Question

8. Select a specialized cell type of the integumentary system and describe the appearance, function and location of the cell. Additionally, select a specialized cell type of the skeletal system and describe the appearance, function and location of the cell 9. Describe three ways in which aging impacts the skin and three ways in which aging impacts the skeletal system 10. Select one disorder of the integumentary system and briefly describe the disorder in terms of cause, symptoms, treatments and who is impacted by this disorder. Additionally, select one disorder of the skeletal system and briefly describe the disorder in terms of cause, symptoms, treatments and who is impacted by this disorder.

Answer 1

8. Specialized cell type of integumentary system

The main functions of integumentary system are protection, absorption of nutrients & homeostasis. In structure it consists of a keratinized stratified squamous epithelium; four types of cells are KERATINOCYTES, MELANOCYTES, MERKEL CELLS & LANGERHANS CELS.

LANGERHANS CELLS

Langerhans cells (LCs) are a unique population of tissue-resident macrphages that form a network of cells across the epidermis of the skin, but which have the ability to migrate from the epidermis to draining lymph nodes. Their location at the skin barrier suggests a key role as immune sentinels. Langerhans cells are tissue resident dendritic cells of the skin, and contains organelles called BIRBECK GRANULES. They are present in all layers of epithelium and are most prominent in the stratum spinosum.

On electron microscopic examination, characteristic "TENNIS RACKET" shaped granules are seen. Langerhans cells are identical to tissue macrphages & present antigens to lymphocytes, with which they interact through specific surface receptors.

Functions of Langerhans cells are:

• In skin infections, the local Langerhans cells take up & process microbial antigens to become fully functional antigen presenting cells
• Langerhans cells can also take on a dendritic cell like phenotype & migrate to lymph nodes to interact with naive T- cells
• Langerin is a protein found in Langerhans cells, & dendritic cells.

Specialized cell of skeletal system

There are three types of specialised cells in human bones: OSTEOBLASTS, OSTEOCYTES & OSTEOCLASTS.

OSTEOBLASTS

These are the cells that form new bone. They also come from bone marrow & are related to structural cells. They have only one nucleus. OSTEOBLASTS work in team to build bone. They produce new bone called osteoid which is made of bone collagen & other protein. Then they control Calcium & mineral deposition. They are found on the surface of the new bone. It can stmulstim calcium and phosphate release to serum. OSTEOBLASTS signal osteoclasts, which lead to increased bone resorption & mobilization of calcium & phosphate.

osteoblasts cells are cubiodal, or low columnar in shape with large darkly staining nuclei. Small areas of pink stained mateemat can sometimes be seen in the cytoplasm of osteoblasts.