1.10 PHYSIOLOGY - Motor Flashcards
Other name for unitary smooth muscle
Syncitial smooth muscle
Visceral smooth muscle
3 types of muscles
Skeletal
Cardiac
Smooth
Smooth muscles with gap junctions
Unitary smooth muscle
Smooth muscles with no true Action potential (junctional potential only)
Multi-unit smooth muscle
Smooth muscle utilizing slow wave, spike potentials and plataeu potentials
Unitary
Rhythmic, intermittent smooth muscle
Phasic smooth muscle
Continuously active smooth muscle
Tonic smooth muscle
Skeletal muscle more active in the glycolytic pathway
Fast twitch
Examples of slow twitch fibers
Soleus, antigravity back muscles
Examples of fast twitch muscles
EOMS
Covers the muscle fascicle
Perimysium
Type of muscles arrange in sarcomeres
Skeletal and cardiac
Plasma membrane surrounding the muscle fiber
Sarcolemma
Invaginations of the sarcolemma in close proximity to the terminal cisternse of the SR
T tubules
Endoplasmic reticulum surrounding myofibril
Sarcoplasmic reticulum
Boundary of the sarcomere
Z lines
Thick filaments
Myosin
Thin filaments
Actin
Tropomyosin
Troponin
3 types of troponins
Trop T - attaches troponin complex to tropomyosin
Trop I inhibits actin myosin binding
Trop C -calcium binding protein
Tethers myosin to z- lines
Titin - also the largest protein in the human body
Stabilizes the sarcolemmma and prevents contraction induced rupture.
Dystrophin
Binds actin to z-lines
Actinin, capz protein
Binds z lines to sarcolemma
Desmin
Acts as a molecular ruler that sets the length of actin during assembly
Nebulin
What do you call actin and myosin interaction in the sliding filament model?
Cross bridge formation
What does negative pole and positive pole mean?
Negative pole - toward the M-line
positive pole - towards the Z-line
Sequesters Ca for storage
Calsequestrin
Receptors activated by DHPR receptors
Ryanodine receptors
What is the distance achieved in each cross-bridge cycle?
10 nm
What is a motor unit?
Consists of a somatic motor neuron plus all muscle fibers it stimulates.
Small motor units are recruited first before big motor units
Size principle
Multiple fiber summation
Spatial summation
Frequency summation
Temporal summation
What is the Staircase/Treppe Effect
Each contraction occurs after complete relaxation producing stronger contraction each time.
Basis for the Treppe effect
Ca2+ accumulation, pH changes, increased temperature
Complete fusion of individual muscle contraction when Ca 2+ is all used up
Tetany
Which of the following tetanizes at a lower stimulus frquency? Fast or slow twitch?
Slow-twitch
Which if the following has a larger maximal force during tetany?
Fast twitch
Active tension reflect what?
Number of cross bridges that cycle
Velocity of cross bridging reflects
Speed of cross-bridging cycling
Isometric contraction
Length is held constant
Load is held constant
Isotonic contraction
2 types of isotonic contraction
Concentric contraction (weight up) Eccentric contraction (lowering weight down)
Remember book diagram
Protective mechanism to prevent muscle cell injury or death
Muscle fatigue
Relationship of muscle fatigue to glycogen and lactate
Directly prop to lactate and inversely prop to glycogen
Relies both on intra and extracellular calcium
Cardiac muscle
Why is there no tetany in cardiac muscles?
Due to the long refractory period brought about by phase 2
Location of transverse tubules in cardiac muscles
In the Z lines
Location of transverse tubules of skeletal muscles
At the ends of the I bands
Sarcoplasmic reticulum is more developed im cardiac or skeletal?
Skeletal
Are there troponins in smooth muscle?
None
Secondary messenger for calcium release in smooth muscles
IP3
Trop C equivalent in smooth muscle
Calmodulin
Phosphorylates myosin
MLCK
Trop I equivalent in smooth muscle
Caldesmon and Calponin
Additioj of phosphate means the smooth muscle is active. True or false.
True
Enzyme that removes phosphate
MLCP
Caldesmon and Calponin are inhibited by
Ca-Calmodulin complex
Similar to z discs in smooth muscles
Dense bodies
Rudimentary structure in smooth muscles compared to skeletal muscles
SR
Rudimentary t tubules
Caveoli
Connect dense bodies with cytoskeletal network in smooth muscle
Desmin and vimentin
Intermediate filaments
Force of contraction in smooth muscles are stronger or weaker than skeletal muscle
Stronger
Spinal cord neurons important in control of muscles
Anterior motor neurons
Interneurons
Renshaw cell
Anterior motor neuron for extrafusal fibers
Alpha motor neuron
Angerior motor neuron for intrafusal fibers
Gamma motor neuron
Facilitates lateral inhibition in the control of muscles
Renshaw cell
Detects position of body in space
Proprioception
2 major proprioceptors
Muscle spindle and golgi tendon
Muscle spindles and are arranged in a ________ and detects changes in ___________
Parallel
Muscle length and rate of change of muscle length
Golgi tendon and are arranged in a ________ and detects changes in ___________
Series
Muscle tension
Functional unit of the cerebellum
Purkinje and deep nuclear cell
Which functional unit of the cerebellum is the middle layer and is always inhibitory?
Purkinje