Embryology

Yes any abnormalities that occur in the cap stage (eg dens in dente) will then remain as part of the tooth in the ensuing stages.If differentation of cells of enamel organ does not happen in bell stage, apposition of enamel, dentine etc will be affected.

Immunology

Finally got on the blog! have posted this on FB as well.

I wanted to post some questions i have from the Marieb Workbook for people to try:
Immunology:
1. The three major elements of te bodys innate defense system are:
The ___, consisting of the skin and ______; defensive cells, such as _____ and phagocytes; and a whole deluge of _______
2. Indicate the sites of activity of the secretions of the surface membranes:
Lyzosome is found in the body secretions called ____ and ____. Fluids with an acid PH are found in the ____ and ____. Sebum is a product of ____ glands and acts at the surface of the________.
3. What are the three important characteristics of the adaptive immune response?
4. Define Immunocompetence:
5. What signifies that a lymphocyte has become immunocompetent?
6. As an infant receives her first does of oral polio vacine, the nurse explains to her parents that the vacine is a preparation of weakened virus. What time of immunity will the infant develop?
7. How does chewing sugar free gum decrease the likelyhood of caries?
Mutliple Choice:
Which of the following are cardinal signs of inflamation:
a - phagocytosis
b- leukocytosis
c- edema
d- pain
Chemical mediators of inflamation include:
a- pyrogens
b- histamine
c- prostaglandins
d- Lymphokines
Which term describes the WBCs ability of squeeze through capillary endothelium into tissue spaces?
a- diapedesis
b- margination
c- degranulation
d - positive chemotaxis.

If you want the other sections i'll put them up x

Practice exam! 2005

Hi, just a quick question I tried to attemp part B) of one of the questions from the immunology section! Following on from the cardinal signs of inflammation (which was fine) I know that histamine, complementm kinins and prostaglandins are all chemical mediators.. I've researched the ones I dont know well at all.. But still having trouble putting it in context/answer.. has anyone else done this question and could help me out?

Embryology

Are the 4 cell types of enamel organ (IEE, OEE, SR and SI) first present in Bell stage and if so does that mean that in Cap stage they are all just classed as enamel organ as they are still differentiating?

Immunology Workshop

There was a question in our Immunology Workshop that asked why does loose connective tissue appear more cellular than dense irregular CT. Any ideas?

IMMUNOLOGY REVISION

Is anyone interested in answering these questions that I've come up with and just comparing our answers and clarifying certain things? As I think the more questions we can become familiar with and answer the more clear it becomes :)!! Here are some questions:

1) Briefly explain the 3 lines of defence
2) What are the cardinal signs of inflammation?
3) Explain a type one allergic response (anaphylaxsis), both the first contact stage (sensitisation) and the second contact stage (subsequent response)
4) Explain the clinical link with Diabetes and Perio

Feel free to post question you've come up with yourself aswell!!

Revision Semester 2 Neurology

Great to see so many of you at the revision session today.

I have listed some MCQs for you to answer in this shared forum and discuss.

Have fun::

1.    Which of the following is an element of the peripheral nervous system?
a. Receptors
b. Cervical plexus
c. Ganglia
d. Trigeminal nerve
e. All of the above

2.    The colloquialism "gray matter" refers to somebody using his intellect or reasoning ability. In reality, what is gray matter?
a. Meninges
b. Myelinated nerve fibers
c. Cell bodies
d. Nodes of Ranvier
e. Neurofilaments

3.    All of the following are properties of neurons, except:
a. High metabolic rate
b. Longevity
c. Specialized for conduction
d. High mitotic rate
e. Limited ability for oxygen deprivation

4.   The action potential of a nerve cell:

            a)  results from a large increase in the membrane permeability to sodium ions.

              b)   can summate one with another.

              c)    may vary considerably in amplitude.

              d)    becomes larger as stimulus strength increases.

5.    The velocity of action potential propagation:

       a)   is independent of an axon’s diameter.

       b)  depends on the thickness of the myelin around the axon.

       c)   will be unaffected if the axon becomes demyelinated.

       d)     is fastest in unmyelinated axons. 

6.               In a neuron, neurotransmitters are stored in 

         a)   the cell body

         b)   vesicles within dendrites 

         c)    the cytoplasm of the nucleus

        d)   vesicles within axon terminal 

7.   Which of the following actions would be considered a parasympathetic response?

           A)   increase in heart rate

B)   decrease in digestion

            C)   increase in salivation

            D)   decrease in salivation

   

Short Answer:

1. Outline your understanding of a voltage gated channel. 

2. What is a receptor? Which type of receptors are found in the human body?

3. What role do the association neurons play in the CNS?

 

Neurophysiology: Exam revision

Mikaela has devised a flow chart for the propagation of an action potential outlined below. She is kind enough to allow us to share this with the class for comment:

Steps of Neurophysiology By Mikaela Aldenhoven

Polarised membrane /resting potential = more negatively charged ions inside the cell and more positively charged ions outside the cell in the extracellular fluid

Stimuli (neurotransmitter) causes gates in cell membrane to open slightly

Sodium trickles into the cell

When the inside of the cell reaches its threshold, the sodium gates open wider and sodium rushes into the cell causing depolarisation

The sodium diffuses through the cytoplasm of the axon and another action potential is created at the adjacent node (node to node)

Sodium gates close and potassium gates open

Potassium diffuses out of the cell to the extracellular fluid

The neuron is polarised again (resting potential)

The sodium potassium pump transports sodium out and potassium into the cell

Would anyone like to comment on this or add anything?

Blood Supply/Lymphatics case studies 5 - Ginny Vitis

You are examining Ginny’s mouth and note chronic gingivitis in her lower anterior region. On the diagram provided track and label the possible routes of venous drainage from the gingiva in the lower left hand side incisor region.

Blood Supply/Lymphatics case studies 4 - Sally Bracken

Sally had her deciduous lateral incisor (52) knocked out when she ran into a pole. Using the diagrams provided, track and describe the pathway of blood from her heart to the ‘break’ in the CVS

Blood Supply/Lymphatics case studies 3 - Anton Sill

When updating Anton’s medical history, he mentions that he has recently had his tonsils and adenoids removed after several bouts of tonsillitis.

On the following diagram, mark the sites of where the surgery would have occurred.

What is the function of tonsils? Differentiate between tonsils and lymph nodes.

Blood Supply/Lymphatics case studies 1 - Lyn Noder

As part of your extra-oral examination of Mrs Noder, you are palpating the relevant lymph nodes of her head and neck.

You detect lymphadenopathy in her submental and submandibular lymph nodes.

On the following diagram label the areas that you would find these lymph nodes.

What may the lymphadenopathy indicate?

What areas would you examine intra-orally to confirm your findings?

Blood Supply/Lymphatics case studies 2 - Drew Blood

Patient Two: Mr Drew Blood

During your intra-oral examination of Mr Blood you detect a large buccal abscess adjacent to his lower right first permanent molar (46). He reports that the “lump” has been there for some time and is often extremely painful. He then takes Panadeine Forte to alleviate the symptoms. Beyond the obvious dental problems, what is the threat to Mr Blood’s general state of health, given the physiology of blood supply and drainage of the oral area?

PRACTICE EXAM PAPER - ORAL HISTOLOGY

SECTION A

MULTIPLE CHOICE QUESTIONS – circle the correct answer in this test booklet.

1. Enamel is formed by which type of cell?

A) Odontoblasts
B) Enameloblasts
C) Ameloblasts
D) Fibroblasts

2. Enamel is usually % mineralised by weight:

A) 50
B) 65
C) 70
D) 96

3. Which of the following dental tissues are derived from the same embryonic source?

A) Enamel and dentine
B) Enamel and pulp
C) Enamel, dentine and pulp
D) Dentine and pulp

4. The peritubular dentine found surrounding each tubule is:

A) not true dentine
B) less calcified than intertubular dentine
C) more calcified than intertubular dentine
D) not different from intertubular dentine

5. In a healthy, mature tooth where is the location of the cell body of an odontoblast?

A) at the dentino-enamel junction
B) in the outer wall of the pulp
C) in the centre of the dentinal tubules
D) within the pulpal core

6. Secondary dentine forms:

A) before the completion of the apical foramen
B) in response to trauma
C) at the dentino-enamel junction
D) on the outside wall of the pulp

7. Enamel rods are longest:
(i) cusps tips
(ii) at the CEJ
(iii) incisal edges
(iv) at the bottom of fissures

A) i and ii
B) i and iv
C) ii and iii
D) i and iii

8. Incremental lines within the enamel that appear to transverse the rods are known as:

A) Lines of Retzius
B) Imbrication lines of Von Ebner
C) Enamel spindles
D) Perikymata


9. Which of the following properties is NOT characteristic of enamel?

A) Dynamic tissue
B) Highly mineralised
C) Nonvital
D) Highly vascular


10. Partially calcified enamel faults, which often extend from the DEJ to the outer surface, are known as:

A) Enamel tufts
B) Gnarled enamel
C) Enamel spindles
D) Enamel lamellae

PART B Short Answer Questions

1. Describe how fluoride interacts with enamel during amelogenesis and post-eruptively
(5 marks)


2. You are placing a fissure sealant in a molar tooth. A step in the process is applying an acid etching solution to the enamel area to be sealed. Describe how the histology of enamel tissues enables the sealant to adhere to the tooth using the acid etch technique
(8 marks)



3. Describe the age changes that occur in the dental pulp? How do these changes affect the response of the dental pulp to an injury such as dental caries?
(6 marks)



4. You are examining a patient and note that due to using a hard toothbrush and a vigorous action, they have worn away some of the enamel on the buccal surfaces of their molars.
4a What symptoms may these patients be experiencing and explain why?
(3 marks)











4b What would this patient be at higher risk for on these affected surfaces? Give reasons for your answer.
(2 marks)
5. Ivor Payne has come into the surgery with a toothache in his upper left quadrant. Clinically only a small break in the enamel through an occlusal pit of 26 can be detected.




A bitewing radiograph of the area shows occlusal caries well established into dentine of the 26

5a Discuss the histological properties of enamel and dentine that explain why the caries appears radiographically.
(6 marks)













5b Why would Ivor be experiencing pain from the tooth?
(4 marks)














5c What mechanisms can the pulp initiate to protect itself from the bacterial invasion?
(3 marks)

6. The following diagram shows the developing dentine and enamel tissues during the apposition stage of tooth development.
Developing enamel
Diagram from Bath-Balogh M and Fehrenbach MJ (2006) Illustrated Dental Embryology, Histology and Anatomy, 2nd edition, Elsevier Saunders: St Louis
Developing dentine


6a Label the diagram where indicated. Then in the space below, discuss the purpose of each labelled feature (9 marks)
















6b Describe what occurs to the ameloblasts and odontoblasts after formation of their relevant dental tissues, and what implications this has for the tooth.
(4 marks)







7. The junctional epithelium (JE) is considered to be the first line of defence that protects the underlying connective tissue from onslaught from bacterial toxins. How does the JE performs this function from a histological perspective.
(5 marks)











8. During a clinic session a patient presents with clinically healthy gingival tissues.
(6 marks)

a. Describe how you would record the appearance of healthy gingival tissues on your examination sheet?










b. The presence of stippling is one indicator of gingival health. Explain what causes stippling on a histological level.














c. You notice that in one area, around the 34, there is an isolated area of 4-5 mm of recession. Outline any possible cause/s of this isolated case.












9. Explain how the periodontal ligament performs the following functions:
(7 marks)


Formative/regenerative







Nutritive








Sensory








Adaptive








Supportive








10. What radiographic indications could give you evidence of a healthy attachment apparatus? (4 marks)















11. Draw a series of clearly labelled diagrams to represent a tooth and its supporting structures. The following must be included: (pencil can be used to answer this question) (18 marks)

Enamel Alveolar crest
Dentine CEJ
Cementum Apex
Junctional epithelium Lamina dura
Sulcular epithelium Free gingiva
Gingival margin Attached gingiva
Mucogingival junction Alveolar mucosa
Free gingival groove Gingival col area