The HUMAN
BRAIN
Protective Structures
Meninges Three layers of
connective tissue that
enclose the brain
Dura Mater
Arachnoid
Pia Mater
Dura Mater
Outermost layer
Thickest and
toughest part of the
meninges
There are two
layers, the outer
layer is fused to the
cranial bones.
Dura Mater In various places,
the two layers
separate to allow
venous channels
called dural sinuses
to drain blood from
the brain.
Function
containment of the
cerebrospinal fluid
in the brain.
ArachnoidMiddle layer of
the meninges
Loosley attached
to the pia mater by
weblike fibers.
Function Allows
for movement of
cerebrospinal
fluid.
Cerebrospinal Fluid
Fluid that circulates
in and around the
brain.
Protects the brain
from shock and injury.
Function-Transports
nutrients and waste to
and from cells.
.
Cerebrospinal Fluid
Formed in four spaces
called ventricals.
The ventricals hold a
vascular portion called
the choroid plexus,
which produces the
cerebrospinal fluid by
filtering the blood and
cellular excretion.
Pia Mater Innermost layer of
the meninges
A delicate connective
tissue that covers the
brain and spinal chord
Function-Holds the
blood vessels that
supply nutrients and
oxygen to the brain
and spinal cord.
Meninges
CerebralHemispheres
Structure of the Hemispheres
Two layers
An outer layer of
gray matter
called the
cerebral
cortex.
Supported by an
inner layer of
white matter
Structure of the hemispheres
Each hemisphere has four lobes
Frontal
Parietal
Temporal
Occipital
Gray Matter – The Cerebral Cortex
The most highly evolved portion of the brain.
Arranged in folds of elevations called
gyri, and grooves
called sulci
Structure of the hemispheres
Gyri and Sulci
The surfaces on
which brain cells
reside.
More surface = more
complex calculations
Structure of the hemispheres
White Matter
Connects the gray
matter areas with
one another and
with other parts of
the brain.
Dispersed in a tree
like pattern
Made of
myelinated fibers
White and Gray Matter
White matter
Gray Matter
Structure of the hemispheres
Corpus Callosum
Largest white matter
structure in the brain
Facilitates communication
between the right and left
hemispheres by electrical
impulses
Structure of the hemispheres
Basal Ganglia
Base of forbrain, deep
in each hemisphere.
Functions: helps to re-
gulate body movement
and facial expressions.
Structure of the hemispheres
Internal Capsule
In between the hemi-
spheres and the brain
stem
Function – Carries im-
pulses between the
cerebral hemispheres
and the brainstem.
Functions of the Cerebral Cortex
The functions of the Cerebral Cortex are
localized according to the four lobes. They
are named for the
overlying cranial
bones.
CEREBRAL CORTEX FUNCTIONS
CEREBRAL CORTEX- Functions
Conscious deliberation
Voluntary actions
Memory
Association
Discrimination
Judgement
Functions of the Cerebral Cortex
The Frontal Lobe lies
anterior to the central
sulcus.
Functions of the Cerebral
Cortex
Some Frontal Lobe Functions Contains an area that provides the conscious
control of skeletal muscles.
Contains two areas that are important in
speech
Functions of the Cerebral Cortex
The Parietal Lobe
occupies the superior
part of each hemisphere
and lies posterior to the
central nucleus
Functions of the Cerebral Cortex
Some Parietal Lobe Functions
Contains a primary sensory area where
impulses from the skin are interpreted
Estimates distance and size.
Functions of the Cerebral Cortex
The Temporal Lobe lies
inferior the lateral sulcus
snd folds under the hemi-
sphere on each side.
Functions of the Cerebral Cortex
Some Temporal Lobe Functions
Responsible for receiving and interpreting
auditory impulses from the ear.
An olfactory area that concerns the sense
of smell.
Functions of the Cerebral Cortex
The Occipital Lobe
lies posterior to the
parietal lobe and
extends over the
cerebellum.
Functions of the Cerebral Cortex
Some Occipital Lobe Functions
Visual receiving area and visual ass-
ociation for interpreting impulses from
the retina of the eye.
Functions of the Cerebral Cortex
The Insula lies deep within each hemisphere
and
cannot be seen
from the surface.
Functions of the Cerebral Cortex
The Insula Functions
Visceral reactions and judgments
Receives, integrates and responds to
autonomic influx.
Communication areas of the lobes
TEMPORAL LOBE
Auditory Cortex
Lies at the posterior
area of the temporal
lobe
Contains the auditory
receiving and
association areas.
Communication areas of the lobes
Auditory Receiving Area
Detects sound impulses from
the surrounding environment
Auditory association area
Interprets and translates the
sound impulses.
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Communication areas of the lobes
FRONTAL LOBE- Motor cortex
Lies anterior to the most inferior part of the
frontal lobe
Contains the Broca area
Communication areas of the lobes
Broca Area – Responsible for spoken and
written communication.
Functions- Controls:
Muscles in the tongue
Soft Palate
The larynyx
Lies anterior to the area that controls the arm
and hand muscles that produce written speech
DiencephalonThe area between
the cerebral
hemispheres
and the brain stem.
Contains the
thalamus
and the
hypothalamus.
The Thalamus
Sorts and directs sensory
impulses to areas of the
cerebral cortex.
Nearly all sensory
impulses travel through
the thalamus.
Important role in sleep
and
wakefullness.
Hypothalamus
Located inferior to the
thalamus
The Boss of you.
Hypothalamus
Helps maintain
homeostasis
Controls autonomic
function such as:
heartbeat, blood flow,
and hormone secretion.
Controls the pituitary
gland.
Pituitary Gland
A „master gland‟ lo-
cated at the bottom
of the hypothalamus.
Pea sized
Assists in the regulation
of homeostasis.
Pituitary Gland
Functions Helps to regulate:
Growth
Blood pressure
Child birth
Sex organ function
Thyroid gland
Metabolism
Temperature regulation
Hypothalamus/ Pituitary
Homeostasis
Balance
Maintenance
of body con-
ditions within
set limits.
The Limbic System
Located between the
cerebrum and diencephalon
Includes the Hip-
pocampus
Links conscious functions
of the cerebral cortex and
autonomic functions of the
brainstem.
The Limbic System
Located between the
cerebrum and diencephalon
Includes the Hip-
pocampus
Links conscious functions
of the cerebral cortex and
autonomic functions of the
brainstem.
The Limbic System
Emotional states and
behavior
Formation of long
term memory
The Hippocampus
Long term
memory
Spacial
navigation
The Hippocampus
The Brain Stem
The brainstem
is located in the
anterior region
below the cerebrum
The Brain Stem
Connects the cerebrum and the
diencephalon with the spinal cord.
The brainstem includes:
The Midbrain
The Pons
The Medulla Oblongata
The Midbrain
The midbrain is located below the center of the
cerebrum.
The midbrain forms the superior part of the brain
stem.
The Midbrain
The midbrain consists of centers that are
concerned with aspects of vision and
hearing.
The Pons
Located anterior to the cerebellum.
Lies between the midbrain and the medulla
Connects the two halves of the cerebellum
with the brainstem.
Medulla Oblongata
Located between the pons and
spinal cord.
Contains gray matter which
has centers that play an
important role in many
involuntary actions such as
respiration.
The centers are called vital
centers.
The Medulla Vital Centers
The respiratory center
The cardiac center
The vasomotor center
The Cerebellum “Little Brain”
Divided into two hemispheres,
and one middle part(vermis).
Outer layer gray matter, inner
layer white matter.
Located above the brainstem,
and beneath the occipital
lobes.
The Cerebellum
Functions:
Coordination in voluntary
movement.
Helps maintain balance
and equilibrium.
Helps maintain muscle
tone.
Brain Studies
Imaging used to study the brain
without physically entering it
CT Scan Provides photographs of the bone,
soft tissue, and cavities of the brain. Used to de-
tect:
Scar tissue accumulations
Anatomic lesions such as tumors
Brain Studies
MRI Magnetic Resonance Imaging
Shows more views than CT scans
Often reveals issues that the CT
scan can miss such as tumors, scar
tissue, and hemorrhaging.
Brain Studies
The Electroencephalograph records
Electrical currents produced by the brain‟s
Nerve cells.
Brain Studies EEG
Cranial Nerves
Cranial Nerves
12 pairs of cranial nerves
Numbered 1- 12 based on
connection with the brain.
Originate in the brain stem
Divided into 4 categories
based on the impulses they
send.
Cranial Nerves Types
Special sensory impulses
Located in special sense
organs in the head, responsible
for:
Smell
Taste
Vision
Hearing
Cranial Nerves Types
General sensory impulses
Originate from receptors through the body.
Pain
Touch
Temp
Pressure
Vibration
Deep muscle sense
Cranial Nerves Types
Somatic Motor Impulses
Voluntary control of skeletal muscles
Cranial Nerves Types
VISCERAL MOTOR IMPULSES
Part of autonomic nervous system
Involuntary control of glands
and involuntary muscle
Aging and the Nervous System
Aging of the brain
The brain loses 5-10 % of it’s
volume between
the ages of 20-90.
The grooves widen and the
surface shrinks.
Aging in the brain
Senile plaque forms
Synapses and neurons
decrease, esp in the cere-
bral cortex.
Aging of
the Brain
Aging in the brain
Movement is slowed
Information processing slows
Chance of stroke, and alzheimers increases
Dementia
Loss of cognitive ability in a previously-unimpaired
person, beyond what might be expected from
normal aging.
Massage - Yes
Alzheimers
Alzheimer’s
disease leads to
nerve cell death
and tissue loss
throughout the
brain. Over time,
the brain shrinks
dramatically,
affecting nearly all
its functions.
Massage –Yes, best to
start in early stages
Multiple Sclerosis
Eats away at the protective
sheath that covers your
nerves. This interferes with
the communication between
your brain and the rest of
your body.
Massage- During
remissions
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