Unit 1 Skeletal Muscle Anatomy Flashcards
Skeletal Muscle Cellular Organelles
- Nuclei
- Synthetic Machinery
- Mitochondria
What is an important characteristic regarding the nuclei of skeletal muscle?
Multinucleated
Location of myonuclei in the muscle?
-Dispersed along the inner surface of the plasmalemma, particularly dense in the motor end-plate region
Contents of myonuclei
- Nuclear DNA
- RNA (m and t)
- Ribosomes
- Codons
Components of the Synthetic Machinery
- Endoplasmic Reticulum
- Ribosomes
Characteristics of the Endoplasmic Reticulum
- Associated with nucleus
- transportation and modification of cellular proteins outside of cell
Role of Ribosomes
Coordinate protein synthesis
Substances associated with mitochondira
- ATP
- NADH
- FADH2
Metabolic processes associated with mitochondria
Electron Transport Chain
Bioenergetic imperative for mitochondria to operate
Oxygen (Aerobic)
Location of mitochondria within the muscle cell
between myofibrils in the z-line region and in relation to nuclei and motor end-plate
Unique feature of mitochondria when viewed cross sectionally
oval shaped
Key structural features of mitochondria
- Inner and Outer membrane
- inner membrane folds called cristae
- Matrix between cristate
What is housed in the inter-cristae matrix
- Krebs cycle enzyme
- Mitochondrial DNA (mtDNA)
Types of mitochondria
- Subsarcolemal
- Intermyofibrillar
Primary location of subsarcolemmal mitochondria
Immediately beneath cell membrane (sarcolemma)
What is the functional significance of the location of subsarcolemmal mitochondria?
They can easily receive arterial oxygen
Key difference between Intermyfibrillar and subsarcolemmal type mitochondria?
Intermyofibrillar may have higher activity per unit mass
Key role of intermyofibrillar mitochondria
Maintaining ATP supply for energy transduction during contraction
Intermyfibrillar Mitochondria Location
Deep within the cell in the contractile elements
Cytoplasmic Components
ANAEROBIC
1. Soluble Proteins, Cytoskeletal Components
2. Glycogen Granules
3. Glycolytic Enzymes