CH 7: NERVOUS SYSTEM Flashcards
(25 cards)
Subdivisions of nervous system
CNS
PNS:
Afferent
Efferent:
Somatic
Autonomic:
Enteric
Sympathetic
Parasympathetic
Main functions of nervous system
sensory, integrative, motor
Ganglion
cluster of neural cell bodies in the PNS
Types of axonal transport
anterograde (forward, cell body –> axon terminal)
retrograde (backward, axon terminal –> cell body)
Where are neurotransmitters stored
In the synaptic end bulbs of neurons, within synaptic vesicles
Name of bundle of neural axons in CNS vs PNS
CNS: Tract
PNS: Nerve
Functional classes of neurons
Sensory (afferent neurons)
Integrative (interneurons)
Motor (efferent neurons)
Types of Neuroglia in CNS
Astrocytes, Oligodendrocytes, Microglia, Ependymal cells
Function of Astrocytes
protect brain (blood-brain barrier)
Function of Oligodendrocytes
Create myelin sheath around axon
Function of Microglia
remove waste/debris
Function of Ependymal cells
produce and circulate cerebrospinal fluid (CSF)
Neuroglia in PNS
Schwann Cells
Function of Shwann cells
produce myelin sheath around axons of neurons in PNS
Nodes of Ranvier
Gaps in myelin sheath in PNS, created by schwann cells
White matter in CNS is comprised of mostly ______ axons
myelinated (myelin sheath is white, hence “white” matter)
What makes up the grey matter in CNS?
unmyelinated axons, neuronal cell bodies, dendrites, axon terminals etc.
Regeneration tube
produced by schwann cells in PNS to try to repair a neuron, but cell body MUST be intact
What type of ion channel helps generate a graded potential?
ligand-gated and mechanically-gated channels
What causes voltage gated channels to open?
change in membrane potential (voltage)
What role do voltage-gated channels play in neuron signaling?
generate and conduct action potentials
Cells that have a membrane potential are considered _________
polarized
Directions of Na+ and K+ concentration and electrical gradients at resting potential
Na+
concentration (outside –> inside)
electrical (outside –> inside)
IN SAME DIRECTION
K+
concentration ( inside –> outside)
electrical (outside –> inside)
IN OPPOSITE DIRECTIONS
what causes the intracellular area to have a negative charge?
K+ ions can permeate more easily out of cell (down concentration gradient), making the intracellular space negative compared to extracellular fluid
