9. Musculatory System I Flashcards
Formative immature cells of muscles; present in fetal stage; func: mitosis
Myoblasts
Non striated
Involuntary
Can divide
Smooth muscle
Spindle shaped muscle tissue
Smooth muscle
Only mature muscle tissue that can divide
Smooth muscle
Striated
Voluntary
Multinucleated
Hypertrophy only cannot multiply
Skeletal muscle
Location of nucleus of skeletal muscle
Lateral surface
Striated
Involuntary
Cannot multiply; hypertrophy only
Cardiac muscle
What type of muscle cell or tissue is the HEART
Cardiac muscle
What connects cardiac muscle cells together
Intercalated discs
Cellular junctions in cardiac muscles
Desmosomes
Gap junctions
Outermost ct layer that covers MUSCLE BELLY
Epimysium
Middle layer covers FASCICLES
Perimysium
Innermost; covers MUSCLE CELLS OR FIBERS
Endomysium
Connects muscle to bone
Tendon
Connects bone to bone
Ligaments
Group of muscle fibers covered by perimysium
Fascicle
Cell membrane or plasma membrane of muscles made up of phospholipid bilayer
Sarcolemma
Structures that makes up the muscle cell or fiber
Myofibrils
Structures that makes up myofibrils
Myofilaments
2 kinds of myofilaments
Thin filaments
Thick filaments
Thin filaments is composed of what protein
Actin
Thick filaments are composed of what protein
Myosin
Shape of myosin
Golf club
Functional or contractile unit of muscle; from Z disc to another Z disc
Sarcomere
Separates one sarcomere to another
Attachment for thin filaments
Passes in the middle of the I band
Z discs
Contains thick but no thin filaments (MYOSIN ONLY)
H zone
Passes in the middle of H zone
M line
Aka dArk band
A band
Aka lIght band
I band
Blocks the myosin binding sites in actin (relax muscle)
Tropomyosin
Holds the tropomyosin in place
Binding site for Ca ions to allow movt of tropomyosin
Troponin
Perpendicular sarcolemma
Transverse tubules or T tubules
Endoplasmic reticulum of muscle fiber
Sarcoplasmic reticulum
Storage for calcium
Sarcoplasmic reticulum
Most impt substance for muscular contraction
Calcium
Dilated end sacks of Sarcoplasmic reticulum
Terminal cisterns
Cytoplasm of a muscle fiber
Sarcoplasm
Stored chains of glucose
Glycogen
Glycogen is mainly stored in
Liver
Skeletal muscle
Adipocytes
Process: glycogen to glucose
Glycogenolysis
Maximum storage of glycogen
2 lbs
Process: glucose to glycogen
Glycogenesis
When does the body produce glycogen
Hyperglycemic state
Hormone responsible for production of insulin (glycogen stored in insulin sensitive cells)
Beta cells of pancreas
Protein that binds OXYGEN=red color of muscle
Counterpart of RBC (hemoglobin=red color)
Myoglobin
Largest protein of the body found in muscles
Titin
Total muscles in the body
650 muscles
Attachment for THICK filaments
M line
Overlapping thick and thin filaments
A band
Attachment of THIN filaments
Z line or disc
Filaments seen in light or I band
Thin filaments only
Aka theory of muscle contraction
Sliding filament mechanism
% of ICF
40% ICF
% OF ECF
20%
What is the resting membrane potential? (mV)
-70mV (-90mV in guyton)
Most numerous ca+ion in ECF
Na+
Most numerous ca+ion in ICF
K+
Charge inside the cell when it is in resting state or polarized state
Resting membrane potential
1st channel to open once there’s electrical current
Voltage-gated Na+ channels
Why is depolarization and repolarization happens? (What process)
Na goes in
K goes out
Because of simple diffusion
Na+ influx = cell more + = ____
Wherein, cell from negative to a positive state
Remove a cell in a polarized state(-)
Depolarization
Channels that are delayed to open
Opens after action potential
Voltage-gated K+ channels
K+ efflux(out) = cell goes back to resting state =___
Change charge of cell from + to NEGATIVE
Repolarization
What is the Threshold stimulus to generate an action potential
-55mV
Signal that has potential to trigger an axon
Action potential
Corrects position of Na+(out) and K+(in)
Sodium potassium pumps
Ratio in Na-K pumps (“2PISO3”)
2 potassium in
3 sodium out
In precontraction phase, an ACTION POTENTIAL from nerve fiber stimulates ___ to open
Voltage gated Calcium channels
Calcium influx causes release of _ in the NMJ
Ach
It is a neurotransmitter or a chemical messenger (LIGAND)
Acetylcholine
Part of the NMJ where Ach binds
Nicotinic receptors or “Ligand”-gated Na+ channels
Na+ enters muscle fiber (Depolarization) creating a ____
Muscle action potential
Muscle action potential travels to what part of the muscle cell
Sarcolemma and T tubules