NEET MDS Synopsis
Polyprotic Acids
Biochemistry
Polyprotic Acids
• Some acids are polyprotic acids; they can lose more than one proton.
• In this case, the conjugate base is also a weak acid.
• For example: Carbonic acid (H2CO3 ) can lose two protons sequentially.
• Each dissociation has a unique Ka and pKa value.
Ka1 = [H+ ][HCO3 - ] / [H2CO3]
Ka2 = [H+ ][CO3 -2 ] / [HCO3- ]
Note: (The difference between a weak acid and its conjugate base differ is one hydrogen)
Sutures
Oral and Maxillofacial Surgery
Absorbable
Natural
Catgut
Tansor fascia lata
Collagen tape
Synthetic
Polyglycolic acid (Dexon)
Polyglactin (Vicryl)
Polydioxanone (PDS)
Non-absorbable
Natural
Linen
Cotton
Silk
Synthetic
Nylon
Terylene (Dacron)
Polypropylene (Prolene)
Characteristics of Immunoglobulin subclasses
General Pathology
Characteristics of Immunoglobulin subclasses
I. Ig G:
(i) Predominant portion (80%) of Ig.
(ii) Molecular weight 150, 000
(iii) Sedimentation coefficient of 7S.
(iv) Crosses placental barrier and to extra cellular fluid.
(v) Mostly neutralising effect. May be complement fixing.
(vi) Half life of 23 days.
2.IgM :
(i) Pentamer of Ig.
(ii) Molecular weight 900, 000
(iii) 19S.
(iv) More effective complement fixation and cells lysis
(v) Earliest to be produced in infections.
(vi) Does not cross placental barrier.
(vii) Halflife of 5 days.
3. Ig A :
Secretory antibody. Found in intestinal, respiratory secretions tears, saliva and urine also.
Secreted usually as a dinner with secretory piece.
Mol. weight variable (160,000+)
7 S to 14 S.
Half life of 6 days.
4.Ig D :
Found in traces.
7 S.
Does not cross placenta.
5. Ig E
Normally not traceable
7-8 S (MoL weight 200,000)
Cytophilic antibody, responsible for some hypersensitivity states,
ATROPHY
General Pathology
ATROPHY
It is the acquired decrease in the size of an organ due to decrease in the size and/or number of its constituent cells.
Causes:
(1) Physiological
- Foetal involution.
o Branchial clefts.
o Ductus arterious.
- Involution of thymus and other lymphoid organs in childhood and adolescence.
- In adults:
o Post-partum uterus.
o Post-menopausal ovaries and uterus
o Post-lactational breast
o Thymus.
(2) Pathological:
- Generalised as in
o Ageing.
o Severe starvation and cachexia
- Localised :
o Disuse atropy of bone and muscle.
o Ischaemic atrophy as in arteriosclerotic kidney. .
o Pressure atrophy due to tumours and of kidney in hydronephrosis.
o Lack of trophic stimulus to endocrines and gonads.
FUNGAL INFECTION- Histoplasmosis
General Pathology
FUNGAL INFECTION
Histoplasmosis
A disease caused by Histoplasma capsulatum, causing primary pulmonary lesions and hematogenous dissemination.
Symptoms and Signs
The disease has three main forms. Acute primary histoplasmosis is usually asymptomatic
Progressive disseminated histoplasmosis follows hematogenous spread from the lungs that is not controlled by normal cell-mediated host defense mechanisms. Characteristically, generalized involvement of the reticuloendothelial system, with hepatosplenomegaly, lymphadenopathy, bone marrow involvement, and sometimes oral or GI ulcerations occurs, particularly in chronic cases
Progressive disseminated histoplasmosis is one of the defining opportunistic infections for AIDS.
Chronic cavitary histoplasmosis is characterized by pulmonary lesions that are often apical and resemble cavitary TB. The manifestations are worsening cough and dyspnea, progressing eventually to disabling respiratory dysfunction. Dissemination does not occur
Diagnosis
Culture of H. capsulatum from sputum, lymph nodes, bone marrow, liver biopsy, blood, urine, or oral ulcerations confirms the diagnosis
The hepatic portal system
PhysiologyThe hepatic portal system
The capillary beds of most tissues drain into veins that lead directly back to the heart. But blood draining the intestines is an exception. The veins draining the intestine lead to a second set of capillary beds in the liver. Here the liver removes many of the materials that were absorbed by the intestine:
Glucose is removed and converted into glycogen.
Other monosaccharides are removed and converted into glucose.
Excess amino acids are removed and deaminated.
The amino group is converted into urea.
The residue can then enter the pathways of cellular respiration and be oxidized for energy.
Many nonnutritive molecules, such as ingested drugs, are removed by the liver and, often, detoxified.
The liver serves as a gatekeeper between the intestines and the general circulation. It screens blood reaching it in the hepatic portal system so that its composition when it leaves will be close to normal for the body.
Furthermore, this homeostatic mechanism works both ways. When, for example, the concentration of glucose in the blood drops between meals, the liver releases more to the blood by
converting its glycogen stores to glucose (glycogenolysis)
converting certain amino acids into glucose (gluconeogenesis).
Classification
Pharmacology
Classification
1. Natural Alkaloids of Opium
Phenanthrenes -> morphine, codeine, thebaine
Benzylisoquinolines -> papaverine, noscapine
2. Semi-synthetic Derivatives
diacetylmorphine (heroin) hydromorphone, oxymorphone hydrocodone, oxycodone
3. Synthetic Derivatives
phenylpiperidines pethidine, fentanyl, alfentanyl, sufentnyl
benzmorphans pentazocine, phenazocine, cyclazocine
propionanilides methadone
morphinans levorphanol
Mahlers Stages of Development
PedodonticsMahler's Stages of Development
Normal Autistic Phase (0-1 year):
Overview: In this initial phase, infants are
primarily focused on their own needs and experiences. They are not yet
aware of the external world or the presence of others.
Characteristics: Infants are in a state of
self-absorption, and their primary focus is on basic needs such as
feeding and comfort. They may not respond to external stimuli or
caregivers in a meaningful way.
Application in Pedodontics: During this stage,
dental professionals may not have direct interactions with infants, as
their focus is on basic care. However, creating a soothing environment
can help infants feel secure during dental visits.
Normal Symbiotic Phase (3-4 weeks to 4-5 months):
Overview: In this phase, infants begin to develop a
sense of connection with their primary caregiver, typically the mother.
They start to recognize the caregiver as a source of comfort and
security.
Characteristics: Infants may show signs of
attachment and begin to respond to their caregiver's presence. They rely
on the caregiver for emotional support and comfort.
Application in Pedodontics: During dental visits,
having a parent or caregiver present can help infants feel more secure.
Dental professionals can encourage caregivers to hold or comfort the
child during procedures to foster a sense of safety.
Separation-Individuation Process (5 to 36 months):
This process is further divided into several sub-stages, each
representing a critical aspect of a child's development of independence
and self-identity.
Differentiation (5-10 months):
Overview: Infants begin to differentiate
themselves from their caregivers. They start to explore their
environment while still seeking reassurance from their caregiver.
Application in Pedodontics: Dental
professionals can encourage exploration by allowing children to
touch and interact with dental tools in a safe manner, helping them
feel more comfortable.
Practicing Period (10-16 months):
Overview: During this stage, children actively
practice their newfound mobility and independence. They may explore
their surroundings more confidently.
Application in Pedodontics: Allowing children
to walk or move around the dental office (within safe limits) can
help them feel more in control and less anxious.
Rapprochement (16-24 months):
Overview: Children begin to seek a balance
between independence and the need for closeness to their caregiver.
They may alternate between wanting to explore and wanting comfort.
Application in Pedodontics: Dental
professionals can support this stage by providing reassurance and
comfort when children express anxiety, while also encouraging them
to engage with the dental environment.
Consolidation and Object Constancy (24-36 months):
Overview: In this final sub-stage, children
develop a more stable sense of self and an understanding that their
caregiver exists even when not in sight. They begin to form a more
complex understanding of relationships.
Application in Pedodontics: By this stage,
children can better understand the dental process and may be more
willing to cooperate. Dental professionals can explain procedures in
simple terms, reinforcing the idea that the dentist is there to help