Practice 3
Tonsils
Introduction to teeth
Tonsils – Waldeyer's ring
Group of peripheral lymphoid organs positioned at the entrance into naso- and oropharynx
Total 6 (tonsillae palatinae, tonsillae tubariae, tonsilla lingualis, tonsilla pharyngea)
Mucosal organs – accumulation of lymphoid tissue in lamina propria
B - dependent areas - secondary lymph follicles
T - dependent regions - interfollicular zones
Palatine tonsils
Positioned on the right and left side between glossopalatal and pharyngopalatal arches, ovoid shape, deep and
branched tonsillar crypts, there are usually up to 35 (contain detritus), tonsil separated by fibrous capsula – can have
septs.
The surface of the tonsil is covered by a stratified squamous epithelium
In lamina propria are large lymphatic follicles with light germinal centers
Brighter center - contains centroblasts
Epithelium above nodules (differences):
The structure of the epithelium and the
contacts between the cells are very loose,
caused by infiltration by lymphocytes,
macrophages, dendritic cells, discontinuous
basement membrane
FAE – (follicle associated epithelium)
Palatine tonsils
A B
A
B
Tonsilla palatina (H.E.)
1 – stratified squamous epithelium
2 – lymphocytes infiltrated
epithelium (FAE)
3 – secondary lymph nodules or
follicles
4 – detritus in tonsilar crypt
Tonsilar crypt in detail (H.E.)
2 – with lymphocytes infiltrated
epithelium
3 – germinal centre of a secondary
nodule
4 – detritus
Lymphocytes which penetrate into the oral cavity are referred to as salivary bodiesPalatine tonsils
Group of lymph nodules (folliculi linguales) in the mucosa of lamina propria on the dorsal side of radix linguae
behind the circumvallate papillae
Surface covered by stratified squamous epithelium
At the bottom of shallow crypts are openings of purely mucinous Webers glands (gll. Linguales posteriores)
Crypts are perpetually washed outs – no detritus.
No obvious capsula.
Lingual tonsil
Lingual tonsil
Located on the top of pharynx (fornix pharyngis)
From the other it differs by the surface covered by pseudostratified columnar
epithelium which might contain goblet cells
Shallow crypts
In childhood tonsilla pharyngea can often be hypertrophic which cause
problems with nose breathing
Paired tonsil
Group of small lymphoid tissue in lamina propria of mucosa in the
pharyngeal opening of the eustachian tube (ostium pharyngeum tubae
auditivae)
Pharyngeal tonsil (Adenoid)
Tubal tonsils (Gerlach tonsils)
Basics in the phylogenesis and comparative tooth anatomy
Teeth - calcified structures that derive from the ectoderm and ectomezenchyme (neural crest)
Evolutionarily in phylogeny, they appear only in the jawed vertebrates – Gnathostomata
Ancestor of teeth - placoid scales in fishes that covered the surface of the body and the oral cavity
Lampres, cyclostomata
Set of all teeth = dentition
Set of all teeth = dentition
Types of dentition
Shape of teeth: homodont - identical in shape
heterodont - different in shape
(in mammals dentes incisivi, canini, praemolares and molares)
According to the number of replacements (sets of teeth) during life:
monofyodont - e.g., Holocephala - chimeras)
difyodont (dentes decidui, dentes permanentes) – e.g. mammals
polyphyodont - e.g., fish, lower amphibians
According to the attachment of the teeth to the jaw:
acrodont - attach to the jaw from above (bony fish, amphibians)
pleurodont - on the jaw from the side (for reptiles)
thecodont - inserted into dental sockets –
recent mammals (dinosaurs, crocodiles)
Set of all teeth = dentition
Podle typu růstu zubů: Brachyodont - Long root
Hypselodont - No root – continuously-growing
Hypsodont - High crown
Mesodont
Diphyodont
Heterodont
Thecodont
Brachydont
Human dentition is:
Tooth numbering
Several possibilities
Beginning letter
incisors – dentes incisivi I1, I2/ i1 , i2
canines – dens caninus C / c
premolars – dentes premolares P1, P2 / p 1, p 2
molars – dentes molares M1, M2, M3 / m1, m2, m3
Number
international marking using "two-digit code"
(ISO System - International Standards Organization Designation system: teeth divided into quadrants (clockwise):
1 - 4 dentes permanentes
5 - 8 dentes decidui
Dentes permanentes
Dentes decidui
coronal vestibular (labial, bucal)
apical lingual (palatinal)
Directions
Mesial
(towards the midline)
Distal
(towards the last molar)
S
Tooth and dental socket, periodontium, gingiva
crown, neck, root
TERMINOLOGIE:
Dentes decidui (lactei) 20
Dentes permanentes 28-32
Corona dentis (crown)
Collum (neck)
Radix (root) 1-3
Cavum et canalis radicis dentis (cavity and root canal)
Pulpa dentis (pulp)
Foramen apicis radicis (opening at the tip of the root)
Alveolus
Periodontium
Tooth
(dens)
gingiva
Cavitas dentis passing to canalis radicis dentis
Anatomical vs clinical crown
Anatomical vs klinical root
Foramen apicis radicis Dentis
Tissues of tooth
Enamel - enamel, subst. adamantina (row adamas, adamantos = diamond steel), substantia vitrea (lat. vitrum = glass)
Dentin - dentin, substantia eburnea (l. Ebur = ivory)
Cementum - substantia ossea, crusta petrosa
Dental pulp - pulpa dentis
Babirusa
Tusks