N1 Nervous System Overview Flashcards
The neuron is also referred to as the ____ cell of the nervous system
Functional
The structural portion of the nervous system refers to the ___ and contains the ____ and _____
Anatomy (think of the anatomical structures)
CNS (Central Nervous System)
PNS (Peripheral Nervous System)
The structures of the CNS are encased by ____ while the structures of the ____ are not
Bone, PNS
The PNS contains ____ which are collections of neuron cell bodies and ____ which are collections of axons
Ganglia
Nerves
The CNS is made up of ___ which contains collections of neuron cell bodies and ____ which contains collections of axons and processes
Gray matter
White matter
The nervous system can also be categorized based on function and breaks down into ____ and _____
Somatic (body wall)
Visceral (organs)
Afferent pathways are also referred to as ___
Sensory meaning that they carry sensory information to the CNS (signals arrive to CNS)
Efferent pathways are also referred to as ____
Motor
Carry outputs to lead to an action being performed
The autonomic nervous system is also referred to as _____
(Think of pathways)
Visceral efferent (motor) pathway
The four lobes of the brain
Frontal
Parietal
Temporal
Occipital
The main sulci and fissures are
Central sulcus
Lateral fissure also called the Sylvian Fissure
Parietoocipital sulcus
Calcarine Fissure
How many pairs of spinal nerves come out of the spinal cord?
31
8 cervical
12 thoracic
5 lumbar
5 sacral
1-2 coccygeal
What is the conus meduallaris?
The cone that forms at the end of the spinal cord
What is the cauda equina?
The horse tail like branches that come off the conus medullaris
In the spinal nerve, the posterior root is made up of ____ (type of neuron)
Pseudounipolar sensory neurons
In the spinal nerve, the posterior root ganglion is made up of _____
Cell bodies of sensory neurons
In the spinal nerve, the anterior root is made up of ___
Multipolar motor neurons
The autonomic nervous system is made up of the
Parasympathetic and sympathetic division
The sympathetic division of the nervous system is referred to as ___ and causes ___
Fight or flight
Pupil dilation, bronchodilation, cardiac acceleration, inhibition of digestion
The parasympathetic division is referred to as ___ and causes ____
Rest and digest
Pupil constriction, bronchoconstriction, cardiac deceleration, stimulation of digestion, salivation, etc
Structures of the sympathetic division of the ANS
T1 to L3 levels of the spinal cord
Structures of the parasympathetic division of the ANS
Cranial nerves and sacral part of the spinal cord
The CNS is made up of ___ (grey matter) and ___ (white matter)
Nuclei, tracts
The PNS is made up of ___ and ____
Ganglia, nerves
Anterior, posterior, superior, inferior, rostral, caudal,ventral,dorsal
Anterior (towards front)
Posterior (towards back)
Inferior (towards the bottom)
Superior (toward the top)
Rostral (towards beak)
Caudal (towards tail)
Ventral (towards center of earth)
Dorsal (towards the sky)
What is the horizontal plane?
Parallel with the ground
What is the coronal plane?
Think of a crown on the head and then slice down
What is a sagittal plane?
Think of separating the brain into two hemispheres
What is a neuron?
Functional unit of the nervous system
Multipolar neurons compose ____
About 99% of all neurons
Pseudounipolar neurons compose _____
Sensory ganglia
Bipolar neurons compose _____
Retina, cranial nerve I, cranial nerve VIII
The function of dendrites is to ___
Bring input in
The purpose of axons is to
Carry the output
How many layers does the cerebral cortex have?
Six
What are the names of the six layers of the cerebral cortex?
I: Molecular
II: External granular
III: External pyramidal
IV: Internal granular
V: Internal pyramidal
VI: Multiform
The cerebral cortex has pyramidal cells have cell bodies that are ___ shaped
Pyramid
The cerebral cortex has Purkinje cells which contain lots of ____
Cell bodies
The cell body of a neuron contains what kind of structures?
Nucleus, nucleolus, Nissl Bodies (ribosomes and endoplasmic reticulum), golgi complexes, mitochondria, neurofilaments, microtubules
Dendrites contain which structures?
Same organelles as the cell body of neuron except the nucleus
(Nissl bodies: ribosomes and endoplasmic reticulum, golgi complexes, mitochondria, neurofilaments, microtubules)
Pyramidal cells are typically part of ___ systems
Motor
Purkinje cells are mainly found in the _____
Cerebellum
What structures do axons contain?
Mitochondria, neurofilaments, microtubules
Axons DO NOT have ______
Protein making machinery
5 notable components of a neuron
Nissl bodies
Axon Hillock
Initial Segment
Internodal segment
Node of Ranvier
The glial cells of the CNS include
Oligodendrocytes, astrocytes, ependymal cells, and microglial cells
What is the function of oligodendrocytes and what part of the nervous system do they belong to?
Function: Myelination of axons, one can myelinate many axons
Located in the CNS
Has multiple processes
What disease demyelinates neurons of the central nervous system? What is the current treatment for this disease?
Multiple sclerosis
Interferon: diminishes the immune response
What is the function of astrocytes and what part of the nervous system do they belong to?
Function: regulate extracellular ionic environment, guide migrating neurons during brain development, blood-brain barrier*****
Located in the CNS
Astrocytes form part of the blood-brain barrier by regulating _____
Tight junctions
What is the function of Schwann cells and what part of the nervous system do they belong to?
Function: myelination of axons, one Schwann cell myelinates only one axon, see regeneration with Schwann cells
Located in the PNS
What are the functions of satellite cells and what part of the nervous system do they belong to?
Support cells
Located in the PNS
What are the features of the sensory ganglia in the PNS?
-Sensory, think of posterior root ganglia
-Contains pseudounipolar neurons
-Neuron density is higher
-Satellite cells are greater
-No synapses
What are the features of the autonomic ganglia in the PNS?
-Motor
-Multipolar neurons
-Neuron density lower
-Satellite cells fewer
-Contains synapses
What is the myelin sheath synapse?
Leads to fast transmission of electrical signals through an axon
Presynaptic areas: release neurotransmitters
Postsynaptic areas: cause a response
What are the features of a myelin sheath?
-Contains up to 50 plasma membrane layers
-Created by oligodendrocytes in the CNS
-Created by Schwann cells in the PNS
What is the internodal segment of a myelin sheath?
Segment that is myelinated and connected to cells that create the myelin sheath
In the PNS, myelinated axons are enclosed by up to 50 ______ _____ layers of ___ cells
Plasma membrane
Schwann
In the PNS, unmyelinated axons are enclosed by _____ of plasma membrane of ___ cells
Invaginations, Schwann
What is a synapse?
An area where a neuron makes contact with a target and something happens
How do you distinguish a neuromuscular synapse?
Junctional folds in the skeletal muscle
Acetylcholine neurotransmitter
Axon terminals often have tons of ______ for energy production
Mitochondria
CNS synapse: what is an axosomatic synapse?
Axon synapses with cell body (soma)
CNS synapse: what is an axodendritic synapse?
Axon synapses on dendrite
CNS synapse: what is an axoaxonic synapse?
Axon synapses on another axon
