Chapter 11 Flashcards
(28 cards)
Universal characteristics of muscles:
- Excitability
- Conductivity
- Contractility
- Extensibility
- Elasticity
Skeletal muscle characteristics
- Produce movement
- Maintain posture and body position, support soft tissues
- Control of body openings and passages
- Maintain body temperature - produce heat
- store nutrients
- Glycemic control
Connective tissue sheaths provide…
Routes for blood vessels and nerves to enter the muscle, stabilize their positions
Fascia =
Sheet of connective tissues that separates neighboring muscles or groups from each other or subcutaneous tissue
Epimysium
Dense irregular connective tissue
Perimysium
Surrounds fascicles (usually bundles of 2-60 fibers)
Endomysium
Delicate, loose connective tissue sheath, chemical environment is important for muscle function
Sarcolemma
Plasma membrane
Sarcoplasm
Cytoplasm
Myofibrils
Long protein cords
Mitochondria
Aerobic cellular respiration
Triads
Transverse tubule and terminal cisternae of sarcoplasmic reticulum
Myofibiril are long chains of sarcomeres that ___ during contraction
Shorten
Actin and myosin are considered _____ proteins
Contractile
Tropomyosin and troponin are considered _____ proteins
Regulatory
What links actin to the sarcolemma?
Dystrophin
How do we get contraction of all the sarcomemeres within a muscle fiber at once?
Excitation- contraction coupling
Membrane potential =
Voltage across the membrane
voltage =
Electrical potential energy due to separation of oppositely charged particles (in our case ions!)
High concentration OUTSIDE the cell =
-sodium (Na+)
-chloride (Cl-)
High concentration OUTSIDE the cell =
-sodium (Na+)
-chloride (Cl-)
Higher concentration INSIDE the cell:
- potassium (k+)
- protein anions
Electrical gradient =
Ions are attracted to opposite charges, repelled by like charges
There are more __ channels than __ channels
K+ , Na+
