Stem cells and reproduction Flashcards
What are stem cells?
- Undifferentiated mass cells with the ability to divide and differentiate into various cells/ tissues
- Master cells that act as foundation cells for every organ, tissue and cell in the body
- Programmed to perform particular tasks
- Serve as a repair machine for the body
What are features of stem cells?
- Capable of dividing and renewing themselves for long periods
- unspecialised and can give rise to specialised cell types
- Uncommited until it recieves a signal to develop into a specialised cell
What is a totipotent stem cell?
- a stem cell with the ability to differentiate into all types of cell of the embryo as well as the placenta
What are pluripotent stem cells?
- stem cell sthat can differentiate into any tissue type except placental tissue
What are multipotent stem cells?
- Stem cells that can differentiate into multiple specialised cells of a closely related family of cells e.g. haematopoetic stem cell
What are unipotent stem cells ?
- stem cells that can only produce one cell type
- Have self renewal properties (e.g. muscle stem cell. cardiac stem cell)
What are embryonic stem cells?
- Cells found in the early development of an embryo
- Taken from the inside of a blastocyst (early stage embryo) that is not yet implanted in the womb
- Made up of an outer layer of cells, a fluid filled space and a group of cells called the inner cell mass
- ES found in the inner cell mass
How are human embryonic stem cells isolated?
- Human ES are isolated by transferring the inner cell mass into a plastic lab culture dish that contains the culture medium (nutrient broth)
- Cells are removed gently and plated into several fresh culture dishes. The process is repeated many times for many months = subculturing. Each cycle = a passage
- Stimulate the cells with a specific stimulant to differentiate into a specific cell type
embryonic,..
What are some advantages of ESCs?
- Flexible : can have the potential to differentiate into any cell
- Immortal - one esc can provide an endless supply of cells with defined characteristics
- Availability - embryos from in vitro fertilisation clinics
What are some disadvantages of embryonic stem cells?
- Destruction of developing human life
- Immunogenic - embryonic stem cells from random embryo = likely rejection after transplantation
- Tumorigenic - capable of forming tumours or promoting tumour formation
What are adult stem cells?
- Found in the human body and umbillical cord bloof
- Tissue specific stem cell
- Source - bone marrow but also found in many organs and tissues
- ASCs = more specialised. Assigned to a specific cell family such as blood cells, nerve cells etc.
- The primary roles = maintazins and repairs tissue where they are found.
Adult stem..
What are some advantages of ASCS?
- Flexible
- Somewhat specialised - inducement may be simpler
- Not immunogenic - same person recieving their own stem cell
- Relative ease of procurement ( harversting of skin, muscle, marrow, fat etc)
- Non-tumorigenic
- No harm
Adult
What are disadvantages of ASCS?
- Limited quantity - hard to obtain in large numbers
- Finite - may not live as long as embryonic stem cells in culture
- Less flexible - may be more difficult to reprogram to form other tissue types
What are some potential uses of stem cells?
Stroke
Traumatic brain injury
Learning defects
Alzheimer’s disease
Parkinson’s disease
Missing teeth
Wound healing
Bone marrow
transplantation
(currently established)
Spinal cord injury
Osteoarthritis
Rheumatoid arthritis
Baldness
Blindness
Deafness
Amyotrophic lateral- sclerosis
Myocardial infarction
Muscular dystrophy
Crohn’s disease
Diabetes
Multiple sites:
Cancers
What are hematopoietic stem cells?
- multipotent primitive stem cells that develop into different blood cell types
