Lecture exam 4 1/2 (CNS)
periosteal layer
against skull bones, attached to periosteum at cristi Galli, sella turcica, sutures
primary gustatory area
base of post central gyrus in parietal lobe and insula receives taste input
projection fibers
conduct impulses between cerebrum and other brain regions
association fibers
conduct impulses between the gyri in the SAME hemisphere
descending (motor)
conduct impulses down spinal cord
ascending (sensory)
conduct impulses toward the brain
Parts of brain stem and connected to
connected to spinal cord midbrain, pons, medulla oblongata
RAS function
consciousness, awakening, attention, sensory awareness
commissural fibers
corpus collosum, anterior posteriorr commissures connect corresponding gyri in right and left hemispheres
upper motor neurons
corticospinal tracts
Pia mater location
covers entire CNS, and CNS blood vessels
auditory association area location
inferior and posterior to the primary auditory area in the temporal lobe
hypothalamus location
inferior to thalamus
dura mater layers
periosteal layer and meningeal layer
denticulate ligaments present in which mater
pia mater
cerebral cortex function
plays roles in emotions, motivation, smell, learning, memory, impulsive desires
primary visual area
posterior tip of occipital receives visual input( shape, color, movement)
Cerebellum location
posterior to brainstem
cerebellum location
posterior to pons, forms posterior wall of 4th ventricle
Primary motor areas location
precentral gyrus of frontal lobe
motor areas of cerebrum
premotor brocas motor
Hypothalamus composition
primarily nuclei
primary sensory areas of cortex
primary somatosensory area primary visual area primary auditory area primary gustatory area primary olfactory area
arachnoid villi anatomy
projections of arachnoid matter into sutures
Blood brain barrier function
protects brain front harmful chemicals and pathogens in blood
thalamus composition
two masses of gray connected by intermediate mass
damage to RAS ----
unconsciousness
hypothalamus functions
maxillary bodies (relay for olfactory) infundibulum (pit to hypothalamus) monitor glucose, temp, osmotic pressure Control of ANS - pb, hear rate, pup contraction/dilation hormone production reg emotion and behavior thrist hunger body temp rolse in circadian rhythm and awakening part of limbic system, emotion and pleasure control
vetebral column
- bone of vertebra serve as protection - spinal cord in vertebral canal (verbral foramina)
denticulate ligaments
- extension of pia matter that fuses with arachnoid and dura mater - protect against shock and sudden displacement (hold spinal cord to dura mater)
premotor area function
- generates nerve impulse patterens for learned motor (writing) - receives input from thalamus, prefrontal, and sensory association areas - send AP for voluntary motor commands to primary motor cortex and basal nuclei (caudate and putamen)
lateral horn
- only in thoracic, upper lumbar and sacral segmets somas of autonomic motor neurons
primary somatosensory area
- post central gyrus of parietal lobe - localize exact points of body where sensation is occurring (touch, propiroreceptiom pain, itch, tickle, temp) - map of body (each region of cortex has diff areas, size of cortical region dependent on number of receptor. more is more)
somatosensory areas location
- posterior to primary somatosensoru - in parietal lobe
amygdala function
- receives PROCESSED sensory info creates emotional responce sends output to prefrontal cortex and hypothalamaus
central canal of spinal cord
- runs entire length of spinal cord - filled with CSF
primary motor area function
- sends AP to specific skeletal muscle for voluntary motor contractions - map of body/homunculus
hippocampus function
- stores short term/working memory - comm with thalamus and cerebrum to store memories long term, especially sleep
blood brain barrier structure
1) tight junctions between epithelial cells in capillaries that supply brain 2) cappilarries surrounded by thick basement membrane 3) processes of astrocytes surround cappillaries and selectively allow entrance of substances
decussation (crossing) of pyramids
1) tracts cross in inferior portion of medulla 2) Allows right side of brain to control and receive input from left and vice versa
medulla oblongata centers
1) vital center (nuclei) 2) non vital centers
cerebellum composition
1) Gray matter cortex (folia- slender leaves of gray) 2) white matter abhor vitae in center 3) two hemispheres connected by thin vermis (worm)
leaky areas of the BBB list three
1) Hypothalamus: monsters blood comp (pH, glucose, pressure) 2) Pituitary gland: release hormones 3) Pineal gland: releases melatonin
Distribution of grey/white in CNS
1) Inner core of spinal cord is gray, outside is white 2) Outer cortex brain is gray, white has gray clusters (nuclei)
Circulation of CSF 1-4
1) as CSF circulates, nutrients and wastes are exchanged between the CSF and the IF of the CNS through ep cells 2) Circulation is driven by hydrostatic pressure of cilia of ependymal cells 3) Lateral ventricles 4) Interventricular foreman
CSF production steps 1-3
1) at choroid plexus of ventral walls, capillaries surround ependymal cells forming the blood- CSF barrier 2) Ependymal cells make CSF by filtration of substances from in choroid plexus and secrete CSF into ventricles - ions, go into interstitial fluid of nervous tissue, waste go away from interstitial into CSF into venous circ 3) blood- CSF- barrier: ependymal cells connected by tight junctions attached to choroid plexus
inferior coniculli
1) auditory tract: from receptors of hearing in ear to thalamus 2) reflex center: startle response from loud noises
vital centers function
1) cardiovascular center : heart rate, blood vessel diameter 2) respiratory center: controls rhythm of breathing (additional reg by pons)
white matter of cerebrum
1) commissural fibers 2) association fibers 3) projection fibers
cerebellum function
1) coordinate movement, posture/balance, skilled movement
thalamus function
1) final relay pt for sensory info to cerebral cortex (not olfactory) from spinal cord, brainstem, and midbrain 2) crude interpretation of pain, temp, pressure (not localized) 3) crude consciousness and awareness (emotions, alter ness, memory) 4) motor info from basal nuclei and cerebellum to primary motor cortex in cerebrum
molecules that can cross blood brain barrier
1) glucose actively transported 2) lipid soluble molecules (gases alchohol, steroid) 3) h20 and ions move through channels (Fas diff)
Cross section of spinal cord
1) gray meter in butterfly shape
limbic system
1) hippocampus 2) amygdala 3) olfactory bulb 4) parts of thalamus 5) hypothalamus 6) parts of cerebral cortex
medulla oblongata composition
1) motor and sensory tracts (axons) 2) Large sensory and motor tracts (Corticospinal) form pyramids
function of basal nuclei
1) prevent unwanted movement - aid In muscle transitions, stabilizing 2) relax antagonist muscles 3) prefrontal and premotor cortices send nerve impulses for voluntary activities to caudate and putamen nuclei 4) globus pallidus and substantial nigra send output through thalamus to premotor and prefrontal cortices which send AP to primary motor cortex to stimulate or inhibit muscles
Molecules that CANNOT cross blood brain barrier
1) proteins (neurotransmitters) 2) Certain antibiotics (tetra) 3) Large water soluble molecules
epithalamus function
1) release melatonin, production and release of melatonin increases with darkness 2) circadian rhythm
pons functions
1) respiratory centers: work with respiratory center of medulla oblongata for breathing control 2) pontine nuclei: relay motor impulses from cerebral cortex to cerebellum via middle peduncles
functions of CNS
1) shock absorption, support 2) chemical protection 3) carries oxygen, glucose, 02. and removes waste like ions
cerebral cortex 3 parts
1) sulci - shallow grooves 2) fissures - deep grooves 3) gyri - folds of cortex
asending pathways have three neuron types
1st order, 2nd order, 3rd order
prefrontal cortex developed at age
20
Rate of reabsorption of arachnoid villi
20 ml/ hour, 480 ml/ day
brain consumes how much of body oxygen and glucose
20 percent
cerebellum is - largest part of brain
2nd largest
cerebellum peduncles
3 pairs of peduncles that connect cerebellum to brainstem, cerebrum, and spinal cord
each hemisphere has how many lobes
5
Circulation of CSF 5-8
5) 3rd ventricles (more CSF added) 6) cerebral aquaduct 7) 4th ventricle (more CSF added) - through medial and lateral apertures, enters subarachnoid space and circulates around brain and SC 8) Through arachnoid graduations into venous sinus which returns fluid to blood stream
how many neurons in what space in cerebellum
50 percent neurons in 1/10th space
CSF production amount
500 ml/ day
Cerebrum compostions
Cerebral cortex, white matter, gray matter.
sensory
Reticular activating system (RAS)
meningeal layer
against arachnoid mater
premotor area location
anterior to primary motor area
arachnoid mater contains...
arachnoid villi/granulations
2 tracts
ascending (sensory) descending (motor)
gray mater
basal nuclei
insula function
base emotions (fear, anger, disgust) taste
CSF start and end
blood vessels of chord plexus, ends at dural plexus
posterior association area location
bordered by somatosensory, visual, auditory association areas
Brain stem!!!!
brain stem now...
hydrocephalus
can occur if CSF not returned to blood stream, caused by tumors, inflammation, malformation, injury, meningitis, hemorrhage
basal nuclei parts
caudate nucleus, putamen, globus pallidus
pons is bridge between
cerebellum, cerebrum, medulla
CSF location
circulates through ventricles of brain and central canal of spinal cord
peduncles also....
compare intention to reality of movement
insula location
deep in lateral sulcus
pia mater has D. L
denticulate ligaments
tracts are
distinct bundles of axons having common origin or destination, and carry similar types of information
Parkinsons and loss of neuron dopamine
dopamine from sub, nigra, inhibit neurons of the basal nuclei. in Parkinson's, subs. nigra. release less dopamine, basal nuclei become overactive causing antagonist muscles to remain active
three horns
dorsal horn, ventral horn, lateral horn
Meninges three maters
dura mater, arachnoid mater, pia mater
meningeal and periosteal layers separated to form
dural venous sinuses
spaces in meniges
epidural space, dura mater, arachnoid mater (has subarachnoid space), pia mater
brocas area location
frontal lobe inferior to primary motor area
five lobes are
frontal, parietal, temporal, occipital, insula
parietal lobe
general senses, taste
basal nuclei are.
gray metter scattered within white matter of cerebrum
temporal lobe
hearing, smell, learning/memory
1st order neurons
impulses fron unipolar Neuron soma located in ganglion (PNS) to spinal cord
cerebrum (sensory cerebral areas)
incoming information to cerebrum
gyri function in
increasing surface area of brain
Prefrontal cortex functions
integrates input from posterior association and limbic frustration, tension, anxiety predict consequences of action
cerebrum location/ size
largest, most superior
brocas areas function
left side: planning and production of speech (97 percent left) right: with wernickes area, adds emotional content to speech sends impulse to premotor and primary motor area to control -- breathing, larynx, pharynx, and mouth
wernickes area function
left: interprets meaning of speech/wrtitten language right: emotional content
Reticulal Formation location/composition
loose network of nuclei extending through medulla, pons, midbrain nuclei and tracts (motor and sensory)
primary olfactory area
medial aspect of temporal lobe receives smell input
inferior peduncles
monster actual movement (propioreceptors)
leaky areas of BBB function
monster blood composition or release hormones into the blood
middle peduncles
monster intention for movement from cerebrum via pontine nucleus
Medulla oblongata location
most inferior portion of brain from foreman magnum to pons
Each hemisphere interprets sensory info from and forms __ to ___ side
motor outputs, opposite
functions of motor
motor: regulate muscle tone (somatic motor control)
white matter
myelinated axons
white matter in spinal cord
myelinated axons
Spinal cord functions.
nerves: carry sensory and motor info to and from CNS cord: help homeostasis with quick reflex to stimuli carries sensory and motor info to and from brain via ascending and descending tracts
Gray clusters in brain is
nuclei
size of cortical region in primary motor area is prop to
number of motor units
lower motor neurons
originate at ventral horn and transmit impulses to skeletal muscles.
out put from basal nuclei
out put from globes pallid is nucleus to thalamus to primary motor cortex
cerebral cortex structure
outer layer of gray, 2-4 mm thick, billions of neurons
arachnoid villi function
reabsorption of CSF into venous blood stream
posterior association area function
receives impulses from somatosensory, aud, visual, and primary areas and thalamus integrates info from different sensory association areas to form thoughts sends impulses to prefrontal cortex for proper response
somatosensory areas function
receives input from primary somatosensory and thalamus, integration and interpretation of somatic sensations memory of past somatosensory experiences (eg. mosquito has landed on arm)
visual association areas functions
receives input from primary visual, integrates and interprets visual sensations and recognizes and interprets patterns.
auditory association area function
recognizes sound as speech, music, or noise
substantial nigra (nuclei) functions
releases dopamine to basal nuclei of cerebrum
repetitive and unusual stimuli
repetitive stimuli filtered out by RAS, unusual stimuli sent to cerebrum
Cerebrum structure
right and left hemispheres separated by longitudinal fissure
superior peduncles
send corrective information to motor areas of cerebrum via thalamus
RAS location
sensory tracts to cerebral cortex vis thalamus (not olfactory)
Gray matter
soma, dendrites, axon hillocks
2nd order neurons
somas in dorsal horn of spinal cord or medulla - impulses to cerebellum or thalamus - spinothalamic or spinocerebrellar
3rd order neurons
somas in thalamus, impulses transmitted to primary somatosensory cortex of cerebrum
ventral horn
somas of somatic motor neurons
butterfly composed of
somas, dendrites, unmyelinated axons, interneurons and three horns and gray commusure
dorsal horn
somatic and automatic sensory nuclei (interneurons that relay sensory info)
association sensory areas of cortex
somatosensory, visual association areas, auditory association areas, wernickes area, posterior association area
Tectum parts
superior and inferior colliculus
Epithalamus (pineal gland) location
superior and posterior to thalamus
primary auditory area
superior portion of temporal lobe and insula interprets pitch and rhythm of sound
diencephalon location and surrounded by
superior to brain stem, surrounded by cerebrum
pons location
superior to medulla oblongata, inferior to midbrain
midbrain location
superior to pons, inferior to diencephalon
visual association areas location
superior to primary association area in occipital lobe
gray commisure
surrounds central canal
Diencephalon location
surrounds the third ventricle
wernickes area location
temporal and parietal lobes
parts of diencephalon
thalamus and hypothalamus
meninges
three layers of connective tissue covering brain and spinal cord
white mater also contains
tracts
cerebellum separated by cerebrum by
transverse tissue
descending pathways have two neuron types
upper motor neurons lower motor neurons
protection of spinal cord
vertebral column, meninges (w maters)
occipital lobe
vision
superior coniculli function
visual relflex center, extrinsic eye muscles, pupillary reflex
frontal lobe
voluntary movement, motivation, planning, memory, mood, emotion, judgement, inhibition
non vital center functions
vomiting, coughing, sneezing
most tract named
where there soma are and axons end