Stem Cells Flashcards
what are stem cells
- undifferentiated cells which can be used to make different cells within the body.
- they can divide infinitely and are all identical to each other
types of stem cells
EMBRYONIC STEM CELLS
SOMATIC STEM CELLS
what are embryonic stem cells
the ‘primary’ cells found in an embryo that continuously replicated to form the organs and tissues of a fetus
what are somatic stem cells
-stem cells found in adults found throughout the body for SELF RENEWAL and DIFFERENTIATION. Usually can only differentiate to its ‘organ of origin”
what is differentiation
- it involves the expression of some genes and not others in the cell genome
- the ability of a cell to become any cell, as it hasn’t been given a ‘purpose’ yet
why are stem cells practical
- they can be used for medical purposes (grow tissues, organs) +therapeutic uses
- repair tissue
- important for embryonic development
- cloning!
what levels of potency exist + what is it
POTENCY: ability to differentiate
TOTIPOTENT: all possible cells (embryonic stem cells)
PLURIPOTENT: almost all cells
MULTIPOTENT: closely related family of cells
OLIGOPOTENT: few cells
UNIPOTENT: only cells of own type
Discuss the ethics of stem cells
PRO
- suffering of patients could be reduced
- diseases could be cured
- better treatments developments (might even replace them with cure)
- less cost than treating disease/diabetes
- use of stem cells from adults/patients could overcome objections to production of embryos for stem cell research
CON
- patient groups support use of embryonic stem cells; religious groups oppose
- moral status views differs
- restriction on research in some countries due to cultural/religious traditions
- risk to patient (stem cells could develop tumors, rejection, need for immunosuppressants)
- death of early stage embryos
how do multicellular organisms develop specialized tissues
only some genes are expressed in each cell type/tissue; tissues therefore develop differently/become differentiated’
for example: nerve cells (NEURONS) are differentiated and their function is to transmit messages from one part of your body to another, usually from the brain
discuss stargarts diseseas
- stargardts diease is an inherited condition in which the gene that codes for the processing of VITAMIN A is defect
- vitamin A= important for the light-sensitive cells in the retina
cause= loss of central vision, then eventually, peripheral vision
how do stem cells have a role in it?
- produce the missing light-sensitive cells
discuss leukemia
- leukiemia is the cancer within the blood (abnormal # of white blood cells)
- chemo kills cancer cells and normal rbc cells
- stem cells used to produce normal cells (rbc)
give another example for a disease that can be related to stem cell therapy
parkinsons and alzeihmers
