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Flashcards in Epithelia and skin Deck (18)
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What are the diameters of FOV for each objective lense?

x 4 = 4.5mm

x 10 = 1.8mm

x 40 = 0.45mm


What are the different arrangements of epithelium?

1. Simple epithelium

2. Stratified epithelium


What are the different types of simple epithelium?

1. Squamous (diffusion surfaces, e.g. alveoli, endothelium)

2. Cuboidal (absorption/secretion, e.g. small exocrine ducts, nephron)

3. Columnar (absorption/secretion, e.g. intestines, large exocrine ducts)

4. Pseudostratified (airway, e.g. trachea)


What are the characteristics of transitional epithelium?

- Surface (umbrella) cells are large, dome-shaped and often overlap 2 or more cells beneath.

- Basal/intermediate cells are polygonal in shape and change size depending on distension.


Where is transitional epithelium found?

- Bladder

- Ureters

- Parts of urethra


How can cilia be distinguished from microvilli in EM?

Cilia contain microtubules while villi don't


What are the structures present in junctional complex?

1. Tight junction (zonula occludens)

2. Intermediate junction (zonula adherens)

3. Desmosome (macula adherens)

4. Gap junction


What are the layers of skin?

1. Epidermis

2. Dermis

3. Hypodermis


What are the layers of the epidermis?

1. Stratum corneum: Dead, flattened, innulceated cells full of keratin.

(2. Stratum lucidum: Thick skin only)

3. Stratum granulosum: Cells containing dense cytoplasmic granules contributing to keratin formation.

4. Stratum spinosum: Cells containing cytoplasmic spines.

5. Stratum germinativum (stratum basale): Cuboidal cells anchored to the basement membrane that carry out active cell division.


What type of epithelium is skin?

Stratified keratinised squamous epithelium


What do the spines in the stratum spinosum represent?

Punctate desmosomes binding each adjacent cell


What are the layers of the hair follicle?

1. External root sheath: Downward epidermal extension

2. Cuticle

3. Cortex

4. Medulla

5. Inner root sheath


What structures are associated with the hair follicles?

- Sebaceous glands

- Arrector pili muscles


What are the types of sweat glands?

1. Eccrine

2. Apocrine


What is the function and location of Pacinian corpuscules?

Function: Detect deep pressure and vibration

Location: Hypodermis


What type of epithelium is found in sweat glands?

- Secretory portion: Simple cuboidal epithelium

- Duct: Stratified (2 layers) cuboidal epithelium


What are the places in the body that don't have sweat glands?

- Lips

- External genitalia


What is the function of the terminal web?

To allow for limited movement of cell apex and microvilli