Lecture 8 - Neuronal Organization Flashcards
Peripheral Nervous System consists of
All the nerves outside the brain and spinal cord
Central Nervous System consists of
Brain and Spinal Cord
Afferent branches send…
internal and external stimuli to CNS/brain
Types of autonomic nervous system
parasympathetic and sympathetic nervous system
Sympathethic Nervous System
FIGHT OR FLIGHT
Parasympathetic Nervous System
REST AND DIGEST
Stimuli traveling through explain
-Starts off at the PNS with a stimuli (can be internal or external)
-Receptors convert the stimuli into an electrical signal (part of PNS)
-Signal travels via afferent neurons to the CNS, which processes the signals
-The response exits via efferent neurons to the PNS, the response can be autonomic or somatic
What is the spinal cord made of
cervical, thoracic, lumber and sacral vertebrae- nerves are coming out of these vertebrae and are synapsing onto appropriate cells
What is ganglion
Ganglion is collection of cell bodies of neurons outside the CNS , while nerves are the axons of neurons that may be afferents carrying sensations or efferents carrying motor commands
Neurotransmitters released from the postganglionic synapse in the parasympathetic nervous system
Acetylcholine or Nitric Oxide
Neurotransmitters released from the postganglionic synapse in the sympathetic nervous system
Norepinephrine
Types of Spinal Nerves
Sensory Neuron and Motor Neurons
Sensory Neurons
transmit sensory information from the environment to the CNS
Motor Neurons
transmit messages from the CNS to the muscles
Nerves from the base of the brain are called
Cranial nerves
Nerves from the spinal cord are called
Spinal nerves
What are the three divisions of the brain
Forebrain
Midbrain
Hindbrain
3 parts of the autonomic nervous system are
preganglionic neuron, postganglionic neuron and the target organ
Nerves are
group of axons from neurons organized in fascicles and surrounded by layers of connective tissue and also contain blood vessels
In the sympathetic nervous system
-The cell body of the preganglionic is located in the spinal cord and releases acetylcholine
-Acetylcholine is stimulating the postganglionic, located next to the spinal cord (the cell body is located in a sympathetic ganglion) and releases norepinephrine/noradrenaline
-The preganglionic neuron is synapsing onto many postganglionic neurons (thus gives us a fast respond in flight/fight situation)
In the parasympathetic nervous system
-the cell body of the preganglionic neuron is located in the brainstem or the sacral spinal cord and releases acetylcholine
-the postganglionic neuron is in a ganglion near the target organ and releases acetylcholine or sometimes nitric oxide
A bundle of neurons is called
A fascicle which is wrapped in the perineurium
Nerves and neuron are interchangable?
No
Group of fascicles and blood vessels wrapped in epineurium is called
Nerve
