Download Document

Chapter 14
The Brain
and Cranial Nerves
The cranial nerves
CN I
CN II
CN III
CN IV
CN V
CN VI
CN VII
CN VIII
CN IX
CN X
CN XI
CN XII
Olfactory
Optic
Occulomotor
Trochlear
Trigeminal
Abducens
Facial
Accoustic
Glossopharyngeal
Vagus
Spinal Accessory
Hypoglossal
On
Old
Olympian
Towering
Tops
A
Finn
And
German
Viewed
Some
Hopps
A Quick brain overview
cerebrum
cerebral hemispheres
neural cortex (gray matter)
gyri
ridges
sulci
depressions
fissures
fig. 14-1
Brain landmarks
cerebrum
conscious thoughts
sensations
intellect
memory
complex movements
cerebellar hemispheres
coordinates complex
muscle actions
fig. 14-1
cerebellum
thalamus
relay, process sensory info
hypothalamus
emotions, autonomics, hormones
pituitary gland
midbrain -
process visual
hearing info
pons
fiber tract
fig. 14-1
medulla oblongata
autonomics, etc.
embryology
brain:
tube
wall
cavity
embryology
five brain vesicles:
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon
cerebrum
thalamus
midcerebellum/pons
medulla ob.
embryology
five brain vesicles:
all hollow
fluid-filled spaces
ventricles
with CSF
(cerebrospinal fluid)
brain ventricles:
telencephalon
diencephalon
mesencephalon
metencephalon
myelencephalon
lateral v
third v
cerebral aqueduct
fourth v
fourth v
third
third
cerebral
aqueduct
fourth
fig. 14-2
fourth
ventricles
(and central canal of the spinal cord)
are all connected to each other
all filled with CSF
brain is surrounded by:
1.bones of cranium
2.meninges
dura mater
arachnoid mater
pia mater
3.CSF
inside and around outside
CSF
cushion brain/spinal cord
supports brain
transport nutrients/wastes
produced by lining of cavities
circultates in and around brain
blood supply to brain
neural tissue does not have
reserves of glucose, O2 etc.,
has a very good blood supply
internal carotid arteries
vertebral arteries
blood supply to brain
CVA (stroke)
blood supply to part of the brain
is cut off
tissue begins to die
infarction
blood supply to brain
blood-brain barrier
restrict access to neural tissue
of most molecules
capillary endothelial cells
tight junctions
astrocyte foot processes
astrocytes
fig. 12-4
A&P Jeopardy
What is a nucleus ?
The cellular organelle containing the DNA
What is a nucleus ?
A collection of NCB in the CNS
(nerve cell bodies)
What is a ganglion ?
A collection of NCB in the PNS
review
cranial nerves
name and number
brain
5 vesicles and fates
CSF
in and around CNS
good blood supply to brain
blood / brain barrier
nucleus vs. ganglion
The Brain
medulla oblongata
autonomic reflexes
cranial nerve nuclei
relay stations
medulla oblongata
all info
brain
spinal cord
passes through
medulla oblongata
autonomic reflexes
heart rate
heart contraction strength
peripheral blood flow
respiration rate
medulla oblongata
motor nuclei for cranial nerves:
CN IX, X, XI, XII
muscles of pharynx, neck, back
viscera
medulla oblongata
sensory nuclei for cranial nerves:
CN VIII
from inner ear
medulla oblongata
relay stations:
nucleus gracilis
nucleus cuneatus
somatic
sensory
solitary nucleus
visceral
sensory
olivary nucleus
somatic
motor
pons
links cerebellum with…
…everything else
lots of tracts passing through
pons
cranial nerve nuclei
motor:
CN V, VI, VII
jaw and some face muscles
sensory:
CN VIII
vestibular
cochlear
nuclei
cerebellum
adjust postural muscles of body
fine-tune motor movements
fig. 14-7
Purkinje cells in cortex
each one can receive input from up
to 200,000 synapses
input from:
proprioception
visual
tactile
balance
auditory
fig. 14-7
ataxia
(lack of order) a disturbance in
muscular coordination
physical damage
stroke
drugs (EtOH)
mesencephalon
corpora quadrigemina
superior colliculi
inferior colliculi
mesencephalon
relay for
corpora quadrigemina
superior colliculi
visual
reflex center for eyes, head, neck
response to bright light
mesencephalon
relay for
corpora quadrigemina
superior colliculi
inferior colliculi
visual
auditory
reflex center for head, neck, trunk
response to loud noise
mesencephalon
tegmentum
red nucleus
control arm position and
background muscle tone
substantia nigra
regulates basal nuclei
mesencephalon
headquarters of RAS
diencephalon
epithalamus
pineal gland
melatonin
thalamus
relay info to basal nuclei
and cerebrum
hypothalamus
control and integration
hormones, emotions
d/n
diencephalon
thalamus
R & L separated by third v.
5 groups of nuclei
anterior
medial
ventral
posterior
lateral
diencephalon
thalamus
anterior
part of limbic system
(later, emotions/motivation)
diencephalon
thalamus
medial
connect emotional centers
of hypothalamus with frontal
lobes of cerebrum
diencephalon
thalamus
ventral
info from basal nuclei to
motor areas of cerebrum
relay senses to cerebrum
diencephalon
thalamus
posterior
integrate, relay sensory
information to cerebrum
LGN visual
MGN auditory
diencephalon
thalamus
lateral
feeback loops with limbic s
emotions
integration of senses
fig. 14-9
diencephalon
hypothalamus
below thalamus
optic chiasm
mamillary bodies
infundibulum
fig. 14-10
diencephalon
hypothalamus
subconscious control of
skeletal muscle
(facial expression with emotions)
diencephalon
hypothalamus
control autonomic centers of
medulla and pons
heart rate, bp, resp, digest
diencephalon
hypothalamus
coordinate nervous and
endocrine systems
diencephalon
hypothalamus
produce two hormones
ADH
antidiuretic hormone
Oxytocin
smooth muscle
contraction
diencephalon
hypothalamus
produce emotions/drives
hunger, thirst
diencephalon
hypothalamus
Coordinate Voluntary
and Autonomic functions
Take out a sheet of paper for a
surprise 300 point quiz…
increased heart rate, breathing, etc.
diencephalon
hypothalamus
regulate body temperature
by controlling blood flow to
the skin
diencephalon
hypothalamus
controls circadian rhythms
Early April
Poster session (Centrum)
Also other Biology seminars
The limbic system
nuclei and tract along border of
cerebrum and diencephalon
functions:
establish emotional states
link conscious with unconscious
facilitate memory storage/recall
a “motivational system”
The limbic system
limbic lobe of cerebrum (1)
cingulate gyrus
dentate gyrus
parahippocampal gyrus
gyri conceal hippocampus (2)
learning
long-term memory
fig. 14-11
fig. 14-11
The limbic system
amygdaloid body (3)
interface between limbiccerebrum
sensory systems
regulate heart rate (sym)
link emotions/memories
The limbic system
fornix
fiber tract between
hippocampus and
hypothalamus
table 14-7
The cerebrum
largest region of brain
conscious thoughts
intellectual functions
processing of
sensory and motor info
surface is gray matter
cerebral cortex
The cerebrum
hemispheres (R and L)
separated by longitudinal fissure
divided into lobes
fig. 14-12
The cerebrum
hemispheres (R and L)
receive/send info
to opposite side of body
have different functions
The cerebrum
white matter
fibers
association
interconnect - same side
commissural
interconnect R and L
projection
fibers to other structures
label corpus callosum
fig. 14-13
The cerebrum
basal nuclei
several nuclei
caudate nucleus
lentiform nucleus
globus pallidus
putamen
fig. 14-14
The cerebrum
basal nuclei
subconscious control of
skeletal muscle tone
coordination of learned
movements
The cerebrum
basal nuclei
inhibited by dopamine from the
substantia nigra
if s.n. is destroyed or
dopamine levels decline…
basal nuclei are overactive…
increase in muscle tone…
The cerebrum
basal nuclei
…Parkinson’s disease
difficulty starting
muscle movements
fig. 14-12
The cerebrum
primary motor cortex
frontal lobe
pyramidal cells (UMN)
piano analogy
primary sensory cortex
parietal lobe
touch, pain, pressure,
taste, vibrations, temp.
(if thalamus relays it)
fig. 14-15
mapping
The cerebrum
other “sense” cortex
visual
auditory
olfactory
gustatory
occipital
temporal
temporal
frontal
fig. 14-15
The cerebrum
association areas
interpret incoming information
fig. 14-15
The cerebrum
association areas
interpret incoming information
e.g.,
visual association area
associate visual symbols with object
C A R
=
The cerebrum
association areas
interpret incoming information
visual association area
someone with damage here would “see” the
symbols “C A R” but would have no idea that
they mean something
The cerebrum
premotor cortex
coordination of learned movements
repetition programs in “patterns”
of stimulation
back to the piano analogy
The cerebrum
integrative centers
receive lots of information
direct extremely complex motor
activities, analytical functions, …
some centers are restricted
to one side
hemispheric lateralization
The cerebrum
integrative centers
for example:
general interpretive center
(aka Wernicke’s area; left side)
receives input from
all sensory areas
The cerebrum
integrative centers
for example:
general interpretive center
(aka Wernicke’s area; left side)
damage affects ability to
interpret what is seen and
heard
sit
here
fig. 14-15b
The cerebrum
integrative centers
for example:
speech center
(aka., Broca’s area; left side)
coordinates activity of pharynx,
tongue, cheeks, jaw, lips, etc.,
The cerebrum
integrative centers
for example:
prefrontal cortex
receives and coordinates input from all
association areas
performs abstract
intellectual functions,
predicting consequences
The cerebrum
integrative centers
for example:
prefrontal cortex
generates feelings of frustration,
anxiety, tension…
severe its’ connections and remove
those feelings
The cerebrum
integrative centers
for example:
prefrontal cortex
prefrontal lobotomy
“cure” mental patients
The cerebrum
hemispheric lateralization
each hemisphere has specific
functions not done by the other
side
fig 14-6
The cerebrum
Monitoring brain activity
directly stimulate areas
behavioral changes with injury
Phineas Gage
PET scan, MRI’s
The cerebrum
Monitoring brain activity
electrical activity:
EEG
(electroencephalogram)
(brain waves)
The cerebrum
Monitoring brain activity
electrical activity:
different wave patterns
alpha
beta
theta
delta
normal resting adult
concentration, stress
children, frustrated adults
deep sleep, injury
fig 14-17
The cerebrum
Monitoring brain activity
electrical activity:
seizure:
temporary, drastic
changes in electrical
activity of cerebrum
epilepsy
clinical conditions caused by a seizure
epilepsy
and cutting corpus callosum
split brain