4. BAMS Pharm/Psych/Oral Bio

Question 1

Pharmacology

1. Describe first-pass metabolism
2. Describe 3 advantages and disadvantages of oral drug administration
3. Name 5 types of parenteral drug administration
4. Describe 3 advantages and disadvantages of parenteral drug administration

Answer 1

1. Concentration of drug is greatly reduced before reaching systemic circulation in the liver/gut. Occurs with orally administered drugs that have to pass through GIT once before reaching systemic circulation
2. Socially acceptable, easy to tolerate, can be self-administered
   Slow onset, variable absorption, affected by first-pass metabolism
3. IV, IM, SC, TD, inhalation
4. Predictable plasma levels, not affected by first-pass metabolism, quicker onset
   More expensive, lead to more severe allergic reactions, difficulty with access/self-medication

Question 2

Psych 1

1. Define anxiety
2. 2 types of affective disorders
3. 4 symptoms of depression
4. Define schizophrenia
5. 4 symptoms
6. Describe 2 types of eating disorders
7. Name 2 categories of anti-depressants and how they work

Answer 2

1. Normal response to life experiences but pathological if exaggerated, frequent or chronic
2. Depression, paranoia, mania, manic-depressive
3. Low mood, reduced interest and motivation, poor concentration, lethargy, tiredness, loss of confidence and self-esteem, sleep disturbance, early morning wakening, appetite disturbance and weight loss
4. Fundamental and characteristic distortion of thinking and perception. Multifactorial abnormality of dopaminergic neurotransmission
5. Auditory hallucinations, delusions of thought control, delusions of though, delusional perception
6. Anorexia - altered perception of body image - restricting or binge/purge types
   Bulimia - normal weight - binge eating and compensating behaviours - vomiting, excessive exercising, fasting, laxative use
7. TCAs - for treatment-resistant depression. Block serotonin and noradrenaline transporters, causing increased concentration of these neurotransmitters at synapse and enhanced neurotransmission
   SSRIs - when NTs fired into synapse, some don’t cross the synapse are are reclaimed by pre-synaptic cells. SSRIs inhibit the reuptake of serotonin in these situations. Serotonin stays in synapse longer than usual and can repeatedly stimulate post-synaptic cell receptors, increasing signalling (short-term) and affecting mood, anxiety, sleep, appetite, etc.

Question 3

Oral Biology

1. What is the embryological origin of dental tissues
2. 5 stages of tooth development
3. Briefly describe embryology of tooth development
4. Describe the feeding process in 3 stages
5. Describe the squeeze-back mechanism
6. Describe the difference between swallowing solids and liquids
7. 4 ways reflux is prevented

Answer 3

1. Enamel - ectoderm
   Dentine, cementum, pulp, PDL, alveolus - ectomesenchyme
2. Initiation, morphogenesis, cytodifferentiation, matrix secretion, root formation
3. 6wks IUL - PEB forms
   7wks IUL - dental lamina forms
   8-10wks IUL - enamel organ and dental papilla form
   12wks IUL - enamel organ (IEE, EEE) form a cap over papilla
   14wks IUL - enamel organ differentiation (IEE, EEE, stratum intermedium, stellate reticulum), tooth shape defined
   18wks IUL - crown shape well defined, enamel and dentine apposition begin. Papilla cells adjacent to IEE differentiate into odontoblasts. This induces IEE cells to differentiate into ameloblasts. Crown formation begins then cervical loop migration maps out crown shape. Root shape defined by apical growth of cervical loop (HERS), initiating root dentine formation. Once initial layer is formed, HERS breaks up and remnants persist as debris of Malassez. Mesenchymal cells from follicle are induced to differentiate into cementoblasts. Fibres from developing PDL are embedded into cementum (Sharpey’s fibres)
4. Ingestion - movement of food into mouth
   Stage I transport - material moved from anterior mouth to posterior teeth
   Mechanical processing - breakdown of foods before swallowing
   Swallowing - food bolus transported through lower pharynx and oesophagus into stomach. Food prevented from entering airway by laryngeal inlet closure, vocal fold adduction, upper and forward movement of larynx, apnoea. Swallowing phases - oral/buccal phase, pharyngeal stage, oesophageal stage
5. Forward movement of tongue creates contact between tongue and hard palate. Contact zone moves progressively backward, squeezing processed food through fauces
6. Liquids - swallowed from mouth with posterior oral seal
   Solids - swallowed from oropharynx with no posterior oral seal
7. Upper and lower oesophageal sphincters, elevation of soft palate, sides of tongue contacting fauces, dorm of tongue contacting posterior pharyngeal walls