SAQ 2016

Question 1

When does primary epithelial band occur?

Answer 1

When does primary epithelial band occur?

Question 2

Name 2 structures that develop from primary epithelial band.

Answer 2

• Dental lamina

- Vestibule

Question 3

What is the first mesenchymal marker for tooth eruption ?

Answer 3

I

Question 4

IEE then will collapse forming REE. State the role of REE.

Answer 4

Protect the tooth before it erupts

Question 5

explain about the root formation of single rooted tooth.

Answer 5

i) Crown formation completes, root formation starts ii) Tooth start to erupt when 1/3 of root forms
iii) Begins with cervical loop (CL) that is responsible for root development iv) CL consist of IEE and EEE v)
Proliferates to form double layer of cells known as Hertwig’s Epithelial Root Sheath (HERS)
vi) HERS induces outer cells of dental papilla undergo differentiation and form odontoblast
vii) Odontoblast will undergo dentinogenesis viii) Begins to secrete predentine ix) Root lengthening, HERS extends downwrad until it encloses the dental papilla x) An opening of primary apical foramen, for nerve and blood vessels left xi) After root dentin completed, HERS disintegrates
xii) Cells become epithelial rests of Malassez

Question 6

State 2 theories of tooth eruption other than root formation theory.

Answer 6

• Field model

- Clone model

Question 7

Give the relationship of maxillary and mandibular teeth in ideal occlusion.

Answer 7

• All teeth is in contact with two opposing teeth except 18 and 41
• 13 located between 43 and 44
• Mesiobuccal cusp of 16 is in contact with mesiobuccal groove of 46

Question 8

State the condition of the relationship in the Class II malocclusion.

Answer 8

i) Class II, Div I
- Mesiobuccal cusp of 16 is anterior to the mesiobuccal groove of 46
- Anterior teeth, especially central incisors, are protuded
- Incisors display proclined position
ii) Class II, Div II
- Similar to Div I onlt that the central incisors are retroclined

Question 9

What causes mesial drift?

Answer 9

• Anterior component of occlusal force
• Contraction of transeptal ligament
• Soft tissue pressure

Question 10

State one function of the following cranial nerve nuclei:

Edinger-westphal, nucleus solitarius

Answer 10

• Edinger-westphal = Parasympathetic stimulation

- Nucleus solitarius : Sensory nucleus for vagus nerve (Taste)

Question 11

Name two cranial nerve associated with the following salivatory nuclei:

Superior salivatory nucleus, Inferior salivatory nucleus

Answer 11

• Superior salivatory nucleus : Facial nerve

- Inferior salivatory nucleus: Glossopharyngeal nerve

Question 12

Denticulate ligament

Answer 12

• Flat membranous, continuation of the pia mater - Located at midline between ventral & dorsal root.

Question 13

Cauda equina

Answer 13

• A horse tail-shaped bundle of spinal nerve originating from L5 level
• Nerves that are responsilbe for the innervation of the lower limbs

Question 14

Conus medullaris

Answer 14

• Terminal portion of the spinal cord

- Forms around the level of L1

Question 15

Filum terminale

Answer 15

• A strand of connective tissue at the extend from tip of conus medullaris
• Composed of the pia mater

Question 16

What are the three meninges layer?

Answer 16

Pia, arachnoid & dura matter

Question 17

What is the tract that cause Friedreich’s ataxia?

Answer 17

Spinocerebellar tract

Question 18

Name 3 structures that make up the interatrial septum.

Answer 18

• Septum primum
• Septum intermedium
• Septum secundum

Question 19

Bronchiole

Answer 19

Pseudostratified columnar epithelium with cilia & goblet cell

Question 20

Alveoli

Answer 20

Simple squamous epithelial cell

Question 21

Give the formula for alveolar ventilation.

Answer 21

VA = (VT-VD) × f
VT = Tidal volume VD = Dead space f = Respiration rate

Question 22

Give 2 factors that can affect lung compliance.

Answer 22

• Alveolar surface tension

- Elasticity of lung tissue

Question 23

Define lung compliance.

Answer 23

Change of lung volume from per unit of change in transpulmonary pressure

Question 24

With the aid of flow chart explainhow excess mucous could block smell sensation.

Answer 24

• Excess mucous is due to the bacteria infection
• Results in the swelling of membrane of the nose
• Odor molecules dissolves & less concentrated
• Sensory receptors of olfactory cell in olfactory bulb less sensitive
• Stimulus cannot be transmitted through the olfactory nerve
• Less smell detected in the brain.

Question 25

How does lost sensation of smell and taste affect Mrs Bridget's well being?

Answer 25

Loss sense of smell and taste cannot generate the flavour of food

Question 26

State ONE theoretical model that explain taste sensation.

Answer 26

- Labelled-line model - Individual receptor cell is tuned with single taste modalities - Innervated by individually tuned nerve fiber.

Question 27

State the anomaly of this tooth that is found in Caucasoids and the area of the anomaly. (1 m)

Answer 27

Cusp of Carabelli, mesiolingual cusp area of 16/26

Question 28

State other anomaly that usually occur on the furcation area of this multirooted tooth.

Answer 28

Taurodontism

Question 29

Type of mutation in sickle cell anaemia.

Answer 29

Point mutation

Question 30

Technique to detect sickcle cell anaemia.

Answer 30

Polymerase Chain Reaction (PCR)

Question 31

Steps of the technique, pcr

Answer 31

i) Denature the DNA strand in the 94o C ii) Anneal the DNA with the primers in 37-65oC iii) Extend the DNA synthesis from primers using Taq DNA polymerase at 70-75oC

Question 32

What are the facial prominences that give rise to cleft lip and palate?

Answer 32

- Lack of fusion between medial nasal process and maxillary process - Lack of fusion between primary palate or palatine shelves or between primary and secondary palate

Question 33

Outline the development of anterior two thirds of the tongue

Answer 33

- Anterior 2/3 of tongue develop from first pharyngeal arch - Three swellings, two from lingual swelling and 1 from tuberculum impar - Lingual swelling enlarge and merges with each other & tuberculum impar - Innervation to this area is lingual branch of the trigeminal nerve.

Question 34

Poiseulle’s equation,

Answer 34

- Airway radius determine the airway resistance - Airway radius ↑, airway resistance ↓ - Flow of air ↑ - Most important factor, raised to the fourth power

Question 35

What is the effect of growth hormone in protein metabolism?

Answer 35

- Uptake of amino acid into the cell ↑ - [Amino acid] in the plasma ↓ - Rate of protein synthesis ↑ - Positive nitrogen balance

Question 36

Name two hypothalamic hormone that stimulate growth hormone secretion from anterior pituitary

Answer 36

- Growth Hormone releasing Hormone (GHRH) | - Thyrotropin Releasing Hormone (TRH)

Question 37

State the effect of insulin to

Answer 37

- Plasma potassium level :↑ | - Hepatic glycogenolysis :↓

Question 38

Name two metabolites that stimulate insulin release from pancreas

Answer 38

Glucose and amino acids

Question 39

Normal range of fasting plasma glucose level

Answer 39

4.0 – 6.0 mmol/L ( 72 – 108 mg/dL )

Question 40

Explain the effect of angiotensin II.

Answer 40

- Stimulates aldosterone production - Leads to sodium retention, reabsorbed from the plasma - Water will follow the direction of sodium - Angiotensin II also stimulates ADH which causes water reabsorption from collecting ducts - Activation of receptors causes vasoconstriction of renal arteries, RBF ↓

Question 41

Define and give formula of renal clearance.

Answer 41

Volume of plasma that completely cleared of the substance in one minute

Question 42

Body fluid composition ( ECF,ICF,ISF,Plasma-each berapa percent?)

Answer 42

- ECF: 20% of TBW - ICF: 40% of TBW - ISF - Plasma

Question 43

Give source of energy during starvation.

Answer 43

- Fatty acids - Glycogen - Amino acids

Question 44

What is the most important organ that the hormone mentioned in

Answer 44

Liver

Question 45

State the hormone released during starvation

Answer 45

Glucagon

Question 46

Explain why less energy is produced in oxidation of odd numbered unsaturated fatty acids?

Answer 46

- It skips one step | - Does not undergo oxidation of acyl CoA to trans-Δ-enoyl-CoA, FADH2 not produced

Question 47

What is the extra enzyme invoved in oxidation of unsaturated fatty acids, double bond at odd numbered carbon?

Answer 47

Enoyl CoA isomerase

Question 48

How are activated fatty acids transported?

Answer 48

- Fatty acyl carnitine transported across the inner mitochondrial membrane in exchange for carnitine by an antiport translocase - In mitochondrial matrix, fatty acyl carnitine reacts with CoA in a reaction catalyzed by carnitine acyltransferase II (CAT-II), yields fatty acyl CoA and carnitine - Fatty acyl CoA is now ready to undergo beta-oxidation

Question 49

Write the chemical equation for activation of fatty acids.

Answer 49

R-COOH + CoASH + ATP R-CO-SCoA + AMP + PPi