The Brain
Structures, Functions, and Injuries
Older Brain Structures: Brainstem

The Brainstem is the oldest part of the brain, beginning
where the spinal cord swells and enters the skull. It is
responsible for automatic survival functions.
Medulla

The Medulla is the
base of the brainstem
that controls
___________ and
_______________.
Pons

Involved in coordinating
movement, sleeping, waking, and
dreaming

Brainstem is a crossover point,
where most nerves to and from each
side of the brain connect with
body’s opposite side
Reticular Formation

Filters incoming
stimuli & relays
important info to
other areas of the
brain

“Netlike”
network of
neurons
Thalamus
Thalamus


Sitting atop brainstem
Receives information from
all senses (except smell)
and routes it to the higher
brain regions that deal with
seeing, hearing, tasting,
touching

“Hub in which traffics
passes en route to various
destinations”
Thalamus


Brain’s sensory
switchboard, located
on top of the
brainstem.
It directs messages to
the sensory areas in
the cortex and
transmits replies to
the cerebellum and
medulla.
Cerebellum


The “little brain”
attached to the rear of
the brainstem.
It helps coordinate
voluntary movements
and balance.

Also involved in:
nonverbal learning,
memory
Older Brain Functions

“Older” brain functions all occur without any
conscious effort

Brain processes most information outside of our
awareness
The Limbic System



Limbic System is a
doughnut-shaped system
of neural structures at the
border of the brainstem
and cerebrum
Associated with emotions
such as fear, aggression
and drives for food and
sex.
It includes the
hippocampus, amygdala,
and hypothalamus.
Limbic System

Hippocampus: processes memory

Injury:
.
.

Amygdala

Amygdala: two lima bean-sized neural clusters
Influences aggression and fear
 Processes emotional memories
 Injury or Damage:

.
.

Hypothalamus

Hypothalamus: important link in chain of
command governing bodily maintenance

Some neural clusters influence:


Hunger, Thirst, Body Temp, Sexual Behaviors
Monitors both blood chemistry and takes orders
from other parts of the brain
Limbic System


Hypothalamus Directs
maintenance
activities like eating,
drinking, body
temperature, and
control of
emotions.
Helps govern the
endocrine system
via the pituitary
gland.
Video of an
actual brain
Hypothalamus = Reward Center


Read on page 72 & 73
Olds 1958: located other “pleasure centers”
What rats actually experience we don’t know
 Allowed to press pedals to trigger their own
stimulation
 Feverish pace – 7000 times an hour – until they
dropped from exhaustion

Reward Center
Sanjiv Talwar, SUNY Downstate
**Rats cross an electrified
grid for self-stimulation
when electrodes are placed
in the reward
(hypothalamus) center (top
picture).
**When the limbic system
is manipulated, a rat will
navigate fields or climb up
a tree (bottom picture).
Reward Center

Do humans have limbic centers for pleasure?

Neurosurgeon implanted electrodes in such areas
Stimulated patients reported mild pleasure
 However not driven into a frenzy(rat)


Researches believe that _____________ disorders
may stem from a reward deficiency syndrome
Genetically disposed deficiency in natural brain systems
for pleasure
 People crave whatever provides that missing pleasure or
relieves negative feelings

Mind Control?




http://www.learner.org/resources/series142.html?pop
=yes&pid=1593
This video links human aggressive behavior with
specific regions of the brain.
Scenes from classic experiments show stimulation of a
bull's brain to stop it from charging and excitation of a
cat's hypothalamus to trigger aggression.
A striking case of violent human behavior is then linked
to a brain lesion — the surgical removal of which
restored normal emotional control

70 -- Tickling
Midbrain
Forebrain Structures


Thalamus
Limbic system
Hippocampus
 Amygdala
 Hypothalamus


Cerebrum
Cerebral cortex
 Lobes

Hindbrain Structures

Brainstem



Medulla
Cerebellum
Pons