Prickle cell layer

Acanthosis Increased thickness of the prickle cell layer of the skin. 

Prickle cell layer with membranecoating granules... 

Intermediate layer Prickle cell layer Basal layer... 

Figure 7.1 Structure of non-keratinized oral epithelium, as found in the sublingual and buccal regions of the oral cavity. (Note keratinized epithelium has a broadly similar structure however, the epithelial cell layers comprise basal layer, prickle cell layer, granular layer and keratinized layer)...

The nonkeratinized regions of the oral mucosa, the mobile mucosa of the cheeks, lips, ventral surface of the tongue, soft palate and the oral sulcular and junctional epithelia are permeable to fluids and small molecules (Sect. 5.2.1). The prickle cell layer of these epithelia expresses mostly K4 and K13 instead of K1 and K10. 

The succeeding outer layer is the stratum spinosum, or prickle cell layer it consists of several layers of irregular polyhedral cells (Figure 1.2, Figure 1.4). These cells are connected to adjacent stratum spinosum cells and to the stratum basale cells... 

Acanthosis—benign overgrowth of the prickle-cell layer of the skin Acetylcholine—chemical transmitter of nerve impulses across synapses Acidosis—pathological condition resulting from accumulation of acid in, or loss of base from, the blood or body tissues... 

In epithelia which are about to keratinize, the prickle cell layer merges into the flatter stratum granulosum in which keratohyalin granules appear in the cytoplasm. The final stage of differentiation results in the formation of the stratum comeum, which is the keratin layer itself. It contains fully comified, shrunken, flattened and featureless cells and is sharply demarcated from the underlying granular layer. 

The skin of the rat, according to Sullivan and Nicholls, showed loss of hair around the ears and the snout, the remainder of the hair, if pigmented, becoming gray. There was hyperkeratosis and increase of the prickle cell layer in the skin (acanthosis). The whole skin eventually became atrophic. 

Fig. 36. Cutaneous side of the vestibule of the nose of a pyridoxine-deficient rat, showing marked surface hyperkeratosis and acanthosis of the epidermis. Vacuolation of prickle cell layer can be seen in some places.

Figure 10.6 Epidermolytic hyperkeratosis, (a) Tonofibrillar clumps TQ and shells (TS) in the uppermost prickle cell layer (compare with Figures 10.4a and 10.7b) x4000. (b) Blister formation by acanthokeratolysis due to unilateral separation of desmosomes from one of their two neighbouring cells (open arrow) after loss of their inserting tonofilaments x8000. (c) Cytolytic blister formation without enlargement of intercellular spaces x4000...

Figure 10.7 Ichthyosis hystrix type Curth-Macklin. (a) Unbroken concentric shell of tonofilaments (TS) surrounding the nucleus (N) and perinuclear cytoplasm with ribosomes and granular endoplasmic reticulum (ER) x 16 000. (b) 3 binucleate cells ( ) in the prickle cell layer (compare with Figure 10.6a) x4000...

The skin consists of three main layers the epidermis, the dermis and the subcutis. The epidermis is a stratified squamous epithelium, which is about o.i-mm thick. In some parts of the body, for example the glabrous skin of the palms and soles, this layer is thicker (0.4-1.4 mm). The main cell type of the epidermis is the keratinocyte this produces the protein keratin. The four layers of the epidermis - the basal, prickle and granular cell layers and the horny layer... 

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