Physiology of Nerve & Muscle Flashcards
What is the resting membrane potential?
The inside of neurons is electrically negative compared to the outside due to ion concentration gradients and differential permeability of the membrane to K+ compared to Na+.
What are the main types of ion channels?
- Voltage-gated ion channels
- Mechanically gated ion channels
- Chemically (ligand) gated channels
What is the role of the Na/K-ATPase?
Maintains the concentration gradients of Na+ and K+ across the membrane through energy-dependent primary active transport.
What determines the resting membrane potential (RMP)?
The concentration gradients of main ions and their experimentally determined permeability.
What is the Goldman-Hodgkin-Katz equation used for?
Calculates the resting membrane potential (RMP) considering the concentration and permeability of main ions.
What is the typical RMP value for neurons?
-70 mV
Fill in the blank: The resting membrane potential is highly sensitive to changes in _______.
[K+]out
True or False: The action potential is generated by passive (local) potentials.
False
What is the function of oligodendrocytes in the Central Nervous System?
Form the myelin sheath.
What is the role of astrocytes?
Provide nutrients, maintain extracellular environment, and provide structural support.
What type of neuron is responsible for output?
Projection neurons
What is the significance of myelin in the nervous system?
Increases conduction velocity of action potentials.
What are the two types of cells in the Peripheral Nervous System involved in myelination?
- Schwann cells
- Satellite cells
What are the main types of glial cells?
- Oligodendrocytes
- Astrocytes
- Microglia
- Ependymal cells
What is the velocity range for action potential propagation in peripheral nerves?
0.5-120 m/s
Fill in the blank: Neurons and nerves can be classified based on their _______.
[anatomy and function]
What is excitation-contraction coupling?
The mechanism that links muscle excitation to muscle contraction.
What factors influence muscle force generation?
- Length of the muscle
- Velocity of length change
What is the role of microglia?
Mount the immune response in the Central Nervous System.
What is the typical classification scheme for axons within nerves?
Based on diameter and conduction velocity.
What is the physiological basis of synaptic transmission?
Involves the release of neurotransmitters across the synaptic cleft to transmit signals between neurons.
What is the effect of doubling extracellular K+ on RMP?
It can cause changes in RMP, affecting neuronal excitability.
What happens during ‘spreading depolarization’ in the brain?
Involves increased extracellular K+, which worsens brain injury.
What is an example of a mechanically gated ion channel?
Touch receptors
