1. Introductory Psychology: Biological Bases of Behavior
AP Psychology: unit II
Topic: Nervous System and Endocrine System

2. 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

3. 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

4. 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)

5. Biological Bases: Central Nervous
The Reflex Arc

6. Biological Bases: Central Nervous
The Reflex Arc

7. 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

8. 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

9. 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

10. 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

11. 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

12. 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

14. The Biological Bases: The Endocrine System
Part THREE
DEFINITION: A system that helps coordinate & integrate complex psychological reactions
THE BODY’S SECONDARY COMMUNICATION

15. 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

16. 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

17. 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”

18. Biological Bases: Endocrine System
Thyroid
Characteristics
Located inside the neck
Regulates metabolism
Hormones
Thyroxin
Alertness & energy levels
Weight
Hypothyroidism
Hyperthyroidism

19. 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

20. 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

21. 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