1.2 Concepts of Psychobiology

Question 1

Psychobiology

Answer 1

• Biological foundations of cognitive, emotional and behavioral processes
• Neuroscientific Revolution
• Biology causes behavior
• Mental illness is being considered a physical disorder

Question 2

Brain

Answer 2

Forebrain - Cerebrum and Diencephalon
Midbrain - Mesencephalon
Hindbrain - Pons, Medulla, Cerebellum

Question 3

Forebrain

Answer 3

Cerebrum - Largest part of the brain. Left and right hemisphere are separated by the corpus callosum.
(Surface of cerebrum consists of gray matter called the cerebral cortex - Considered the thinking structures of the brain)

Basal Ganglia - Other gray matter areas that control subconscious voluntary movement such as swinging arms while walking.

Question 4

Cerebral Cortex

Answer 4

Frontal Lobe - Controls voluntary movement and emotional experiences
Temporal Lobe - Auditory, smell and expression of emotion
Parietal Lobe - Sensory (touch, pain taste)
Occipital Lobe - Vision and interpretation

Question 5

Diencephalon

Answer 5

Connects cerebrum with lower brain
- Thalamus, Hypothalamus (Limbic System)

Thalamus - Integrates sensory input (except smell) to interpret the whole picture. Also blocks minor sensations

Hypothalamus - Regulates pituitary gland, visceral responses during emotional states, appetite, temperature, blood pressure, thirst, circadian rhythm

Limbic System - Associated with emotions (anxiety, anger, love, joy, hope, sexual and social behavior)

Question 6

Mesencephalon

Answer 6

• Located in midbrain responsible for integration of visual, auditory, and righting reflexes

Visual Reflexes - Turning away from dangerous objects in view
Auditory Reflexes - Turning towards sounds
Righting Reflex - Keeping head upright and maintaining balance

Question 7

Hind Brain

Answer 7

Pons - Relays messages between parts of nervous system. Controls respiration and skeletal muscle tone. Associated with sleep and dreaming (Brain Stem)

Medulla - Connects spinal cord and pons. Regulates HR, BP, RR. Controls reflexes (swallow, sneeze, cough, vomit)

Cerebellum - Controls involuntary movement such as muscular tone, coordination, posture, equilibrium.

Question 8

Neurons

Answer 8

• CNS nerve cells that generate and transmit electrochemical impulses.

Cell body - Contains nucleus
Dendrites - Transmits impulse towards cell body
Axons - Transmits impulse away from cell body

Question 9

Neuron Classes

Answer 9

Afferent - Interprets senses (transmits from receptor to CNS)
Efferent - Muscle response to senses (From CNS to Periphery)
Interneurons - 99% of nerve cells. Pathway between efferent and afferent neurons.

Synapse - Junction between 2 neurons.
Synaptic Cleft - Space between axon and dendrite of neurons

Neurotransmitters - Chemicals at axon terminal of neurons that are released by electrical impulses to the synaptic cleft. Neurotransmitters get sent to receptor sites of the next neuron and determines whether another impulse is generated.

Question 10

Autonomic Nervous System

Answer 10

Influenced heavily by emotion

Sympathetic - Dominant during stress and prepares body for fight-or-flight. Increases HR and RR. Blood is shunted from vital organs to muscles

Parasympathetic - Dominant during rest and relaxation. Results in decreased HR and increased metabolism (elimination functions)

Question 11

Neurotransmitter Categories

Answer 11

• Cholinergics
• Monoamines
• Amino Acids
• Neuropeptides

Question 12

Cholinergics

Answer 12

• Acetylcholine
• Significant in transmission that occurs between nerves and muscles

Function

• Sleep, arousal, pain, perception, coordination of movement, memory retention
• Involved in Parkinson’s and Alzheimer’s

Question 13

Monoamines

Answer 13

Norepinephrine - Results in fight-or-flight. Regulates mood, cognition, perception, cardiovascular function, sleep. Involved in mood disorders (depression, mania, anxiety, schizophrenia)

Dopamine - Regulates movement, coordination, emotion, voluntary decision making. Increased levels are associated with schizophrenia and mania

Serotonin - Plays a role in sleep, arousal, libido, appetite, mood, aggression, pain. Associated with schizophrenia, mania, mood disorders.

Histamine - Plays a role in medicating allergic and inflammatory reactions. Also associated with wakefulness and depressive illness.

Question 14

Neurotransmitters

Answer 14

Acetylcholine - Learning new information, contracting muscle fibers, memory.

Dopamine - Movement, attention (concentration), learning, and pleasure. Increases alertness and concentration, making you less sleepy and more alert. Low levels of dopamine are associated with depression and high levels associated with schizophrenia.

Serotonin - Regulates mood, sleep, appetite and aggression. Low levels are associated with depression/anxiety and elevated levels associated with better moods.

Norepinephrine - Eating, alertness, wakefulness. With dopamine, they play a large role in attention/focus

Endorphins - Released during exercise that reduce pain/stress during exercise and elevate mood.

GABA - Keeps you calm. Inhibitory effect that slows down neurotransmitters. Low levels cause depression/anxiety, YOGA can increase GABA levels or green tea.

Question 15

Neuroendocrinology

Answer 15

• Study of interaction between nervous and endocrine system

- Effects of hormones on cognitive, emotional and behavioral function

Question 16

Pituitary Gland

Answer 16

• Master gland that controls the endocrine system

Posterior Pituitary - ADH and Oxytocin

Anterior Pituitary - GH, TSH, Adrenocorticotropic Hormone, Prolactin, Gonadotropic Hormone, Melanocyte Stimulating Hormone.

Question 17

Antidiuretic Hormone

Answer 17

• Conserves body water
• Regulates BP
• Release is stimulated by pain, emotional stress, dehydration, increased plasma concentration, and decreased blood volume.
• Can be the cause of polydipsia (abnormal thirst) in mental illness patients (schizophrenia)

Question 18

Oxytocin

Answer 18

• Stimulates uterus contractions
• Stimulates milk ejection
• Released in response to stress and sexual arousal.

Question 19

Growth Hormone

Answer 19

• Responsible for growth in children and protein synthesis throughout life
• Deficiency in major depressive disorders
• Abnormalities noted in patients with anorexia nervosa

Question 20

Thyroid Stimulating Hormone

Answer 20

• Integral with metabolism of food and regulation of temperature
• Associated with mood disorders, anxiety, eating disorders, schizophrenia and dementia.

Question 21

Adrenocorticotropic Hormone

Answer 21

• Stimulates adrenal cortex to release cortisol

- Associated with mood disorders, PTSD, Alzheimer’s, substance abuse

Question 22

Prolactin

Answer 22

• Reproductive function and milk production

- High levels associated with depression, decreased libido, anxiety, irritability, negative symptoms of schizophrenia

Question 23

Gonadotropic Hormones

Answer 23

• Maturation of ovarian follicles and secretion of estrogen in women
• Initiates sperm production in men

Question 24

Melanocyte-Stimulating Hormone

Answer 24

• Stimulates pineal gland to secrete melatonin

- Melatonin disorder is the etiology of seasonal affective disorders.

Question 25

Circadian Rhythm

Answer 25

Affected by cycles of light and dark

• Sleep and Wake Cycle
• Body Temperature
• Patterns of activity
• Hormone Secretion

Question 26

Genetics

Answer 26

• Study of transmission of certain characteristics to offspring

Genotype - Total set of genes in an individual
Phenotypes - Physical manifestations of a genotype. Can be genetic or acquired.
(Eye color, height, blood type, hair color)

Psychiatric disorders are a combination of genetics and environment

Question 27

Twin Studies

Answer 27

• Appearance of a disorder in 2 genetically identical twins is strong evidence of genetic involvement

Question 28

Adoption Studies

Answer 28

• Shows influence of environment vs genetics in development of psychiatric disorders.

Question 29

Psychoneuroimmunology

Answer 29

Combines study of nervous, endocrine and immune systems.
Relationship between these systems

Nervous System - Anxiety, depression, insomnia
Endocrine System - Thyroid, adrenal, gonadal
Immune System - Inflammation, infection, allergies, pain

• Individuals are more susceptible to physical illness following stressful events
• Increased production of epinephrine and norepinephrine occur in response to stress and decreases immunity
• Onset of schizophrenia is related to abnormalities in the immune system

Question 30

Psychopharmacology

Answer 30

• Primary treatment for mental disorders

Psychotropic Drugs (Effect Synaptic Transmission)

• Reuptake inhibitor drugs block reuptake of neurotransmitters which elevates levels
• Inhibiting catabolic enzymes promotes buildup of neurotransmitters in synaptic sites
• Antagonist block neurotransmitter activity
• Agonist increase neurotransmitter activity

Question 31

DEFINITIONS

Answer 31

Neuroanatomy/Neurophysiology - Structures of the brain and their correlation to human behavior
Neuroendocrinology - Interaction of endocrine and nervous system and the role of the endocrine glands over their hormones
Psychoneuroimmunology - Influence of stress on the immune system and its role in susceptibility to illness.
Psychopharmacology - Increasing use of psychotropic drugs in treatment of mental illness
Neuronal Process - Function of nerve cells
Genetic Influences - Hereditary factors that predispose individuals to certain psychiatric disorders
Diagnostic Technology - Keeping informed about the latest technological procedures for diagnosing brain structure and functioning
Circadian Rhythm - Regulation of biochemical function over periods of rhythmic cycles and their influence in predicting certain behaviors