Exam 1 Flashcards
What is the Nissil Stain used for?
Stains RNA in ribosomes on the endoplasmic reticulum in cell bodies and the nucleolus; Also stains glial cells but very lightly and mostly in the nucleolus
What is the weakness of the Nissil Stain
does not stain dendrites or axons
What is the golgi stain (silver stain) used for
stains the entire neuron including the dendrites and axons
What is a myelin stain used for
staining myelinated axons due to the stains affinity for lipids
Why is the myelin stain useful for diagnosis
Identifies regions which have areas of demyelination therefore is useful for diagnosis diseases like multiple scelerosis
How is immunocytochemistry used for cell labeling?
Antibodies are created against the antigen (Molecule of Interest), the primary antibody attaches to the antigen and the secondary antibody with a visible tag then attaches to the primary antibody
what is a flurophore
a molecule that will emit light when stimulated
What is double labeling?
Different antibodies can bind to different proteins on the same neuron; will show as a combination color of the two antibody tags (red+green=yellow)
what is a multipolar neuron
have multiple dendrites and one axon
what is a bipolar neuron
has one dendrite and one axon
what is a pseudo-unipolar neuron
have a single axon with peripheral and central branches
Describe a sensory neuron
Bipolar or pseudo-unipolar
receive input from receptors in the PNS
Transmits signals from peripheral receptors to CNS
Afferent Neuron
what is an afferent neuron
a neuron carrying a signal from the PNS to the CNS
Describe a motor Neuron
multipolar neurons
transmits signals from the CNS to an effector in the PNS
efferent neuron
what is an efferent neuron
a neuron carrying a signal from the CNS to the PNS
Describe an interneuron
usually multipolar
neither sensory nor motor
located entirely in the CNS
describe glial cells
non-neuronal cells that have a range of functions in the nervous system
What are the glial cells found in the CNS
oligodendrocytes, astrocytes, ependymal cells, microglia
what are the glial cells found in the PNS
schwann cells
what is the function of microglia
phagocytosis of foreign and dead material after injury to the brain
what is the function of ependymal cells
lines cavities in the CNS
what is the function of astrocytes
Regulation of:
ion concentration in the cerebrospinal fluid
neurotransmitter concentration in the cerebrospinal fluid/synaptic cleft
blood flow in blood vessels within the brain
what is the function of oligodendrocytes
forms myelin in the CNS
what is the function of schwann cells
forms myelin in the PNS
what is the difference between schwann cells and oligodendrocytes
one oligodendrocyte contacts multiple axons while one schwann cell contacts a single axon
what are the two divisions of the peripheral
nervous system
somatic and autonomic
what is the function of the somatic nervous system
nerves innervating skeletal muscle (voluntary control and reflexes)
what is the function the autonomic nervous system
nerves innervating smooth muscle, glands, and organs (involuntary control)
what is the meaning of contralateral
referring to structures on the opposite of the midline
what is ipsilateral
referring to structures on the same side of the midline
what is the meaning of bilateral
referring to a mirror image across the midline
what is the difference between distal vs proximal
distal - farther from the midline
proximal - closer to the midline
what is the difference between medial vs lateral
medial - closer to the midline
lateral - farther from the midline
what is the horizontal plane of the brain
cuts side to side, front to back; horizontal to the ground
what is the horizontal plane in the spinal cord
vertical to the ground
what is the coronal plan in the brain
vertical to the ground; cuts side to side top to bottom
what is the coronal plane in the spinal cord
horizontal to the ground
what is the sagittal plane
cuts from top to bottom, front to back
mid-sagittal vs parasagittal
mid-sagittal – at the midline
parasagittal - lateral to the midline
(can tall if its para sagittal if you can see the eye; if it is mid sag then you would see nose)
what is gastrulation
blastocyst transitions to a gastrula
what is a gastrula
when the embryo is a hollow cup shape with three layers
what are the three layers of the gastrula
mesoderm, ectoderm, endoderm
what is the outside layer of the gastrula and what does it become
ectoderm; becomes the skin and nervous system
what are the stages of neurulation
- Cells in the mesoderm form the notochord
- The notochord causes the ectoderm above it to thicken and become the neural plate
- The neural plate rolls up and forms the neural groove, which is surrounded by the neural folds
- These structures continue to turn in on themselves forming the neural tube (inside) and the neural crest (above the neural tube)
- the anterior end will form the cephalic end which will become the brain
- the posterior end will become the spinal cord
- each end has a neuropore which remains open for several weeks
what results if the posterior neuropore fails to close
spina bifida
what results if the anterior neurophore fails to close
anencephaly
what does the neural tube give rise to
motor neurons, preganglionic motor neurons of the ANS, interneurons, astrocytes, oligodendrocytes
what do the neural crest cells give rise to
sensory neurons, post ganglionic motor neurons of the ANS, Pia mater, Arachnoid cells, schwann cells
what is the ependymal zone of the neural tube
inside of the neural tube (lining of the central canal) a.k.a neuroepithelium
what is the mantle zone of the neural tube
the middle layer
what is the marginal zone of the neural tube
the outermost layer
what is the function of radial glial
they guide neurons to their correct location
what happens to radial glial cells when they are no longer needed
they differentiate into astrocytes
what does the mantle zone become in an adult brain
gray matter
what does the marginal zone become in an adult brain
white matter
how do axons of sensory neurons project
they project through the marginal zone into the mantle zone
how do axons of spinal motor neurons project
they project out through the marginal zone
how is white matter and gray matter organized in the spinal cord
white matter (marginal zone) develops external to gray matter (mantle zone)
what does the neural tube look like at 4 to 6 weeks of gestation
- the dorsal half is the alar plate
- the ventral half is the basal plate
what is the alar plate
contains interneurons that will receive input from the axons of sensory neurons
what is the basal plate
the origin of motor neurons
what happens during encephalization
neuroblasts migrate into the marginal zone where they form layers
what is the organization of gray and white matter in the cerebellar and cerebral cortices
gray matter develops external to white matter
what is the three vesicle stage at four weeks gestation
- prosencephalon
- mesencephalon
- rhombencephalon
what does the rhombencephalon develop into at five weeks gestation
metencephalon , myelencephalon (hindbrain)
what does the caudal neural tube develop into at five weeks gestation
spinal cord
what does the myelencephalon develop into at five weeks gestation
medulla
what does the metencephalon develop into at five weeks gestation
pons, cerebellum
what does the mesencephalon develop into at five weeks gestation
midbrain
what the prosencephalon develop into at five weeks gestation
telencephalon, diencephalon (forebrain)
what does the telencephalon develop into at five weeks gestation
cerebral cortex, basal ganglia, rhinencephalon
what does the rhinencephalon develop into at five weeks gestation
olafactory bulb
what does the diencephalon develop into at five weeks gestation
thalamus, hypothalamus, optic vesicle
where does the lateral ventricles develop at five weeks gestation
telencephalon
where does the third ventricle develop at five weeks gestation
diencephalon
where does the cerebral aqueduct develop at five weeks gestation
mesencephalon
where does the fourth ventricle develop at five weeks gestation
in met- and myelencephalon
where does the central canal develop at five weeks gestation
in spinal cord
what and where is the cephalic flexure
between the midbrain and hindbrain and is responsible for the 90 degree bend in the neuraxis
what happens at the 3 month gestation period
expansion in telencephalon, growth now covers diencephalon, ventricles undergo expansion with the rest of the structures
what happens as the brain develops further (6 months to 9 months)
expansion of the cerebral hemispheres progresses outwardly in the form of a C, to increase surface area and fit more cells the cortex folds in on itself
what are funiculi aka spinal columns
bundles of axons that run up or down the spinal cord
what are fasiculi (sing. fasciculus)
subdivisions of large spinal columns
what are tracts
axon pathways within the spinal cord and the brain
what is the cauda equina
the roots of the ventral and dorsal spinal nerves, which form a bundle within the lowest part of the spinal column.
what is the lumbar cistern
a space filled with cerebrospinal fluid in which the cauda equina sits
where does the spinal cord end
between the L1 and L2 vertebrae
why is a spinal tap performed in the lumbar cistern
the spinal nerves are able to move out of the way due to floating in the CSF in the lumbar cistern so there is no damage to the spinal nerves
which spinal segment has the most amount of gray matter and why
the cervical level due to lots of motor neurons for fine motor control of arms and hands
which is the spinal segment with the third most amount of gray matter
thoracic level
which is the spinal segment with the second most amount of gray matter and why
lumbar level due to motor neurons projecting to the legs
what are the three main divisions of the brainstem
midbrain, pons, medulla
what are the functions/components of the brainstem
vegetative functions
cranial nerves
ascending and descending axons
rhythmic and crude motor control
what are the medullary pyramids
contains fibers of the corticospinal tract
located on VENTRAL surface of brain stem
what is the pyramidal decussation
when fibers of the corticospinal tract cross to the contralateral side of the body
what are the inferior olives
provide afferent input to cerebellum
located on the ventral surface of the brainstem
what is the pons
located on the ventral side of the brainstem
connects the brainstem and cerebellum via axons that form the cerebellar peduncles
what are the pontine nuclei
clusters of neurons between axons in the pons
convey motor information from the cortex to the cerebellum
located in the pons
what are the cerebellar peduncles
contains axons relaying information into and out of the cerebellum
what is the cerebral peduncle
contain ascending sensory axons and descending motor axons
what are the mammillary bodies
on ventral side
associated with the hypothalamus
what is the inferior colliculi
relay auditory information to the thalamus
what is the superior colliculi
relay visual and other sensory information to motor neurons involved in orienting movements
what are distinguishing features of the midbrain
cerebral pendules
cerebral aquaduct
what are distinguishing features of the rostral medulla
fourth ventricle, inferior olive
what are the distinguishing features of the caudal medulla
central canal, pyramidal decussation, pyramid
what are the distinguishing features of the middle medulla
central canal, pyramid
what are the higher parts of the brain
cerebellum, diencephalon, telencephalon
what are the parts of the diencephalon
thalamus, hypothalamus
what are the parts of the telencephalon
basal ganglia and cerebral cortex
what is the function of the cerebellum
motor coordination, error correction, motor learning, timing of movements
what is the function of the thalamus
relay station; receives sensory information to primary sensory cortices, projects to and receives feedback projections from the cortex
what is the function of the hypothalamus
regulation of autonomic nervous system
releases hormones (attached to pituitary gland)
major visceral center
what is the function of the basal ganglia
motor planning/gating
what is a major characteristic of the components of the telencephalon
has a backwards C shape
what is the central sulcus
separates the frontal lobe from the parietal lobe
what is the lateral fissue
separates the parietal lobe and frontal lobe from the temporal lobe
what is the lamboid suture
separates parietal and occipital bones
what is the sagittal suture
lies along midline and separates two parietal bones
what is the coronal suture
separates frontal and parietal bones
what is the squamous suture
separates temporal bone from parietal and occipital bones
what is the primary cortices
receives sensory input from the thalamus (except for the olfactory cortex) and from association cortices, involved in early processing of sensory input
what are the association cortices
send and receive information only from other cortical areas
involved in “higher order” sensory, motor, and cognitive functions
what is the function the association cortices of the occipital lobe
involved in early cortical visual processing
what is the function of the primary visual cortex (V1)
organized as a map of the retina
what is the function of the primary somatosensory cortex (S1) in the parietal lobe
somatosensory inputs to each hemisphere come from the contralateral side of the body
what is the function of the association cortices of the parietal lobe (posterior parietal complex)
high level visual processing, perception of the spatial organization of the world
what is the function of the primary motor cortex (M1) of the frontal lobe
controls voluntary movements primarily of the contralateral body
what are the association cortices of the frontal lobe and what are their functions
broca’s area (language)
prefrontal cortex (long term planning, working memory, and judgement)
what is the primary cortex of the temporal lobe and what is its function
primary auditory cortex; organizes pitch of sounds
what is the association cortices of the temporal lobe and what are its functions
wenickes area (language)
recognizing objects
memory
what is the primary cortex of the insular lobe
gustatory cortex
