Lecture 15 content Flashcards
how does the CNS develop?
- ectoderm folds inwardds to room hollow neural tube
- central canal is remanant of origional neural tube
- filled cerebrospinal fluid (CSF)
What is the general structure of the brain?
- hollow tube filled with CSF
- 3 primary vesicles become 5 secondary brain vesicles
what makes up the for brain?
(prosencephalon
- telencephalon (cerebrum, basal gangia)
- diencephalon (hypo -, epi -, thalmus)
what makes up the midbrain?
(mesencephalon)
- mesencephalon (corpora quadrigemina)
What makes up the hindbrain?
(Rhombencephalon)
- metencephalo (cerebellum, pons)
- myelencephalon (medulla obongata )
where is the lateral ventricles found within?
within telencephalon
where is the 3rd ventricle found within?
within the diencephalon
where is the 4th ventricle found within?
within shared metencephalon and myencephalon
What is the pathway of CSF the ventricles?
lateral ventricles (R&L) > intervetebral foramina > 3rd ventricle >mesencehalic aqueduct (aqueduct of mid brain) > 4th ventricle >central canal > subarachnoid space > aracnoid grandulations > Dural sinus
What is the typical cross section of the spinal cord?
Cortex: white matter: myelinated axons Medulla : grey matter: cell bodies, unmyelinated axons - central canal filled with CSF - Dorsal roots = sensory - ventral roots = motor
What is the typical cross section of the brain?
cortex: grey matter cell bodies, unmyelinated axons
Medulla white matter: myelinated axons
- central canal expands to form 4 ventricles
- some CN (12) project from brain stem (mixed sensory and motor)
What are the functions of the cerebrum?
- Consious thought process
- intellectual though process
- memory storage and processing
- regulation of in-/voluntary somatic motor patterns
describe the cerebrum?
part of the telencephalon
- cerebral functions
- largerst region of the brain
- hollow
- surface features
- 2 hemispheres
- 4 lobes
What separates the 2 ventricles?
septum pellucidum
Gyri
Elevated ridges
Sulci
cleft - like depressions
What do you call deeper grooves between lobes/regions?
Fissures
what is the hemisphere that splits brain into left and right portions?
longitiudinal fissure
what connects the 2 hemispheres?
corpus callosum
What does it mean to be right brained?
sensory information, spatial relationships (creative)
What does it mean to be left brained?
language, reading, writing, speaking (logic)
What is the functions of the frontal lobe?
(murders)
- emotion, motivation, behavioral regulations
- sense of time, reasoning
Where is the speech center or (Brocas area)? and whats its funciton?
Fontal lobe on the = left side 97%
- breathing/vocalizing
In the PRE central gyrus what is the primary cortex?
Primary motor cortex: motor homunculus
In the post central sulcus what is the primary cortex?
Primary sensory cortex: Sensory homunculcus
What are the cortical mapping regions?
Broadmans areas
What happens to the brain in Alzheimers disease? causes?
- genetic mutations +/- environmental factors
- decrease in cortical neurons (frontal lobes)
- decrease in Gyri volume = large sulci
definition of Alzheimer disease and the lobes associated with it
Progressive loss of neurons/ synapses due to proteopathy
frontal = (new memories, motivation)
temporal = (new memories and language)
parietal lobe = (navigation)
what dementia is Alzheimers related to?
75% Seile dementia
- deteriation of organizational/focus tasks
- memory loss (short term follows long term)
What does the diencephalon do?
Brings information like eating (judgement of things)
What makes up the diencephalon? (box)
Epithalmus
thalmus
hypothalmus
3rd ventricle
function of the epithalmus?
(pineal gland)
- pineal gland secretes melatonin (sleep patterns)
function of the Thalmus?
Relay/processing center for sensory infromation
functions of the Hypothalmus?
- controls thirst appetite, body temp
- coordinates the ANS
- coordinates endocrine
- secretes hormones
- oxytocin (uterum prostate)
- antidiuretic hormone (ADH) (kidney) - integrates sensory and motor commands
- related to emotion (conscious and unconscious thought) - pituitary gland lies beneath the hypothalamus
- suspended by infundibulum
- supported within the sella turcica beneath sphenoid
Name the parts of the mesencephalon
- corpora quadrigemina
- superior colliculi
- inferior colliculi - red nucleus
- substantia nigra
- cerebral peduncles
what does the corpora quadrigemina?
- integrates visual/ auditiory data
superior colliculi - sight
inferior colliculi - sound
what does the Red nucleus do?
maintains muscle tone and posture
- swinging arms while walking
What does the Substantia Nigra?
neurotransmitter dopamine
- drop in dopamine causes increase muscle tone “dope”
- pakinsons disease: tremors in muscles
what do the Cerebral peduncles do?
support the cerebrum
what are the parts of the metencepalon?
- cerebellum
- folia - folds of cerebellar cortex
- arbor vitae - grey/ white matter
- punkinje cells - highly branched cells in cortex
- Pons
what are the functions of the cerebellum?
- coordinates postural/skeletal muscles of body
- programming of repetitive movements (subconscious)
- 2 hemispheres and vermis splits between
what are the functions of the cerebellum?
- coordinates postural/skeletal muscles of body
- programming of repetitive movements (subconscious)
- 2 hemispheres and vermis splits between
what are the functions of the cerebellum?
Post. portion of metencephalon
- coordinates postural/skeletal muscles of body
- programming of repetitive movements (subconscious)
- 2 hemispheres and vermis splits between
what are the functions of the cerebellum?
- coordinates postural/skeletal muscles of body
- programming of repetitive movements (subconscious)
- 2 hemispheres and vermis splits between
what is the function of the pons?
anterior portion portion of metencephalon
4 important CN’s (V, VI, VII, VIII)
- respiratory center (fine tuning)
- associated with “sleep paralysis”
what are the 5 important CN associated with the medulla oblongata?
CN VIII CN IX CN X CN XI CN XII
describe the medulla oblongata
- transition from the brain to spinal cord
- autonomic centers for visceral function (cardiovascular, respiratory, digestive systems)
- injury can lead to death (compression of the myelencephalon on the foramen magnum)
- fourth ventricle shared by pons + medulla oblongata
where are the Grey matter on the cerebrum and cerebellum?
neuron bodies make up the cortex/cortical surface or non-cortical concentration of cells = nucleus
where are the white matter on the cerebrum and cerebellum?
White: myelinated axons (sub-cortical)
- association fibers between gyri within hemisphere
- commissural fibers between gyri of opp. hemispheres
- projection fibers ascend/decend to CNS
What are the functions of the Limbic System?
- includes many nuclei spread through brain
- rather than anatomical grouping of nuclei
- Links conscious thought w/ autonomic functions of brain stem
- behavior and emotional states: thirst, hunger, sex
- learning and the storage/recal of long-term memory
- smell of grandma = emotion
What is Synesthesia ?
(letters/ numbers may be interpreted as colors, and sounds as shapes)
typically a hereditary neurological condition
- common among artists and poets
- “error” in the re-assembly various inputs (cross wirring)
- hyper-connectivity within the libic (PET/MRI brain-imaging technology)
falx cerebri
- runs between cerebral hemispheres
- anchored anteriorly to crista galli of ethmoid
Falx cerebelli
runs between cerebellar hemispheres
Tentorium cerebelli
runs between cerebrum and cerebellum
Diaphragma sellae
- encloses the pituitary gland
Dural sinuses
delamination of dura mater
- forms cavity for venous blood
- outermost layer forms enodsteum
What is the circulation of the CSF?
- produced by choroid plexus
- capillary beds in each ventricle
- refined filtrate in blood
- circulates: ventricles, central canal, subarachnoid
- recovered vi arachnoid villi (arachnoid grandulations)
- transports nutrients and removes waste products
- CSF cushions neural tissue - “floats” the brain
What are the 2 types of Hydrocehalus?
- internal hydrocephalus
- external hydrocehalus
What is internal hydrocephalus ?
- failure of the CSF to escape from the ventricles
- expansion of CSF
What is external hydrocephalus?
failure of the CSF to be returned to the dural sinuses
- CSF into brain (crush brain)
