Flashcards in MOD 7.1 - Cell Adaptations Deck (29):
What is the definition of regeneration?
Cell losses are replaced by identical cells that originate from stem cells
Describe the regenerative ability of smooth muscle and striated muscle
- Smooth = good
- Striated = limited
Describe the regenerative ability of:
- Epithelia = good
- Adipocytes = unable
- Mesothelia = good
- Melanocytes = usually too much/too little
Describe the regenerative ability of articular cartilage and tendons
What stimulates regeneration?
- Cell to cell communication
- Growth factors
What is reconstitution?
Replacement of a lost part of the body
What is hyperplasia?
The increase in tissue or organ size due to an increase in cell number (not permanent cells)
Give 2 pathological examples of hyperplasia
- Thyroid goitres
Give 2 physiological examples of hyperplasia
- Endometrium under the influence of oestrogen
- Bone marrow when hypoxic
What is hypertrophy?
The increase in tissue or organ size due to an increase in cell size (permanent cell populations)
How are hyperplasia and hypertrophy similar?
- Physiologically controlled
What causes hypertrophy?
- Increased functional demand
- Hormonal stimulation
- Leads to more structural components
What is compensatory hypertrophy?
One organ in a pair takes on the workload of the other due to loss of function/removal
Give 2 physiological examples of hypertrophy
- Skeletal muscle
- Smooth muscle of the pregnant uterus
Give 2 pathological examples of hypertrophy
- Cardiac muscle
- Prostate gland (causes hypertrophy of bladder smooth muscle)
Give 3 examples of causes of cardiac muscle hypertrophy
- Valvular disease
- Athletes (have chance to recover so no bad side effects)
What is atrophy?
The shrinkage of an organ or tissue due to an acquired decrease in size/ decrease in number of cells
Give three pathological examples of causes of atrophy
- Denervation (muscle)
- Inadequate blood supply (inadequate o2 and nutrition)
Give a physiological example of a cause of atrophy
- Ovarian atrophy in post menopausal women
What is the cause of organ/tissue atrophy?
A combination of atrophy and apoptosis
What is metaplasia?
The reversible change of one differentiated cell for another (non permanent cells). Most clear in epithelia
What is the cause of metaplasia?
Adaptation under stress
What is dysplasia?
The abnormal maturation of cells within a tissue
What is atresia?
The absence of abnormal narrowing of an opening or passage in the body
What is involution?
The normal programmed shrinkage of an organ
What is aplasia?
The lack of development of a specific organ/tissue in the embryo
What is hypoplasia?
The under/incomplete development of a tissue/organ in the embryo
Under what conditions do scars form? (3)
- Cell population is permanent
- High amount of damage
- Persistent harm