Introduction to Nervous System Flashcards
Nervous system functions
Sensory perception (sensory neuron), integration(interneurons) and motor planning (motor neuron)
What makes up the CNS
Brain and spinal cord (cervical, thoracic, lumbar, sacral, coccygeal)
What makes up the PNS
Nerves and ganglia
What does the CNS do
Information processing, integrates, processes and coordinates sensory input and motor commands.
Afferent vs efferent division
Afferent is for sensory information and efferent is for motor commands
Afferent division
Special sensory receptors (smell, tats, vision, balance and hearing), visceral sensory receptors( monitor internal organs) and somatic sensory receptors( monitor skeletal muscles, joints and skin surface)
RECEPTORS
What does sensory integration
Interneurons do sensory integration and they come up with a motor plan for a response
Efferent division have 2 divisions
Somatic nervous system is for skeletal muscle
Autonomic nervous system is divided into parasympathetic and sympathetic division that act upon smooth and cardiac muscle, glands and adipose tissue.
EFFECTORS
What are the properties of neurons
Excitability- respond stimuli
Conductivity- send signals to distant locations quickly
Secretion- neurotransmitters release
4 universal neurons parts
Dendrites, soma, axon and terminals
Excitatory and inhibitory neurotransmitters
Excitatory- Glutamine, norepinephrine, dopamine
Inhibitory- GABA, serotonin and dopamine
Function classes of Neurons
Sensory afferent neurons-detect stimuli
Interneurons- receive signals from other neurons and make decisions about the response
Motor efferent neurons- send signals to muscles to provide response
Multipolar neuron
Many dendrites, one axon
Bipolar neuron
One dendrite, one axon
Unipolar
No dendrites, one axon and usually an interneuron just for integration of signal
Anaxonic
Many dendrites but no axon usually for signal propagation
Neuron structure
Neurosoma or cell body- control center
Nissl bodies- compartmentalized rough ER
Dendrites- receive signals
Axon- sends action potentials
Axon terminal- ending of axon branch that communicates with another cell, pre-synaptic and post-synaptic
Synapse- where neurotransmitters are released
Receptor region
It’s the cell body, soma that has dendrites
Conductive region for signals
The axon hillock, axon for signal propagation
Effector region
Terminal is the effector region
What do sensory neurons look like
They are multipolar with many dendrites at both axon terminal
Neuroglial cells of the CNS
Oligodendrocytes, astrocytes, microglia, ependymal cells.
Oligodendrocytes
CNS, myelinate to assist conduction
Ependymal cells
Secrete and circulate cerebrospinal fluid
Microglia
Help in defense and disposal, increases when infection in the CNS
Astrocytes
Provide support and nourishment, clear debris, form blood-brain barrier
Schwann cells
PNS, Myelinate to assist conduction
Satellite cells
PNS, Provide support and nourishment
Myelin
Insulation on a wire, big diameter= more conduction
