Year 1 Study Flashcards
(355 cards)
1
Q
What is the percentage composition of minerals within cementum, dentine, enamel and bone respectively?
A
Cementum- 65%, Dentine- 70%, enamel- 96%, bone- 60%
2
Q
What is the main mineral in cementum, enamel and dentine? And what is the chemical symbol for it?
A
Calcium Hydroxyapatite Ca10(PO4)6(OH)2
3
Q
What is the difference between a cementoblast, cementocyte and cementicle?
A
Cementoblasts produce cementum and are at the precementum later. Cementocytes are cementum cells that are freely dispersed within cellular cementum matrix.
A cementicle is a ball of cementum of the periodontal ligament.
4
Q
What is the order of the cementum layers?
A
Precementum, cellular cementum, acellular cementum.
5
Q
What is the difference between tome’s fibre and tome’s process?
A
Tomes fibre is the odontoblastic process of the odoncoblast. Whereas Tom’s process is an extension of the ameloblast.
6
Q
Where is the mature circumpulpal dentine deposited within the enamel matrix?
A
The mineralisation front of the predentine.
7
Q
What is a characteristic of the cementum canaculi?
A
The projections are in the same direction towards the periodontal ligament, whereas canaculi in normal compact bone is multidirectional.
8
Q
What is the main component of the principal fibres in the PDL?
A
Collagen type 1
9
Q
What is the main component of the organic component of dentine, and what does this give rise to?
A
The organic component of dentine is collagen type 1 (tropocollagen), these collagen fibres cause the adressen lines.
10
Q
What are the 4 main subtypes of principle fibres?
A
Apical, oblique, alveolar crest and horizontal fibres.
11
Q
What is immature collagen called and how does it appear histologically?
A
Oxytalan. It appears grey, undifferentiated, smudged near the cementum border within the PDL.
12
Q
What are the epithelial rests of mallassez?
A
Epithelial remnants of hertwigs root sheath within the periodontal ligament.
13
Q
What are epithelial rests of serres?
A
Epithelial remnants from the dental lamina in the gingiva.
14
Q
What do BMP and TGF-beta stand for?
A
Bone morphometric protein and tissue growth factor beta. They regulate osteoblast and chondrocyte formation in bone health.
15
Q
What is the difference between SEM and TEM?
A
Transmission electron microscope is 2D and scanning electron microscope is 3D.
16
Q
What are the central and accessory channels within compact bone called?
A
Haversian canals and Volkmann’s canals.
17
Q
What is the feature in bone which contains osteoclasts for bone remodelling and resorption?
A
Howship’s lacunae.
18
Q
What is a cementicle?
A
It is a ball of cementum within the PDL.
19
Q
What are the incremental lines in cementum called?
A
Incremental lines of salter
20
Q
What type of cementum overlaps enamel?
A
Afibrilar cementum
21
Q
What is the point where cementum and enamel meet called?
A
A butt joint.
22
Q
What is the difference between acellular/ cellular intrinsic/ extrinsic/mixed cementum?
A
cell presence and MATRIX ORIGIN. E.g. extrinsic is originated from the sharpey’s fibres of the PDL and intrinsic fibres are derived from cementoblasts and run parallel to the root surface.
23
Q
What can happen to cementum if it undergoes trauma/stress?
A
It undergoes resorption, then reparative cementum can form in the areas of recession.
24
Q
What does fluoride replace within the hydroxyapatite?
A
Fluoride replaces OH in enamel crystals, inhibiting acid dissolution/ the carboxyl group. The carboxyl group within the enamel prism is very reactive/ susceptible to acid dissolution.
25
What does water between the crystals facilitate?
Ion transportation i.e. fluoride.
26
What is the concentric order of compounds within the enamel prism?
hydroxyl- calcium-phosphate-calcium
27
What are enamel tufts and where are they found?
They are remnants of lipids/ proteins from teeth formation and are found between the dentine and the enamel.
28
What is the most common arrangement of the prisms?
Keyhole arrangement.
29
Why do the enamel prisms have this keyhole appearance?
Due to the Tomes’ processes of the odontoblasts.
30
What are the two different incremental lines of the enamel?
Hunter-schreger bands (horizontal) and Striae of Retzius (obliquely).
31
What is unique about the outer quarter of enamel and why?
It is aprismatic due to the Tomes’ processes not being formed in the initial layer of enamel.
32
What is visible on a crossection of enamel (tree like)?
Striae of Retzius.
33
What is it called when you can see striae of Retzius on the outside of the tooth before erosion?
Perikymata
34
What is a straight dark line within a ground crossection of enamel called and why does it occur?
An enamel lamella, formed due to the hypo mineralisation of a complete enamel prism.
35
What is the difference between caries versus erosion?
Caries is dissolution of enamel due to the acid produced by bacteria, erosion is the acid dissolution of the enamel due to external acids through the diet.
36
What can cause small pits within the enamel surface, usually seen at the same level on the tooth surface?
Hypoplasia, normally due to stunted development due to childhood illness.
37
What are the characteristics of dentine phosphoprotein?
The most acidic protein in the body. It plays a role in remineralisation as it has a high affinity for calcium binding.
38
What are the contour lines of Owen?
Dark line in the dentine due to the dramatic change in dentine formation at the point of tooth eruption.
39
Describe intratubular dentine
15% more mineralised dentine within the tubule. It eventually grows and obliterates the tubule causing translucency with age.
40
Why does the dentine eventually turn translucent?
Due to having the same refractive index as inter-tubular dentine, therefore no contrast.
41
What causes interglobular dentine formation?
The calcospheres fail to form.
42
What is the order of the six dentine layers?
Mantle dentine, circumpulpal dentine,interglobular dentine, granular layer of tome, hyaline layer, predentine.
43
What is different about the granular layer of tome?
The granular layer of tome is only found over root dentine.
44
What is unique about the hyaline layer?
It is only found above the granular layer of tome in the root dentine.
45
What are the two incremental lines of the dentine?
Von Ebner’s lines (smaller) and Andressen lines (larger).
46
What is the difference between secondary, tertiary and sclerotic dentine?
Secondary is formed after root formation, tertiary dentine is irregular dentine due to stress and sclerotic dentine is obliteration of the tubules in response to a harmful stimulus.
47
What is the difference between reactionary dentine and reparative dentine?
Reactionary is more irregular and reparative is more organised and resembles normal dentine more (with tubules).
48
What is seen in response to caries on the dentine?
The dead tracts of fish, to protect the pulp from bacterial and acid invasion from caries.
49
What composition of pulp is water
75%
50
Of the 25% organic matter in pulp, name 3 components
Collagen type 1 / 2, Glycosaminoglycans, proteoglycans
51
What type of nerves give pain and temperature senses in the pulp?
Alpha Delta nerve fibres
52
What type of nerve fibres produce non noxious sensations?
Alpha Beta nerve fibres?
53
What are the majority of nerves in the pulp that produce dull pain called?
Unmyelinated C fibers
54
What is the name of the layer of nerves directly under the odontoblastic layer?
Plexus of Raschkow
55
What peptide is a potent vasodilator within the pulp?
calcitonin gene-related peptide
56
What are the 4 layers of the pulp?
Odontoblastic layer, Cell free zone, Cell rich zone, Bulk of the pulp
57
What is the difference between a true pulp stone and a false pulp stone?
A true pulp stone resembles dentine(as there’s tubules present), whereas false stones resemble bone
58
Where is the hyaline layer within the dentine situated?
Over the layer of tome and root cementum
59
Where is the mantle dentine found?
Above the circumpulpal layer before the enamel starts
60
What are the 4 stages of periodontal disease?
Initial lesion, Early lesion, Established lesion, Advanced lesion
61
Describe early lesion
Red and inflamed ginigivae, and movement of epithelium to collagen depleted areas
62
Describe established lesion
Where lymphocytes migrate into the periodontal tissue and pocket formation occurs
63
Describe Advanced lesion
There is periodontal ligament loss and junctional epithelium migration
64
What is the difference between suprabony and infrabony pockets?
Suprabony pockets have vertical bone loss and infrabony have horizontal bone loss
65
What adaptive immune cells infiltrate the connective tissue in periodontal disease?
B lymphocytes
66
What are the 4 different type of caries classification?
Pit/Fissure caries, root surface caries, recurrent caries, smooth surface caries
67
Name the three different progression rates of caries
Rampant, Arrested, Chronic
68
What is the appearance of arrested caries?
Black
69
What are the 4 parts of an enamel caries lesion?
Translucent zone (loses the interprismatic crystals), Dark zone (hypermineralised due to free minerals), Body of the lesion (the largest zone of demineralisation), surface zone (hypermiseralised)
70
What are the 4 zones of a dentine caries?
Sclerosis zone (increased peritubular dentine for protection), demineralisation (acid in the tubules STERILE), bacterial invasion (liquefaction fossi and bacterial infiltration), zone of destruction (bacteria in the tubules and cracks/ cavitation).
71
What is the critical pH of enamel and dentine respectively?
Enamel 5.5 and dentine 6.3.
72
What are the two aspects of the developing tooth germ lamina?
Vestibular lamina and dental lamina
73
What does each of these lamina develop into?
The vestibular lamina the vestibule (dissolves eventually) and the dental lamina develops into the tooth bud.
74
What happens during the tooth bud stage?
The mesenchyme cells undergo condensation at this stage.
75
What happens at the cap stage?
It undergoes further condensation of the ectomesenchyme to form a ‘cap’
76
What are the different cell types at the different lamina? And what do they develop into?
They develop into cuboidal epithelial cells at the external enamel epithelium (periodontal ligament) and columnar cells at the internal enamel epithelium to then develop into ameloblasts.
77
What cell structures lie within the internal and external enamel epithelium?
The stellate reticulum, ‘star’ shape due to the fluid between the cells and the desmosome holing them together. These cells encourage the correct shape of the future crown.
78
What group of cells goes on to form the pulp?
The papilla (condensed ectomesenchyme).
79
What is the dental follicle, outside of the external enamel epithelium?
The dental follicle is the foundations of the periodontal ligament.
80
Where does the stratum intermedium lie and what does it do?
A thin layer of cells over the internal enamel epithelium which facilitates the transport of material and facilitates protein synthesis
81
What happens to the external enamel epithelium and the dental lamina eventually?
It eventually dissolves after formation of the permanent tooth bud. (sometimes left behind as the epithelial rests of serres.
82
What is the order of formation of the different crown substances?
dentine-enamel-cementum.
83
Explain the induction theory?
inner enamel epithelium (pre-ameloblasts)- papilla DIFFERENTIATE (odontoblasts) dentine- the formation of dentine by the odontoblasts triggers the formation of enamel by the ameloblasts.
84
Where does dentine formation start?
The cusp tips
85
What is the enamel knot?
A localised mass of cells in the internal enamel epithelium at the cusp tips, which is a signalling centre, and is transient.
86
What are the 5 stages of enamel formation?
Pre secretory, secretory, transition, maturation and post maturation stages.
87
What structure is formed during the pre-secretory stage?
The interproximal web by the desmosomes.
88
What create the prism shape of the enamel?
Tom’s processes.
89
What happens during the secretory stage?
secretory granules are transported along the cell and contain proteins and secreted via merocrine secretion.
90
What happens during the transition stage?
A basement membrane forms and the tom’s processes retreat as the whole length of the enamel prism is formed.
91
What happens during the maturation stage?
The organic material (amelogenin) is mineralised into hydroxyapatite. The plasma membrane forms a ruffled border and a smooth border.
92
Describe the ruffled and smooth border stages?
The ruffled border becomes tight and impermeable allowing for absorption of ions like calcium and for mineralisation to occur. During the smooth border stage the tight junctions are lost which allows for the passage of water and the organic matrix.
93
What is the characteristic of the organic matrix such as amelogenin that makes is easily excretable during mineralisation?
It is THIXOTROPIC, meaning it losses is viscosity under increased pressure.
94
What is the difference in pH between the ruffled and smooth border phases?
ruffled is normal pH and smooth is acidic pH
95
What is the reduced enamel epithelium and what is its significance?
It is a layer of both inner and outer enamel epithelium on the surface and later forms the junctional epithelium.
96
What is the difference between reactionary and tertiary dentine?
Reactionary dentine is created by odontoblasts resembling dentine and tertiary dentine is created by any stem cell/odontoblastic like cells and resembles bone more or is less well differentiated.
97
What is circumpulpal dentine formation controlled by?
Dentine phosphoprotein.
98
Describe in detail the formation of dentine?
Dentine phosphoprotein fuses with calcium ions to form crystals within the HOLE ZONES OF THE TROPOCOLLAGEN
99
What developmental structure forms the root?
Hertwig’s root sheath
100
What structure causes the division into multiple roots during formation?
Epithelial shelves
101
What occurs if parts of Hertwig’s root sheath fails to dissolve?
They form the epithelial cells rests of mallasez.
102
What small bridging structures can be found at the enamel dentine junction next to the enamel tufts.
Enamel spindles.
103
What is a clinical complication of enamel pearls?
There is no attachment to PDL as there is no cementum.
104
What is the order of cementum layers?
acellular cementum covers the dentine, cellular cementum is intermediate and prementum layer is before the periodontal ligament. (Think pre-cementum is vital and needs nutrition)
105
What are the microorganisms in the red complex for periodontal disease?
Porphyromonas gingivalis, Tanerella forsythia, treponema denticola.
106
What is unique about the upper 6 tooth morphology and the erruption?
The cusp of carabelle and the fact that is has no predescessor.
107
How to tell if it a primary of secondary tooth mainly?
Look at the length of the roots and if there are multiple roots they are splayed out.
108
What is the foundation of the pharyngeal pouches and where are they initially derived from?
Ectomesenchyme cells, they are derived by the migration of neural crest cells from the frontal prominence.
109
What is the hole what forms initially in the early embryo?
The somatoderm.
110
What is the first pharyngeal arch developing into and what nerve?
The trigeminal nerve, maxillary and mandibular prominence.
111
What syndrome is a result of 1st pouch malformation?
Treacher collins syndrome.
112
What is the nerve and structured created from the second arch?
Facial nerve, facial muscles, inferior hyoid muscles, tympanic structures.
113
What type of cartilage is used to develop the tympanic structures?
Reichert’s cartilage.
114
What about the third arch?
Glossopharyngeal nerve, producing the posterior tongue and the common carotid artery.
115
What about the fourth?
The aortic arch, vagus nerve and main body of the hyoid.
116
What about the 5th arch?
It is transient and does not exist.
117
What about the 6th arch?
The vagus nerve, larynx, pulmonary arteries, retrolaryngeal nerve.
118
What is the purpose of the endoderm?
It produces the organs.
119
What are the different endoderms eventual organs?
1- external auditory meatus, 2nd – pharyngeal pouches and palatine tonsils, 3- parathyroid, 4th- thyroid.
120
What lies directly beneath the heart under the sternum?
The thymus. An immune organ.
121
What is the purpose of the ectoderm?
Forms the pharyngeal grooves, only forms the external auditory meatus
122
What is a transient structure that’s remnants form the foramen caecum?
The thyroglossal duct.
123
What separates the anterior and posterior tongue?
The terminal sulcus. Vallate papillae are in this region.
124
What membrane in the foetal development then goes on to form the mouth?
The buccopharyngeal membrane
125
How many initial facial swellings are there?
5
126
What cartilage forms the TMJ?
Meckel’s cartilage
127
When do the primary palates form?
6 weeks
128
When do the secondary palatal shelves join?
8 weeks, then fuse at 9 weeks.
129
Name at least 2 pellicle microorganisms?
streptococci oralis, mitis
130
Name some initial colonisers
S. salivarius, sangius, vielonella
131
What are some benefits of the initial colonisers?
convert acid to alkaline i.e lactic acids , neutralise urea, reduce competition.
132
What are the stages of biofilm formation?
Pellicle formation, reversible attachment, irreversible attachment, miscrobial succession, mature biofilm, Detachment.
133
Give some examples of the facultative anaerobes
s. mutans, lactobacilli, actiomyces.
134
What is unique about actiomyces?
Root caries.
135
Why are s mutans very cariogenic?
They act on sucrose to break it down into fructans and glycans, which are very sticky and make the biofilm very viscous.
136
What do bacteria do with excess glucose?
Store it as glycogen
137
What are the different types (4) of pit fissures?
V, U, I, K
138
What is the demineralisation pH of root caries?
6.7, due to the proteolysis of the PDL.
139
What is the difference between infected and affected dentine?
Infected = acute bacterial infection soft and demineralised, affected= time to react to the bacteria and sclerotic dentine present.
140
Name 3 practices that can be used to detect caries?
Translumination, radiographs, magnification with loupes.
141
What is the difference between hypoplasia and atrophy?
Hypoplasia is caused by a congenital underdevelopment.
142
Name the 5 different cell abnormalities?
Hyperplasia, hypertrophy, atrophy, dysplasia and metaplasia.
143
What is the difference between dysplasia and metaplasia?
dysplasia is precancerous cells, poor differentiation and disordered growth whereas metaplasia is a complete transformation of the cell into a different cell type, however it is still well differentiated.
144
What is the characteristics of a benign neoplasm?
Contained within a basement membrane and is exophytic
145
What are the defining characteristics of a malignant neoplasm?
angiogenesis and inward infiltration and growth.
146
What does p53 do?
It is a gene that codes apoptosis
147
What is Rb?
Retinoblastoma gene, which stops DNA replication. Both of these work to prevent cancer.
148
What is EGFR?
Epithelial growth factor regulator.
149
What is CD4
A glycoprotein in the immune cells, facilitating activation of the immune system. If faulty can cause immune suppression and avoidance.
150
What is different between an adenoma and other disorders?
Adenomas are usually benign.
151
Name some different cancer types?
Carcinoma (epithelial), lymphoma (of the white blood cells), sarcoma (connective tissues), Leukaemia (blood), glioma (neural cells).
152
What is the difference between exocrine and endocrine?
exocrine is via a duct and endocrine is direct secretion into the bloodstream.
153
What type of gland is a salivary gland?
A tubule-acinar eccrine gland via exocrine secretion.
154
What is pseudostratified epithelium?
It is only 1 later columnar epithelium but it gives the appearance of being multi layered.
155
What are the 5 layers of the skin
Stratum basale, spinosum, granulosum, lucidum, corneum.
156
What are the immune cells of the skin?
The lagerhans cells
157
What are the two layers of the dermis?
The papillary layer (loose) and the reticular layer (dense).
158
What are the different secretory and histological characteristics of the different salivary glands?
Parotid gland is serous and DARK staining, sub mandibular is a mix of both serous and mucoid secretions and sublingual is purely mucoid secretions and is light in colour on the slides.
159
What are the 3 different connective tissue fibres?
Elastin, reticular, collagen.
160
What does SCALP stand for?
Skin, dense connective tissue, aponeurosis, loose connective tissue, pericranium.
161
What are the veins that drain into the subdural sinuses.
emissary veins.
162
What is the function of the aponeurosis?
It anchors the facial muscles to the scalp, in lacerated creates a gaping wound.
163
What branches of the TGN sensory supply the scalp?
All three branches of the TGN.
164
What 3 structures pass through the parotid gland?
The facial nerve, the retromandibular vein and the external carotid artery.
165
What does the deep parotid interface and what happens if there is an abnormality?
The parapharyngeal space, so can cause oesophageal swelling and discomfort.
166
What nerve innervates saliva production by the parotid?
The glossopharyngeal nerve via the lesser petrosal nerve and the auriculotemporal nerve.
167
What nerves innervate saliva from the submandibular and sublingual gland?
The lingual nerve via the chorda tympani.
168
What supplies sensory innervation to the parotid?
The auriculotemporal nerve.
169
What is the sensory ganglion of the facial nerve?
The geniculate ganglion i.e. the chorda tympani and the petrosal nerve.
170
What are the 5 branches of the facial nerve?
The temporal, the zygomatic, the buccal, the MARGINAL mandibular, the cervical.
171
Where does the facial nerve exit the skull?
The stylomastoid foramen, from the pons of the medulla.
172
What nerve branches from the facial nerve before the facial nerve enters the parotid gland and undergoes further division into the 5 branches?
The posterior auricular nerve.
173
What is the landmark in the oral cavity for the placement of dentures?
The retromolar pad, due to it being an area highly resistant to bone absorption due to dense cortical bone.
174
What is the name given to the jaw when the alveolar bone is resorbed?
The edentulous jaw.
175
What are the three branches of the trigeminal nerve?
The ophthalmic, the maxillary and the mandibular branches.
176
Where do each of the branches exit the skull?
Ophthalmic = the superior orbital fissure, maxillary= foramen rotundum, mandibular= foramen Ovalle and foramen spinosum.
177
What passes through the jugular foramen?
The vagus nerve, the glossopharyngeal nerve and the accessory nerve.
178
Name the four types of sinuses?
The maxillary, frontal, ethmoid, sphenoid.
179
What artery lies directly underneath the pterion?
The middle meningeal artery.
180
What bones make up the pterion?
the frontal, parietal, temporal and sphenoid bones meet.
181
What is the suture between the occipital bone and the parietal bone?
The lamboidal suture.
182
What is the difference between the le fort 2 and 3 fractures?
Le fort 2 is pyramidal and only involves the viscerocranium and the le fort 3 involves the viscerocranium and the neurocranium.
183
What innervates the infrahyoid muscles?
The ansa cervicallis.
184
What are the two branches of the opthalamic trigeminal nerve?
The supraorbital and the lacrimal nerve.
185
What are some branches of the mandibular nerve?
palatine, zygomatic, infraorbital and nasopalatine.
186
What is the difference between the lingual and hypoglossal nerve?
Lingual is sensory innervation and hypoglossal is motor innervation of the tongue.
187
What is the difference between afferent and efferent nerve fibres?
Efferent is exiting and therefore providing motor supply and afferent is sensory providing information to the brain.
188
What is the difference between afferent and efferent renal arteries?
afferent arterioles bring blood into your kidneys and efferent arterioles take blood out and away from the glomerulus.
189
What are some branches of the mandibular trigeminal?
The inferior alveolar nerve, lingual, mylohyoid, mental, motor root for mastication.
190
What is unique about the mylohyoid nerve and muscle?
It is innervated by its own mylohyoid nerve, a branch of the trigeminal nerve.
191
What nerve innervates the anterior and posterior belly of the digastric?
Anterior= mandibular trigeminal nerve, posterior= facial nerve.
192
What nerve supplies taste to the anterior 2/3 of the tongue?
The lingual nerve with the chorda tympani.
193
What is the difference between a lower and upper motor lesion?
Lower lesion affects the upper and lower aspect of one side of the face and the upper lesion affects only the lower quadrant of the opposing lesion.
194
Where does the geniculate ganglion loop and what does it do?
It loops in the internal acoustic meatus and it innervates the sensory part of the facial nerve.
195
Where is the motor part of the trigeminal nerve located?
Anterior branch of the mandibular nerve.
196
What is the protective passageway for the mandibular TGN and the maxillary artery called?
The infratemporal fossa.
197
What passes through the foramen spinosum?
The middle meningeal artery.
198
What is the protective passageway of V2 called?
The pyterygopalatine fossa.
199
What are the muscles of mastication?
temporalis, masseter, medial and lateral pterygoid.
200
What is unique about the buccinator?
It is a facial nerve, it is only an accessory muscle of mastication.
201
What is side to side movement of the mandible called?
Lateral excursion.
202
What is the web of the veins draining the maxilla called?
The pterygoid venous plexus.
203
What type of joint is the TMJ?
A gingilomarthoidal joint.
204
What are the different movements of the TMJ?
Superior compartment= gliding, translational joint, inferior compartment= hinge, rotational movement.
205
What is the difference between the TMJ and other joints?
It is made up of dense, avascular connective tissue rather than hyaline cartilage.
206
What ligament is most commonly damaged by alveolar nerve block?
The sphenomandibular ligament.
207
What is the ridge on the inside on the mandible called?
The lingula of the mandible
208
What are the two parts of the temporal bone?
The squamous and the petrous part.
209
What are the 4 compartments of the neck?
The investing layer, the prevertebral layer, the pretracheal layer and the carotid sheath.
210
What is contained within the carotid sheath?
The internal jugular, the vagus nerve and the common carotid.
211
What area can cause a spread of infection from the pharynx to the thorax?
The retropharyngeal space.
212
What are the 4 triangles of the anterior neck?
The sub mental, sub mandibular, carotid and muscular.
213
What superficial vein runs alongside the trachea?
The anterior jugular vein.
214
What nerves innervate the larynx?
The recurrent laryngeal nerve.
215
What vessels supply the thyroid gland?
The superior and inferior thyroid artery and the middle and superior thyroid vein, branches from the jugular vein.
216
What innervates the infrahyoid muscles?
The ansa cervicallis
217
Name the infrahyoid muscles
The stylomastoid, the omohyoid, the sternohyoid and the thyrohyoid.
218
What are the suprahyoid muscles?
The mylohyoid, stylohyoid, digastric muscles.
219
What veins drain into the external jugular vein?
The retromandibular vein and the posterior auricular vein.
220
What neck muscles attach to the first and second rib?
The scalene muscles.
221
What is the sequence of vessels in the intercostal space?
Vein, artery, nerve.
222
What accessory muscles are used for inspiration and expiration respectively?
The external are used for inspiration and internal are used for expiration.
223
Where abouts in the lingula of the lung?
Left lung only.
224
Where would you auscultate the aortic and mitral valve?
Aortic= second right intercostal space and mitral 5th intercostal space, midclavicular.
225
From the left and right aspects of the mediastinum, what can you see?
Left aortic arch and right vena cava.
226
What is ludwigs plane?
It divides the superior and inferior mediastinum.
227
Where does the hemiazygous vein cross over to?
From left to right via the accessory hemiazygous vein.
228
Where does the thoracic duct drain into?
The brachiocephalic vein.
229
Where does the visceral and parietal pleura cover.
Visceral = chest wall and parietal = the chest wall.
230
What does I 8 10 EGGS AT 12 mean?
The IVC, oesophagus and aortic hiatuses of the diagram and at what thoracic vertebrae they exit level to.
231
What is the IVC foramen in the diaphragm called?
The caval foramen
232
What is the fossa ovalis and where is is located?
It is a remnant of the foramen Ovalle in the right atrium.
233
What valves close during systole?
The AV valves between the ventricles.
234
What valves close during diastole?
The tricuspid valves of the aorta and the tricuspid.
235
What valve has two cusps?
The mitral valve.
236
What innervates the SA and AV node?
The cervical plexus sympathetically and the vagus nerve parasympathetically.
237
What is a prion?
A protein of unknown function that resides on the brain.
238
What is the name of the prion responsible for mad cow disease?
Transmissible bovine spongiform encephalopathy caused by PrPc (beta sheets) BSE
239
What makes the prion non-infectious?
Chemicals that disrupt protein and lipids. For example, ethers, phenols, hypochlorite.
240
What is a clinical characteristic of vCJD?
Can involve the lymphatics of the pharynx, biopsy can be taken to aid diagnosis, however definitive diagnosis is post-mortem.
241
What does BSE stand for?
Bovine spongiform encephalitis.
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What is sporadic CJD?
Caused by genetic mutation, autosomal dominant.
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What is the main cause of iatrogenic BSE and therefore CJD spread?
Contaminated blood products and instruments.
244
Do prions have nucleic acids, amino acids or both present?
Only amino acids, as it does not contain any DNA.
245
What is a fungal cell called?
A myocelle
246
What is a eukaryote?
A single celled organism.
247
What are three features of a myocelle?
Produce spores, are eukaryotic and have a polysaccharide membrane.
248
What causes oral thrush?
Candida albicans, more specifically pseudomonas candida albicans.
249
What increases the susceptibility of oral thrush?
Immunodeficiency, type 2 diabetes, broad spectrum antibiotic use, dentures.
250
What is the clinical name for dry mouth?
Xerostomia.
251
What classification of fungi is the candida?
Ascomycetes, spores contained within a sac.
252
What sampling method is usually used to diagnose the type of candida?
Direct smear.
253
Name 2 drugs that treat fungal infections and describe their mechanisms of action.
Voriconazole- inhibits the enzyme that produces glycan for the cell wall formation.
Caspofungin- inhibits the enzyme that produces ergosterol for the cell wall.
254
What is not a reliable diagnostic tool for viruses?
Microscopy, as viruses all morphologically look the same.
255
What is a reliable method of testing for virus type?
PCR and antigen presenting.
256
What antibodies are produced during the acute and latent virus stages respectively?
IgA- acute, IgG- chronic
257
What can antibacterial do that antivirals don’t?
Antibacterial have a cidal effect whereas antivirals are just static.
258
What is a viron?
A viron is an ineffective, extracellular virus with a capsid for protection.
259
What is it called when a virus has a specific affinity for a type of cell?
Tissue tropism.
260
What is viral transmission from mother to baby either ante or post natally called?
Vertical transmission.
261
What is the definition of a biofilm?
A structured community of aggregated bacterial cells, embedded and enclosed in a self-produced extracellular polymetric matrix and adherent to an inert or living surface.
262
What is the difference between noradrenaline and adrenaline?
Noradrenaline is a neurotransmitter whereas adrenaline is a hormone.
263
What are the characteristics of the somatic autonomic nervous system?
They are voluntary skeletal muscle and they have a centralised sympathetic region. They are nicotinic and very fast. They are always INOTROPOC which allows for the fast signalling. THEY ALWAYS EXCITE
264
What are the characteristics of the autonomic nervous system?
They metabotropic so are therefore slower. They have varioles that are spread along the length of the axon and give signals to a wide range of tissues. THEY ALWAYS INHIBIT
265
What are the two types of acetylcholine?
Nicotinic and muscularic
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What type is always preganglionic?
Nicotinic, it is an ionotropic receptor.
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What receptors are always muscularic?
The sweat glands and the salivary glands, the rest are nicotinic.
268
What are the two regions that have direct nerves and no preganglionic nerve fibre?
The adrenal gland and the skeletal muscle.
269
What specific receptors does noradrenaline act on?
Alpha and beta receptors.
270
Where does most resistance within the respiratory system occur?
The upper respiratory tract.
271
What are the two types of cell in the alveoli and what are their functions?
Type 1 cells that allow for gas exchange and type 2 cells that generate surfactant.
272
What is the difference between anatomical and alveolar dead space?
Anatomical dead space is the space within the conducting airways and the residual volume and the alveolar dead space is where the alveoli is being ventilated but poorly perfused.
273
What is shunting?
Shunting is the opposite of alveolar dead space, it is when ventilation is poor compared to perfusion and so the arteriole constricts, diverting blood to a better ventilated area to be better oxygenated.
274
What is the normal tidal volume, inspiratory reserve, expiratory reserve and vital capacity.
TV= 500ml, IR= 3000, ER= 1100.
275
What is the difference between vital capacity and total lung volume?
Vital capacity does not take into account the residual volume.
276
What is the intrapleural pressure?
-3mmhg. ITNRA PLEURAL PRESSURE ALWAS REMAINS NEGATIVE, whereas alveolar pressure becomes positive during inspiration.
277
What is the difference between PA and Pa?
Pa is arterial partial pressure of the gas and PA is alveolar partial pressure of a gas.
278
What is trans pulmonary pressure?
It is the difference between the alveolar pressure and the intrapleural pressure, usually positive.
279
Where in the lung does the surfactant work best?
The base of the lung, as the water molecules and surfactant molecules are close together.
280
What does high compliance and low compliance mean? Give examples of diseases that impact this.
High compliance is lung that has a high increase in volume for a low increase in pressure, low compliance is a high increase in pressure creates a low increase in volume.
281
What is the difference between alveolar and pulmonary ventilation?
Pulmonary is the total air movement in and out the lungs including the anatomical dead space, alveolar is the FRESH AIR getting to the alveoli and is available for gas exchange.
282
What is the characteristics of Mr Jelly and Homer Simpson?
Mr Jelly is hypoventilating as the tidal volume is reduced. Homer Simpson is Hyperventilating due to the bigger tidal volumes.
283
What is atmospheric pressure?
760mmHg
284
What is the normal partial pressure of O2 atmospherically and in the arteries?
100mmHg in healthy lungs.
285
What is the difference between pulmonary and bronchial circulation?
Pulmonary is the deoxygenated blood undergoing gas exchange at the lungs and bronchial is the oxygenated blood supply that supplies the lungs.
286
What is the main reason there is poorer ventilation at the apexes?
There is poorer compliance.
287
What is he partial pressure of CO2 in the tissues and the arterial blood and how is it transported in the bloodstream?
46mmHg in the tissues and 40mmHg in the alveoli, it is transported as carbonic acid
288
What is the pressure of the pulmonary circulation?
High flow, low pressure 25mmHg.
289
What does the PO2 in the tissues need to be for diffusion of oxygen to occur?
40mmHg.
290
Where abouts does the ventilation prefusion equalise the most?
The third rib.
291
What is the VQ ratio at the apex and the base?
Apex >1, base <1.
292
What is the mechanism of haemoglobin?
It sequesters the oxygen, therefore MAINTAINING THE CONCENTRATION GRADIENT and allowing more oxygen to be extracted into the bloodstream.
293
What happens to the Pa O2 in anaemia?
Nothing, it remains the same as the O2 in the plasma is always the same. The total oxygen within the blood SpO2 (includes the O2 taken up by haemoglobin) is reduced.
294
What is DPG?
It binds to haemoglobin to facilitate the transport of oxygen.
295
What is the equation for alveolar ventilation?
AV= RR(tidal volume-Dead space)
296
Where is the portal system of circulation and parallel system effective?
The portal system (in sequence) is in the liver and the parallel system is everywhere else.
297
What is the difference between elastic and muscular arteries?
Elastic is the aorta, muscular is all the other arteries.
298
What is the insulator between the atrium and the ventricles?
The annulus fibrosis.
299
What is a defining histological feature of cardiac muscle?
The intercalated disks.
300
Where abouts does the nervous impulse act on the cardiac cell?
The t tubules are activated by an action potential, which causes a small movement of calcium ions. These then travel down the t tubule to the sarcoplasmic rectilum where a huge influx of calcium ions causes depolarisation and contraction of the cardiac muscle.
301
What cases bradycardia from the cental nervous system?
The vagus nerve causes acetylcholine to act on muscarinic receptors at the SA node, decreasing heart rate.
302
What changes more during tachycardia, systole or diastole?
Diastole
303
What is preload and afterload?
Preload is end diastolic volume and afterload is the total peripheral resistance that the heart must overcome to contract blood out of the left ventricle.
304
Explain the Frank-Starling’s Law?
As the end diastolic volume increases, the contractility of the ventricles increases up to a point, then too high a volume can reduce the contractility.
305
What do beta 1, beta 1, alpha 1 and alpha 2 receptors do?
Alpha 1 and beta 2 are acted on by epinephrine and cause either vasoconstriction or vasodilation. Alpha 2 causes reduced blood pressure by preventing the action of norepinephrine. Beta 1 receptors cause increase in heart contractility by norepinephrine.
Beta act on the heart and alpha act systemically.
306
What is the process by which leukocytes cross the capillary cell membrane into the tissue?
Diapedesis
307
Name the cardinal signs?
Loss of function, redness, heat, swelling, pain.
308
What is the pattern of normal blood flow and how is it changes during acute inflammation?
Normally lamellar, flow slows during acute inflammation to encourage the RBC’s to go to the inside and the WBC’s to go to the outside. Mediated by neutrophil polymorphonuclear leukocyte (PMN).
309
What are the 3 stages of acute inflammation?
Margination and rolling, adhesion and transmigration, migration to interstitial cells.
310
What do the WBC’s adhere to on the endothelial wall?
ICAMs, VCAMs and selectins.
311
What happens to the basement membrane during this?
It undergoes focal degradation by collagenases.
312
What is the name of the chemical gradient that encourages movement of inflammatory cells into the tissues?
Chemotaxis.
313
What do NSAID’s and paracetamol inhibit?
The cyclo oxygenase pathway.
314
A langhan cell versus a lagerhans cell?
A langhan cell is a giant nucleated TB granulomatous cell whereas a langerhans is a dendritic immune cell present within healthy tissues.
315
What is the difference between an monocyte and a macrophage?
A monocyte is a macrophage that is in the bloodstream. Once it migrates into the tissues it becomes a macrophage.
316
What is another name for plasma cells?
B lymphocytes.
317
What do TNF’s do?
They can instruct cell death.
318
What is the purpose of a granuloma?
It prevents the spread of an infection.
319
Where is sarcoidosis normally found?
Crohn’s disease, this can also have oral manifestations.
320
What is the difference between a simple surgical wound and a large, chronic wound?
One heals by primary intention and the other by secondary intention.
321
What is the difference between regenerative and reparative wound healing?
Reparative healing is less specific and loses its parenchymal function compared to regenerative, where the cells undergo better differentiation and retain the cell function after complete healing. Regenerative healing has less of an emphasis on ECM and more of a focus on growth factors.
322
What are the strogmal regions of the tissue?
The extracellular matrix (ECM), connective tissue that surrounds and supports the cells.
323
What is the difference between labile, stable and fixed cells?
Labile are continuously regenerating i.e. the oral mucosa. Stable cells stop dividing when they are fully grown i.e. hepatocytes and fixed cells are neurons who do not regenerate after cell death.
324
What are the three main healing factors?
Inflammatory mediators, ECM, growth factors.
325
What are the three phases of wound healing?
Inflammation, proliferative, maturation.
326
What happens during the maturation of the scar?
Collagenases are released to remodel the scar tissue and make it more supple and resemble the normal tissue. It also helps to shrink the scar’s size.
327
What is the difference between oncotic and hydrostatic pressure?
Oncotic pressure draws fluid into the blood vessel and hydrostatic pressure draws fluid into the tissues.
328
What stimulates production of erythroblasts from the undifferentiated stem cell?
Erythropoietin, produced by the kidneys if it detects hypoxia.
329
What are platelets derived from?
They are fragments of megakaryocytes.
330
What is the main difference between a neutrophil and a lymphocyte?
A neutrophil is granular and a lymphocyte isn’t.
331
What factor allows for adhesion of platelets to the endothelial cell wall?
Von Willebrand Factor.
332
Describe the clotting cascade.
-Prothrombin- Thrombin- fibrinogen-fibrin.
333
What factor number links together the fibrin strands to form the mesh?
Factor 13.
334
What is a main cofactor in the clotting cascade?
Calcium ions.
335
What breaks up the fibrin?
Plasmin. Activated by tissue plasminogen activator to be derived from plasminogen.
336
What simple mechanism can cause anticoagulation?
Vasodilation
337
What are the actions of aspirin and warfarin respectively?
Aspirin prevents platelet aggregation and warfarin inhibits the cofactor vitamin K to be used by the gamaglutamylcarboxylase which then causes clotting.
338
What is the critical pH of enamel, dentine and cementum?
enamel 5.5, dentine 6.3 and cementum 6.7
339
What kind of bacteria is MRSA? (staph aureus)
A gram positive cocci in clusters.
340
What kind of bacteria is treponema denticola?
A spirochaete.
341
What kind of bacteria shapes are p. gingivalis and other later colonisers?
They are gram negative rods.
342
What is special about p. gingivalis?
It is a keystone pathogen, meaning small amounts of this can cause dysbiosis.
343
What is desiccation of the teeth?
It is the process of drying out plaque in order to remove the biofilm.
344
What causes mineralisation of plaque to form calculus?
Calcium and phosphorus.
345
What is a carious lesion on the buccal and lingual surface of a molar called?
A pit/fissure caries.
346
What is the difference between sclerotic and reactionary dentine?
Sclerotic dentine is the obliteration of the intratubular dentine and the dead tracts of fish, whereas the reactionary dentine is at the dentine pulp interface.
347
What is the difference between reactionary and reparative dentine?
Reactionary dentine is produced by the odontoblasts and produces similar dentine with some tubules present. Reparative dentine is produced by odontoblast like cells and resembles alveolar bone.
348
What are the 6 IDCAS classifications of caries?
0- no caries, 1- enamel changes, 2- distinct enamel changes, 3- localised enamel breakdown, 4- dark shadow underlying dentine, 5- cavitation into the dentine, extensive cavity into the dentine.
349
Clinical versus anatomical crown?
Anatomical crown is the enamel and CEJ, the clinical crown is above the gingival margin all of the exposed tooth crown.
350
Infective versus affected dentine?
Infective is yellow, mushy dentine and has to be removed. Affective dentine is harder scratchy to remove, dentine tubules are still present.
351
What is the classification of root caries?
grade 1- incipient, grade 2- shallow less then 0.5mm , grade 3 greater than 0.5mm depth and grade 4- pulpal involvement.
352
What is an incipient carious lesion?
Enamel caries, not cavitated to the dentine.
353
What are the WHO classification of caries?
D1- detectable enamel lesion, D2- cavitated enamel lesion only, D3- cavities in dentine, D4- Lesions extending to the pulp.
354
What direction of ion movement causes hot and cold sensation?
Hot sensation is movement of fluid out of the tubules and cold is movement into the tubules.
355
What are the nerve plexuses called in the pulp that cause sensitivity?
Plexus of Rashckow.
