Cell biology Flashcards
What are the types of cells in the nervous system?
- Glial
- Neurons
- Neural stem cells
Macroglial cell involved with cell signaling, blood-brain barrier, development, support for neuron, clean up cellular debris, produce growth substances to keen neurons alive, and form a framework for migration of neurons during development (radial glia)
Astrocytes
What are the myelin-prducing cells?
- Schwann cells
2. Oligodendrocytes
What are the functions of myelin?
- Insulate axons and cell bodies of neurons from each other
2. Speed up AP
What cleans up debris in the PNS?
Schwann cells
Promote regeneration in the peripheral nervous system; Surround unmyelinated axons, but do not form a myelin sheath
Schwann cells
Phagocytic cells; Macrophages that migrate into brain; Normally at rest in brain; Become activated after injury, infection or disease
Microglia
Contains nucleus; Site of protein synthesis; Receives and processes information from other neurons
Soma
Project from soma; Specialized for receiving information and also processes information
Dendrites
At ends of axon branches; Specialized for transmission of information to other cells at the synapse; Usually use neurotransmitters to transmit the information
Presynaptic terminal
The mechanism for the relatively rapid transport of organelles and molecules to and from the presynaptic terminal
Axoplasmic transport (anterograde=from soma out, retrograde=opposite)
How fast does slow axoplasmic transport occur? why is this important?
1 mm/day; this is the rate at which neurons grow back
How many axons do psuedounipolar neurons have?
2 (both processes are axons
Transmitting information from one neuron to another is a function of _____ type neuron
bipolar
Cell type: Receive and integrate large amounts of information; Spinal motor neurons; Purkinje cells in cerebellum
Multipolar
Almost all sensory neurons in the body are ______ type neurons
Psuedounipolar
Psuedounipolar neurons are at type of _______ neurons
Bipolar
A single axon has several branches that terminate on many different cells
Divergence
Name the 3 different places a single sensory neuron sends signals to. What is this an example of?
- Interneurons that mediate reflexes
- Cerebral cortex for consciousness of sensation
- Cerebellum (unconscious proprioception)
Divergence
Multiple inputs from different neurons terminate on a single neuron
Convergence
Neurons may respond to 2 or more stimuli (Texture and temperature). This is an example of
Convergence
Rods and cones respond to points of light.
Retina detect On center/Off surround.
Visual cortex responds to bars of light.
This is an example of complex stimuli representative of:
Convergence
True or Flase:
Most neurons require excitatory input from more than one neuron in order to fire an action potential.
True (AKA summation)
What occurs with demylenination?
there is a slowing or even blocking of action potentials
What 4 things cause peripheral demyelination?
- Metabolic abnormalities
- Viruses
- Toxic chemicals
- Immune system
Disease of peripheral demyelination; Schwann cells affected; Thought to be autoimmune attack on myelin in peripheral nervous system in response to another infection
Guillan-Barre
Central nervous system demyelination; Autoimmune disease; Will see patches of demyelination, called plaques, due to the degeneration of oligodendrocytes; In chronic cases, the myelin sheath is replaced by glial scarring; high incidence in white women
Multiple Sclerosis (MS)
