Transcript autonomic nervous system

I. The Central Nervous System (CNS)
A: Spinal cord and brainstem
B: Brain
1. Cerebellum
2. Lobes and cortices of cerebral cortex/cerebrum (Funky Moms Smoke
Pot On Tuesdays)
a) frontal
b) motor and somatosensory cortices
c) parietal
d) occipital
e) temporal
3. Corpus callosum
III: Limbic system
1. hypothalamus
2. pituitary gland
3. amygdala
4. hippocampus
B. Hindbrain, midbrain & forebrain
Hindbrain: Pons, medulla oblongata, cerebellum
Midbrain
Forebrain: Cerebrum, thalamus, hypothalamus
The Brain
For purposes of studying form and function, scientists
break the brain down in many ways:
A. 2 hemispheres (left and right)
The brain’s 2 hemispheres are
symmetrical in form but not in function
Brain’s symmetry:
•Anatomically, the 2 hemispheres are
almost symmetrical (left hemisphere
tends to be slightly larger than right)
•All lobes and glands in brain have a
left and right version
Lateralization: The brain’s 2 hemispheres
have regions that serve different, yet
complementary functions
•e.g. Language is usually associated
with left hemisphere BUT grasping
sarcasm, metaphors, subtleties of
language occurs in right hemisphere.
Video snippet: brain hemispherectomy
C. Cerebrum is divided up into lobes and cortices
The brain made simple
Front of brain
Rear of brain
Broca’s area
Wernicke’s area
angular gyrus:
connects Wernicke’s to other sensory areas
Damage results in inability to read, write,
comprehend written word, read music....
Parts of the Central Nervous System (CNS)
A. Spinal cord & brainstem
1.
2.
Spinal cord transmits messages (motor
& sensory) between brain and rest of
body and reflex messages between
nerves and spine
Brainstem—part of spinal cord that
enters brain
– Midbrain: involved in muscle
movement and integration of
sensory input
– Medulla: controls heart rate,
breathing
– Pons: movement, posture
– Reticular formation:
• arousal
– cut=coma
– electric stimulation=awake
Damage to the spinal cord or
brainstem can lead to:
Any predictions before I show you?
• DEATH (if medulla is severed, heart and breathing stop)
• CNS information highway is cut in ½ (brain and rest of body
cannot communicate)
• Paralysis and lack of feeling below area injured—YET not all
messages must go to brain!! Reflex response can remain after
spinal injury, including bladder control, sexual function, knee
jerk
B1. Cerebellum—the most primitive part of the brain
• LOCATION: Base of brainstem in rear of head
• SIZE: Baseball (1 in each hemisphere)
• FUNCTIONS:
– Coordinates voluntary movement, posture,
balance
– Stores implicit memories!
Damage to the cerebellum can
lead to:
• loss of coordination of motor movement/inability to reach
out and grab things
• seeming like you are drunk
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B2. Cerebrum (AKA cerebral
cortex)
Thin layer of deeply folded
tissue (AKA gray matter);
divided into 4 lobes based
on different functions
– Frontal
– Parietal
– Temporal
– Occipital
• No pain receptors allows
for electrode stimulation of
cortex to determine
function
• Video snippet: brain song
• Pinky and brain video
snippet
B2a: Frontal Lobes
• LOCATION: Top front of head, above temporal
lobes
• SIZE: Grapefruit (1 in each hemisphere)
• FUNCTION?
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Emotional control center
“Home” of personality
problem solving
spontaneity
long-term memory
language Home to Broca’s Area (speech
production)
initiation
judgment
impulse control
social and sexual behavior
LAST PART OF BRAIN TO DEVELOP IN
ADOLESCENCE!!!
Damage to the frontal lobes can lead to:
Do we even want to go there?
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Loss of spontaneity in interacting with others
Loss of flexibility in thinking
Persistence of a single thought (Perseveration)
Inability to focus on task
Mood changes
Broca’s aphasia –inability to speak fluently (clip)
Left damage leads to apathy, indifference and a loss of
initiative though person does not “feel” depressed
(pseudodepression)
• Right damage leads to immature behavior, lack of tact and
restraint (pseudopsychopathy) without mental/emotional
deficits
In sum: personality and attention changes!
B2b: Somatosensory and Motorsensory Cortexes
• Somatosensory cortex and motorsensory
cortex lie on either side of division
between parietal and frontal lobes
• Somatosensory cortex (on parietal lobe):
neurons receive TOUCH sensory
information
• Motorsensory cortex (on frontal lobe):
neurons send messages to control body
movement/muscles
Motor homunculus video clip
B2c: Parietal Lobes
• LOCATION: Top rear of head, above
occipital and temporal lobes
• SIZE: Grapefruit (1 in each
hemisphere)
• FUNCTION? Home of the
somatosensory cortex!
– Sensory perception (integrating all
sensory information into 1
cognition/thought)
– perception of stimuli related to touch,
pressure, temperature and pain.
– Spatial relations
Damage to the parietal lobes can lead to:
Any predictions before I show you?
Damage to the left parietal lobe can result in
• "Gerstmann's Syndrome”
– right-left confusion
– difficulty with writing (agraphia)
– difficulty with mathematics (acalculia)
• disorders of language (aphasia)
• inability to perceive objects normally (agnosia) (clip)
Damage to the right parietal lobe can result in:
• neglecting part of the body or space (contralateral neglect), which
can impair many self-care skills such as dressing and washing
• difficulty in making things (constructional apraxia) and drawing
B2d: Occipital Lobes
• LOCATION: Rear of head, above
cerebellum
• SIZE: Baseball (1 in each
hemisphere)
• FUNCTION?
– Visual perception—all information
taken in from eyes is processed in this
lobe
Damage to the occipital lobe can lead to:
Any predictions before I show you?
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Defects in vision
Difficulty with locating objects in environment.
Difficulty with identifying colors (Color Agnosia).
Production of hallucinations
Word blindness - inability to recognize words.
Difficulty in recognizing drawn objects.
Inability to recognize the movement of an object (Movement
Agnosia).
• Difficulties with reading and writing.
B2e: Temporal Lobes
• LOCATION: Right and left side of head
above ears
• SIZE: Grapefruit (1 in each
hemisphere)
• FUNCTION?
– Hearing ability
– speech processing
• Home to Wernicke’s Area
Damage to Temporal Lobes can lead
to…
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disturbance of language comprehension
altered personality and affective behavior
altered sexual behavior (increase or decrease sex drive)
Difficulty in recognizing faces (Prosopagnosia video clip) (Clip 2)
Difficulty in understanding spoken words (Wernicke's Aphasia clip)
Disturbance with selective attention to what we see and hear
Difficulty with identification of, and verbalization about objects
Short-term memory loss
Interference with long-term memory
Inability to categorize objects (Catagorization).
Right lobe damage can cause persistent talking
Increased aggressive behavior
B3. Corpus callosum
Video snippet severed corpus callosum
Human brain—interior view of left
hemisphere
C: the Limbic System
(AKA “inner brain”)
• LOCATION: Deep within
brain, next to thalamus, at
top of brain stem
• SIZE/SHAPE: Doughnut
shaped
• FUNCTION? The 4 F’s :
_____________,
____________,
_____________,
_____________
and memory!!
A. Hypothalamus: “body’s regulator”
1. In charge of endocrine system
2. Regulates hunger, thirst, response to pain,
levels of pleasure, sexual satisfaction, anger
and aggressive behavior
– rats self-pleasure non-stop when
hooked to electric device in
pleasure/reward center
– rats eat non-stop when ventromedial
nucleus portion of hypothalamus
stimulated; stop eating if lesioned
3. Regulates the autonomic nervous system
pulse, blood pressure, breathing, and
arousal in response to emotional
circumstances.
B. Pituitary Gland (also part of endocrine system)
• Growth hormone
• Creates hormones messages
and directs body’s other
glands to produce hormones
C. Amygdala: Flight or fight response
Video snippet
• Directs aggressive and
fearful responses
– Lesion=less aggression,
more mild, meek
demeanor
– stimulation=extreme
aggression!
D. Hippocampus
• Converts shortterm memory to
long-term
Answer Key: How’d you do at labeling your brain?
II. PNS
What is the PNS?
The nerves that run throughout your body connecting your
sensory organs (skin, eyes, ears, tongue, nose) to your brain
and spine (CNS)
2 parts: somatic and autonomic
1.Somatic nervous system: controls voluntary muscle
movement and reflex responses (balance, blinking, knee jerk)
2.Autonomic: controls involuntary internal organ actions
a) Sympathetic: Drives flight or fight response during
stressful/strenuous events
a) Speeds up heart, directs blood flow to muscles that need
most oxygen, suspends digestion
b) Parasympathetic: relaxation
Autonomic Nervous System
• 2 parts: sympathetic and parasympathetic
– Sympathetic: Drives flight or fight response during
stressful/strenuous events
• Speeds up heart
• directs blood flow to muscles that need most oxygen
• suspends digestion
– Parasympathetic: relaxation, slows down systems
to return to homeostasis after shock, stress
Peripheral Nervous System:
Autonomic system parts
PNS (shown in blue) and
CNS (shown in red)
neurons/nerves
Incoming signals, internal processing,
outgoing signals
•Sensory/afferent nerves: PNS nerves carry signals
from body to CNS spinal cord and brain
•Receptors: receive information (sound, light, heat,
pressure, flavor, smell) from environment (auditory
receptors, olfactory, visual, kinesthetic, taste buds)
•Motor./efferent nerves: carry outgoing signals
from the CNS to the muscles, skin, and glands of
body
•Interneurons: CNS neurons that receive and
perceive incoming from sensory receptors and
organs and send outgoing information to muscles
III. Endocrine System
• What? Network of glands
located in brain and body
• Function? Sends hormone
chemical messages to body’s
organs to control:
– metabolism
– growth
– sexual development
• In females: ovulation,
menstruation, and lactation
• In males: sperm production,
deepening of voice, growth of
sex organs
III. Endocrine System (cont)
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Thyroid gland produces hormone that
regulates metabolism (how quickly/slowly one
digests food)
– Not enough hormone (hypothyroidism)=
sluggish, no appetite
– Too much hormone
(hyperthyroidism)=eat a lot, hyperactive
Adrenal glands release cortisol adrenalin
when person frightened or angry
Hypothalamus (part of limbic system)
coordinates communication between
endocrine and nervous systems
Pineal gland “3rd eye” releases melatonin
which regulates sleep cycle (circadian
rhythms)
Pituitary gland—”master gland” Maker of
growth hormone, second in command to
hypothalamus directs other glands to
produce/release hormones
Parathryroid—produce calcium for bone
growth