Lecture 1 - Organization of the Nervous System Flashcards
What is the CNS and PNS and what are their properties in terms of regeneration?
The CNS is the brain and spinal cord including the neurons and neuroglia located there
The PNS is the neurons and neural tissue elsewhere
-PNS can regenerate CNS cannot regenerate since they are stuck in G0 of the cell cycle
What are the two divisions of the PNS and the corresponding subdivisions of those two divisions?
PNS - somatic (voluntary) and autonomic (involuntary)
-the somatic system: afferent sensory neurons; efferent motor neurons
-the autonomic system: parasympathetic (rest and digest) and sympathetic (fight or flight) branches
What are the neuroanatomical directions for the brain?
-rostral = close to nose
-caudal = back of brain
-dorsal = top side of brain
-ventral - under belly of brain
-anterior = rostral
-posterior = caudal
-superior = dorsal
-inferior = ventral
What are the neuroanatomical directions for the spinal cord?
rostral = top of spinal cord close to brain or the cervical spinal cord
caudal = bottom of spinal cord close to butt or the sacral spinal cord
ventral - spinal cord close to belly
dorsal - spinal cord close to back
anterior = ventral spinal cord
posterior = dorsal spinal cord
superior = rostral spinal cord
inferior = dorsal spinal cord
What are the overlaps of the neuroanatomical directions for the spinal cord and brain?
superior = dorsal brain = rostral spinal cord
inferior = ventral brain = caudal spinal cord
anterior = rostral brain = ventral spinal cord
posterior = caudal brain = dorsal spinal cord
What are the planes for the brain?
-sagittal plane is vertical - can be mid or parasagittal
-horizontal plane is parallel to the floor
-frontal plane or coronal plane is like a headband
What are flexures?
bends only present in utero in development
Which flexure persist in bi pedal organisms even after birth and what does it cause?
Cervical flexure; causes a 90 degree bend between the brain and the spinal cord
-in other organisms all the flexures disappear in quadrupedal organisms which make them horizontal organisms since they no longer have the bend
What is the cephalic flexure and does it persist?
cephalic flexure - slight bend between the brain stem and the spinal cord
-yes it is present in both bipedal and quadrapedal organisms
What is a shallow valley in the brain?
sulcus
What is a small hill in the brain?
gyrus
What is a deep valley in the brain?
fissure
What is the frontal lobe and what is it involved in?
-frontal lobe is rostral in the brain
-involved in executive function and decisions and planning and decision making, cognitive inhibition, motor function, aspects of personality, long terms learning (overall: movement and executive function)
What is the parietal lobe and what is it involved in?
-parietal lobe - caudal to the frontal lobe
-involved in somatosensation, detecting innocuous touch and pain, spatial orientation
-when people have a stroke on the right side of the brain they neglect the left side of the body (tends to be contralateral)
What is the temporal lobe and what is it involved in?
-the temporal lobe is on the dorsal rostral side of the brain below the frontal lobes
-it is involved in language and memory and speaking; tend to be on the right side of the temporal lobe
What is the occipital lobe and what is it involved in?
-the occipital lobe is caudal and ventral in the brain below the parietal lobe
-it is involved in sight such as visual processing and early perception and relaying those perceptions to other lobes (i.e. object, word, and face recognition)
What is the central sulcus?
separates the frontal and parietal lobes
What is the lateral sulcus or sylvian fissure?
separates the frontal and parietal lobes from the temporal lobe
What is the insula and what is it involved in?
-under the sylvian fissure or lateral sulcus and it is below the frontal and temporal lobes
-involved in speech production and processing pain and disgust
What is the diencephalon and what two structures does it relate to?
the diencephalon is related to the thalamus and hypothalamus
-the thalamus in the diencephalon functions as a relay center which receives sensory information and relays it to other motor cortical and subcortical regions
What is the brainstem, what are the three parts of the brainstem and where is it located relative to the diencephalon?
-the oldest part of the brain where autonomic and essential motor functions are localized to its structures
-midbrain, pons, and medulla oblongata
-it is caudal and ventral to the diencephalon
What does the midbrain do and what is another name for it?
-important for motion detection and other visual processing including sound localization as well
-mesencephalon
What is the pons, what structure is it related to, and what is another name for it?
-important to note that between the pons and cerebellum is the fourth ventricle
-related to the bulb
-it and the cerebellum form the mentencephalon
What is the medulla oblongata and what is another name for it?
-controls the respiratory system and the heart rate via the autonomic nervous system
-myencephalon
What exits the brainstem?
cranial nerves
What is the corpus callousum and what does it have alot of due to its axonal projections?
-great extent of white matter
-is a white matter bridge which communicates between the two hemispheres
What other two structures also help communicate between the two hemispheres of the brain?
-anterior and posterior commissure
Where is the cerebellum located in the brain?
caudal and ventral
What is gray matter and what is an example of it in the CNS and PNS respectively?
-gray matter is the accumulation of cell bodies
-in the CNS that is the cell bodies of neurons which exist in a terms called nuclei or nucleus if singular cell cluster
-in the PNS the cell bodies of neurons are called ganglia or ganglion if singular
-in the CNS and PNS nuclei and ganglia are used to define a set of cells which work together
What is white matter and why is it white?
-the axons of the cell bodies which project out
-it is white due to the high lipid content of the axons since they are myelinated
What is the arrangement of white and gray matter in the spinal cord and what “shape” does it seem to form?
-the white matter surrounds the central gray matter creating a butterfly esque shape
What is the meninges?
-three layers which protect the brain and spinal cord
What are the three layers of the meninges?
-dura mater
-arachnoid layer
-pia mater
What is the dura mater?
-outer meningeal layer which translates to tough mother and provides protection between the brain and the skull and the spinal cord and the vertebral column
What is the arachnoid layer and what does it contain?
-the middle meningeal layer
-it is named for its resemblance to spiderwebs since it contains collagen and connective tissue and sinuses; very dense connective tissue
What are sinuses?
-empty cavities in the brain
What is the Pia mater?
-the innermost meningeal layer
-translated to soft mother and contains blood vessels; very attached to the cortical surface and has great vasculature due to blood vessels making it difficult to separate from the brain
What is the condition when the three meningeal layers are inflammed?
meningitis
What is a ventricle and how many total are there in the brain?
-a deliberate hole or cavity in the brain filled with CSF
-the four ventricles plus the central hole through which the spinal cord passes
What is CSF?
-cerebrospinal fluid and it is a filtrate of blood filled with ions and molecules needed for the brain
What structure are the lateral ventricles associated with?
the forebrain
What cluster of cells is found near the lateral ventricles and what do they do?
arachnoid clusters; produce CSF
How does CSF travel?
through the ventricles and then to the spinal cord where it is recycled
1.CSF is produced by the arachnoid clusters surrounding the lateral ventricles
2. CSF flows to the third ventricle below the hypothalamus
3. CSF travels down to the central canal which reaches the spinal cord
What happens if a tumor is present in the ventricle?
the ventricles can misshapen causing pressure on the surrounding brain tissue
What is the term for abnormally large ventricles and what can it cause?
-hydrocephalus, causes pressure on other tissues
What are the four cranial nerve associated with the eye?
optic nerve CN II (sensory)
oculomotor nerve CN III (motor)
trochlear nerve CN IV (motor)
abducens nerve CN VI (motor)
What are the three cranial nerves associated with the tongue?
-facial nerve CN VII (both sensory and motor)
-glossopharyngeal nerve CN IX (both sensory and motor)
-hypoglossal nerve CN XII (motor)
What does the optic nerve CN II do?
-sensory neuron which convey info from the retina about visual stimuli
What does the oculomotor nerve CN III do?
-motor nerve which controls four out of the six intraocular muscles that allow for light movement and the pupillary light reflex
What does the trochlear nerve CN IV do?
-somatic motor neuron which controls one of the six ocular muscles
Whats does the abducens nerve CN VI do?
-somatic motor neurons which controls one of the six ocular muscles
What does the facial nerve CN VII do?
-both sensory and motor and it controls sensation in the face and is not regulated by the trigeminal nerve; controls the anterior two thirds of the tongue to convey feeling and gustatory info
What does the glossopharyngeal nerve CN IX?
-both sensory and motor controls the gustatory info from the posterior one third of the tongue and the muscles for swallowing
What does the hypoglossal nerve CN XII do?
-motor nerve which controls the muscles for speech
What are the four regions of the spinal cord going rostral to caudal?
-cervical - neck and upper back
-thoracic - torso or trunk region
-lumbar - hips and legs
-sacral - lower back
What is the dorsal horn of the spinal cord?
-where sensory cell bodies or gray matter is
What is the ventral horn of the spinal cord?
-where motor cell bodies or gray matter is
What happens to the cranium and brain in size with evolution?
-it shrinks and has more sulci or gyri
What is indicative of greater complexity in the brain?
-more sulci and gyri
-size is not indicative
