Transcript Document

Brain Anatomy
Dura Mater
•Superficial
•Fuses brain to
skull
Arachnoid
•Reduces friction
•Filled with CSF;
shock absorber
Pia Mater
Very Vascular;
needs a lot of
oxygen due to high
metabolic rate of
neurons
1. Cerebrum
2. Diencephalon
3. Midbrain
4. Pons
5. Medulla
Oblongata
6. Cerebellum
Precentral gyrus – Motor Strip
Postcentral gyrus – Sensory Strip
Central Sulcus – separates
frontal from parietal lobe
Gyri: elevated ridges
Sulci: furrows
Bridge between Right and Left Hemispheres
•Enables Right and Left sides to communicate with each other
Problems
“Split Brain” Syndrome
Functions:
•Cognition and Memory
•Prefrontal Area: involved with
intellect, complex learning abilities
and personality; plays a role in
mood; feelings of frustration and
anxiety are formed here
•“Gatekeeper” Judgment, critical
thinking and reasoning skills
Problems
Relationships between events,
memory loss, behavior
disorders, Inappropriate social
and/or sexual behavior
Prefrontal lobotomy – 1950s
Function:
•Motor Strip: Control voluntary
motor function
•Premotor Cortex: skill area;
controls learned motor skills
Broca’s area
•Left hemisphere
•Directs the muscles of
tongue, throat and lips
when speaking
•Becomes active as we
plan to speak
•Syntax and grammar
rules are remembered
Try This!!
Yes the bick. I would say tha the vick daysis
nosis or chipickers.
Represents problems with Broca’s area!!
Only found in the left hemisphere of the frontal lobe
Problems will affect our ability to pronounce words,
form sentences, speaking becomes a problem
Located in parietal, temporal and occipital lobes
Primary Somatosensory Cortex
•Spatial Discrimination – ability to
identify the body region being
stimulated
•Area is identified by receiving
information from skin sensory
receptors and proprioceptors in
skeletal muscles.
•Try This!!
•Problems
•Inability to locate and recognize
body parts; disorientation
•Can’t discriminate between
different sensory stimuli
•Located
posterior to
Primary
Somatosensory
Cortex
•Major function
to analyze
different
sensory stimuli
(temp, pressure
•Evaluate what
the body is
feeling
•Try this!!
•Different senses
are distributed
through all
lobes
•Auditory Areas – sound waves
are interpreted
•Gustatory cortex – perception
of taste
•Olfactory Cortex – interprets
chemical odors
Language
•Wernicke’s area – called the
speech area
•Language comprehension
•Understanding jokes
•Reading unfamiliar sounds
Problems
•Hearing problems
•Aphasia – inability to speak
Visual Areas
•Receives stimuli from eyes
•Interprets information from
past experiences
Problems
Loss of vision or “seeing
stars”
Can’t recognize the object
you see
Posterior Association Area
• Large region including
parietal, temporal and
occipital lobes
• Plays a role in
recognizing faces,
patterns, and
identifying
surroundings
• Also includes
Wernicke’s area
Connects to cerebrum
Includes:
•Thalamus,
•Hypothalamus,
•Limbic system
•Pineal gland (epithalamus)
•Pituitary gland
Greek for “Inner room”
•Contains relay and
processing centers
•Relay Station; involved in
memory process
•Sorts out information, edits
•Gateway to cerebrum
Controls Body Homeostasis
•Autonomic Nervous System
•Influences BP
•HR (force and rate)
•Digestive tract motility
•Emotions
•Pleasure, fear, rage
•Sex Drive
•Body temperature regulation
•Food intake; hunger
•Thirst (water balance)
•No blood-brain barrier
•Circadian rhythms
•Control of Endocrine
(secrete ADH, oxytocin)
Hypothalamus and Pineal Gland
Problems with hypothalamus
• Problems
– Hormonal Imbalances
– Hypothermia
– Diabetes
– Obesity
– Sleep Disturbances
– Dehydration
Pineal Gland
• Part of epithalamus
• Secretes hormone melatonin
– Helps regulate Sleep-Wake
Cycle
Hypothalamus is heart of Limbic
System: Emotional Brain
“Ring”
•Contains Amygdala
•Recognizes angry or fearful
facial expressions
•Contains Hippocampus
•Involved with learning, longterm memory and storage
Problems
H.M. Case Study STM to LTM
•Had difficulty remembering anything
after his surgery
•Was able to learn new motor skills,
despite not being able to remember
learning them
•Link between NS and
Endocrine system
•Produces GH and TSH
•Posterior part of gland is
a hormone storage area
Pituitary Gland ->
Primitive Brain
•Pathway between lower
brain and spinal cord
and lower brain and
higher brain functions
•Contains 2 pairs of sensory nuclei
(Colliculi); Auditory and Visual Reflex
Centers I.e. rxns to flashlight or loud
noises
•Motor nuclei for 2 cranial nerves (III,
IV) involved in eye movements
•III Oculomotor – eye movement
•IV Trochlear – rotates eye up and
down
•Cerebral Peduncles – descending
bundles of motor nerve fibers –
connect to cerebellum
•RAS center begins here; Filters out
repetitive sensory stimuli. (99% of all
stimuli is ignored)
Corpus Quadrigemini
Superior Colliculi
Midbrain
•Visual Reflex Centers
•Follow movement with
eye
•Associated with
Cranial nerve III
Inferior Colliculi
•Auditory Reflex
•Startle Reflex
Bridge: Connects cerebellum
to brain stem; cerebrum and
S. cord
Relay Center
Bridge
Cranial Nerves (V-VIII) are
attached here
Respiratory Center –
Involuntary Control of pace
and depth of breathing
Problems
Hyperventilation
Connects Brain to S. cord; relays
info to Thalamus
Contains major centers for
Autonomic Regulation such as HR,
Bp, respiration and digestive
activities
Cardiac Center – adjusts
force and rate of heart beat
Vasomotor Center –
regulates BP
Respiratory Center –
controls rate and depth of breathing
with N. Fdbk loop in pons.
Controls other pleasant body
Activities: vomit, hiccupps, cough,
sneeze, swallow, and gag
Again no blood-brain barrier!
•Coordination; fine tunes
voluntary and involuntary
movement (Sports)
•Receives stimuli from
proprioceptors – evaluate
body position
•Maintains balance and
posture
Imbalances
•Ataxia; Lack of
coordination
•Tremors
•Alcohol – affects motor
skills; reaction time
•Easily passes through
blood-brain barrier
Olfactory – On
Optic – old
Oculomotor – Olympus
Trochlear – towering
Trigeminal – tops
Abducens – a
Facial – Finn
Vestibulocochlear – valued
Glossopharyngeal - good
Vagus – venison
Accessory – and
Hypoglossal – Hops.
I. Olfactory – smell
II. Optic – sight
III. Oculomotor – eye movement;
pupil dilate/constrict
IV. Trochlear – eye movement
downward
V. Trigeminal - 3branches
opthalmalic (s)
maxillary (s)
mandibular (m)
VI. Abducens – lateral eye movement
VII. Facial – branches into 5 motor
nerves of face; taste
VIII.Vestobulocochlear – hearing
IX. Glossopharyngeal – swallowing
and gag reflex; taste
X. Vagus – swallowing; runs to
heart and digestive system
XI. Accessory – shoulders and neck
XII. Hypoglossal – movement of
tongue; taste