Neuroanatomy and Endocrinology Notes

Malignant Hypertension and Atherosclerosis

• Malignant hypertension is characterized by hard exudates and disc swelling.
• Atherosclerosis and embolism are also mentioned.

Cardiovascular System

• The cardiovascular system (CVS) is the transport system, responsible for the circulation of blood around the body.
• Components:
  • Cardiac pump (heart)
  • Vascular tubes
  • Blood

Vascular Tubes

• Types:
  • Arteries
  • Arterioles
  • Capillaries
  • Venules
  • Veins
• Circulation:
  • Pulmonary circulation
  • Systemic circulation

Structure of Blood Vessels

• Arteries:
  • Thick walls with endothelium, lumen, elastic, and collagen fibers.
• Veins:
  • Thinner walls compared to arteries, with endothelium, lumen, elastic, and collagen fibers.
• Capillaries:
  • Very thin endothelium (one cell thick).

Blood Flow

• Deoxygenated blood flows from the body via the venae cavae to the right atrium (RA) of the heart.
• Blood flows from the RA to the right ventricle (RV), then to the lungs via the pulmonary artery.
• In the lungs, blood is oxygenated and returns to the left atrium (LA) via the pulmonary vein.
• Blood flows from the LA to the left ventricle (LV), and then is pumped out to the body via the dorsal aorta.
• The liver receives blood via the hepatic portal vein from the gut.

Functions of the Cardiovascular System

• Links the external environment to tissues.
• Distributes essential metabolites:
  • Oxygen (O2) from lungs
  • Nutrients from the gut
• Removes products of metabolism:
  • Carbon dioxide (CO2) from tissues
  • By-products to lungs, kidney, liver
• Circulates hormones of the endocrine system.
• Distributes heat to maintain body temperature.
• Transports blood coagulation factors.
• Transports cells and antibodies for defense.
• Other homeostatic functions.

Heart Wall Structure

• Three layers:
  • Endocardium: thin layer of endothelium
  • Myocardium: cardiac muscle
    • Branching muscle cells with intercalating discs forming a syncytium (acts as one unit)
    • Continuous cycle of contraction/relaxation
  • Epicardium: thin external membrane

Heart Function

• Left and right sides function as two separate pumps.
• Four chambers:
  • Atria (receive blood returning to the heart)
  • Ventricles (pump blood out of the heart)
• Unidirectional blood flow:
  • Veins -> atria -> ventricles -> arteries
  • Ensured by four 1-way valves

Blood Flow Through the Heart

• One circuit of CVS involves blood passing through the heart twice.
• Begins in the right-hand side (RHS).

Cardiac Cycle

• Valves:
  • Blood enters both atria; atria contract.
  • Ventricles fill: atrioventricular (AV) valves open, semilunar (SL) valves shut.
  • Ventricles contract: AV valves shut, semilunar (SL) valves open.
• Consists of:
  • Diastole: relaxation and filling
  • Systole: contraction and pumping
• The heart begins its cycle in diastole.

Heart Valves

• Present in high-pressure areas.
• Prevent backflow.
• Mitral valve (left side)
• Tricuspid valve (right side)
• Tendinous cords and papillary muscles support the valves.

Blood Vessels

• Arteries: carry oxygenated blood from the heart.
• Veins: carry deoxygenated blood to the heart.
• Capillaries.

Vessel Structure

• Three layers:
  • Tunica intima (inner): endothelial surface
  • Tunica media (middle): smooth muscle/elastic tissue
  • Tunica adventitia (outer): connective tissue

Blood Flow Velocity

• Dependent on diameter.
• Aorta, arteries, arterioles, capillaries, venules, veins, vena cava.
• The total cross-sectional area and velocity of blood flow are related.

Respiratory System

• Ensures that metabolic demands of the body are met by supplying O2 and removing CO2.
• Comprised of lungs and pulmonary circulation.

Functions of Respiratory System

• Air distributor.
• Gas exchanger.
• Filters, warms, and humidifies air.
• Influences sound production.
• Regulation of pH in the body.

Respiratory Processes

• Air entrance via nose/mouth and journey to the lungs.
• Lung mechanics.
• Pulmonary ventilation and gas transfer.
• Blood gas transport: O2 and CO2.
• Regulation of respiration.

Passage of Air to the Lungs

• Trachea: first open passageway (cartilaginous).
• Bronchus: 1°, 2°, 3°.
• Bronchioles.
• Alveoli:
  • 300 million alveoli in 2 lungs.
  • Single-cell layer: simple squamous epithelium.
• Air is filtered, warmed, and moistened.
• Ciliated mucous membranes protect.

Lung Mechanics: Ventilation

• Thoracic cavity brings about changes in lung volume.
• Inspiration and Expiration.
• Key structures: nasal cavity, epiglottis, glottis, larynx, trachea, lungs, ribs, intercostal muscles, pleural cavity, heart, bronchus, bronchioles, diaphragm, abdominal cavity, pleural membranes, thorax.

Inspiration

• Chest cavity expands.
• Lung volume increases.
• Alveoli pressure decreases.
• Air moves in.
• Muscles involved: diaphragm, external intercostal muscles, sternocleidomastoid, and pectoralis minor muscles.

Expiration

• Thorax cavity decreases.
• Lung volume decreases.
• Pressure in alveoli increases.
• Air moves out.
• External intercostal muscles relax.

Gaseous Exchange

• Alveoli: primary structure for gas exchange.
• Occurs between alveolar air and capillary blood.
• Large surface area (SA).
• Two-way exchange across the respiratory membrane:
  • O2 out of alveoli.
  • CO2 into alveoli.

Pressure Gradients

• Gaseous exchange is driven by pressure gradients.
• Partial pressures of O2 (PO2) and CO2 (PCO2) in alveoli and capillaries facilitate exchange.

Transport of Gases in Blood

• Hemoglobin.
• O2 binds to the Fe of the heme group.
• CO2 binds to amine groups of amino acids of pps.

Transport of O2

• Increasing PO2:
  • $Hb + O<em>2 \rightarrow HbO</em>2$ (oxyhemoglobin) (97%)
  • O2 dissolved in plasma (3%)
  • O2 from lungs diffuses into blood.

O2 Dissociation Curve

• Illustrates the relationship between the partial pressure of oxygen and the saturation of hemoglobin.

Transport of CO2

• Three main methods:
  1. Dissolved CO2:
     • 7% of total
     • Dissolved in plasma
  2. Carbaminohemoglobin:
     • 23%
     • Binds protein portion of Hb

Dissociation of CO2

• Increasing PCO2 accelerates association.
• Decreasing PCO2 slows association.

Bicarbonate Ions

• 70% of CO2 is transported as bicarbonate ions.
• Reaction catalyzed by carbonic anhydrase in red blood cells:
  $CO<em>2 + H</em>2O \rightleftharpoons H<em>2CO</em>3 \rightleftharpoons H^+ + HCO_3^-$
• Bicarbonate ions diffuse into plasma.

Summary of Gas Exchange

• O2 moves from alveoli to pulmonary capillaries and then to systemic capillaries.
• CO2 moves from systemic capillaries to pulmonary capillaries and then to alveoli.

Endocrine System

• Endocrine glands (ductless) secrete hormones into the blood.
• Hormones are transferred with blood to all other cells of the body.
• Specific cells of the body respond to specific hormones.

Hormones

• Hormones travel in the blood to their distant target cells, where they regulate or direct a particular function.
• The same chemical messengers may be either a hormone or a neurotransmitter, depending on its source and mode of delivery to target cells.
  • Example: norepinephrine (=noradrenaline).
    • Released as a neurotransmitter by nerve fibers into synaptic clefts, binding to -adrenergic receptors
    • Released as a hormone by the adrenal medulla.

Tropic and Non-Tropic Hormones

• Tropic hormone: A hormone that has as its primary function the regulation of hormone secretion by another endocrine gland.
  • Example:
    • Thyrotropin-releasing hormone (TRH) stimulates the release of TSH from the anterior pituitary.
    • Thyroid stimulating hormone (TSH) from the anterior pituitary stimulates thyroid hormone secretion by the thyroid gland.
• Non-tropic hormone: A hormone that primarily exerts its effects on non-endocrine target tissue.
  • Example: thyroid hormone, which increases the rate of oxygen consumption and metabolic activity of almost all cells.
• T3: triiodothyronine
• T4: thyroxine

Hormone Classes

• Three distinct classes according to their biochemical structure:
  1. Peptides (specific amino acids arranged in a chain of varying length); hydrophilic
  2. Amines (derived from the amino acid, tyrosine)
  3. Steroids (neutral lipids derived from cholesterol); hydrophobic
• Hormone Transport:
  • Hydrophilic peptide hormones are transported simply dissolved in the plasma.
  • Hydrophobic steroid hormones circulate in the blood to their target cells reversibly bound to plasma proteins.

Examples of Hormone Structures

• Protein and Peptide Hormones: Insulin, Growth hormone, Endothelin.
• Steroid Hormones: Derived from Cholesterol, including Glucocorticoids, Mineralocorticoids, Androgens, Estrogens, Progestogens, Vitamin D.
• Tyrosine Derivatives: Examples include Thyroxine and Epinephrine (adrenalin).

Hormone Action on Target Cells

• Hydrophilic hormones cannot pass through lipid membrane barriers.
  • They bind to specific receptors on the outer plasma membrane surface of the target cells.
• Hydrophobic hormones easily pass through the surface membrane.
  • They bind with specific receptors located inside the target cell.
• Target cell response differs for different hormones and between different target cells that respond to the same hormone.

Hydrophilic Hormone Action

• Examples: growth hormone or TRH
• Bind to receptors on the cell surface.
• Activated receptors initiate a signaling cascade leading to regulation of enzyme activity or affecting ion channels.

Effector Enzyme Example: Adenylate Cyclase & Epinephrine

• Epinephrine (adrenalin) binding in the liver stimulates the synthesis of the second messenger cAMP.
• Cyclic AMP binds to and activates protein kinase A (PKA).
• PKA phosphorylates and activates phosphorylase, which converts glycogen into glucose-6-P.
• Glucose-6-P is converted to glucose and released to the blood.

Hydrophobic Hormone Action

• Examples: corticosteroids, vitamin D, thyroxine.
• Hydrophobic hormones function by binding and activating specific receptors inside the target cells.
• Activated receptors regulate gene expression to form new intracellular proteins, producing the desired effect.

Paracrine and Autocrine Effects

• Once in circulation, hormones affect the function of the target tissue.
• Some hormones exert an effect on cells of the organ from which they were released (paracrine effect).
• Some hormones exert effects on the same cell type (autocrine effect).

Endocrine System Functions

• Coordinates functioning between different organs through hormones.
• Controls activities that require duration rather than speed:
  • Regulates metabolism, water, and electrolyte balance (homeostasis).
  • Induces adaptive changes during stressful situations.
  • Promotes smooth, sequential growth and development.
  • Regulates red blood cell production.
  • Controls and integrates both circulation and digestion/absorption of food (along with the autonomic nervous system).

Major Endocrine Glands

• Hypothalamus, Pineal gland, Pituitary gland, Parathyroid glands, Thyroid gland, Pancreas, Adrenal glands, Ovaries, Testes.

Hypothalamus

• Size of a pearl.
• Directs many important functions:
  • Control center for autonomic functions of the peripheral nervous system.
  • Influences emotional responses as part of the limbic system.
  • Maintains homeostasis through connections with the endocrine and nervous systems.
• Considered the real “master gland”.

Hypothalamus Hormone Production

• Neurosecretory neuronal cell bodies in hypothalamus produce hormones vasopressin and oxytocin.
• Neuronal terminals in the posterior pituitary release vasopressin and oxytocin into systemic blood when neurons are excited.
  • Vasopressin receptors in arterioles cause vasoconstriction.
  • Vasopressin receptors in nephrons cause conservation of water during urine formation.

Hypothalamus Control of Pituitary

• Blood vessel connections between the hypothalamus and pituitary gland allow hypothalamic hormones to control pituitary hormone secretion:
  • Corticotropin-releasing hormone (CRH)
  • Thyrotropin-releasing hormone (TRH)
  • Gonadotropin-releasing hormone (GnRH)
  • Growth hormone-releasing hormone (GHRH)
  • Growth hormone-inhibiting hormone (GHIH, somatostatin)
  • Prolactin-inhibiting hormone (PIH, dopamine)

Pituitary Gland

• Located at the base of the brain.
• Secretes the largest number of different hormones with the widest range of effects.
• Divided into two parts: anterior lobe and posterior lobe.

Anterior Pituitary

• The anterior pituitary responds to chemical messages from the bloodstream to produce numerous hormones.
• Secretes:
  • Growth hormone (GH, somatotropin)
  • Thyroid-stimulating hormone (TSH)
  • Adrenocorticotropic hormone (ACTH)
  • Follicle-stimulating hormone (FSH)
  • Luteinizing hormone (LH)
  • Prolactin (PRL)
• Controls the activity of many other endocrine glands (thyroid, ovaries, adrenal, etc.).

Posterior Pituitary

• Controlled by the nervous system.
• Secretes two hormones produced by the hypothalamus:
  • Vasopressin: causes blood pressure to rise; regulates water amount in the blood, cells, and ECM.
  • Oxytocin: causes the uterus to contract during childbirth and initiates lactation; released during orgasm in both sexes.

Pineal Gland

• Pine cone-shaped gland.
• Produces and secretes several important hormones including melatonin.
• Melatonin: natural sleep-inducing agent.
  • Helps keep circadian rhythms in synchrony with the light-dark cycle.
  • Daylight reduces melatonin production (photoentrainment); blood levels are high at night and low during the day.

Melanopsin and Light Sensitivity

• Melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) innervate the hypothalamic suprachiasmatic nucleus (SCN).
• SCN relays the message to the pineal gland → suppression of melatonin release.
• Exposure of the retina to light (particularly blue light) suppresses melatonin secretion by the pineal gland.

Melanopsin Characteristics

• Pigment consisting of opsin and 11-cis-retinal.
• Shares more homology with invertebrate rhabdomeric opsins (r-opsins) than with ciliary opsins of vertebrate species (c-opsins).
• Typical structure for G-protein coupled receptor (GPCR).
• Expressed in intrinsically photosensitive retinal ganglion cells (ipRGCs) which account for ~0.2% of all RGCs in humans.

ipRGCs Photosensitivity

• Photosensitivity maximum of ipRGCs at ~480 nm.
• Generation of action potential with a maximal frequency of 40/s about 3 s after a flash of light.

Retinohypothalamic Tract and SCN

• Axons of the ipRGCs belonging to the retinohypothalamic tract project directly to the suprachiasmatic nuclei (SCN) in the hypothalamus via the optic nerve and the optic chiasm.
• Photoentrainment: the SCN receives and interprets information on environmental light, dark, and day length.
• SCN regulates melatonin secretion by the pineal gland (P) through its sympathetic innervation.
• SCN is a master circadian pacemaker.
• Synthesis of the “sleep” hormone, melatonin.

Circadian Rhythms Generation in SCN

• Circadian rhythms are generated in the suprachiasmatic nucleus (SCN) of the hypothalamus.
• 2017 Nobel Prize in Physiology or Medicine awarded to Jeffrey C. Hall, Michael Rosbash, and Michael W. Young
  • “for their discoveries of molecular mechanisms controlling the circadian rhythm”

Circadian Rhythm Disruption

• Affects multiple organs and contributes to many diseases.
• Causes: shift-work, lifestyle, lack of photoentrainment, genetics.
• Effects: impaired memory, irritability, anxiety, mood disorders, dementia.

Light Therapy

• Light source emitting blue light: LED-based light or fluorescent light.
• Indoor lighting provides much less light than sunlight.
  • Seasonal affective disorder (SAD, winter depression).

Thyroid and Parathyroid Glands

• Thyroid Gland: Located in the front of the neck. Secretes thyroid hormone, thyroxine, which regulates overall body metabolism.
  • Thyroxine imbalances can lead to irritability (overactive) or drowsiness (under-active).
• Parathyroid Glands: Four tiny pea-shaped glands located behind the thyroid. Secrete parathyroid hormone, parathormone, which controls calcium and phosphate levels in the blood and tissue fluids.
  • Affects the excitability of the nervous system.

Adrenal Glands

• Small, triangular-shaped endocrine glands located on top of each kidney.
• Functions:
  • Maintain salt levels in the blood.
  • Maintain blood pressure
  • Help control kidney function
  • Control overall fluid concentrations in the body.
• Each has two parts: an outer adrenal cortex and an inner adrenal medulla.

Adrenal Gland Sections

• The cortex and medulla of the adrenal gland secrete different hormones.
• Adrenal cortex is essential to life, but the medulla may be removed without life-threatening effects.
• Both the cortex and medulla influence the body's responses to stress.

Adrenal Cortex Hormones

• The adrenal cortex consists of three different regions, each producing a different group or type of hormones.
• All cortical hormones are synthesized from cholesterol and are considered steroids:
  • Mineralocorticoids:
    • Secreted by the outermost region; principle one is aldosterone
    • Acts to conserve sodium ions and water in the body.
  • Glucocorticoids:
    • Secreted by the middle region; principle one is cortisol
    • Increases blood glucose levels.
  • Gonadocorticoids (sex hormones):
    • Secreted by the innermost region; androgens and estrogens
    • Secreted in minimal amounts in both sexes, but their effect is usually masked by the hormones from the testes and ovaries.

Adrenal Medulla Hormones

• Develops from neural tissue.
• Synthesizes from tyrosine and secretes two hormones: epinephrine (adrenaline) and norepinephrine (noradrenaline).
• These two hormones (catecholamines) are secreted in response to sympathetic nerves, particularly during stressful situations.
• Receptors for catecholamines are widely distributed throughout the body.
• Effects include:
  • Increased heart rate and blood pressure.
  • Blood vessel constriction in the skin and gastrointestinal tract.
  • Bronchiole dilation.
  • Increased metabolism, characteristic of the fight-or-flight response.
• A lack of hormones from the adrenal medulla produces no life-threatening effects.
• Hypersecretion, usually from a tumor, causes prolonged or continual sympathetic responses.

Pancreas

• Located deep in the abdomen behind the stomach; primarily a digestive organ.
• Contains extremely important endocrine cells which secrete insulin, glucagon, somatostatin, and others.
  • Control blood sugar and overall glucose metabolism and help control other endocrine cells of the digestive tract.

Pancreas Cell Types

• Small groups of cells in the pancreas that function as an endocrine gland: the islets of Langerhans.
  • The α (or A) cells secrete the hormone glucagon.
  • The β (or B) cells secrete insulin.
  • The δ (or D) cells secrete somatostatin.
  • The pancreatic polypeptide (PP) cells secrete pancreatic polypeptide.

Human Endocrine System: Other Glands and Organs

• Illustrations showing various glands, tissues, and organs with endocrine functions, including the pituitary, pineal, thyroid, parathyroid, thymus, heart, liver, stomach, adrenal gland, pancreas, duodenum, kidney, adipose tissue, skin, ovaries (female), placenta (pregnant female), and testes (male).

Regulation of Hormone Secretion

• Direct Feedback: Pancreatic beta cells respond to increased blood glucose by secreting insulin.
  • Insulin increases cellular uptake of glucose, decreasing blood glucose levels.
  • This is a negative feedback loop.

Negative Feedback Loop: Hypothalamus-Pituitary-Thyroid Axis

• Hypothalamus releases TRH, which stimulates the pituitary to release TSH.
• TSH stimulates the thyroid to release thyroxine.
• Thyroxine exerts negative feedback on both the hypothalamus and pituitary to regulate hormone release.

Circadian Rhythms: Synchronization and Entrainment

• Pathway:
  • Light stimulates melanopsin-containing retina ganglion cells, which remove inhibition from the Suprachiasmatic nucleus (SCN).
  • SCN then affects the pineal gland.
  • The melatonin produced is cyclical
• This whole cycle resets circadian rhythms to match the light-dark cycle in effector organs throughout the body.

Positive and Negative Feedback: Female Reproductive System

• Positive Feedback:
  • Increased estrogen production from the Graafian follicle will stimulate a LH surge.
• Negative Feedback:
  • Inhibin from the ovary regulates FSH release.
  • Progesterone from the corpus luteum regulates the tonic release of LH.
• Hormones involved:
  • GnRH, FSH, LH, estrogen, progesterone, inhibin.

Endocrine System Complexity

• A single endocrine gland may produce multiple hormones with different control mechanisms and different functions (e.g., the anterior pituitary gland releases six different types of hormones).
• A single hormone may be secreted by different endocrine glands (e.g., somatostatin is produced by the hypothalamus and pancreas).
• A single hormone may have more than one type of target cell and therefore can induce more than one type of effect (e.g., vasopressin promotes water reabsorption by kidneys and vasoconstriction of arterioles).
• A single target cell may be influenced by more than one hormone.
• Cells may contain an array of different receptors for responding in different ways to different hormones.

Additional Resources

• Robert Sapolsky's lectures on neurology and endocrinology at Stanford University (YouTube).
• Relevant for understanding the major principles and complexities in neuronal and hormonal signaling (including neural circuits in the retina).

Cognitive Differences in Optometry and Vision Science Patients

• Differences in people with cognitive issues.
• Presented by Dr. Ben Mead (MeadB@cardiff.ac.uk).

Aims of the Session

• Understand individual differences in humans, including intellect, personality, emotions, and mental illness.
• Appreciate how these differences manifest in patients.
• Begin to understand how these differences may affect your clinical approach.

Personality

• Who we are.
• How we project ourselves to the world.
• The set of characteristics that underlie our behavior patterns and intrapersonal communication.

Personality Types

• Originally devised to explain illness-prone personalities (e.g., Type A prone to CHD, Type C prone to cancer).
• Link to illness not fully supported; personality type model may be too simplistic.
• Types:
  • Type A: Competitive, restless, highly strung
  • Type B: Relaxed, tolerant, passive
  • Type C: Stoic, passive, and unassertive
  • Type D: Negative, socially inhibited

Jung’s Psychological Types

• A psychoanalytic approach to personality developed by Carl Jung.
• Attitudes:
  • Introversion and extraversion
• Functions:
  • Sensation and intuition (irrational functions)
  • Thinking and feeling (rational functions)

Myers-Briggs Type Indicator

• Divides people into categories along four dimensions:
  • Extraversion-Introversion
  • Sensing-Intuition
  • Thinking-Feeling
  • Judgment-Perception

Five-Factor Model

• ‘Big Five’ personality factors:
  • Openness to experience
  • Conscientiousness
  • Extraversion
  • Agreeableness
  • Neuroticism

Exploring the Five Factors

• Health behavior:
  • Conscientiousness: associated with health-protective behavior
  • Neuroticism: associated with health-risk behavior

Intelligence

• Terms associated: Moron, Retard, Idiot, Imbecile, Genius, Gifted, Brainy, Clever

What is Intelligence?

• Learning: The acquisition of knowledge and skills through experience.
• Intelligence: The ability to acquire knowledge and skills through experience.

General Intelligence

• Strong cognitive abilities in one area are correlated with strong cognitive abilities in other areas
• General intelligence, g:
  • A measure of the underlying cognitive abilities that influence mental performance.

Measuring Human Intelligence

• In 1904, Alfred Binet was asked to develop a method for identifying struggling students.
• Developed the Binet-Simon test with Théodore Simon.
• Based around the concept of mental age:
  • A measure of cognitive development relative to others of the same age.

Intelligence Quotient (IQ)

• Formal measure of intelligence relative to age.
• Adapted by William Stern in 1912 and Lewis Terman in 1916.
  • $IQ = \frac{Mental Age}{Chronological Age} \times 100$
• Interpretations:
  • IQ < 100: Mental age below chronological age
  • IQ = 100: Mental age same as chronological age
  • IQ > 100: Mental age above chronological age

Intelligence and Life Expectancy

• Meta-analysis shows a correlation between intelligence and life expectancy.
• 1 SD increase of IQ corresponds to a hazard ratio of approximately 0.8.

Learning Disabilities

• IQ used to be solely used for classifying learning disabilities, now a range of other factors are taken into acount.
• Former/Equivalent Terms:
  • 0-25: Idiot/Severe learning disability
  • 25-50: Imbecile/Moderate learning disability
  • 50-70: Moron/Feeble-minded/Mild learning disability
  • 70+: Normal

Multiple Intelligences

• Argument that intelligence is not a general ability, but a number of specific ones.
• Multiple intelligence theories include:
  • Sternberg’s Triarchic theory
  • Gardner’s Eight Frames of Mind

Sternberg’s Triarchic Theory

• Standard IQ tests focus on analytical intelligence.
• Triarchic theory also includes:
  • Creative intelligence
  • Practical intelligence

Gardner’s Eight Frames of Mind

• Linguistic/verbal
• Logico-mathematical
• Spatial
• Bodily-kinaesthetic
• Musical
• Interpersonal
• Intrapersonal
• Naturalist

Changes in Intelligence in Middle Adulthood

• Fluid intelligence (relating visual stimuli, analysis speed, working memory capacity):
  • Declines, beginning in early adulthood.
• Crystallized intelligence (knowledge and experience, judgment ability, verbal and social skills):
  • Increases, peaking during middle adulthood.

Emotion

• Emotion – The internal feeling (sadness, happiness).
• Emotional expression – the outward physiological expression of the feeling (crying, smiling).

Introduction - Emotion

• Affective neuroscience - The study of mood and emotion.
• Emotions more challenging to study than sensory/motor systems.
• Brain mechanisms of emotion derived from animal models, human studies, and brain lesions
• Love, hate, disgust, joy, fear, anger

Theories of Emotion

• The Cannon–Bard theory
  • Emotions occur independent of emotional expression—no correlation with physiological state (1920s)
  • “I feel afraid, so my heart pounds.” or “I’m sad which makes me cry”
  • Based on sensory input reaching the thalamus as well as cortical input
• The James–Lange theory
  • Emotion experienced in response to physiological changes in body (late 1800s)
  • “My heart is pounding, so I must be afraid” or crying makes us sad
  • Removing the physical change will also remove the emotion which is the basis for meditation