Brain and Cranial Nerves Flashcards
4 principle parts of the brain
cerebellum
cerebrum
brainstem: pons, medulla and midbrain
diencephalon: hypothalamus, thalamus, pineal gland
coverings of the brain
bone, meninges and fluid
3 parts of meninges
dura mater, arachnoid mater, pia mater
dura mater extensions
falx cerebri, tentorium cerebelli, falx cerebelli
functions of cerebrospinal fluid
mechanical protection: floats brain and softens hits on bony wall
chemical protection: optimal ionic concentrations fro action potetnials
circulation: nutrients and products to and from bloodstream
production of CSF
produced from choroid plexus- capillaries covered in ependymal cells
found in the lateral, third and fourth ventricles
parts for release of CSF
1 median aperture and 2 lateral apertures allow for it to exit from the interior of the brain
CSF is reabsorbed by the
arachnoid villi
components found in the medulla oblongata
-ascending sensory tracts
- descending motor tracts
- nuclei of 5 cranial nerves
- cardiovascular centre
- respiratory centre
- reflec centres
ventral surface buldge of the medulla oblongata
-pyramids
- large motor tracts
- decussation of most fibres
olivary nucleus
- proprioreceptive signals
- neurons send input to the cerebellum
- gives precision to movements
ventral surface of the medulla oblongata
ventral surface bulge and the olive: olivary nucleus
dorsal surface of medulla oblongata
nucleus gracilis and nucleus cuneatus which are sensory nuerons and relay infomation to the thalamus
cranial nerves 8-12 arise from the medulla
pons
-pneumotaxic and apneustic centres to control breathing
- middle cerebellar peduncles to carry sensory info to the cerebellum
- cranial nerves 5-7
midbrain
extends from pons to diencephalon
what connects to third ventricle to fourth ventricle
cerebral aqueduct
parts of midbrain
cerebral penduncles: clusters of motor and sensory neurons
- substantia nigra: helps control subconcious muscle activity
- red nucleus: rich blood supply and iron containing pigment. cortex and cerebellum coordinate muscle movemnst by sending them here.
corpora quadrigemina: made up of superior and inferior colliculi: coordinate eye and head movement with visual and sounds
what areas of the brain are the cranial nerves attached to
1,2 with the forebrain
3,4 with the midbrain
5-7 pons
8-12 dorsal medulla oblongata
six extrinsic eye muscles
4 rectus muscles (inferior, superior, lateral and medial)
2 oblique muscles (superior and inferior)
cranial nerves for eextrinsic eye muscles
lateral rectus - 6
medial rectus - 3
superior rectus - 3
inferior rectus - 3
inferior oblique - 3
superiod oblique- 4
reticular formation
complex netwrok of scattered nuclei in the medulla, pons and midbrain.
alerts cerebral cortex to sensory signals to awaken from sleep
,aintains consciousness
part fo cerebellum
2 hemispheres
2 lobes :anterior and posterior
vermis : the central area
cerebellar cortex (folia) - gray matter
arbor vitae- white matter
transverse fissure between cerebellum and cerebrun
function of the cerebellum
sense of equilibium, fine tunes body movements and manages balance and posture
3 cerebellar peduncles
superior - carries motor fibres that extend to motor control areas
middle - carries sensory fibres from the cerebral cortex and basal ganglia
inferior- sensory information from the spinal chord
what parts surround the 3rd ventricle
the diencephalon
the superior part is the thalamus and the walls and floor is the hypothalamus
what si the thalamus
mass fo gray matter on each side of the brain. relay station for sensory information before going to the cortex, crude perception of some sensations
functions of thalamic nuclei
-relay auditory, visual impulses and taste and somatic sensations
- receive impulses from the cerebellum and basal ganglia
- the anterior nucleus is concerned with emotions, memory and cognition
how many nuclei in the 4 major regions of the hypothalamus
about a dozen or so
relay station for olfactory reflexes in the hypothalamus
mamillary bodies
what structure suspends the pituitary gland
infundibulum
functions of the hypothalamus
- regulates daily patterns of sleep
- body temperature
-feeding, thirst and satiety centres - regulates rage, agression, pain and arousal
-contains cell bodies of axons that end in the posterior pituitary and secrete hormones
-synthesizes regulatory hormones that control the anterior pituitary gland - controls and integrates activity of the autonomic nervous system which regulates smooth and acardiac muscle and glands
strcuturs in the epithalamus
pineal gland which secretes melatonin in the dark and promotes sleepiness and sets the biological clock.
habenular nuclei: emotional rsponses to odours
function of subthalamus
work with the basal ganglia, cerebrun and cerebellum in controlling body movement
function of circumventricular organs
found in the walls of the 3rd and 4th ventricles
moniter changes in blood chemistry due to a lakc of blood brain barrier
corpus collasum
band of white matter connecting the left and right hemispheres
4 lobes of the brain
occipital temporal frontal and parietal
sulci that speerate the lobes
-longitudinal fissure seperates left and right
-central sulcus between the frontal and parietal lobes (has precentral and postcentral gyri)
-parieto-occipital sulcus between parietal and occipital lobes
- lateral sulcus seperating the frontal and parietal lobes from the temporal lobe
structure found witihin the lateral sulcus
insula
structure found witihin the lateral sulcus
insula
3 types of fibres in cerebral white matter
-association fibres between gyri in the same hemisphere
- commissural fibres between one heisphere nd another
-projection fibres from descending and ascneding tracts
connections of the basal ganglia
connections to the red nucleus, substantia nigra and subthalamus
has an input nad output with the hypothalamus, thalamus and cerebral cortex
function fo the basal ganglia
control large automatic movements of the skeletal muscles
parts of the limbic system
hippocampus
cingulate gyrus
mamillary body of hypothalamus
parahippocampal gyrus
amygdala
olfactory bulb
functions of the limbic system
strong emotions, stromg pain, straong emotions also increase memory
4 primary sensory areas of the cerebral cortex
primary somatosensory area - postcentral gyrus- 1,2,3
primary visual area 17
primary auditory area 41 42
primary gustatory area 43
2 main motor areas of the cerebral cortex
primary motor area - precentral gyrus - 4 ( voluntary contractions of skletal muscle)
motor speech area - 44- Broca’s area- production ofspeech
association areas of the cerebral cortex
- somatosensory areas 5 and 7 to interpret and integrate
- visual associaition area 18 and 19 to recognize and evaluate
- WErnicke’s auditory association area 22 where words beocme speech
-gnostic area 5,7,39,40 integrate all senses and respond - premotor area 6 learn skilled movements
- frontal eye field 8
where are language areas located
left cerebral hemisphere in most people
what is aphasia
inability to use or comprehend words
types of aphasia
nonfluent aphasia is the inability to properly form words (damage to Brocca’s speech area, know what to say but cant speak it)
fluent aphasia- faulty understanding of spoken or written workds (word deafness or word blindness) - damage to common integrative area or auditory associaition area
hemisphere lateralization right vs left
left- math and science skills, spoken and written language, reasoning
right- music and artistry, spac and pattern perception, recognition of faes and emotions, generating emotional content of language
4 waves of electroencephalogram
alpha - awake and resting
beta mental activity
theta emotional stress
delta deep sleep
cranial nerves names
1- olfactory nerve
2- optic nerve
3- oculomotor
4- trochlear nerve
5- trigeminal
6- adducens nerve
7- facial
8- vestibulocochlear nerve
9- glossopharengeal nerve
10- vagus nerve
11- spinal accessory nerve
12- hypoglossal nerve
oh oh oh to touch and feel very good velvet ah such heaven
1 olfactory nerv
sense of smell
2 optic nerve
sense of vision - retina
3 oculomotor
4 extrinsic eye muscles
2 instrinsic eye muslces (pupil and retina)
raises eyelid
4 trochlear
superior oblique eye muscle
5 trigeminal
motor- muscles of mastication
sensory- ophtalmic, maxillary, mandibular
6 adducens
lateral rectus eye muscle
7 facial nerve
motor- facial muscles, salivary and nasal mucus glands and tear glands
sensory - anterior 2/3 of tongue
8 vestibulocochlear nerve
cochlear nerve - hearing (damage leads to tinnitus or deafness)
vestibular nerve- balance (damage leads to vertigo or ataxia
9 glossopharangeal nerve
stylopharyngeal muscle lifts the throats whiel swallowing
secretion sof th eparotid gland
somatic sensation in posterior 1/3 of the tongue
10 vagus nerve
receives sensations from viscera
controls cardiac muscle and smooth muscle of viscera
secretions of digestive fluid
11 spinal accessory
cranial portion- arises in medulla and controls throat and soft palate
spinal portion- arises from cervical spinal chord and controls sternocleidomastoid and trapezoids
12 hypoglossal
muscles of tongue during speech and swallowing
development of nervesous system
begins in 3rd week
ectoderm forms a thickening (neural plate)
plate folds inwards to form neural groove
edges fold and form nueral tube
neural crest tissue froms on top
what does neural crest tissue form
spinal and cranial nerves
dorsal root and vranial nerve ganglia
adrenal gland medulla
layers of neural tube form:-
marginal layer which forms white matter
mantle layer forms gray matter
ependymal layer forms lining of cavities within NS
3 anterior enlargements by the end of the 4th week
-prosencephalon - forebrain
-mesencephalon- midbrain
-rhombencephalon- hindbrain
5 enlarged areas by the end of 5th week
prosencephalon–> telencephalon and diencephalon
mesencephalon
rhombencephalon–> metencephalon and myelencephalon
cerebrovascular accident
lack of blood flow to the brain which damages brain tissue
cause by two types of strokes: ischemic(decreased blood flow)
hemorrhagic(rupture of vessel)
transient ischemic attack
episode of temporary cerebral dysfunction caused by impaired blood flwo to the brain
