NEET MDS Synopsis
Muscles Around the Nose
AnatomyMuscles Around the Nose
The Nasalis Muscle
This muscle consists of a transverse (compressor naris) and alar (dilator naris) parts.
It is supplied by the buccal branch of the facial nerve.
Diagnostic Methods for Early Caries Detection
Conservative Dentistry
Diagnostic Methods for Early Caries Detection
Early detection of caries is essential for effective management and
treatment. Various diagnostic methods can be employed to identify caries
activity at early stages:
1. Identification of Subsurface Demineralization
Inspection: Visual examination of the tooth surface for
signs of demineralization, such as white spots or discoloration.
Radiographic Methods: X-rays can reveal subsurface
carious lesions that are not visible to the naked eye, allowing for early
intervention.
Dye Uptake Methods: Application of specific dyes that
can penetrate demineralized areas, highlighting the extent of carious
lesions.
2. Bacterial Testing
Microbial Analysis: Testing for the presence of
specific cariogenic bacteria (e.g., Streptococcus mutans) can provide
insight into the caries risk and activity level.
Salivary Testing: Salivary samples can be analyzed for
bacterial counts, which can help assess the risk of caries development.
3. Assessment of Environmental Conditions
pH Measurement: Monitoring the pH of saliva can
indicate the potential for demineralization. A lower pH (acidic environment)
is conducive to caries development.
Salivary Flow: Evaluating salivary flow rates can help
determine the protective capacity of saliva against caries. Reduced salivary
flow can increase caries risk.
Salivary Buffering Capacity: The ability of saliva to
neutralize acids is crucial for maintaining oral health. Assessing this
capacity can provide valuable information about caries risk.
Fifth Generation:
Pharmacology
Fifth Generation:
These are extended spectrum antibiotics.
Ceftaroline, Ceftobiprole
CENTRAL NERVOUS SYSTEM PHARMACOLOGY
Pharmacology
CENTRAL NERVOUS SYSTEM PHARMACOLOGY
Antipsychotic Drugs
1. Phenothiazines
a. Aliphatic derivatives
(1) Chlorpromaxine
b. Piperidine derivatives
(1) Thioridazine
(2) Mesoridazine
c. Piperazine derivatives
(1) Fluphenazine
(2) Perphenazine
(3) Prochlorperazine
(4) Trifluoperazine
2. Haloperidol resembles the piperazine phenothiazines.
3. Thiothixene resembles the piperazine phenothiazines.
4. Others (e.g., loxapine, pimozide).
5. Newer and more atypical antipsychotic drugs:
a. Clozapine
b. Olanzapine
c. Quetiapine
d. Risperidone
e. Ziprasidone
f. Aripiprazole
Antidepressant Drugs
Drug treatment of depression is based on increasing serotonin (5-HT) or NE (or both) at synapses in selective tracts in the brain. This can be accomplished by different mechanisms.
Treatment takes several weeks to reach full clinical efficacy.
1. Tricyclic antidepressants (TCAs)
a. Amitriptyline
b. Desipramine
c. Doxepin
d. Imipramine
e. Protriptyline
2. Selective serotonin reuptake inhibitors (SSRIs)
a. Fluoxetine
b. Paroxetine
c. Sertraline
d. Fluvoxamine
e. Citalopram
3. Monoamine oxidase inhibitors (MAOIs)
a. Tranylcypromine
b. Phenelzine
4. Miscellaneous antidepressants
a. Bupropion
b. Maprotiline
c. Mirtazapine
d. Trazodone
e. St. John’s Wort
Antimania Drugs
These drugs are used to treat manic-depressive illness.
A. Drugs
1. Lithium
2. Carbamazepine
3. Valproic acid
Sedative Hypnotics
1. Benzodiazepines
2. Barbiturates
3. Zolpidem and zaleplon
4. Chloral hydrate
5. Buspirone
6. Other sedatives (e.g., mephenesin, meprobamate, methocarbamol, carisoprodol, cyclobenzaprine)
7. Baclofen
8. Antihistamines (e.g., diphenhydramine)
9. Ethyl alcohol
Antiepileptic Drugs
Phenytoin
Carbamazepine
Phenobarbital
Primidone
Gabapentin
Valproic acid
Ethosuximide
Anti-Parkinson Drugs
a. L-dopa plus carbidopa (Sinemet).
b. Bromocriptine, pergolide, pramipexole, ropinirole.
c. Benztropine, trihexyphenidyl, biperiden, procyclidine.
d. Diphenhydramine.
e. Amantadine.
f. Tolcapone and entacapone.
g. Selegiline.
Ichthyosis vulgaris
General Pathology
Ichthyosis vulgaris is a genetic disease characterized by increased cohesiveness of the cells in the stratum corneum, resulting up in a piling up stratum corneum (scales like a fish).
Anterior Crossbite
OrthodonticsAnterior Crossbite
Anterior crossbite is a dental condition where one or more
of the upper front teeth (maxillary incisors) are positioned behind the lower
front teeth (mandibular incisors) when the jaws are closed. This misalignment
can lead to functional issues, aesthetic concerns, and potential wear on the
teeth. Correcting anterior crossbite is essential for achieving proper occlusion
and improving overall dental health.
Methods to Correct Anterior Crossbite
Acrylic Incline Plane:
Description: An acrylic incline plane is a
removable appliance that can be used to guide the movement of the teeth.
It is designed to create a ramp-like surface that encourages the
maxillary incisors to move forward.
Mechanism: The incline plane helps to reposition
the maxillary teeth by providing a surface that directs the teeth into a
more favorable position during function.
Reverse Stainless Steel Crown:
Description: A reverse stainless steel crown can be
used in cases where the anterior teeth are significantly misaligned.
This crown is designed to provide a stable and durable solution for
correcting the crossbite.
Mechanism: The crown can be adjusted to help
reposition the maxillary teeth, allowing them to move into a more normal
relationship with the mandibular teeth.
Hawley Retainer with Recurve Springs:
Description: A Hawley retainer is a removable
orthodontic appliance that can be modified with recurve springs to
correct anterior crossbite.
Mechanism: The recurve springs apply gentle
pressure to the maxillary incisors, tipping them forward into a more
favorable position relative to the mandibular teeth. This appliance is
comfortable, easily retained, and predictable in its effects.
Fixed Labial-Lingual Appliance:
Description: A fixed labial-lingual appliance is a
type of orthodontic device that is bonded to the teeth and can be used
to correct crossbites.
Mechanism: This appliance works by applying
continuous forces to the maxillary teeth, tipping them forward and
correcting the crossbite. It may include a vertical removable arch for
ease of adjustment and recurve springs to facilitate movement.
Vertical Removable Arch:
Description: This appliance can be used in
conjunction with other devices to provide additional support and
adjustment capabilities.
Mechanism: The vertical removable arch allows for
easy modifications and adjustments, helping to jump the crossbite by
repositioning the maxillary teeth.
Reflexes
PhysiologyReflexes
A reflex is a direct connection between stimulus and response, which does not require conscious thought. There are voluntary and involuntary reflexes.
The Stretch Reflex:
The stretch reflex in its simplest form involves only 2 neurons, and is therefore sometimes called a 2-neuron reflex. The two neurons are a sensory and a motor neuron. The sensory neuron is stimulated by stretch (extension) of a muscle. Stretch of a muscle normally happens when its antagonist contracts, or artificially when its tendon is stretched, as in the knee jerk reflex. Muscles contain receptors called muscle spindles. These receptors respond to the muscles's stretch. They send stimuli back to the spinal cord through a sensory neuron which connects directly to a motor neuron serving the same muscle. This causes the muscle to contract, reversing the stretch. The stretch reflex is important in helping to coordinate normal movements in which antagonistic muscles are contracted and relaxed in sequence, and in keeping the muscle from overstretching.
Since at the time of the muscle stretch its antagonist was contracting, in order to avoid damage it must be inhibited or tuned off in the reflex. So an additional connection through an interneuron sends an inhibitory pathway to the antagonist of the stretched muscle - this is called reciprocal inhibition.
The Deep Tendon Reflex:
Tendon receptors respond to the contraction of a muscle. Their function, like that of stretch reflexes, is the coordination of muscles and body movements. The deep tendon reflex involves sensory neurons, interneurons, and motor neurons. The response reverses the original stimulus therefore causing relaxation of the muscle stimulated. In order to facilitate that the reflex sends excitatory stimuli to the antagonists causing them to contract - reciprocal activation.
The stretch and tendon reflexes complement one another. When one muscle is stretching and stimulating the stretch reflex, its antagonist is contracting and stimulating the tendon reflex. The two reflexes cause the same responses thus enhancing one another.
The Crossed Extensor Reflex -
The crossed extensor reflex is just a withdrawal reflex on one side with the addition of inhibitory pathways needed to maintain balance and coordination. For example, you step on a nail with your right foot as you are walking along. This will initiate a withdrawal of your right leg. Since your quadriceps muscles, the extensors, were contracting to place your foot forward, they will now be inhibited and the flexors, the hamstrings will now be excited on your right leg. But in order to maintain your balance and not fall down your left leg, which was flexing, will now be extended to plant your left foot (e.g. crossed extensor). So on the left leg the flexor muscles which were contracting will be inhibited, and the extensor muscles will be excited
Immunoglobulins.
General Pathology
Immunoglobulins. (Ig)
These are made up of polypeptide chains. Each molecule is constituted by two heavy and two light chains, linked by disulfide (S-S) bonds. The h~ chains are of 5 types, with corresponding, types or immunoglobulin. IgG (gamma), IgM (mu µ ), IgA(alpha α), IgD(delta ), IgE(epsilon)
Each of these can have light chains of either kappa (k) or lambda type.Each chain has a constant portion (constant for the subtype) land a variable portion (antigen specific).
Enzyme digestion can split the Ig molecule into.2 Fab (antibody binding) fragments and one Fc (crystallisable, complement binding ) fragment.
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,