Secondary Lymphoid Organs

Secondary Lymphoid Organs

Mucosa associated lymphoid tissues (MALT) :

The mucosa lining the alimentary, respiratory, genitourinary and other
lumina and surfaces are constantly exposed to numerous antigens. These
areas are endowed with a rich collection of lymphoid cells, either specialized
aggregates as the Peyer’s patches or Scattered isolated lymphoid follicles
– collectively called the Mucosa associated lymphoid tissues (MALT).

Such lymphoid tissues in the gut are called Gut associated lymphoid tissue
(GALT) and those in the respiratory tract are called Bronchus associated
lymphoid tissue (BALT). MALT contains lymphoid cells as well as
phagocytic cells. Both B and T cells are present. The mucosa is endowed
with secretory IgA. The mucosal regions afford/confer protection from many
enteric and respiratory infections. (Secondary Lymphoid Organs)

Antigens

The terms immunogen and antigen are often used synonymously.
However, these terms imply two closely related entities. The first describes a
molecule that provokes an immune response(immunogenicity) and hence is
called an immunogen. The other describes a molecule which reacts with the
antibody produced, or with the activated cellular constituents of cell
mediated immunity(antigenicity), and is referred to as an antigen. (Secondary Lymphoid Organs)

In contrast to this is the hapten. Haptens are small well defined
chemical groups such as dinitrophenol (DNP) which are not immunogenic on
their own but will react with preformed antibodies. To make a hapten immunogenic, it must be linked to a carrier molecule which is itself immunogenic.
Antigens are recognized not only by antibodies, but also by antigen
specific T cell receptors. In contrast to immunoglobulins, which usually
recognize intact antigens, T cell surface receptors recognize processed
antigens on the surface of antigen presenting cells. (Secondary Lymphoid Organs)

Related Topics in Zoology:

Bio Zoology All Important Topics

  1. Microbiology Introduction and History of Medical Microbiology
  2. Pasteur, Koch, Lister
  3. Structure of Viruses
  4. Viral genetics
  5. Virus Culture
  6. Viral Diseases
  7. Bacteria Structure Culture
  8. Bacterial Genetics
  9. Bacterial Diseases
  10. Protozoan microbiology
  11. Pathogenecity of Microorganisms
  12. Antimicrobial Resistance
  13. Antibiotics and Chemotherapy
  14. AIDS – HIV

Unit 3 – Immunology Topic List Zoology

  1. IMMUNOLOGY
  2. Acquired Immunity
  3. Structure and Functions of the Immune System
  4. Peripheral Lymphoid Organs
  5. Secondary Lymphoid Organs
  6. Antigenic determinants and epitopes
  7. Antibodies – Immunoglobulins
  8. Transplantation immunology
  9. Genetic basis of organ transplants
  10. Immune system disorders

Comments

Post a Comment

Popular posts from this blog

Root Canal Treatment

Image
Root Canal Treatment Root Canal Treatment is a modern dental procedure to save a tooth in which the pulp (the living tissue within a tooth) has died or become untreatably diseased, usually as a result of extensive dental caries. Steps involved in Root Canal Treatment (1) A hole is drilled into the crown to remove all material from the pulp chamber. The root canals are then cleaned with fine-tipped instruments. The procedure is usually monitored by X-rays. (2) The cavity is washed out, and antibiotic paste and a temporary filling are packed into it. Some days later, the filling is removed and the canals are checked for sterlity. (3) When no infection can be detected, the cavity is filled with a sealing paste and/or tapering solid “point” made of gutta – percha resin mixed with zinc and bismuth oxides. The mouth of cavity is then sealed with cement. Related Topics in Zoology: Bio Zoology All Important Topics Human Physiology Introduction Nutrition Carbohydrates Poly hydroxyaldehydes...
Read more

Eye Infections and Eye Care

Image
Eye Infections and Eye Care Eye Infections 1. Stye A stye is an acute infection of the glands located at the eyelid margin. There is swelling, pain, itching and redness in a small area at the lid margin. Treatment consists of using frequent warm compresses on the eye. (Eye Infections) 2. Conjunctivitis: Infection in the conjuctiva is called conjunctivitis. Due to the infection the invisible blood vessels within the conjunctiva become engorged. Inflammation of the conjuctiva causes redness, discomfort and a discharge from the affected eye. The most common causes for conjunctivitis are infections (in children) and allergy (in adults). (Eye Infections) 2a. Infective conjunctivitis : Most conjunctival infection are caused by bacteria (e.g staphylococci) and are spread by hand-to-eye contact or by viruses associated with a cold, sore throat, or illness such as measles, viral conjunctivitis sometimes occurs in epidemics, spreading rapidly through schools and other groups. (Eye Infections) 2b...
Read more

Botanical description of Hibiscus rosa sinensis

Image
Botanical description of Hibiscus rosa sinensis Hibiscus rosa sinensis Botanical description of Hibiscus rosa sinensis Hibiscus rosa sinensis General Characters Habit Perennial shrub. Root Tap root system. Stem Aerial, erect, cylindrical, woody and branched. Leaf Simple, Alternate, petiolate, stipulate, serrate, glabrous, apex acuminate with multicostate reticulate venation. Inflorescence Solitary cyme and axillary. Flower Pedicel jointed, bracteate, bracteolate, bisexual, large, showy, pentamerous, dichlamydeous, actinomorphic, complete and hypogynous and mucilage is present in floral parts. Epicalyx 5 to 8 bracteoles outer to the calyx. They are green and free. Calyx Sepals 5, green, gamosepalous showing valvate aestivation and odd sepal is posterior in position. Corolla Petals 5, variously coloured, polypetalous but fused at the base and showing twisted aestivation. Androecium Numerous stamens, monadelphous, filaments are fused to form a staminal tube around the style. Staminal tube...
Read more