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