Lecture 3 Flashcards
Skeletal Muscle structures
1- Sarcolemma 2- T-tubules 3- Sarcoplasmic reticulum 4- Terminal Cisternae 5- Mitochondria 6- Myofibrils 7- Sarcomeres
Myofilaments
1- Thick filament
2- Thin filaments
Thick filaments
Myosin
Thin Filaments
1- Actin
2- Tropomyosin
3- Troponin
Review slides 7-10
review slides son!
Intercalated Discs
The plasma membranes of adjacent cardiac muscle cells interlock at dark-staining junctions
type of Intercalated Discs
1- Desmosomes
2- Gap Junctions
Desmosomes
Prevent adjacent cardiac cells from separating during contraction
Gap Junction
Allow ions to pass freely from cell to cell, directly transmitting the depolarizing current across the entire heart
Functional Syncutium
Cardiac fibers are electrically coupled by the gap junctions, the entire myocardium behaves as a single coordinated unit
Three proteins that cardiac troponin consists of
1- Cardiac Troponin C (cTnC)
2- Cardiac Troponin I (cTnI)
3- Cardiac Troponin T (cTnT)
Cardiac Troponin C
Calcium Binding
Cardiac Troponin I
Inhibitory
Cardiac Troponin T
Tropomyosin binding
Skeletal and cardiac troponinT (as well as I) differ
in amino acid sequence
Angina and myocardial infraction
-due to myocardial ischemia
-Chest Pain
-
Myocardial ischemia results of
atherosclerosis
Pain associated in anginal
1- Exertion 2- Emotion 3- eating 4- cold short lived and relieved by NTG (Nitroglycerine)
Myocardial Infraction pain
- occurs spontaneously
- more long-lasting
- not relieved by NTG (nitroglycerine)
Angina characteristics
1- no cell death to myocardium
due to resupply of blood
Myocardial Infraction characteristic
1- Cell death
2- my result in death if enough cells die.
Prefered markers for detecting myocardoial cell injury
Cardia Troponin I (cTnI) or T (cTnT)
- both rise 2-6 hours after injury
- both peak in 12-24 hours
- cTnl can stay elevated for 5-8 days
- cTnT for 5-14 days
