Tissue engineering is an interdisciplinary field of engineering and life sciences that seeks to develop biological substitutes that restore, maintain, or improve the function of tissues or whole organs. It involves the placing of cells into tissue scaffolds with bioactive compounds to form new viable tissue for a medical or research purpose.
Inflammation is the classic response of the body to injury and follows a common sequence of events. The area is red, feels warm to the touch, swells, and is painful. Injured cells, mast cells, and resident macrophages release chemical signals that cause vasodilation and fluid leakage in the surrounding tissue. The repair phase includes blood clotting, followed by regeneration of tissue as fibroblasts deposit collagen. Some tissues regenerate more readily than others. Epithelial and connective tissues replace damaged or dead cells from a supply of adult stem cells. Muscle and nervous tissues undergo either slow regeneration or do not repair at all.
Age affects all the tissues and organs of the body. Damaged cells do not regenerate as rapidly as in younger people. Perception of sensation and effectiveness of response are lost in the nervous system. Muscles atrophy, and bones lose mass and become brittle. Collagen decreases in some connective tissue, and joints stiffen.
apoptosis
programmed cell death
atrophy
loss of mass and function
clotting
also called coagulation; complex process by which blood components form a plug to stop bleeding
histamine
chemical compound released by mast cells in response to injury that causes vasodilation and endothelium permeability
inflammation
response of tissue to injury
necrosis
accidental death of cells and tissues
primary union
condition of a wound where the wound edges are close enough to be brought together and fastened if necessary, allowing quicker and more thorough healing
secondary union
wound healing facilitated by wound contraction
vasodilation
widening of blood vessels
wound contraction
process whereby the borders of a wound are physically drawn together
Approximately one month.
A mass of cancer cells that continue to grow and divide.
1. Which of the following processes is not a cardinal sign of inflammation?
A) redness
B) heat
C) fever
D) swelling
C
2. When a mast cell reacts to an irritation, which of the following chemicals does it release?
A) collagen
B) histamine
C) hyaluronic acid
D) meylin
B
3. Atrophy refers to ________.
A) loss of elasticity
B) loss of mass
C) loss of rigidity
D) loss of permeability
B
4. Individuals can slow the rate of aging by modifying all of these lifestyle aspects except for ________.
A) diet
B) exercise
C) genetic factors
D) stress
C
5. Which of the following methods is not used in tissue engineering?
A) microchips for cell culture
B) hydrogels deposited by 3D printing
C) computational bioimaging of cells
D) robotic lab automation
E) none of the above
E
1. Why is it important to watch for increased redness, swelling and pain after a cut or abrasion has been cleaned and bandaged?
These symptoms would indicate that infection is present.
2. Aspirin is a non-steroidal anti-inflammatory drug (NSAID) that inhibits the formation of blood clots and is taken regularly by individuals with a heart condition. Steroids such as cortisol are used to control some autoimmune diseases and severe arthritis by down-regulating the inflammatory response. After reading the role of inflammation in the body’s response to infection, can you predict an undesirable consequence of taking anti-inflammatory drugs on a regular basis?
Since NSAIDs or other anti-inflammatory drugs inhibit the formation of blood clots, regular and prolonged use of these drugs may promote internal bleeding, such as bleeding in the stomach. Excessive levels of cortisol would suppress inflammation, which could slow the wound healing process.
3. As an individual ages, a constellation of symptoms begins the decline to the point where an individual’s functioning is compromised. Identify and discuss two factors that have a role in factors leading to the compromised situation.
The genetic makeup and the lifestyle of each individual are factors which determine the degree of decline in cells, tissues, and organs as an individual ages.
4. Discuss changes that occur in cells as a person ages.
All cells experience changes with aging. They become larger, and many cannot divide and regenerate. Because of alterations in cell membranes, transport of oxygen and nutrients into the cell and removal of carbon dioxide and waste products are not as efficient in the elderly. Cells lose their ability to function, or they begin to function abnormally, leading to disease and cancer.