular disease based on the function of memory cell induced due to mild, heat killed pathogen administrated during immunization.

• Physiological barriers to the entry of microorganisms into the human body  are tears in the eyes, saliva in the mouth and HCl  in the  stomach.
• The enzymes lysozymes are found in tears and saliva and inhibit the synthesis of peptidoglycan present  in the  cell wall of  microorganisms  especially eubacteria.
• Disease-causing microorganism enters through different routes into the body. The physiological barrier prevents their entry. Tears act as a physiological barrier for entry of pathogen.