Title: Your Amazing Brain
1Your Amazing Brain
- Receives information within a fraction of a
second, too minuscule to measure - Acts on the external universe allows you to
cry, walk, play a musical instrument - Utilizes language one of your most advanced
functions - Possesses emotions creates your affective
universe
2Your Amazing Brain
- Thinks is responsible for your memory,
intelligence, your thoughts - Controls your autonomic functions heart rate,
breathing, homeostasis - Controls your immune system protects you from
viruses
3(No Transcript)
4(No Transcript)
5Peripheral Nervous System
- Handles the CNSs input and output.
- Contains all the portions of the NS outside of
the brain and spinal cord. - Contains sensory nerves and motor nerves
- Divided into autonomic nervous system and somatic
nervous system.
6Peripheral Nervous System
- Sensory Nerves
- (to the brain)
- Carry messages from special reporters in the
skin, muscles, and other internal and external
sense organs to the spinal cord and then to the
brain
- Motor Nerves
- (from the brain)
- Carry orders from CNS to muscles, glands to
contract and produce chemical messengers
7Peripheral Nervous System
- Somatic NS
- Consists of nerves connected to sensory receptors
and skeletal muscles - Permits voluntary action (writing your name)
- Autonomic NS
- Permits the involuntary functioning of blood
vessels, glands, and internal organs such as the
bladder, stomach and heart
8Autonomic Nervous System
- Sympathetic NS
- Like the accelerator of your car
- Mobilizes the body for action
- Increases heart rate
- Elevates blood pressure
- Parasympathetic NS
- Like the brakes in your car
- Slows the body down to keep its rhythm
- Enables the body to conserve and store energy
9Sympathetic NSand Emotion
- You perceive the sensory stimulus.
- The adrenal gland sends two hormones epinephrine
and norepinephrine. - They activate the sympathetic nervous system.
- That produces a state of arousal or alertness
that provides the body with the energy to act
(the pupils dilate, the heart beats faster, and
breathing speeds up).
10(No Transcript)
11Central Nervous System
- The Spinal Cord
- The Brain
12The Spinal Cord
- Protected by a column of bones
- Produces some behaviors of its own without the
help of the brain - These spinal reflexes are automatic, requesting
no conscious effort - Sometimes they are influenced by thought and
emotion - Example touching a hot iron
13The Brain
- Areas of the Brain
- The Four Lobes of the Brain
- Lateralization
14(No Transcript)
15The Hindbrain
- Medulla breathing, heart rate
- Pons sleeping, walking, dreaming
- Riticular Activating System alertness,
attention - Cerebellum balance, coordination for the
muscles
16The Forebrain
- Thalamus
- Direct sensory messages to higher centers in the
brain - The sight of sunset is directed to a visual area
- The only sense that completely bypasses the
thalamus is the sense of smell, which has its
private switching station, the olfactory bulb
17The ForebrainThe Limbic System
- The Amygdala
- Responsible for evaluating sensory information
- It determines its emotional importance
- It makes the decision to approach or to withdraw
- Its initial response may be overridden by the
appraisal of the cerebral cortex - The Hippocampus
- The gate way to memory
- The Hypothalamus
- It is involved with drives associated with
survival such as hunger, thirst, emotion, sex,
and reproduction
18The ForebrainThe Limbic System
19The Endocrine System
20The Endocrine System
- The bodys slow chemical communication system a
set of glands that secrete hormones into the
blood stream.
21The Endocrine SystemA Set of Glands
- Thyroid gland affects metabolism
- Pancreas regulates the level of sugar in the
blood - Parathyroids help regulate the level of calcium
in the blood - Ovary secretes sex female hormones (estrogen)
- Testes secrete sex male hormone (Androgens)
22The Endocrine SystemA Set of Glands
- The Adrenal Glands
- A pair of endocrine glands just above the kidney
- They secrete epinephrine and norepinephrine which
help to arouse the body in times of stress.
23The Endocrine SystemA Set of Glands
- The Pineal Gland
- Helps secrete melatonin which helps to regulate
daily biological rhythms and promotes sleep.
24The Endocrine SystemA Set of Glands
- The Pituitary Gland
- A sort of master gland
- It is cherry-sized endocrine gland
- The hormones it secretes affect growth and the
secretion of other endocrine glands - The real boss is the hypothalamus
25Feedback System
26The Forebrain
- The Cerebrum
- Higher forms of thinking take place in it
- It is divided into two halves called the cerebral
hemispheres that are connected by a large band of
fibers called the corpus callosum - They have different tasks (lateralization)
-
27The Forebrain
- The Cerebral Cortex
- The cerebrum is covered by several thin layers of
densely packed cells known as the cerebral cortex - On each cerebral hemisphere, deep fissures divide
the cortex into 4 lobes
28(No Transcript)
29The Four Lobes of theCerebral Cortex
30(No Transcript)
31Functions of the Cortex
- Motor Cortex an area of the frontal lobes that
controls voluntary movements. - It sends messages out to the body.
- When stimulating, specific parts of the
region in the left or right hemisphere, specific
body parts moved on the opposite side of the
body.
32Functions of the Cortex
- Sensory Cortex the area at the front of the
parietal lobes that receives, registers, and
processes body sensations. - Association Functions areas of the cerebral
cortex that are not involved in primary motor or
sensory functions rather, they are involved in
higher mental functions such as learning,
remembering, thinking, and speaking.
33Functions of the Cortex
- Language
- 1- Brocas Area an area of the frontal lobe,
usually in the left hemisphere, that directs the
muscle movements involved in speech - 2- Wernickes Area a brain area involved in
language comprehension and expression usually in
the left temporal lobe.
34Specialization and Integration in Language
- 1- Visual cortex receives written words as
visual stimulation. - 2- Angular gyrus transforms visual
representations into an auditory code. - 3- Wernickes area interprets auditory code.
- 4- Brocas area controls speech muscles via the
motor cortex. - 5- Motor cortex word is pronounced.
35Lateralization
- Left Hemisphere
- Verbal competence
- Speaking, reading, thinking reasoning
- Processes info in sequence
- One piece of data at a time
- logical
- Right Hemisphere
- Nonverbal areas
- Comprehension, spatial relationships, drawing,
music, emotion - Processes info. As a whole
- intuitive
36Emotion and Lateralization
- Left Hemisphere
- Important for the expression of positive emotion
- Damage to the L.H. leads to loss of the capacity
of joy. - Activation in the L.H. leads to tendencies to
approach other people.
- Right Hemisphere
- Important for the expression of negative emotion
- Damage to the R.H. may make people euphoric.
- Activation in the R.H. leads to tendencies to
withdraw from people.
37(No Transcript)
38(No Transcript)
39(No Transcript)
40Neurons
- The NS is made up in part of neurons
- They are held in place by glial cells
- The Function of Glial Cells
- Provide neurons with nutrients
- Insulate neurons
- Remove cellular debris when neurons die
41The Structure of the Neuron
- 1- Dendrites
- Act like antennas receiving messages
- 2- The Cell Body
- Contains the biochemical machinery to keep the
neuron alive - 3- The Axon
- Transmits messages away from the cell body to
other neurons
42How Neurons Communicate
43Myelin Sheath
- Surrounds the axons
- A layer of fatty material, which is derived from
glial cells - There are 2 purposes of the myelin sheath
- To prevent signals from adjacent cells from
interfering with each other - To speed up the production of neural impulses
44Stop!
- Is the brain capable of reorganizing itself if
damaged?
45Plasticity
- When one brain area is damaged, other areas may
in time reorganize and take over some of its
functions. - If neurons are destroyed, nearby neurons may
partly compensate for the damage by making new
connections that replace the lost ones. - Examples How the sense of touch in blind men
invades the visual part of the brain. - How the brain struggles to recover from a
minor stroke.
46Stop!
- Could damaged neurons in the central nervous
system multiply and grow back?
47Precursor Cells(Immature Cells)
- Precursor cells can give birth to new neurons
when immersed in a growth-promotion protein - Physical and mental exercise promote the survival
and the production of new precursor cells - Stress can prohibit the production of new cells
- Nicotine can kill precursor cells
48Chemical Messengers in the NS
- Neurotransmitters
- Endorphins
- Hormones
49Neurotransmitters
- Neurotransmitters travel from one neuron to
another. Changes occur in the receiving neurons
membrane, - The ultimate effect is either
- Excitatory the probability that the receiving
neuron will fire increases - Inhibitory the probability that the receiving
neuron will fire decreases
50Neurotransmitters
- Serotonin
- Sleep, appetite, sensory perception, temperature
regulation, pain suppression, and mood - Dopamine
- Voluntary movement, learning, memory, and emotion
- Acetylcholine
- Muscle action, cognitive functioning, memory, and
emotion
51Neurotransmitters
- Norepinephrine
- Increased heart rate and the slowing of
intestinal activity during stress, learning,
memory, dreaming, waking from sleep, and emotion - GABA
- (gama-aminobutyic acid)
- The major inhibitory neurotransmitter in the brain
52Why Not Flood the Brain with Artificial Opiates?
- The brain may stop producing its own natural
opiates. - For a drug addict, the result is agony until the
brain resumes production of its natural opiates
or receives more artificial opiates.
53Is Designing a Drug Easy?
- Dopamine as a drug doesnt help because dopamine
doesnt cross the blood-brain barrier by which
the brain fences out unwanted chemicals
circulating in the blood. - L-dopa, a raw material the brain can convert to
dopamine, can sneak through the fence.
54How Drugs and Other Chemicals Alter
Neurotransmitters
- The agonist molecule excites. It mimics the
effects of a neurotransmitter on the receiving
neuron. - Morphine mimics the action of neurotransmitters
by stimulating receptors in the brain involved in
mood and pain sensation.
- The antagonist molecule inhibits by blocking the
neurotransmitters or by diminishing their
release. - Botulin poison causes paralysis by blocking
receptors for acetylcholine (a neurotransmitter
that produces muscle movement)
55Endorphins
- They have an effect similar to that of opiates.
- They reduce pain and promote pleasure.
- They play a role in appetite, sexual activity,
blood pressure, mood, learning, and memory. - Some endorphins function as neurotransmitters.
56EndorphinsNeuromodulators
- Most endorphins act as neuromodulators, which
alter the effect of neurotransmitters by limiting
or prolonging their effects.
57Hormones
- Insulin
- Produced by the pancreas
- Regulates the bodys use of glucose affects
appetite - Melatonin
- Secreted by the pineal gland
- Helps to regulate daily biological rhythms and
promotes sleep.
58Hormones
- Adrenal Hormones
- Produced by the adrenal glands are involved in
emotion and stress. They rise in response to
nonemotional conditions, such as cold, heat, pin
injury, and physical exercise, and in response to
some drugs such as caffeine and nicotine. - The Outer Part
- Cortisol
- The Inner Part
- Epinephrine (adrenalin) Norepinephrine
-
59Hormones
- Sex Hormones
- Are secreted by the gonads and by the adrenal
glands - Androgens
- Masculinizing Hormones
- Estrogens
- Feminizing Hormones
60Neurotransmitters Hormones
- Acetylcholine
- Shortage in acetylcholine may be associated with
Alzheimers disease - Dopamine
- The degeneration of brain cells that produce and
use another neurotransmitter, dopamine, appears
to cause symptoms of Parkinsons disease. - Low levels of dopamine may cause ADHD
61Neurotransmitters Hormones
- Serotonin
- Decrease in norepinephrine and serotonin is
associated with depression. Elevated levels
along with other biochemical and brain
abnormalities have been implicated in childhood
autism. - Norepinephrine
- Norepinephrine, epinephrine, and adrenaline are
associated with excitement and stress.
62Neurotransmitters Hormones
- Cortisol
- Cortisol is associated with stress. Increase in
cortisol damages the brain and may be associated
with posttraumatic stress. - GABA
- Abnormal GABA levels have between implicated in
sleep and eating disorders and in compulsive
disorders. - Glutamate
- Glutamate, serotonin, and high levels of dopamine
have been associated with schizophrenia