Cardiac Cell Bio

Question 1

What are some differences of cardiac m vs skeletal m (8)

Answer 1

smaller myocytes
Intercalated discs
involuntary
more mito
myoglobin
more blood vessels
LIPID droplets!
MB creatine kinase

Question 2

Intercalated discs 2 portions and components

Answer 2

transverse segment is mostly desmosomes and fascia adherens

longitudinal section: gap junctions

Question 3

Chronology of MI

Answer 3

immediately: cardiac enzymes
15 hours inflammation
1-3 days wound healing
1-4 days angiogenesis with VEGF and FGF
weeks scar tissue due to collagen crosslinking

Question 4

cardiac muscle regenerate?

Answer 4

yes 1% per year but cannot replace MI effects

Question 5

7 tried ways of regenerating cardiomyocytes

Answer 5

1. skeletal muscle myoblasts-arrythmias
2. cardiac fibroblasts (endogenous)-too much scarring
3. existing cardiomyocytes (endogenous)-maybe. by inhibiting tumor suppressors
4. adult heart stem cells (endogenous)-ckit positive cells, in niches, need to mobilize
5. adult heart stem cells (transplant)-no significant findings; no harm
6. bone marrow transp-currently need to ID best bone marrow type
7. CM induced from ipsc- from dermal cells, can beat, but canit contract?