Anatomy-32 Home work # 2 1. Describe the five layers of the epidermis 2. List th

Question

Anatomy-32 Home work # 2 1. Describe the five layers of the epidermis 2. List the different types of cells present in the integumentary system (indluding in epidermis, and bone) and their functions 3. What are the signs of inflammation and describe the process of inflammation in detail 4. Mention the three types of burns and how do they differ from each other 5. Differentiate between the intramembranous ossification and endochondral ossfication .What are the factors that affect bone growth? 7. What are the two processes involved in bone remodeling and what cells are involved in bone remodeling? 8. Name the cranial and facial bones of the axial skeleton 9. List three important differences between the male and female pelvic 10. Name the different synovial joints in the body and give an example of each

Explanation / Answer

1) The epidermis is composed of keratinized, stratified squamous epithelium. It consists of five layers of epithelial cells, which depends on its location in the body. It is the most superficial layer of skin. Functions of the epidermis are touch sensation and protection against microorganisms.

It consists five separate layers:

i) Stratum Corneum – It is the most superficial layer of both thick and thin skin. It consists of numerous layers of flattened, dead cells, which have thickened plasma membrane. It makes the surface unsuitable for the development of many microorganisms. This layer is composed of the many dead skin cells. This layer helps to repel water.

ii) Stratum Lucidum - It is a thin zone superficial to the stratum granulosum. The keratinocytes are densely packed with a clear protein called as eleidin in this layer. It has a pale, featureless appearance with unclear cell boundaries. This layer is found only on the palms of the hands, fingertips and the soles of the feet.

iii) Stratum Granulosum – It is the most superficial layer of the epidermis. It consists of keratinocytes, which moved out of the stratum spinosum. They help in the production of large quantities of the proteins keratohyalin and keratin. Keratohyalin collects in electron dense keratohyalin granules. These granules surround the keratin filaments. It protects the epidermis and stops the distribution of nutrients and wastes into and out of the cells. Keratin is a protein. It is the main constituent of skin. It forms the basic structural component of hair and nails in humans. It is very useful substance therefore it also forms the claws of dogs and cats, the horns of cattle and rhinos, the feathers of birds etc.

iv) Stratum Spinosum - Each keratinocyte in the stratum spinosum contains bundles of protein filaments, which expend from one side of the cell to the other. These bundles are known as tonofibrils, which start and end at a desmosome. The tonofibrils act as cross braces, strengthening and supporting the cell junctions. They are mitotically active and continue to divide, which form the epithelium thicker. Melanocytes are present in this layer as dendritic cells. These cells play an essential role in triggering an immune response against epidermal cancer cells and pathogens. This layer gives the skin strength and flexibility.

v) Stratum Basale – It is the deepest epidermal layer. This single layer of cells is attached to the basal lamina and that separates the epidermis from the loose connective tissue of the adjacent dermis. Keratinocytes are most important cells in this layer. They are formed before moving up to the surface of the epidermis and being shed into the surroundings as dead skin cells.

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.