Chapter 2 - Biology of the Mind

Question 1

What is phrenology?

Answer 1

Franz Gall - early 1800s.

The study of bumps on the skull and their relationship to mental abilities and characteristics.

Skull model “map” functions, traits, abilities, and their location on the skill. Strengths are bumps and weaknesses are indentations.

It yielded the idea of localization of function - different parts of the brain do different things.

Question 2

What are neurons?

Answer 2

Nerve calls - “atoms of the mind.”

Question 3

Describe the structure of a neuron.

Answer 3

Cell body - the cell’s life support.
Dendrites - receive messages from other cells.
Terminal branches of axons - form junctions with other cells.
Axon - passes messages away from the cell body to other neurons, muscles, and glands.
Neuron impulse - electrical signal traveling down the axon.
Myelin sheath - fatty substance that covers the axon and helps speed up neural impulses.

There are billions of neurons throughout the body.

Question 4

Define action potential.

Answer 4

A negative impulse that travels down the axon like a wave. It moves down the axon through positive and negative ions from the cell body to terminal branches. To send the signal to another cell, the message must find a way to cross the gap between cells, called the synapse.

The neurons receive excite / inhibit signals from other neurons. When the excite signal overpowers the inhibit signal, neurons fire. This is called “all or none.”

Question 5

What is the synapse?

Answer 5

The junction between the axon tip of the sending neuron and the dendrite / cell body of the receiving neuron. To cross the gap, chemicals called neurotransmitters are used.

Question 6

What is reuptake?

Answer 6

Recycling neurotransmitters.

Leftover NTs not received by another neuron are taken back up by the sending neuron.

Question 7

How do anti-depression drugs use reuptake?

Answer 7

Anti-depression drugs block reuptake from happening in order to raise serotonin levels.

Question 8

What is serotonin?

Answer 8

Neurotransmitter that affects mood, hunger, sleep, and arousal. An undersupply of serotonin can cause depression.

Question 9

What is dopamine?

Answer 9

Neurotransmitter that influences movement, learning, attention, and emotion. An oversupply can cause schizophrenia and an undersupply can cause Parkinson’s and ADHD.

Question 10

What is norepinephrine?

Answer 10

Neurotransmitter that helps control alertness and arousal.

Question 11

How do neurotransmitters activate receptors?

Answer 11

A neurotransmitter molecule has a molecular structure that precisely fits the receptor site, like a key.

Question 12

What is an agonist?

Answer 12

It fills the receptor site and activates it by acting like a neurotransmitter.

Ex. morphine mimics the action of endorphins to dull pain in traumatic situations.

Question 13

What is an antagonist?

Answer 13

It fills the “lock” so the neurotransmitter can’t get in and activate the receptor site (close enough to fit but not similar enough to activate).

Ex. antihistamine inhibits the actions of histamine.

Question 14

What is the central nervous system (CNS)?

Answer 14

The brain and spinal cord.

Question 15

What is the peripheral nervous system (PNS)?

Answer 15

The ‘rest’ of the nervous system - communicates information between the brain and the rest of the body.

Question 16

What are the different types of neurons?

Answer 16

Sensory neurons.
Motor neurons.
Interneurons.

Question 17

Define sensory neurons.

Answer 17

They carry in messages fro the body’s tissues and sensory receptors to the CNS for processing.

Question 18

Define motor neurons.

Answer 18

They carry instructions out from the CNS to the body’s tissues.

Question 19

Define interneurons.

Answer 19

They process information between sensory input and motor output.

Question 20

What are nerves?

Answer 20

Bundles of axons that perform the same action so are grouped together - “neurons that fire together wire together.”

They are part of the PNS and connect muscles, glands, and sense organs to the CNS.

Question 21

What two groups is the PNS divided into and what is the function of each group?

Answer 21

Autonomic - controls self-regulated action of internal organs and glands.

Somatic - controls voluntary movement of skeletal muscles.

Question 22

The autonomic system is further broken down into what two groups?

Answer 22

Sympathetic nervous system - arousing nervous system responsible for the fight of flight reflex. Only meant for short term use.

Parasympathetic nervous system - calms you down, responsible for rest and digestion.

Question 23

Notes about neurons and the body.

Answer 23

The brain is a web of neural networks that changes in response to experience. Complex webs of interconnected neurons form with experience - “neurons that fire together wire together.”

The spinal cord is full of interneurons that sometimes have a mind of their own - functions that happen without you having to think about it. - reflexes.

Ex. pulling your hand away from a hot surface before your brain processes that it’s hot.

Question 24

What is the endocrine system?

Answer 24

A set of glands that produce chemical messages called hormones that are sent throughout the body. These hormones are produced in various glands around the body.

Question 25

What are the adrenal glands?

Answer 25

Located near the kidneys, they produce hormones such as epinephrine, norepinephrine, and cortisol. The sympathetic nervous system tells it when to release these hormones. The effect is increased heart rate, increased blood pressure, and increased blood sugar to provide the energy for fight or flight.

Question 26

What is the pituitary gland?

Answer 26

The “master gland.”

It is controlled by the hypothalamus and produces growth hormones, especially during sleep, and oxytocin - the “bonding” hormone.

Question 27

What are the areas of the brain and what is the function of each?

Answer 27

Brainstem and cerebellum - coordinates the body, located in the middle of the brain - evolutionary oldest.

Limbic (border) system - manages emotions and connects thought to the body.

Cortex (outer covering) - integrates information. Most recent evolutionary development.

Question 28

What is located at the top of the spinal cord?

Answer 28

The brainstem, including the pons and medulla.

The pons helps coordinate automatic, unconscious movements. The medulla controls heartbeat, breathing, and other basic functions.

Question 29

What are the parts and functions of the brainstem?

Answer 29

Thalamus - “sensory switchboard.” Receives information from the senses and sends it to higher brain regions.

Reticular formation - enables alertness.

Cerebellum - “little brain.” Helps coordinate voluntary movement and has many other functions, including enabling nonverbal learning and memory.

Question 30

What are the parts and functions of the limbic system?

Answer 30

Hippocampus - processes conscious (verbal) memories and works with the amygdala to form emotionally charged memories.

Amygdala - processes emotions, especially rage and fear. It helps stamp in memories to save life in future.

Hypothalamus - regulates body temperature and enables adequate food and water intake (homeostasis) and is involved in the sex drive. It directs the endocrine system via messages to the pituitary gland. Also acts as the body’s reward center.

Question 31

What is the cerebral cortex?

Answer 31

Outer gray “bark” structure that is wrinkled in order to create more surface area for 20+ billion neurons. Inner white stuff - axons linking parts of the brain. 180+ billion glial cells, which feed and protect neurons and assist neural transmission with 300 billion synaptic connections.

Question 32

What are the four lobes of the cerebral cortex?

Answer 32

Frontal lobes (located directly behind forehead). Involved in speaking and muscle movements, making plans, and judgements.

Parietal lobes. Included the sensory cortex.

Occipital lobes (located at the back of the head). Included visual areas that receive visual information from the opposite visual field.

Temporal lobes (behind the ears). Included the auditory processing areas.

Question 33

Notes about memory and sensory strips.

Answer 33

Output: motor cortex - left hemisphere section controls the body’s right side.

Input: sensory cortex - left hemisphere receives input from the body’s right side.

Axons receive motor signals from the cortex and axons send sensory information to the cortex.

Question 34

How do neural prosthetics work?

Answer 34

A robotic arm is operated through controls embedded in the motor strip of the cortex.

Question 35

What is the function of the frontal lobes?

Answer 35

They are active in executive functions, such as judgment, planning, and inhibition of impulses.

Frontal lobes are also active in the use of working memory and the processing of new memories - hippocampus processes memories and sends to the cortex to store.

Question 36

Who was Phineas Gage?

Answer 36

A railroad worker who had a metal rod shot through his skull, destroying his eye and part of his frontal lobes. After healing he was able to function but his personality changed; he was rude, odd, irritable, and unpredictable.

Damage to the frontal lobes could result in loss of ability to suppress impulses and modulate emotions.

Question 37

Talk about brain plasticity.

Answer 37

If the brain is damaged the brain does not repair damaged neurons but it can restore some functions by forming new connections, reassigning existing networks, and inserting new neurons.

Ex. constraint induced therapy to get the “bad” side working again.

Question 38

What have split brain studies shown?

Answer 38

To end severe whole brain seizures, some people have had surgery to cut the corpus callosum, a band of axons connecting the hemispheres. Typically seizures end and people go back to functioning normally.

Question 39

What is the split visual field?

Answer 39

Each hemisphere does not perceive what each eye sees. Instead it perceives the half of the view in front of you that goes with the half of the body that is controlled by that hemisphere.

Question 40

Which half of the brain controls speech?

Answer 40

Only the left half of the body has enough verbal ability to express its thoughts out loud.

Question 41

What are some differences between the right and left half of the brain?

Answer 41

Left - logic and thoughts, details, language (words and definitions), calculation, pieces and details.

Right - feelings and intuitions, the “big picture,” language (tone, inflection, context), perception, wholes, including the self.

Right handed people are usually left brain dominant and more than half of left handed people are both brain dominant.