Transcript Unit 2 Notes - NS and ES

Introductory Psychology:
Biological Bases of Behavior
AP PSYCHOLOGY: UNIT II
Topic: Nervous
System and
Endocrine System
The Biological Bases:
Central Nervous System
PART ONE
DEFINITION: The CNS is composed of
the brain & the spinal cord, both of which
are composed of neurons and glial cells
that control the life-sustaining functions
of the body as well as all thought,
emotion and behavior
THE BODY’S COMMAND CENTER
Biological Bases: Central Nervous
 The brain is the TRUE
CORE of the nervous system



Interprets information
Makes decisions
Sends commands
 Despite the importance of
the brain, it would be
completely useless without
the spinal cord
Biological Bases: Central Nervous
 The Spinal Cord

A long bundle of neurons; connects the brain to
the body; also responsible for fast, lifesaving
reflexes
 Carries information from the body’s tissues &
sensory organs to the brain (via afferent
{sensory} neurons)
 Carries
motor impulses from the brain to the
body’s muscles and glands (via efferent
{motor} neurons)
Biological Bases: Central Nervous
The Reflex Arc
Biological Bases: Central Nervous
The Reflex Arc
The Biological Bases:
Peripheral Nervous System
PART TWO
DEFINTION: The PNS is made up of all
the nerves and neurons that lie outside
the brain & spinal cord; allows the brain
& spinal cord to communicate with the
sensory systems of the eyes, ears, skin,
and mouth and allows the brain & spinal
cord to control the muscles & glands of
the body
Biological Bases: Peripheral Nervous
 The PNS can be divided
into TWO major systems

Somatic Nervous System

Autonomic Nervous System
 Sympathetic Nervous
System
 Parasympathetic Nervous
System
Biological Bases: Peripheral Nervous
 Somatic Nervous System

Characteristics
 Sensory Pathway
 All of the nerves that carry messages from the
senses to the central nervous system; contain
afferent neurons
 Motor
Pathway
 All of the nerves that carry messages from the
central nervous system to the voluntary
muscles of the body; contain efferent neurons
Biological Bases: Peripheral Nervous
 Autonomic Nervous System

Characteristics
 More or less automatic
 Controls
organs, glands & involuntary muscles
 Comprised of two systems
• Sympathetic Nervous System
• Parasympathetic Nervous System
Biological Bases: Peripheral Nervous
 Sympathetic Nervous System
 Characteristics
Located in the middle of the spinal column
 Reacts to stressful events & bodily arousal
 “Fight-or-Flight” System


Specific Reactions?
Dilates pupils
 Increases heart rate & breathing
 Stops digestion & excretion

The sympathetic division
demonstrates sympathy
for one’s emotions
Biological Bases: Peripheral Nervous
 Parasympathetic Nervous System
 Characteristics
Located on either side of the sympathetic division
 Restores the body to normal functioning after arousal
 “Rest-and-Digest” System


Specific Reactions?
Constricts pupils
 Slows heart rate & breathing
 Reactivates digestion & excretion


Also responsible for most of the ordinary, day-to-day
bodily functioning
The Biological Bases:
The Endocrine System
PART THREE
DEFINITION: A system that helps
coordinate & integrate complex
psychological reactions
THE BODY’S SECONDARY
COMMUNICATION
Biological Bases: Endocrine System
 Hormones

Chemical substances
(similar in function to
neurotransmitters) that
help regulate bodily
functions; released
directly into the
bloodstream by the
endocrine glands
 Fit into receptor sites on
their target organs; affect
behavior
Biological Bases: Endocrine System
 Pituitary Gland
 Characteristics
Located just below the hypothalamus
 Considered the “master” gland
 Controls or influences ALL of the
other endocrine glands


Hormones
Oxytocin
 Stimulates contractions of the uterus, production of
milk, sexual behavior and pair bonding
 Growth Hormone
 Promotes growth from infancy to adulthood

Biological Bases: Endocrine System
 Pineal Gland
 Characteristics
Near the base of the
cerebrum; back of the brain
 Helps to regulate the
sleep-wake cycle



Hormones

Melatonin
 Tracks day length & influences sleep patterns
 Disturbances in melatonin are responsible for “jet lag”
Biological Bases: Endocrine System
 Thyroid

Characteristics
 Located inside the neck
 Regulates metabolism

Hormones
 Thyroxin
 Alertness & energy levels
 Weight
Hypothyroidism
 Hyperthyroidism

Biological Bases: Endocrine System
 Pancreas
Characteristics
 Located deep in the
abdomen
 Regulates blood-sugar
 Hormones
 Insulin
 Regulates carbohydrate & fat metabolism;
lowers blood-sugar levels
 Glucagon
 Raises blood-sugar levels

Biological Bases: Endocrine System
 Adrenal Glands
 Characteristics
Located at the top of the kidneys
 Secretes 30 different hormones to deal with stress,
regulate salt intake, etc.


Hormones
Adrenaline (Epinephrine)
 Arouses the body in times of stress
 Cortisol
 Helps manage stress, releases glucose into your
bloodstream & increases blood pressure for increased
physical activity

Biological Bases: Endocrine System
 Ovaries (gonads)
 Estrogen

Responsible for the
development and
maintenance of female
secondary sex
characteristics
 Testes (gonads)
 Testosterone

Principle male sex hormone