The Brain And Cranial Nerves

Front 1

functions of the brain (4)

Back 1

registering sensations, correlating with other stored info, decision making, taking action

Front 2

requires how much O2?

Back 2

20% of total body's O2

Front 3

attains full growth and weight by

Back 3

20, 3lbs

Front 4

will experience permanent damage if...

Back 4

deprived of O2 for 5 mins

Front 5

glucose deficiency may produce...

Back 5

mental confusion, dizziness, convulsions, unconsciousness

Front 6

major parts of the brain

Back 6

brain stem, diencephalon, cerebrum, and cerebellum

Front 7

brain is covered by...

Back 7

cranial bones and cranial meninges

Front 8

3 extensions of the meningeal layer of the dura mater separate parts of the brain:

Back 8

Falx Carebri: extends through longitudinal fissure.
Falx Cerebelli: divides cerebellum into right and left.
Tentorium Cerebelli: separates crevellum from occipital lobe

Front 9

Cerebrospinal fluid

Back 9

clear colorless fluid, 100-200 ml, fills ventricle of brain, subarachnoid space of cranium and spinal canal

Front 10

Formation of CSF (4) ventricles

Back 10

Lateral: (first and second) CSF production. Epedymal cells make CSF.
Third: drains lateral ventricles through interconnecting opening, foramania manro.
Fourth: drains third ventricle through cerevral aqueduct

Front 11

pathway for CSF flow

Back 11

choroid plexus--> lateral ventricals (foramina monro) --> third ventrical (cerebral aqueduct) --> fourth ventrical --> central canal

Front 12

Hydrocephalus

Back 12

CSF cant drain properly due to an obstruction of ventricles or subarachnoid space. a buildup will occur causing increased brain pressure. common in the fetus

Front 13

Medulla Oblongata

Back 13

continuous with the upper part of the spinal cord.
develops from the Hindbrain

Front 14

White matter of the medulla oblongata

Back 14

myelinated motor (descending) and sensory (ascending) tracts.
Pyramids: largest motor tracts, triangular structures. anterior surface of medulla. descending motor tracts make up corticospinal tract
Decussation: neurons in left cerebral cortex. controls skeletal muscles on right side of body

Front 15

Grey matter of the medulla oblongata

Back 15

collection of cell bodies for CN VII-XII. autonomic reflex centers, nissle bodies, cell bodies, unmyelinated axons

Front 16

What does grey matter of the medulla oblongata control?

Back 16

breathing rhythm, cardiac control, vasomotor (bp), coughing, vomitting, sneezing, swallowing and hiccuping, reflex centers recieve afferent from cranial and spinal nerves

Front 17

Pons

Back 17

develops from the hindbrain. separates medulla from the midbrain, anterior surface of brain stem.

Front 18

white matter of pons

Back 18

interconnects different levels of the brain by tracts, transverse tracts (connect hemispheres of cerebellum) and longitudinal tracts (interconnects cord, medulla and cerebellum with midbrain).
relays nerve impulses related to voluntary skeletal movements from cerebral cortex to cerebellum

Front 19

Grey matter of the pons

Back 19

neclei origin of CN V, VI, VII and VIII and the pneumotaxic and apneustic centers. they work along the medulla to control rate and rhythm of breathing. Pons prevents lungs from overexpanding

Front 20

Midbrain

Back 20

connects pons and diencephalon.
cerebral aqueduct: transports CSF (3rd and 4th).

Front 21

White matter of midbrain

Back 21

organized into cerebral peduncles. convey motor and sensory impulses (motor= corticospinal, sensory= spinothalamic)

Front 22

Grey matter of the midbrain

Back 22

nuclei for origin for CN III and IV and the corporta quadrigemina (2 pairs of rounded nuclei on roof of midbrain).
Superior colliculi: visual reflex center (move head and eyes follow.
Inferior Colliculi: Auditory reflex center (hearing can lead you)

Front 23

Reticular Formation

Back 23

column of grey matter interspersed among fibers of white matter, extends from medulla to thalamus.
ascending sensory pathways relayed to thalamus and cerebral cortex.

Front 24

Reticular Activating System (RAS) three functions

Back 24

1- regulation of muscle tone, 2- consciousness and alertness. 3- arousal from sleep with stimuli from eyes ears, skin and muscles

Front 25

cerebellum

Back 25

"little brain" develops from the hindbrain.

Front 26

grey matter of the cerebellum

Back 26

convoluted outer surface called cerebellar cortex.
two cerebellar hemispheres are interconnected by region called vermis.

Front 27

White batter of the cerebellum

Back 27

deep in cortex, separated into 3 cerebellar tracts:
Superior (mostly motor, carries impulses from the cerebellum to midbrain and thalamus).
Middle ( carries fibers that descend from cortex, motor).
Inferior cerebellar peduncles ( carries fibers ascending from cord and medulla.
Arbor Vitae: resembles a tree

Front 28

Cerebellum functions (4)

Back 28

Error Control in body movements: executes movement intended by cerebral cortex.

Predictive Function: detects speed and progress in body movements, can slow or stop functions in order to accomplish a voluntary activity.

Efficient Body- Movement: influences antagonistic muscles, coordinate relaxation and contraction

Maintains muscle tone: posture and equilibrium

Front 29

Injury to cerebellum

Back 29

Cerebellar Ataxia: drunken uncoordinated walking, nystagmus (tremor of eyes)

Front 30

Thalamus

Back 30

contains mostly grey matter. Principle relay station for sensory pathways to cerebral cortex.
receives all sensory impulses EXCEPT SMELL. from spinal cord, brain stem, cerebellum and cerebrum.

recognizes pain, temp. and awareness of touch and pressure.

Cognition

Front 31

hypothalamus and three regions

Back 31

inferior to thalamus... mamillary: relay station of smell.
tuberal: contains infundibulums (pituitary gland attached here).
supraoptic: produces 2 hormones, adh and oxytocin

Front 32

homeostatic function of the hypothalamus

Back 32

controls ANS, integrates activity of nervous system with endocrine system (produces hormones), regulates emotional behaviors, regulates eating and drinking, regulates body temp. by heat gain (shivering and vasoconstriction) and heat loss (sweating, vasodialation) centers

Front 33

cerebrum

Back 33

largest part of the brain.
Cerebral cortex (surface): composed of grey matter (gyri and sulci. white matter is deep

Front 34

hemispheres of cerebrum

Back 34

longitudinal fissure separates right and left half.
corpus callosum: bundle of transverse white fibers
commissural tract: white matter connecting hemespheres

Front 35

Lobes (5)

Back 35

Frontal: all motor
parietal: separated from frontal lobe by central sulcus (roland)sensory info received and interpreted
Temporal: interior to frontal and parietal, sparated by lateral sulcus (sylvius). hearing, smell, taste.
Occipital: vision
Insula: deep to frontal, parietal, and temporal. controls bp, bladder and stroke recovery)

Front 36

White matter

Back 36

myelinated fiber tracts running in 3 directions:
Association fibers: connects one part of cortex to another in SAME hemisphere.
Commissural Fibers: corpus callosum
Projection Fibers: connect cortex to lower part of CNS (thalamus, brain stem, cord)

Front 37

Cerebral Nuclei: Basal Ganglia

Back 37

paired masses of grey matter deep within cerebral hemisphere, rich in dopamine, maintenance of muscle tone. Dopaminergic neurons.

Front 38

Sensory areas of cerebral cortex

Back 38

reception and interpretation of sensory impusles

Front 39

primary somatosensory cortex

Back 39

parietal lobe, posterior to central sulcus.
receives sensory impulses from cutaneous, muscle and visceral receptors. size is related to # of sensory receptors.
Humunculus

Front 40

somatosensory association cortex and 4 aspects of sensory perception

Back 40

receives sensory impulses directly from thalamus.
1. sensory experiences.
2. distinguishes one sense from another
3. distinguishes hot from warm
4. determines shape and texture

Front 41

primary visual cortex

Back 41

occipital lobe.
1- visual association cortex: visual memory, recognition and evaluation. Optic nerves meet and cross at optic chiasm.

Front 42

Primary auditory cortex

Back 42

temporal lobe, recognizes pitch and rhythm.
1- auditory association cortex (Wernicke's area): permits auditory memory, recognizes meaning of speech, and distinguishes between speech, noise and music

Front 43

Primary gustatory cortex

Back 43

interprets sensations related to taste

Front 44

primary olfactory cortex

Back 44

smell

Front 45

cranial nerves

Back 45

12 pairs, originate from brain. named on basis of distribution, numbered by order of attachment from anterior to posterior. some are only sensory fibers, most are mixed.

Front 46

Olfactory CN

Back 46

I, sensory, smell

Front 47

Optic CN

Back 47

II, sensory, vision

Front 48

Trigeminal (3) CN

Back 48

V, mixed, sensory to upper eyelid, skin of nose and forehead
V1: Ophthalmis
V2: Maxillary
V3: Mandibular

Front 49

Vestibulocochlear CN

Back 49

VIII, motor, Hearing and equilibrium
VIII1: cochlear
VIII2: vstibular

Front 50

Glossopharyngeal CN

Back 50

IX, mixed, sensory and motor to swallowing muscles, sensory to pharynx