3. Brain Stem Keeps You Breathing
• Another brain part that's small
but mighty is the brain stem.
The brain stem sits beneath
the cerebrum and in front of
the cerebellum. It connects
the rest of the brain to the
spinal cord, which runs down
your neck and back. The brain
stem is in charge of all the
functions your body needs to
stay alive, like breathing air,
digesting food, and circulating
blood.
5. Brain Stem
• Functions:
• Breathing
• Heart Rate
• Blood Pressure
• The brain stem is a general term for the area of
the brain between the thalamus and spinal cord.
Structures within the brain stem include the
medulla, tectum, tegmentum, and pons. Areas
responsible for the most basic functions of life
such as breathing, heart rate and blood pressure.
6. medulla
• Part of the brain stem
important for breathing
and respiration
7. Pons
• Area of the brainstem
between the medulla and
the midbrain
• Tectum "Roof" of the
midbrain.
• Tegmentum "Floor" of the
midbrain.
8. Cerebellum
• It controls balance,
movement, and coordination
(how your muscles work
together). Because of your
cerebellum, you can stand
upright, keep your balance,
and move around. Think about
a surfer riding the waves on
his/her board. What does
he/she need most to stay
balanced? The best surfboard?
The coolest wetsuit? Nope —
he/she needs his cerebellum!
11. thalamus
• Thalamus
• Functions:
• Sensory processing
• Movement
• The thalamus receives sensory
information and relays this
information to the cerebral
cortex. The cerebral cortex
also sends information to the
thalamus which then transmits
this information to other areas
of the brain and spinal cord
12. limbic system
• Functions:
• Emotions
• Memory
• The limbic system (or the limbic areas) is a group
of structures that includes the amygdala, the
hippocampus, mammillary bodies and cingulate
gyrus. These areas are important for controlling
the emotional response to a given situation. The
hippocampus is also important for memory
13. Amygdala
Your brain has a little bunch of cells on each side
called the amygdala. The word amygdala is Latin for
almond, and that's what this area looks like.
Scientists believe that the amygdala is responsible
for emotion. It's normal to feel all different kinds of
emotions, good and bad. Sometimes you might feel
a little sad, and other times you might feel scared,
or silly, or glad.
14. Amygdala
• A group of 90 healthy gay and heterosexual
adults, men and women, were scanned by the
Karolinska Institute scientists to measure the
volume of both sides, or hemispheres, of their
brain.
• When these results were collected, it was found
that lesbians and heterosexual men shared a
particular "asymmetry" in their hemisphere size,
while heterosexual women and gay men had no
difference between the size of the different
halves of their brain.
15. Amygdala
• In other words, structurally, at least, the brains of gay
men were more like heterosexual women, and gay
women more like heterosexual men.
• A further experiment found that in one particular area
of the brain, the amygdala, there were other significant
differences.
• In heterosexual men and gay women, there were more
nerve "connections" in the right side of the amygdala,
compared with the left.
• The reverse, with more neural connections in the left
amygdala, was the case in homosexual men and
heterosexual women.
16. hippocampus
• Hippocampus
• Functions:
• Learning
• Memory
• The hippocampus is one part of the limbic
system that is important for memory and
learning
18. Hypothalamus
• The hypothalamus is composed of several different
areas and is located at the base of the brain. Although
it is the size of only a pea (about 1/300 of the total
brain weight), the hypothalamus is responsible for
some very important functions. One important
function of the hypothalamus is the control of body
temperature. The hypothalamus acts as a "thermostat"
by sensing changes in body temperature and then
sending signals to adjust the temperature. For
example, if you are too hot, the hypothalamus detects
this and then sends a signal to expand the capillaries in
your skin. This causes blood to be cooled faster. The
hypothalamus also controls the pituitary.
19. Hypothalamus
Functions:
• Body Temperature
• Emotions
• Hunger
• Thirst
• Circadian Rhythms These are daily rhythms to many of our
physiological functions and activities....our sleep, body
temperature, alertness, neurotransmitter levels. Many of
these rhythms run on a cycle of about 24 hours. Rhythms that
run on this 24 cycle are called Circadian Rhythms.
20. • This little gland also plays a role with lots of
other hormones, like ones that control the
amount of sugars and water in your body. And
it helps keep your metabolism going. Your
metabolism is everything that goes on in your
body to keep it alive and growing and supplied
with energy, like breathing, digesting food,
and moving your blood around.
22. Pituitary Gland
• The pituitary gland is a small round organ that is about
1 centimeter in diameter and occupies a small groove
in the base of the skull.
• Weighs 0.5 to 1 gram, this small pea-sized gland is able
to influence every other endocrine gland in the body
and therefore known as the “master gland”.
• The pituitary gland is controlled to a large extent by the
hypothalamus. We will see it next.
• The hypothalamus is able to send stimulatory or
inhibitory hormones to the pituitary gland thereby
regulating its action on other endocrine glands and the
body as a whole.
23. Pituitary gland
• Pituitary Gland Controls Growth
• The pituitary gland is very small — only about the
size of a pea! Its job is to produce and release
hormones into your body. If your clothes from
last year are too small, it's because your pituitary
gland released special hormones that made you
grow. This gland is a big player in puberty too.
This is the time when boys' and girls' bodies go
through major changes as they slowly become
men and women, all thanks to hormones
released by the pituitary gland.
24. Corpus callosum
• From a top view, notice
how the brain is divided
into two halves, called
hemispheres. Each
hemisphere
communicates with the
other through the
corpus callosum, a
bundle of nerve fibers.
26. Cerebral Cortex
• Thought
• Voluntary movement
• Language
• Reasoning
• Perception
• The cortex is a sheet of tissue that makes up the outer layer of the
brain. The thickness of the cerebral cortex varies from 2 to 6 mm.
The right and left sides of the cerebral cortex are connected by a
thick band of nerve fibers called the "corpus callosum.“ In higher
mammals such as humans, the cerebral cortex looks like it has
many bumps and grooves. A bump or bulge on the cortex is called a
gyrus (the plural of the word gyrus is "gyri") and a groove is called a
sulcus (the plural of the word sulcus is "sulci"). Lower mammals,
such as rats and mice, have very few gyri and sulci.
27. Cerebral hemispheres
• The cerebrum has two halves, with one on
either side of the head. Some scientists think
that the right half helps you think about
abstract things like music, colors, and shapes.
The left half is said to be more analytical,
helping you with math, logic, and speech.
Scientists do know for sure that the right half
of the cerebrum controls the left side of your
body, and the left half controls the right side.
28. Cerebrum: synopsis
The biggest part of the brain is the cerebrum. The cerebrum
makes up 85% of the brain's weight.
The cerebrum is the thinking part of the brain and it controls
your voluntary muscles, i.e. the ones that move when you want
them to. When you kick a ball; when you have directed thought;
when you need it to solve math problems, figure out a video
game, and draw a picture.
Your memory lives in the cerebrum — both short-term memory.
The cerebrum also helps you reason and order your life, i.e.
you'd better do your homework now because you won’t have
time to get sufficient sleep if you wait; I shouldn’t buy this
because I will need the money later in the month.
30. Motor Cortex; Broca’s area
• The frontal lobes are involved in motor function,
problem solving, spontaneity, memory, language,
initiation, judgment, impulse control, and social
and sexual behavior.
• The frontal lobes are extremely vulnerable to
injury due to their location at the front of the
cranium.
• MRI studies have shown that the frontal area is
the most common region of injury following mild
to moderate traumatic brain injury (Levin et al.,
1987).
31. Frontal Lobe
• There are important asymmetrical differences in the frontal
lobes. The left frontal lobe is involved in controlling
language related movement, whereas the right frontal lobe
plays a role in non-verbal abilities. Some researchers
emphasize that this rule is not absolute and that with many
people, both lobes are involved in nearly all behavior.
• Disturbance of motor function is typically characterized by
loss of fine movements and strength of the arms, hands
and fingers (Kuypers, 1981).
• Patients with frontal lobe damage exhibit little spontaneous
facial expression, which points to the role of the frontal
lobes in facial expression (Kolb & Milner, 1981). Broca's
Aphasia, or difficulty in speaking, has been associated with
frontal damage by Brown (1972).
32. Frontal Lobe
• One of the most common characteristics of
frontal lobe damage is difficulty in interpreting
feedback from the environment. Perseverating on
a response (Milner, 1964), risk taking, and non-
compliance with rules (Miller, 1985), and
impaired associated learning (using external cues
to help guide behavior) (Drewe, 1975) are a few
examples of this type of deficit.
• The frontal lobes are also thought to play a part
in our spatial orientation, including our body's
orientation in space (Semmes et al., 1963).
33. Frontal Lobe
• One of the most common effects of frontal damage can
be a dramatic change in social behavior. A person's
personality can undergo significant changes after an
injury to the frontal lobes, especially when both lobes
are involved. There are some differences in the left
versus right frontal lobes in this area. Left frontal
damage usually manifests as pseudodepression and
right frontal damage as pseudopsychopathic (Blumer
and Benson, 1975).
• Sexual behavior can also be effected by frontal lesions.
Orbital frontal damage can introduce abnormal sexual
behavior, while dorolateral lesions may reduce sexual
interest (Walker and Blummer, 1975).
35. Somatosensory Cortex:somato=body
• The parietal lobes can be divided into two functional regions. One
involves sensation and perception and the other is concerned with
integrating sensory input, primarily with the visual system.
• The first function integrates sensory information to form a single
perception (cognition). The second function constructs a spatial
coordinate system to represent the world around us.
• Individuals with damage to the parietal lobes often show striking
deficits, such as abnormalities in body image and spatial relations
(Kandel, Schwartz & Jessel, 1991).
• Damage to the left parietal lobe can result in what is called
"Gerstmann's Syndrome." It includes right-left confusion, difficulty
with writing (agraphia) and difficulty with mathematics (acalculia).
It can also produce disorders of language (aphasia) and the inability
to perceive objects normally (agnosia).
36. Parietal Lobe
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. Right side
damage can also cause difficulty in making things
(constructional apraxia), denial of deficits and drawing ability.
Bi-lateral damage (large lesions to both sides) can cause a
visual attention and motor syndrome. This is characterized by
the inability to voluntarily control the gaze (ocular apraxia),
inability to integrate components of a visual scene
(simultanagnosia), and the inability to accurately reach for an
object with visual guidance (optic ataxia) (Westmoreland et
al., 1994).
37. Parietal Lobe
• Special deficits (primarily to memory and personality) can
occur if there is damage to the area between the parietal
and temporal lobes.
• Left parietal-temporal lesions can effect verbal memory
and the ability to recall strings of digits (Warrington &
Weiskrantz, 1977). The right parietal-temporal lobe is
concerned with non-verbal memory.
• Right parietal-temporal lesions can produce significant
changes in personality.
39. Primary Auditory Cortex; Wernicke’s
Area
• Kolb & Wishaw (1990) have identified eight principle symptoms of
temporal lobe damage: 1) disturbance of auditory sensation and
perception, 2) disturbance of selective attention of auditory and
visual input, 3) disorders of visual perception, 4) impaired
organization and categorization of verbal material, 5) disturbance of
language comprehension, 6) impaired long-term memory, 7)
altered personality and affective behavior, 8) altered sexual
behavior.
• Selective attention to visual or auditory input is common with
damage to the temporal lobes (Milner, 1968). Left side lesions
result in decreased recall of verbal and visual content, including
speech perception. Right side lesions result in decreased
recognition of tonal sequences and many musical abilities. Right
side lesions can also effect recognition of visual content (e.g. recall
of faces).
40. Temporal Lobe
• The temporal lobes are involved in the primary
organization of sensory input (Read, 1981). Individuals
with temporal lobes lesions have difficulty placing
words or pictures into categories.
• Language can be effected by temporal lobe damage.
Left temporal lesions disturb recognition of words.
Right temporal damage can cause a loss of inhibition of
talking.
• The temporal lobes are highly associated with memory
skills. Left temporal lesions result in impaired memory
for verbal material. Right side lesions result in recall of
non-verbal material, such as music and drawings.
41. Temporal Lobe
• Seizures of the temporal lobe can have
dramatic effects on an individual's personality.
Temporal lobe epilepsy can cause
perseverative speech, paranoia and aggressive
rages (Blumer and Benson, 1975). Severe
damage to the temporal lobes can also alter
sexual behavior (e.g. increase in activity)
(Blumer and Walker, 1975).
43. Primary Visual Cortex
• The occipital lobes are the center of our visual
perception system. They are not particularly
vulnerable to injury because of their location
at the back of the brain, although any
significant trauma to the brain could produce
subtle changes to our visual-perceptual
system, such as visual field defects, e.g.
visuospatial processing, discrimination of
movement and color discrimination
(Westmoreland et al., 1994).
44. • Damage to one side of the occipital lobe causes loss of
vision with exactly the same "field cut" in both eyes.
• Disorders of the occipital lobe can cause visual
hallucinations and illusions. Visual hallucinations (visual
images with no external stimuli) can be caused by lesions to
the occipital region or temporal lobe seizures. Visual
illusions (distorted perceptions) can take the form of
objects appearing larger or smaller than they actually are,
objects lacking color or objects having abnormal coloring.
• Lesions in the parietal-temporal-occipital association area
can cause word blindness with writing impairments (alexia
and agraphia) (Kandel, Schwartz & Jessell, 1991).
45. Plasticity
• Plasticity, or neuroplasticity, is the lifelong ability
of the brain to reorganize neural pathways based
on new experiences. As we learn, we acquire new
knowledge and skills through instruction or
experience. In order to learn or memorize a fact
or skill, there must be persistent functional
changes in the brain that represent the new
knowledge. The ability of the brain to change
with learning is what is known as neuroplasticity.
To illustrate the concept of plasticity, imagine the
film of a camera.
46. • Pretend that the film represents your brain. Now
imagine using the camera to take a picture of a
tree. When a picture is taken, the film is exposed
to new information -- that of the image of a tree.
In order for the image to be retained, the film
must react to the light and ?change? to record
the image of the tree. Similarly, in order for new
knowledge to be retained in memory, changes in
the brain representing the new knowledge must
occur.
47. • To illustrate plasticity in another way, imagine
making an impression of a coin in a lump of
clay. In order for the impression of the coin to
appear in the clay, changes must occur in the
clay -- the shape of the clay changes as the
coin is pressed into the clay. Similarly, the
neural circuitry in the brain must reorganize in
response to experience or sensory
stimulation.
