MDS PREP
Which of the following is a component of Jackson tried
1) Functional efficiency
2) Structural balance
3) Aesthetic harmony
4) All of the above
Orthodontics
Answer: 4
Broad and short type of face is known as
1) Mesoprosopic
2) Euryprosopic
3) Leptoprosopic
4) None of the above
Orthodontics
Answer: 2
The opsonins which leads to phagocytosis is/are:
1. lgG (Fc fragment)
2. C3b of complement cascade
3. 1gM (Fc fragment) and C5b of complement cascade
4. A and B
Pathology
Answer: 4
Opsonins are molecules that enhance the phagocytosis of antigens by binding to their surfaces and acting as markers or labels that make them more recognizable to phagocytes.
1. lgG (Fc fragment): Immunoglobulin G (IgG) is the most common antibody isotype
in human serum. It plays a crucial role in the secondary immune response. The Fc
region of IgG is the fragment that interacts with Fc receptors present on the
membrane of phagocytic cells. When an antigen is coated with IgG, the Fc
fragments of these antibodies can bind to the Fc receptors, leading to the
activation of the phagocytic process. This is known as antibody-dependent
phagocytosis, where the antibody acts as an opsonin to facilitate the
recognition and engulfment of the antigen by phagocytic cells.
2. C3b of complement cascade: The complement system is a cascade of proteins
that can be activated in response to an infection or the presence of foreign
substances. C3 is a central protein in this system, and when it is cleaved into
C3a and C3b, the latter can bind directly to antigens. C3b acts as an opsonin by
coating the surface of pathogens. The presence of C3b on a microbial surface
allows it to be recognized by complement receptors on phagocytic cells, such as
macrophages. This interaction enhances the efficiency of phagocytosis, as the
receptors can recognize the bound C3b and engulf the antigen more readily.
3. IgM (Fc fragment) and C5b of complement cascade: While IgM is the first
antibody isotype produced in response to an infection and can also opsonize
antigens, it is less efficient than IgG due to its pentameric structure and
lower affinity for phagocytic receptors. However, it is not as commonly
associated with phagocytosis as IgG. Regarding C5b, it is part of the membrane
attack complex (MAC) and is involved in the direct destruction of pathogens
rather than acting as a classical opsonin that leads to phagocytosis. The MAC
assembles on the surface of the antigen and creates pores, leading to osmotic
lysis and destruction of the cell membrane.
The formation of multiple secondary abscesses, after bacteria enter the circulation from a primary source of infection, is referred to as
1. pyemia
2. bacteremia
3. septicemia
4. toxemia
Oral Surgery
Answer: 1
Which one of the following operative instruments is sharpened with hand piece stones
1) Enamel hatches
2) Binangle chisels
3) Curved chisels
4) Spoon excavators
Conservative Dentistry
Answer: 4
Bones usually fracture at the sites of
1) Compressive strain
2) Tensile strain
3) Rich blood supply
4) Thin periosteal covering
Oral Surgery
Answer: 2
Bones usually fracture at sites of tensile strain, where the forces applied exceed the strength of the bone.
An exophytic papillary lesionof the hard palate, consisting of a luminal layer of columnar cells resting on a cuboidal basal layer, with the connective tissue papillae containing plasma cells, could be
1. Monomorphic adenoma
2. Simple ductal papilloma
3. Oxyphilic adenoma
4. Sialadenoma papilliferum
Oral Pathology
Answer: 4
Sialadenoma papilliferum is a rare, benign
salivary gland tumor typically occurring in the palate. It presents as an
exophytic, papillary lesion and histologically shows a dual epithelial layer
(columnar and cuboidal) with connective tissue cores that may contain plasma
cells. The other options, such as monomorphic adenoma or simple ductal papilloma,
lack these specific histological features.