NEET MDS Synopsis
CENTRAL NERVOUS SYSTEM PHARMACOLOGY
Pharmacology
CNS acting drugs are of major therapeutic and clinical importance.
They can produce diverse physiologicaland psychologicaleffects such as:
•Induction of Anesthesia
•Relief of Pain
•Prevention of Epileptic seizures
•Reduction of Anxiety
•Treatment of Parkinsonism
•Treatment of Alzheimer's disease
•Treatment of Depression
•Centrally acting drugs also include drugs that are administered without medical intervention like tea, coffee, nicotine, and opiates.
Muscles of the Forehead
AnatomyMuscles Around the Mouth
The sphincter of the mouth is orbicularis oris and the dilator muscles radiate outward from the lips like the spokes of a wheel.
Orbicularis Oris Muscle
This muscle encircles the mouth and is the sphincter of the oral aperture
This muscle (1) closes the lips, (2) protrudes them and (3) compresses them against the teeth.
It plays an important role in articulation and mastication. Together with the buccinator muscle, it helps to hold the food between the teeth during mastication.
Zygomaticus Major Muscle
It extends from the zygomatic bone to the angle of the mouth.
It draws the corner of the moth superolaterally during smiling and laughing.
Zygomaticus Minor Muscle
This is a narrow slip of muscle, and passes obliquely from the zygomatic bone to the orbicularis oris.
It helps raise the upper lip when showing contempt or to deepen the nasolabial sulcus when showing sadness.
The Buccinator Muscle
This is a thin, flat, rectangular muscle.
It is attached laterally to the alveolar processes of the maxilla and mandible, opposite the molar teeth and the pterygomandibular raphe.
Medially, its fibres mingle with those of orbicularis oris.Innervation: the buccal branch of facial.
It aids mastication and swallowing by pushing the cheeks against the molar teeth during chewing.
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.
Phospholipids Functions
Biochemistry
- There are two important phospholipids, Phosphatidylcholine and Phosphatidylserine found the cell membrane without which cell cannot function normally.
- Phospholipids are also important for optimal brain health as they found the cell membrane of brain cells also which help them to communicate and influence the receptors function. That is the reason food stuff which is rich in phospholipids like soy, eggs and the brain tissue of animals are good for healthy and smart brain.
- Phospholipids are the main component of cell membrane or plasma membrane. The bilayer of phospholipid molecules determine the transition of minerals, nutrients, and drugs in and out of the cell and affect various functions of them.
- As phospholipids are main component of all cell membrane, they influence a number of organs and tissues, such as the heart, blood cells and the immune system. As we grown up the amount of phospholipids decreases and reaches to decline.
- Phospholipids present in cell membrane provide cell permeability and flexibility with various substances as well its ability to move fluently. The arrangement of phospholipid molecules in lipid bilayer prevent amino acids, carbohydrates, nucleic acids, and proteins from moving across the membrane by diffusion. The lipid bi-layer is usually help to prevent adjacent molecules from sticking to each other.
- The selectivity of cell membrane form certain substances are due to the presence of hydrophobic and hydrophilic part molecules and their arrangement in bilayer. This bilayer is also maintained the normal pH of cell to keeps it functioning properly.
- Phospholipids are also useful in the treatment of memory problem associated with chronic substances as they improve the ability of organism to adapt the chronic stress.
Dimensions of Toothbrushes
PeriodontologyDimensions of Toothbrushes
Toothbrushes play a crucial role in maintaining oral hygiene, and their
design can significantly impact their effectiveness. The American Dental
Association (ADA) has established guidelines for the dimensions and
characteristics of acceptable toothbrushes. This lecture will outline these
specifications and discuss their implications for dental health.
Acceptable Dimensions of Toothbrushes
Brushing Surface Dimensions:
Length:
Acceptable brushing surfaces should measure between 1 to
1.25 inches (25.4 to 31.8 mm) long.
Width:
The width of the brushing surface should range from 5/16
to 3/8 inch (7.9 to 9.5 mm).
Rows of Bristles:
Toothbrushes should have 2 to 4 rows of bristles to
effectively clean the teeth and gums.
Tufts per Row:
Each row should contain 5 to 12 tufts of
bristles, allowing for adequate coverage and cleaning ability.
Filament Diameter:
The diameter of the bristles can vary, affecting the stiffness and
cleaning effectiveness:
Soft Filaments:
Diameter of 0.2 mm (0.007 inches). Ideal
for sensitive gums and children.
Medium Filaments:
Diameter of 0.3 mm (0.012 inches). Suitable
for most adults.
Hard Filaments:
Diameter of 0.4 mm (0.014 inches).
Generally not recommended for daily use as they can be abrasive
to the gums and enamel.
Filament Stiffness:
The stiffness of the bristles is determined by the diameter relative
to the length of the filament. Thicker filaments tend to be stiffer,
which can affect the brushing technique and comfort.
Special Considerations for Children's Toothbrushes
Size:
Children's toothbrushes are designed to be smaller to accommodate
their smaller mouths and teeth.
Bristle Thickness:
The bristles are thinner, measuring 0.005 inches (0.1
mm) in diameter, making them gentler on sensitive gums.
Bristle Length:
The bristles are shorter, typically around 0.344 inches (8.7
mm), to ensure effective cleaning without causing discomfort.
Clinical Implications
Choosing the Right Toothbrush:
Dental professionals should guide patients in selecting toothbrushes
that meet ADA specifications to ensure effective plaque removal and gum
protection.
Emphasizing the importance of using soft or medium bristles can help
prevent gum recession and enamel wear.
Education on Brushing Technique:
Proper brushing technique is as important as the toothbrush itself.
Patients should be educated on how to use their toothbrush effectively,
regardless of the type they choose.
Regular Replacement:
Patients should be advised to replace their toothbrush every 3
to 4 months or sooner if the bristles become frayed. This
ensures optimal cleaning effectiveness.
Special Considerations for Children:
Parents should be encouraged to choose appropriately sized
toothbrushes for their children and to supervise brushing to ensure
proper technique and effectiveness.
Meperidine
Pharmacology
Meperidine (Demerol)
Meperidine is a phenylpiperidine and has a number of congeners. It is mostly effective in the CNS and bowel
Produces analgesia, sedation, euphoria and respiratory depression.
Less potent than morphine, 80-100 mg meperidine equals 10 mg morphine.
Shorter duration of action than morphine (2-4 hrs).
Meperidine has greater excitatory activity than does morphine and toxicity may lead to convulsions.
Meperidine appears to have some atropine-like activity.
Does not constrict the pupils to the same extent as morphine.
Does not cause as much constipation as morphine.
Spasmogenic effect on GI and biliary tract smooth muscle is less pronounced than that produced by morphine.
Not an effective antitussive agent.
In contrast to morphine, meperidine increases the force of oxytocin-induced contractions of the uterus.
Often the drug of choice during delivery due to its lack of inhibitory effect on uterine contractions and its relatively short duration of action.
It has serotonergic activity when combined with monoamine oxidase inhibitors, which can produce serotonin toxicity (clonus, hyperreflexia, hyperthermia, and agitation)
Lung volumes and capacities
PhysiologyLung volumes and capacities:
I. Lung`s volumes
1. Tidal volume (TV) : is the volume of air m which is inspired and expired during one quiet breathing . It equals to 500 ml.
2. Inspiratory reserve volume (IRV) : The volume of air that could be inspired over and beyond the tidal volume. It equals to 3000 ml of air.
3. Expiratory reserve volume (ERV) : A volume of air that could be forcefully expired after the end of quiet tidal volume. It is about 1100 ml of air.
4. Residual volume (RV) : the extra volume of air that may remain in the lung after the forceful expiration . It is about 1200 ml of air.
5. Minute volume : the volume of air that is inspired or expired within one minute. It is equal to multiplying of respiratory rate by tidal volume = 12X500= 6000 ml.
It is in female lesser than that in male.
II. Lung`s capacities :
1. Inspiratory capacity: TV + IRV
2. Vital capacity : TV+IRV+ERV
3. Total lung capacity : TV+IRV+ERV+RV
Intrinsic pigmentation of teeth
Pedodontics
Erythroblastosis fetalis
Blue-green colour of primary teeth only. It is due to excessive haemolysis of
RBC. The Staining occurs due to diffusion of bilirubin and biliverdin into the
dentin
Porphyria
Purplish brown pigmentation. to light and blisters on The other features hands
and face e Hypersensitivity are are red red coloured urine, urine,
Cystic fibrosis
(Yellowish gray to dark brown. It is due to tetracycline, which is the drug of
choice in this disease
Tetracycline
Yellow or yellow-brown pigmentation in dentin and to a lesser extent in enamel
that are calcifying during the time the drug is administered. The teeth
fluoresce yellow under UV light