Basics Flashcards
What are the only two exceptions to rule that all neurons have at least one axon and one or more dendrites?
- Amacrine cells of the retina
2. Granule cells of the olfactory bulb
What are Nissl bodies? AKA?
AKA chromophil substance because of its affinity for basic dyes
They are composed of membrane bound ribnucleoproteins (granular endoplasmic reticulum) responsible for synthesis– products are sent to the golgi apparatus
What organelle is noticeable missing from the axon?
Those for protein synthesis or assembly.
Nissl substance, Golgi complex and ribosomes)
What ion channels are located in the nodes of Ranvier?
Voltage gated sodium channels
What covers:
- Individual axons
- Grouping of axons
- An entire nerve (multibundle of axons)
- Individual axons: Endoneurium
- Grouping of axons: Perineurium
- An entire nerve (multibundle of axons): Epineurium
What is the only organelle found in the perkiaryon that is NOT in the dendrite?
Golgi apparatus
What neurons are bipolar?
Retinal cells
Olfactor receptors
Peripheral ganglia of the vestibulocochlear nerve
Sensory dorsal root ganglia is PSEUDOUNIPOLAR
Which neuroglia is the largest?
Astrocytes
Which astrocytes
- Have foot processes that form a continuous glial sheath surrounding blood vessels.
- Found in white matter concerned with transference and repair of damaged tissue
- Found in close proximity to neurons in the gray matter
- Fibrous
- Fibrous
- Protoplasmic
Identify which nerve fiber type and which number desgination
- Proprioreception and motor to skeletal muscles
- Contractile force (Golgi tendon organ)
- Pressure stretch muscle spindle, touch and vibration
- Motor to muscle spindle
- Nerve endings serving pain and temperature and touch
- Sympathetic preganglioninic axons
- Sympathetic post ganglionic
- Proprioreception and motor to skeletal muscles: Aalpha 1a
- Contractile force (Golgi tendon organ) Aalpha 1b
- Pressure stretch muscle spindle, touch and vibration: A beta 2
- Motor to muscle spindle A gamma 2
- Nerve endings serving pain and temperature and touch A delta 3
- Sympathetic preganglioninic axons B
- Sympathetic post ganglionic C 4
PRACTICE WRITING THE TABLE!
What is the speed of the fastest nerve fiber? Type A alpha 1a 1b
70-120m per second
12 to 22 micrometers in size
What is the only type of nerve fiber that is not myelinated?
Type C/ 4
Speed at 0.6-2.0m/s
Incomplete fusion of schwann cell membrane with schwann cell protoplasm is called?
Schmidt-Lanterman clefts
Which can produce myelin for a group of axons rather than just one?
Oligo
Schwann
Oligo
In synaptic transmission, when a AP arrives at the axon terminal what events occur?
Membrane at the terminal is depolarized
Calcium ions enter the permeable membrane terminal
Synaptic vesicles fuse with the presynaptic membrane releasing the NT.
Eg. if NT is Ach then upon contact with the post synaptic membrane there is an increase in permeability to Na thereby causing causing a propagated depolarization