Transcript Reg_Chapter_3[1]

Chapter 3
Biology and Behavior
I. Nervous System
 Nervous System: Involved in thinking,
dreaming, feeling, moving and much more.
Two Main Parts
 Central Nervous System: brain and spinal
cord.
 Peripheral Nervous System: nerve cells that
send messages between the central nervous
system & all the parts of the body.
II. Central Nervous System
 Extends from the brain down the back
 Responsible for spinal reflexes
 Example: touch a hot stove, message sent to
spinal cord, message sent to hand to let go.
II. Peripheral Nervous System
 Two Divisions:
 1) Somatic: Transmits sensory messages to
central nervous system. (activated by touch,
pain, temp changes, etc)
 2) Autonomic: Regulates the bodies vital
functions (heartbeat, breathing, digestion, &
blood pressure)
Autonomic divides into two
 1) Sympathetic: Activated during action
(“fight or flight”)
 2) Parasympathetic: restores the body’s
reserves of energy after an action has occurred.
(heart rate & blood pressure normalized,
breathing is slowed, digestion returns to
normal)
Figure 2.2 A
motor neuron
III. Neurons: Tree like Structures
 Run through our entire body and
communicate with each other
 Send & receive messages from other
structures in the body (muscles & glands)
 More than 100 Billion neurons (mostly found
in the brain)
A. Cell Body
 Cell Body: produces energy that fuels the
activity of the cell
 Can have many dendrites but usually only one
axon
B. Dendrites (Branches)
 Receive information from other neurons and
pass the message through the cell body
C. Axon (Trunk)
 Carries messages away
D. Myelin
 Myelin: covers axon
 White fatty substance that insulates and
protects the axon.
 Helps to speed up transmission of message.
E. Axon Terminals
 Axon Terminals: Smaller branches at the end
of the axon.
F. Synapse
 Area between the axon terminal and another
dendrite.
 New synapses can develop between neurons
that were not previously connected, as when
we learn something new.
IV. Neurotransmitters: Chemicals
 Stored in sacs in the axon terminals
 When a neuron fires, it releases
neurotransmitter sacs.
 Different chemicals cause different physical
reactions
 Example:
– Acetylcholine: involved in controlling our muscles
– Dopamine: motor behavior: too much=
Schizophrenia, too little = Parkinson’s disease.
V. The Endocrine System
 Endocrine System: consists of glands that
secrete substances, called hormones.
Pituitary Gland: Pea sized “master
gland”
 Growth: regulates the growth of muscles,
bones, and other glands.
 Prolactin: stimulates milk production in
women
 Oxytocin: stimulates labor in women
Thyroid Gland
 Produces thyroxin: affects the body’s
metabolism
Adrenal Glands: located above the
kidneys
 Cortical steroids: increase resistance to
stress & promote muscle development
 Causes liver to release stored sugar,
making energy available for emergencies
 Adrenaline & noradrenalin: helps to cope
with stressful situations
Testes & Ovaries: produces
testosterone, estrogen, and
progesterone
 Testosterone: Male sex hormone, but found
in females in small amounts
 A. After 1st 8 weeks of development:
influences the sex of a child
 B. Adolescence: aids in muscle & bone
growth, primary & secondary sex
characteristics. (Reproduction/body hair)
Estrogen & Progesterone: female
sex hormone, but found in males in
small amounts
 A. Estrogen: primary and secondary sex
characteristic (body hair & breast
development)
 B. Progesterone: stimulates growth of
female reproductive organs & helps prepare
the body for pregnancy
 C. Estrogen & Progesterone: regulate
menstrual cycle
 Higher levels of estrogen seem to be
connected with optimal cognitive functioning
& feeling of well-being among women.
Brain Anatomy
Frontal Lobe:
 Problem solving, attention, judgment,
reflection, coordination of movement, sense
of smell, muscle movements, physical
reaction, libido.
Occipital Lobe
 Vision, Reading
Parietal Lobe:
 Sense of touch, response to internal stimuli,
sensory combination and comprehension,
some language & reading functions, some
visual functions.
Temporal Lobe:
 Auditory memories, some hearing, visual
memories, some vision pathways, music,
fear, some language, some speech, some
behaviors & emotions, sense of identity.
Cerebellum:
 Balance, posture, cardiac, respiratory,
vasomotor centers
Sensory Area:
 Legs, torso, head, arms, hands, fingers,
face, lips, tongue
Motor Area:
 Toes, knees, hips, shoulders, wrists, fingers,
neck, eyes, jaw.
Heredity: Our genetic background
 Heredity: the transmission of characteristics
from parents to offspring.
 **Can determine our behavior & physical
appearance**
 Genes: the basic building blocks of heredity.
 **One gene is given by one parent, & one is
given by the other parent.
Chromosomes: made of
deoxyribonucleic acid (DNA)
 ** Normal human cells contain 46
chromosomes.
 >23 from one parent, 23 from the other
parent
 > 22 chromosomes are the same in males
and females, the 23 is the sex chromosome
 ** Males=XY 23rd chromosome, Female=
XX 23rd chromosome
Nature-Nurture Debate
 Nature: genetics influences a person’s
personality most
 **Biological groundwork that prepares a
person to develop in certain ways
 Nurture: environment influences a person’s
personality most.
 **Family, education, culture, living
conditions, etc…
Kinship Studies: helps to determine
what role heredity & environment
play
 ** Twins=100%,Parent/Child=50%,
Brothers/Sisters=50%, Blood AuntsUncles/Niece-Nephews=25%, 1ST cousins=
12.5%
 **Studies certain traits or behavioral
patterns in individuals and then compares
them to those of relatives
 Example: twins & adoptee studies
Twins:
 Identical Twins: share 100% of genes
 ** have same shyness & activity levels,
irritability, sociability, & happiness
 ** more likely to share psychological
disorders like autism & schizophrenia
 Fraternal Twins: share 50% of genes
Twins Reared Apart:
 ** Many shared common psychological &
personality traits like: intelligence,
traditionalism, risk avoidance, aggression,
and leadership.
 ** shared same mannerisms such as how
they stand or sit.