Test #2 Flashcards
What two systems make up the Nervous System?
Central and Peripheral
What are the two types of the Peripheral Nervous System?
Sensory and Motor Cortexes
What four stored programs are played back to initiate motor tasks in which motor units are recruited in precise pattern?
Time, Space, Frequency, Amplitude
What are motor tasks that are played back termed as?
Muscle Memory
What are the basic functional units of the nervous system called?
Neurons (Nerve Cells)
What are neurons responsible for?
Generating and transmitting signals
Name four parts of the Peripheral Nervous System.
Sensory, Somatic Motor, Autonomic, and Internuerons.
Define these terms of the Nervous system:
A)Sensory
B)Somatic Motor
C)Autonomic
D)Interneurons
A) Sensory: Transmit impulses from receptors in skin, joints, muscles, & other peripheral aspects of the body TO the CNS.
B) Somatic Motor: Transmit voluntary impulses to muscle tissue FROM the CNS.
C) Autonomic: Carries involuntary impulses to the heart, smooth muscle, & glands FROM the CNS.
D) Interneurons: Connecting neurons within the spinal cord between Sensory & Motor neurons
What is a Motor Unit?
A single motor neuron & all muscle fibers it innervates.
Does a Motor Unit function as a single unit or multiple units?
Single unit
What two types of contractions do Motor Units provide?
Fast Twitch & Slow Twich
How many muscle fibers are in these types?
A) Small
B) Large
A) 10-100 muscle fibers
B) 300+ muscle fibers
Describe the Action Potential process.
Ion flow changes the polarization of the membrane.
Must reach threshold (irritability)
Once stimulus is received, nerve will propagate its signal (conductivity)
All fibers contract maximally or not at all (all or none)
Is there a voltage difference between the inside and outside of a cell membrane?
Yes
Movement of charged ions across an excitable cell membrane causes the resting membrane voltage to ____________.
Reverse
Breaks in the myelinated membrane (_____ of _________) between Schwann cells increases the conduction ________ of the AP. What is this called?
nodes of Ranvier; velocity
Salutary Conduction.
Why is gray matter gray and white matter white?
Gray matter has cells in it, white matter is myelinated.
What must neurons do to reach threshold?
Gather enough excitatory
What causes contraction?
Calcium causes contraction
Na ions carry + charges (inward/outward), making the (inside/outside) more positive.
Inward; Inside
K ions move + charges (inward/outward), making the (inside/outside) more positive.
Outward; Outside
Resting potential is usually ______
Negative
What does the Sodium-Potassium pump do?
Helps maintain resting potential.
What wraps around bone?
Periosteum
What wraps around muscle bundle?
Epimysium
What wraps the muscle fascicle?
Perimysium
What wraps muscle fibers?
Endomysium
What is the smallest functional unit of muscle?
Sarcolemma
How is force maintained during Titin extension?
When it binds to Actin
What is the function of the Nebulin?
Bind to capping protein Tropamodulin and regulates Actin length
What helps in force transmission between muscle cells?
Cytoskeleton
Lack of Desmin results in what?
Muscle fatigue
What is true of Action Potentials and Motor Units regarding muscles?
Muscles are recruited in orderly fashion and are based on size. (1st -> 3rd, Smaller -> Larger)
What is true of the first motor units recruited during an action potential?
Tend to be smaller, Type I Fibers, better Metabolism, more Mitochondria.
What is true of the second motor units recruited during an action potential?
Type II Fibers, tend to be larger, more lactate generated
What is true of the third motor units recruited during an action potential?
Type II Fibers, tend to be larger, more lactate generated.
How does the Neuromuscular Junction work?
Converts electrical signal to chemical signal.
Depolarizes back to electrical signal.
Primary neurotransmitter is ACh.
Mitochondria allow energy to move into Cleft.
Describe how Sliding Filament Theory works.
Resting State: Not bound, chamber is loaded gun cocked and ready to go.
Weakly Bound State: requires Ca2+ binding.
Strongly Bound State: must release to detach.
Energy Required: Every single Myosin head in every single sarcomere require ATP to move.
