Gross Brain Flashcards
What are the parts of the PNS?
Cranial Nerves
Spinal Nerves
What are parts of the CNS?
Brain
Spinal Cord
What are the divisions of the central nervous sytem?
Prosencephalon
Mesencephalon
Rhomencephalon
Spinal Cord
What is the Proencephalon?
Forebrain
Includes the Telencephalon (cerebral cortex) and diencephalon
What is the Mesencephalon?
It includes the midbrain
What is the Rhombencephalon?
Hindbrain
It includes the Metencephalon (pons) and Myelencephalon (medulla)
What is included in the Brain stem?
Midbrain
Pons
Medulla Oblongata
Whata re the four parts of the adult brain?
Brain Stem
Cerebellum
Diencephalon
Cortex
What are the boundaries of the Medulla Oblongata?
- Caudal - decussationof the pyramids
gradual transition from spinal cord
extends below foramen magnum
- Rostral - pontomedullary junction
What are the functions of the medulla oblongata?
- Cardia center: Force and rate of heartbeat
- Respiratory center: controls rhythm and rate of breathing
Stroke and/or trauma to the medulla oblongata leads to what?
DEATH
What are the parts of the medulla oblongata?
Ventrally
Olive - inferior olivary complex: motor learning
Pyramids - corticospinal tract
decussation of pyramids - background information
Dorsal
Cuneate (outer) and Gracile (two inner)
(tubercle is the bulkier superior portion of the two and the fasciculus is the lower smoother half)
Obex and median sulcus
What are the 4 cranial nerves the originate from the Medulla Oblongata?
CN: IX, X, XI* (originate from dorsal to the olive)
and CN: XII (originate from the medulla, between the pyramids and inferior olive)
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What are the 3 nerves that originate from the pontomedullary junction?
CN: VI, VII, and VIII
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What is the purpose of the Pons?
Relay Signals between Cerebral cortex and Cerebellum
What nerves comes from the pons?
CN: V
Originates from the middle cerebellar peucle
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What are the parts of the pons?
Middle cerebellar peduncle
Connects pons to the cerebellum
The fourth ventricle is found dorsal to what?
Dorsal to the medulla and pons and it sepreates the medullapons from the cerebellum.
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What is creative about the formation of the 4th ventricle?
The fourth ventricle is formed because the presence of the cerebellum causes the roof plate to split and the canal enlarges to become the 4th ventricle over the pons and medulla
*the general embryonic origin of sensory and motor nucleu seen in the spinal cord is maintained
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What are the parts of the midbrain?
Dorsally,
Corpora Quadrigemina
Superior colliculus (visual/oculomotor reflexes)
inferior colliculus (auditory relay center)
What nerve exits the brain immediately caudal to the inferior colliculus?
Trochlear Nerve
CN: IV (originates from the dorsum of the midbrain)
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What are the pars of the midbrain?
Cerebral peduncle (corticospinal tract)
You can also see CN: IV (laterally) and III (medially)
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What is the cerebral aqueduct?
It is the continuation of teh 4th ventricle that is behind the midbrain (tranverses the midbrain)
Where is the tectum located?
The tectum, which also stands for roof, is found dorsal to the cerebral aqueduct.
When you are looking at a cross section of the midbrain midbrain what can you see?
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What is A and B?
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A = Tegmentum
B = Basilar pons
This is an image of what?
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Cerebellum
What is the cerebellum
coordinates and smooths movements
maintains equilibrium
maintains posture
What are the parts of the diencephalon?
Thalamus
hypothalamus
epithalamus
What is the thalamus?
Sensory(exceot olfaction)/motor/limbic relay center for information en route to the cortex
Specific thalmic nuclei project to specific areas of the cortex
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What are the two specific thalmic nuclei?
Medial geniculate nucleus - auditory relay nucleus
Lateral geniculate nucleus - visual relay nucleus
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What is the only nerve that originates from the diencephalon?
Optic nerve
CN II
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This nerve is not a true nerve? Why
CN II is not a true nerve. It is a tract of the CNS
- The retina develops as a diverticulum of the forebrain (optic vesicle)
- Axons of CN II are surrounded by glia, not Schwann cells
- CN II is surrounded by meninges
Patient A comes in with a history of Multiple Scleroisis. Why are you concerned that he may lose his eyesight.
Optic nerve is vunerable to MS
The Visceral Control center of te brain is?
Hypothalamus
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hormones via the pituitary
autonomic nervous system
feeding and drinking
sleep-wake cycles
sexual activity
temperature
memory
This structure is also known as the Pineal Gland and 3rd eye! It controls circadian rhythms by secreting melatonin and also controls the sexual cycles in non-primates
Epithalamus
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What is A?
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3rd Ventricle
Seperates the right and left diencephalon
How do human and rat brain compare?
Humans have a larger percent of Cortex
77%:31%
Humans also have a larger suface area of cortex (cm^2)
2500:6
Name the colored arrows?
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Surface of cerebral cortex is not smooth. Numerous folds!
The folds increase computation power
They are similar between people with particular gyri having specific function
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What do gyri and fissures do?
they divide the cortex into different regions: frontal, parietal, temporal, and occipital cortices
Identify this structure
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Lateral fissure
The lateral fissure separates the temporal lobe from the frontal & parietal lobes
Whay are the different type of Fissures(Sulcus) that we have?
Central Sulcus
Lateral fissure (Sulcus)
Parieto-occipital Suclus
Calcarine Sulcus
Longitudinal fissure
transverse fissure
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This structure ends in a cul-de-sac prior to the lateral sulcus. What is it?
Central Sylcus
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Identify what the question marks are pointing to
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Calcarine Sulcus
This is a superior veiw of?
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Ventricle
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What is a unique characteristic of the cortex?
Structurally it is symmetrical but functionally it is asymmetrical?
What are the characterisitcs of the right brain?
Processes new, unfamiliar faces
Decodes and processes patterns, music, spatial relations
Takes in the “whole”
Considered more creative than the left side
What are the characterisitcs of the left brain?
Language
Numerical Skills
Reasoning abilities
Considered more analytical than the right side
What is the corpus callosum?
Part of the white matter, connects the right and left cerebral hemispheres
What are the parts of the corpus collosum?
Genu
Body
Splenium
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What lies rostral and caudal to the central sulcus?
Pre and post central gyri, respectively
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Brodmann’s area 4 and the corticospinal tract is located where?
Pre-central gyrus
Broadmann’s area 3, 1, 2 is located where?
Post central gyrus
Compare the function of the pre and post central gyri
Precentral gyrus
Primary motor cortex controlling voluntary movement of skeletal muscles
Postcentral gyrus
Primary somatosensory cortex recieveng input conveyed by general sensory systems
The cortical maps of the motor and somatosensory systems, which are tipographically organized, for what?
Somatosensory homunculus (Little Person)
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What are the diffeent gyrus contained in the frontal cortex?
Superior frontal gyrus
Middle Frotnal gyrus
Inferior frontal gyrus
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This part of the brain is responsible for semantic processing (meanings) and phonological processing (sounds)
Broca’s Motor Speech Area
(Left brain)
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What are the different areas of the Frontal cortex>?
Primary motor cortex
Pre-frontal cortes (executive funtion
Broca’s area
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This cortex is part of the limbic system and the pre-frontal cortex. What is it?
Orbitofrontal Cortex - responsible for emotion and reward in decision making
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What are the gyrus and sulcus in the occipital lobe?
Cuneus gyrus - superior
Linhual gyrus - inferior
Calcarine sulcus
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Identify A, B, and C. Which part of the brain are we in?
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Temporal Lobe
A. Superior Temporal Gyrus
B. Middle Temporal gyrus
C. Inferior Temporal gyrus
What are the three structures that are deep to the lateral fissure?
Insula
Superior frontal gyrus
Transverse temporal gyrus of (Heschl)
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This special area in the brain is located in the superior temporal gyrus and platum temporale
Wernicke’s (Speech) Area
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What is known as the primary auditory cortex?
Transverse temporal gyrus of (Heschl)
The parahippocampal gyrus is parts of which system?
It is part of the limbic system
What is the function of the hippocampus?
short-tem, working memory
It includes the uncus and parahippocampal gyrus
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Identify the areas A, B, C, and H
A. Cingulate hyrus
B. motor cortex
C. Central Sulcus
H. Prefrontal Cortex
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Identify area D, E, F, and G
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D. Parietal-occipital sulcus
E. Calcrine Sulcus
F. Area 17
G. Pre-Occipital notch
The cingulate gyrus is part of what sysem and located where?
It is part of the limbic system and seen above the corpus collosum
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What is the basal ganglia?
Subcortical gray matter
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The ventricles are derived from which embryological structure?
Along with the central canal of the cord it is derived from the lumen of the neurotube. It is part of the CNS and filed with cerebral spinal fluid (CSF)
Whay is the purpose of CSF (Ventricular System)?
Reduce traction exerted upon nerves and blood vessels
Cushions (dampens the effect of trauma
Removes metabolites from CNS
Provide stable ionic environment, nutrients
What is CSF consisted of?
water, protein, peptides, sugar, leukocytes, lymphocytes, electrolytes, Na, K, Cl, Mg, Ca
bacteria and viral meningitis or encephalitis increase which cell numbers in the CSF?
Proteins, peptides, sugar, leukocytes, lymphocytes
CSF is produced by what?
Choroid Epithelial Cells
endothelial cells (modified Eoendymal Cells) part of choroid plexus, pial membrane
Choroid plexus is located in the lateral ventricles, 3rd ventricle, and 4th ventricle
It helps maintain delicate extracellular environment of brain
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How many mL of CSF is produced per day?
500
DON’T FORGET
On average how much CSF do we typically have in a given moment?
140mL
Pulsatile fow, under pressure
(turnover rate = 4-5x)
Describe the flow of CSF?
Flows rostrally/downward over the cerebral hemisphere, and downward in the subarachnoid space
Lateral ventricles (foramen of monro) -> 3rd ventricle -> cerebral aqueduct -> 4th ventricle -> subarachnoid space
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Hydrocephaly and Meningitis are what?
Disease of Cerebral Spinal Fluid
What is the Septum Pellucidum?
It seperates the lateral ventricles
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Where is the foramen of monro located?
Under the Septum pellucidum
(it is interventricular)
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How does the CSF get from the 4th ventricle to the subarachnoid space?
Through the foramen of Magendie and 2 foramina of Luschka
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know this image
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What is Hydrocephalus
When the CSF Production > Absorption
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Non-Communication Hydrocephalus
When there is blockage in the flow of CSF, usually at:
1) usually at foramen of Monroor
2) cerebral aqueduct
Pt presents with a large cranium