Chapter 5 Flashcards
Integumentary System
macrophages
part of the body’s defenses
engulfs large pathogens or damaged cells
microphages
smaller phagocytic cells that engulf small pathogens or debris
adipocytes
- “fat cells”
- provides energy, storage, and cushion
- many connective tissues need the energy reserves
mesenchymal cells
cal ultimately differentiate into other needed connective tissue cells especially after an injury
melanocytes
produce the pigment melanin
mast cells
produces a histamine that stimulates inflammation and heparin which prevents blood from clotting.
Both are released after an injury or infection
lymphocytes
helps with body defense and may develop into plasma cells which produce antibodies
What are the steps of tissue repair?
- inflammation
- organization
3 regeneration and fibrosis
What types of tissues are highly regenerative?
- epithelial tissue
- bone tissue
- blood (made in red bone marrow)
- areolar connective tissue
What types of tissues are only slightly regenerative?
- cartilage (all types)
2. skeletal muscles
What types of tissues are nonregenerative?
- cardiac muscle
2. nervous tissue
What two regions make up the skin?
- epidermis - outermost layer - epithelial tissue
2. dermis - makes up majority of skin - vascuralized
keratinocytes
stratified squamous epithelial cells that produce the protein keratin
makes up majority of the epidermis
Langerhans’ cells
originate in the epidermis; act as macrophages
Merkel cells
found in the deepest layer of the epidermis; function as receptors to sense gentle light touch
What are the layers of the epidermis?
- Stratum Corneum
- Stratum Lucidem
- Stratum Granulosum
- Stratum Spinosum
- Stratum Basale
Stratum Basale
- stratum germinativum
- deepest layer of the epidermis
- Usually only 1-2 cells thick
- contains keratinocytes, melanocytes, and merkel cells
- layer has many cells that are actively dividing
stratum spinosum
- “prickly layer”
- cells of this layer have a spiny appearance
- several cell layers thick
- cells contain pre-keratin filaments
- contains majority of the melanin and Langerhans’ cells
stratum granulosum
- “granular layer”
- appears grainy and is only 3-5 cells thick
- keratinocytes in this layer contain lamellated granules (important for water proofing)
- last layer of epidermis where diffusion of nutrients and oxygen from the capillaries can reach the cells (outer 2 layers cells are dying or already dead)
stratum lucidum
- “clear layer”
- clear layer only few cells thick
- dying cells start to line up the keratin fibers parallel to one another
stratum corneum
- “horny layer”
- 20-30 cells thick
- acts as an overcoat to protect underlying layers
- cells are dead
What are the layers of the dermis?
- papillary layer
- reticular layer