NEET MDS Synopsis
RESPIRATORY DISORDERS - Cystic Fibrosis
PhysiologyCystic Fibrosis
→ Thick mucus coagulates in ducts, produces obstruction, Too thick for cilia to move
→ Major Systems Affected: Respiratory System, G. I. Tract,Reproductive Tract
→ Inherited, autosomal recessive gene, most common fatal genetic disorder
→ Major characteristic, Altered electrolyte composition (Saliva & sweat Na+, K+, Cl-)
→ Family history of Cystic Fibrosis
→ Respiratory Infections & G.I.Tract malabsorption
→ Predisposes lung to Secondary infection (Staphylococcus, Pseudomonas)
→ Damages Respiratory Bronchioles and Alveolar ducts, Produces Fibrosis of Lungs, Large cystic dilations)
Plasma
PhysiologyPlasma: is the straw-colored liquid in which the blood cells are suspended.
Composition of blood plasma
Component
Percent
Water
~92
Proteins
6–8
Salts
0.8
Lipids
0.6
Glucose (blood sugar)
0.1
Plasma transports materials needed by cells and materials that must be removed from cells:
various ions (Na+, Ca2+, HCO3−, etc.
glucose and traces of other sugars
amino acids
other organic acids
cholesterol and other lipids
hormones
urea and other wastes
Most of these materials are in transit from a place where they are added to the blood
exchange organs like the intestine
depots of materials like the liver
to places where they will be removed from the blood.
every cell
exchange organs like the kidney, and skin.
OCCLUSION AND DENTAL DEVELOPMENT-Introduction
Dental Anatomy
Genetics and Environment: Introduction
The size of the teeth and the timing of the developing dentition and its eruption are genetically determined. Teeth are highly independent in their development. Also, teeth tend to develop along a genetically predetermined course.: tooth development and general physical development are rather independent of one another. Serious illness, nutritional deprivation, and trauma can significantly impact development of the teeth. This genetic independence (and their durability) gives teeth special importance in the study of evolution.
Teeth erupt full size and are ideal for study throughout life. Most important, age and sex can be recorded.
When teeth erupt into the oral cavity, a new set of factors influence tooth position. As the teeth come into function, genetic and environment determine tooth position.
In real life, however, girls shed deciduous teeth and receive their permanent teeth slightly earlier than boys, possibly reflecting the earlier physical maturation achieved by girls. Teeth are slightly larger in boys that in girls
Folate: Folic Acid, Folacin Folate
Biochemistry
Folate: Folic Acid, Folacin Folate, also known as folic acid or folacin, aids in protein metabolism, promoting red blood cell formation, and lowering the risk for neural tube birth defects. Folate may also play a role in controlling homocysteine levels, thus reducing the risk for coronary heart disease.
RDA for folate is 400 mcg/day for adult males and females. Pregnancy will increase the RDA for folate to 600 mcg/day.
Folate Deficiency
Folate deficiency affects cell growth and protein production, which can lead to overall impaired growth. Deficiency symptoms also include anemia and diarrhea.
A folate deficiency in women who are pregnant or of child bearing age may result in the delivery of a baby with neural tube defects such as spina bifida.
Excision of Lesions Involving the Jaw Bone
General SurgeryExcision of Lesions Involving the Jaw Bone
When excising lesions involving the jaw bone, various terminologies are used
to describe the specific techniques and outcomes of the procedures.
1. Enucleation
Enucleation refers to the separation of a
lesion from the bone while preserving bone continuity. This is achieved by
removing the lesion along an apparent tissue or cleavage plane, which is
often defined by an encapsulating or circumscribing connective tissue
envelope derived from the lesion or surrounding bone.
Key Characteristics:
The lesion is contained within a defined envelope.
Bone continuity is maintained post-excision.
2. Curettage
Curettage involves the removal of a lesion
from the bone by scraping, particularly when the lesion is friable or lacks
an intact encapsulating tissue envelope. This technique may result in the
removal of some surrounding bone.
Key Characteristics:
Indicates the inability to separate the lesion along a distinct
tissue plane.
May involve an inexact or immeasurable thickness of surrounding
bone.
If a measurable margin of bone is removed, it is termed "resection
without continuity defect."
3. Marsupialization
Marsupialization is a surgical procedure
that involves the exteriorization of a lesion by removing overlying tissue
to expose its internal surface. This is done by excising a portion of the
lesion bordering the oral cavity or another body cavity.
Key Characteristics:
Multicompartmented lesions are rendered unicompartmental.
The lesion is clinically cystic, and the excised tissue may include
bone and/or overlying mucosa.
4. Resection Without Continuity Defect
This term describes the excision of a
lesion along with a measurable perimeter of investing bone, without
interrupting bone continuity. The anatomical relationship allows for the
removal of the lesion while preserving the integrity of the bone.
Key Characteristics:
Bone continuity is maintained.
Adjacent soft tissue may be included in the resection.
5. Resection With Continuity Defect
This involves the excision of a lesion that
results in a defect in the continuity of the bone. This is often associated
with more extensive resections.
Key Characteristics:
Bone continuity is interrupted.
May require reconstruction or other interventions to restore
function.
6. Disarticulation
Disarticulation is a special form of
resection that involves the temporomandibular joint (TMJ) and results in a
continuity defect.
Key Characteristics:
Involves the removal of the joint and associated structures.
Results in loss of continuity in the jaw structure.
7. Recontouring
Recontouring refers to the surgical
reduction of the size and/or shape of the surface of a bony lesion or bone
part. The goal is to reshape the bone to conform to the adjacent normal bone
surface or to achieve an aesthetic result.
Key Characteristics:
May involve lesions such as bone hyperplasia, torus, or exostosis.
Can be performed with or without complete eradication of the lesion
(e.g., fibrous dysplasia).
Group A Streptococcus
General Pathology
Group A Streptococcus
- scarlet fever usually begins as a Streptococcal pharyngitis/tonsillitis and then develops an erythematous rash beginning on the trunk and limbs with eventual desquamation.
- rash is due to elaboration of erythrogenic toxin by the organism
- face is usually spared, but, if involved there is a characteristic circumoral pallor and the tongue becomes bright red, thus the term "strawberry tongue".
- post-streptococcal immune complex glomerulonephritis is a possible sequela of scarlet fever.
- Dick test is a skin test that evaluates immunity against scarlet fever; no response indicates immunity (anti-toxin antibodies present); erythema indicates no immunity.
- impetigo due to Streptococcus pyogenes is characterized by honey colored, crusted lesions, while those with a predominantly bullous pattern are primarily due to Staphylococcus aureus.
- cellulitis with lymphangitis ("red streaks") is characteristic of Streptococcus pyogenes.
- hyaluronidase is a spreading factor that favors the spread of infection throughout the subcutaneous tissue unlike Staphylococcus aureus which generates coagulase to keep the pus confined.
- erysipelas refers to a raised, erythematous ("brawny edema"), hot cellulitis, usually on the face that commonly produces septicemia, if left untreated.
DISINFECTION AND STERILIZATION
General Microbiology
DISINFECTION AND STERILIZATION
• Sterilization is the best destruction or com removal_of all forms of micro organisms.
• Disinfection is the destruction of many microorganisms but usually the b spores.
• Antisepsis is the destruction or inhibition of microorganisms in living tissues thereby limiting or preventing the harmful effect of infection.
• Astatic Agent would only inhibit the growth of microorganisms (bacteriostatic, fungistatic, sporostatic).
• Acidal agent would kill the microorganism (bactericidal. virucidal, fungicidal)
• Sterilants are the chemicals which under controlled conditions can kill sporinQ bacteria.
Theories of Tooth Movement
OrthodonticsTheories of Tooth Movement
Pressure-Tension Theory:
Concept: This theory posits that tooth movement
occurs in response to the application of forces that create areas of
pressure and tension in the periodontal ligament (PDL).
Mechanism: When a force is applied to a tooth, the
side of the tooth experiencing pressure (compression) leads to bone
resorption, while the opposite side experiences tension, promoting bone
deposition. This differential response allows the tooth to move in the
direction of the applied force.
Clinical Relevance: This theory underlies the
rationale for using light, continuous forces in orthodontic treatment to
facilitate tooth movement without causing damage to the periodontal
tissues.
Biological Response Theory:
Concept: This theory emphasizes the biological
response of the periodontal ligament and surrounding tissues to
mechanical forces.
Mechanism: The application of force leads to a
cascade of biological events, including the release of signaling
molecules that stimulate osteoclasts (bone resorption) and osteoblasts
(bone formation). This process is influenced by the magnitude, duration,
and direction of the applied forces.
Clinical Relevance: Understanding the biological
response helps orthodontists optimize force application to achieve
desired tooth movement while minimizing adverse effects.
Cortical Bone Theory:
Concept: This theory focuses on the role of
cortical bone in tooth movement.
Mechanism: It suggests that the movement of teeth
is influenced by the remodeling of cortical bone, which is denser and
less responsive than the trabecular bone. The movement of teeth through
the cortical bone requires greater forces and longer durations of
application.
Clinical Relevance: This theory highlights the
importance of considering the surrounding bone structure when planning
orthodontic treatment, especially in cases requiring significant tooth
movement.