The Central Nervous System Flashcards
What stains are used for nerve tissue?
H&E
Nissl Stain
Osmium
Luxol Fast Blue
Silver Staining
Golgi Stain
Basic Neuron Structures
multipolar, bipolar, pseudounipolar
dendrites
cell body
axon
Neuron Configurations
- Motor
- multipolar
- Sensory
- Bipolar
- pseudounipolar
- Integrative
- pyramidal
- interneurons
- Purkinje cell
Neuron Cell Body (Perikaryon)
“trophic center” - supports the process
contains nucleus with well developed nucleolus
nucleus is generally euchromatic → DNA is not compacted due to high transcriptional activity
Highly developed RER → nissl bodies
Axon
Constant diameter
generally do not branch
May be very long
Bidirectional transport
Specific motor proteins → Kinesin (anterograde → body to axon), Dynein (retrograde, axon to body)
Axon hillock → part of signal generation, stains more lightly b/c clear of organelles
Basic Neuron Histology
Dendrites
Small, branching processes important for neural plasticity → learning, adaptation, memory
contains actin filaments
receive and process signals
multiple synapses
Dendrite Histology
Synapses
(example of chemical synapse) Neurotransmitter release promotes ion uptake in postsynaptic membrane
Neurotransmitter
ACh and NE discovered first
can be excitatory or inhibitory
usually amines, amino acids, or small peptides
degraded in synaptic cleft, or taken up by exocytosis (prevent prolonged stimulation)
may act as paracrine hormones outside the. nervous system
Nervous System Organization
- Functional
- sensory
- motor
- Anatomical
- central
- peripheral
Nervous System: Functional Division: Sensory Nervous System
- Some CNS and PNS components → includes all axons that transmit impulses from a peripheral structure to the CNS
- Somatic sensory → transmits input from skin, fascia, joints, and skeletal muscle
- Visceral sensory → transmit input from stomach and intestines (viscera)
Nervous System: Functional Division: Motor Nervous System
- Some CNS and PNS components → includes all axons that transmit from the CNS to a muscle or gland
- Somatic motor (somatic nervous system) → voluntary control of muscles (skeletal)
- Autonomic motor (autonomic nervous system) → involuntary control of smooth muscle, cardiac muscle, and glands
Nervous System: Anatomical Division: Central Nervous System
Brain
Spinal Cord
Overall “command center”, processing and integrating information
Nervous System: Anatomical Division: Peripheral Nervous System
Ganglion (ganglia)
Peripheral nerves (axons of nerves)
Receives and projects information to and from the CNS; mediates some reflexes
Where is grey matter found in the brain?
cortex
Where is white matter found in the brain?
Medulla → nerve fibers and glial cells
Where is grey matter found in the spinal cord?
Medulla
Where is white matter found in the spinal cord?
Cortex
Where is the dorsal horn of the spinal cord?
Back (top)
gray matter
Where is the ventral horn found in the spinal cord?
Front (bottom)
gray matter
What are the three CT layers in the CNS?
Dura mater
arachnoid → subarachnoid space
pia mater (looser CT)
Tract
bundle of nerve fibers
Nuclei
prominate in spinal cord
aggregates of cell bodies
Glial Cells
Supporting Cells
Oligodendrocytes
cells that make myelin sheath
Types of Supporting Cells
Astrocytes
Microglia
Satellite Cells
Myelin Sheath → Oligodendrocytes,, Schwann Cells
Astrocytes
important for support of processes
form part of the blood brain barrier
express glial fibrillary acidic protein (GFAP)