Tissue Injury and Repair Flashcards
Inflammation
The initial and standard response of the body to injury
Cardinal signs of inflammation
Redness, swelling, pain, local heat and loss of function
Necrosis
Accidental cell death, causes inflammation
Apoptosis
Programmed cell death, normal step by step process that destroys cells no longer needed by body
Signs and causes of inflammation
Redness and local heat caused by vasodilation, swelling caused by increased vascular permeability, pain caused by physical and chemical stimulation of nociceptors and loss of function caused by:
- reflex muscle inhibition
- disruption of tissue structure
- fibroplasia and metaplasia
How do fibroblast repair tissue?
Fibroblasts mobilise and divide rapidly to repair the damaged tissue by collagen deposition, forming granulation tissue
Which cells recreate the epidermis?
Basale stem cells (within the stratum basale)
What do basale stem cells do in regards to tissue injury?
Recreate the epidermis
What do blood capillaries do in tissue repair?
Blood capillaries follow fibroblasts and increase blood circulation and oxygen supply to area.
What do immune cells (eg macrophages) do for tissue repair?
Roam area and engulf any foreign matter to reduce change of infection
What is the epidermis composed of?
Composed of keratinised stratified squamous epithelium.
Regeneration time for epidermal cells
Time for epidermal cells to form in stratum basale and migrate to skin surface (~35 days).
Hormones that support normal epidermal growth and repair
Epidermal growth factor, insulin-like factor 1 and growth hormone
What serves to “glue” the epidermis to dermis below
A basement membrane made of fibrous elements and a polysaccharide gel serves to “glue” the epidermis to the dermis below
The dermoepidermal junction
Serves as a partial barrier to the passage of some cells and large molecules
