Test 3 Flashcards
Hoagland’s Hypothesis
Theory proposing that biological clock mediates metabolic rate, and in turn, affects protensity
Protensity
Subjective experience of time as distinguished from clock or physical time
Circadian rythm
Rhythm or pattern of activity that lasts about a day
Biological clock
brain structure or mechanism mediating circadian rhythms and consequently protensity
Zeitgeber
Exogenous stimulus that synchronizes (sets) biological clock such as temperature, meals, noise. #1 is light exposure to the eyes
Retinohypothalamic tract
Branch of optic nerve that projects to the SCN composed of melanopsin
Melanopsin
Light sensitive ganglion cells containing photopigment
Superchiasmatic nucleus (SCN)
Hypothalamic cell group that mediates several visceral functions entrained to the day-night cycle (sleep and body temp)
Ventrolateral Preoptic Nucleus (VLPO)
Cell group in anterior hypothalamus mediating sleep onset, mostly GABA. If you stimulate it you sleep. If you lesion it you get insomnia, come, death.
Orexin
Stimulates arousal system
Polysomnograph (PSG)
multiple, coincident polygram measures to provide a comprehensive assessment of sleep
Electroencephalogram (EEG)
Record of voltage between two electrodes applied to the scalp representing the activity of many neurons over time
Electromyogram (EMG)
Record of gross motor unit potentials
Electrooculogram (EOG)
Record of gross motor unit potentials from extra ocular muscles
Beta Activity
15-60 Hz, 30 uV
Alpha activity
8-12 Hz, 30-80 uV
Theta activity
4-8 Hz, 30-80 uV
Delta activity
.5-4 Hz, 100-200 uV
Sleep spindles
Burst of activity, 10-15 Hz, 50-150 uV
Byproduct of sleep onset
sleep spindles and k complexes
Awake and alert
beta activity
awake and relaxed
alpha activity
stage 1 sleep
theta activity
stage 2 sleep
theta, sleep spindles, k-complexes
Stage 3/4 sleep
theta activity, delta activity; slow wave sleep
REM Sleep
theta activity, beta activity, paradoxical sleep, EOG
REM rebound
Increase in the proportion of time spent in REM sleep in an individual deprived of REM
Fatal Familial insomnia
Inherited prion disease characterized by progressive and ferocious insomnia (leading to hallucinations, dementia, motor deficits (ataxia), sympathetic overdrive (tachycardia), and ultimately death)
Stress
negative experience accompanies by characteristic emotional, behavioral, biochemical, and physiological reactions
SAM (sympathy-adrenomedullary) axis
initiated by locus coeruleus, release of norepinephrine, activates sympathetic nervous system which released epinephrine via adrenal glands
HPA axis
Hypothalamus, pituitary gland, and adrenal gland
Hypothalamus
Paraventricular nucleus (mediated flight or fight response), releases corticotropin-releasing hormone (CRH) which travels via blood supply to pituitary
Pituitary gland
master gland that regulates activity of other glands, CRH stimulates release of adrenocorticotropic hormone (ACTH) from anterior pituitary, travels via blood to adrenal gland
Adrenal gland
glands located atop kidneys that secrete steroids and NTs, ACTH stimulates synthesis and release of glucocorticoid from adrenal cortex (eg Cortisol)
Glucocorticoids
Steroid hormones that support or govern manifold metabolic, cardiovascular, and immunologic functions. Role in stress: increase the production and availability of blood glucose
Addison’s Disease
Endocrine disorder caused by insufficient concentrations of steroid hormones; low blood pressure and hyper pigmentation
Cushing’s Syndrome
Endocrine disorder caused by excessive concentrations of glucocorticoids, hallmark feature is hump on back, caused by steroid medications or adrenal tumor
Feedback loop
distal signal sent back (looped) to control mechanism (to increase/decrease output)
Habituation
Decrease in the response of the nervous system to a repeated stimulus, such as a chronic stressor; chronic stress in SAM axis causes decrease in release of norepinephrine
Sensitization
Enhanced response when a chronically stressed individual is presented with a novel stressor, chronic stress in SAM axis causes greater than normal release of norepinephrine
Dexamethasone challenge
A test that assesses the ability of the HPA axis to regulate glucocorticoid release; decreases cortisol in normal person but increases cortisol in people with impaired HPA axis
Dexamethasone
synthetic glucocorticoid
Hippocampal atrophy
Glutamate excitotoxicity (too many EPSPs, neurons die); loss of hippocampal CRH inhibition = elevated cortisol
Immunosuppression
Can be cased by chronic stress
Psychoneuroimmunology (PNI)
Branch of neuroscience investigating interactions among environmental stimuli, the nervous system, and the immune system
Pathogen
microorganism that can cause disease
Glycoprotein
molecules composed of proteins and carbohydrates that play a role in cell to cell interactions (at cell membrane)
H1N1
Designates two glycoproteins - hemaglutin (h) and neuraminidase (n) expressed by swine virions
Immune system
a diffuse network of interacting cells, cell products, and organs that protect the body from pathogens
Cytokines
proteins and glycoproteins released by certain WBCs (white blood cells) when they are activated or detect an invading pathogen that orchestrate pleiotropic affects
Innate immune system
immune components, such as skin, phagocytotic WBCs, and cytokines that exist prior to pathogen invasion; trigger inflammation to limit damage
Macrophage
WBC; phagocytotic cell activated by chemicals released from foreign microorganisms and by cytokines; engulf pathogen and attack constituent proteins then burp up remnants to alert others; also release cytokines
Neutrophil
phagocytotic white blood cell recruited by inflammation to destroy invader via enzymes, most prevalent WBC, commit cellular suicide (apoptosis = puss)
Natural Killer (NK) cells
WBC designed to destroy invading cells, including tumor cells, parasites, fungi, bacteria, and virus infected cells; two killing mechanisms - trigger apoptosis in infected cells and perforin
Perforin
Cytolytic protein that forms a pore in cell membrane to inject enzymes
Acquired immune system
immune cells that, upon exposure to pathogens, develop a selective immunity that results in faster response should the same pathogen invade again
B cells
cells that produce and release antibodies that originate in bone marrow before migrating to immune tissues
antibody
protein molecules produced by b-cells and circulate through blood after an invasion searching for foreign substances
antigen
surface glycoprotein on pathogens that bind to antibody
T-cells
WBCs that mature in the thymus and have surface bound receptors that recognize foreign particles, recognize only one type of antigen-bound fragments
T-cytotoxis (Tc) cells
CD8 glycoprotein; proliferate, release cytokines and differentiate
T Helper (Th) cells
CD4 glycoprotein, release cytokines to activate or enhance action of macrophages, B-cellsm and Tc cells. “stop war”
autonomic nervous system
hypothalamus (stimulation augments some immune responses) and enervates immune organs, which contain NT receptors; NE and DA, nerve terminals contact lymphocytes
Endocrine system
HPA axis (B): glucocorticoid receptors on WBCs down regulate cytokine synthesis, stress hormones are immunosuppressive (anti-inflammatory); HPG axis: sex hormone receptors on WBCs, estrogen and progesterone decrease pro inflammatory cytokines and increase anti-inflammatory cytokines
TNF alpha
pro-inflammatory cytokines
IL-10
anti-inflammatory cytokines
Nucleus Tractus Solitarius
how cytokines signal hippocampus and hypothalamus since they can’t cross BBB
Sickness behavior
Behavioral changes that develop in individuals during course of infection (weakness, anorexia, social withdrawal, poor concentration, hypersomnia) adaptive function to maintain health
Anorexia
Decreased motivation to eat, which decreases iron levels in blood and presents bacteria from replicating
Heart disease
umbrella term for a variety of conditions that affect the heart muscles, leading cause of death
Coronary heart disease (CHD)
Blockage of the arteries on the surface on the heart that supply blood and oxygen to the heart; underlying cause is atherosclerosis
Atherosclerosis
Condition characterized by the build up of plaque along the inner walls of arteries
Positive remodeling
Most dangerous, typically unstable since it breaks off and causes ruptures
Negative remodeling
Stable
Plaque
Mound of lipid material covered with fibrous connective tissue embedded in artery wall; begins in childhood; narrows the lumen, restricting blood flow
Lipoproteins
blood stream compounds containing a core of lipids in a shell of protein, phospholipid, and cholesterol
High Density Lipoprotein (HDL)
helps remove cholesterol from cells, and in turn, excretion from body
Low density lipoprotein (LDL)
carries cholesterol to cells, starts atherogenesis
Vasoconstriction
Decrease in nitric oxide
Lipid Peroxidation
oxidative deterioration of lipids when free radicals steal electrons from (cell membrane) lipids
C reactive proteins
liver protein synthesized in response to inflammation
Foam cell
macrophages laden with lipids
Atheroma
raised plaques under endothelium
Ischemia
Restriction in blood supply; heart gets and receives less blood than it needs
Angina
Chest pain in area of heart
Embolism
Obstruction of blood flow due to an object (embolus) occluding blood flow (unstable plaque)
Thrombosis
Instruction of blood flow due to a clot (thrombone)
Myocardial Infraction
irreversible necrosis of heart muscle due to reduction to blood flow (oxygen); heart attack
Lazarus syndrom
delayed return of spontaneous circulation after cessation of cardio pulmonary resuscitation
Framingham Heart Study
Longitudinal study of launched in 1948 to investigate the causal factors of heart disease in the general population
Unmodifiable risk factors
age, sex, race, family
Modifiable risk factors
Serum cholesterol, serum c-reactive protein, diet, bad habits
Metabolic syndromes
Cluster of risk factors the increase risk for coronary heart disease and other health problems such as CVA (stroke) characterized by 5 comorbid factors
Hypertension
Elevated blood pressure (commonly) defined as 140/90 mm/Hg
Systolic blood pressure
artery pressure when heart actively pumps
Diastolic blood pressure
Artery pressure when heart relaxed
Tryglycerides
blood lipid that contains glycord combined with fatty acids
Hyperglycemia
High blood glucose concentration defined as more than 100 mg/cl
Glucose
important sugar molecule used by body and brain for fuel (energy)
Basal metabolism
Use of energy to fuel processes such as heat production, maintenance of membrane potentials, and other life sustaining processes
Insulin
Hormone synthesized by beta cells in the pancreas that decrease blood glucose
Cephalic phase
sensory stimuli from food evoke conditioned release of insulin
Digestive phase
food entering stomach and intestines causes release of gut hormones that stimulate pancreas to release insulin
Absorption phase
glucodetectors - cells that detect circulating glucose and inform brain detect glucose and signal pancreas to release insulin
glucose transporter
molecules spamming cell membrane that mediates glucose transportation into cell when activated by insulin
glycogen
complex carbohydrate made by combining glucose molecules for short term storage (in muscle and liver)
Insulin resistance
impaired response to the physiological effects of insulin (including hose on glucose, lipid, and protein metabolism)
Hyperglycemia
High blood glucose
Polyphagia
Frequent hunger
Polydipsia
Frequent thirst
Polyuria
Increased volume of urination
Type 2 diabetes
metabolic disorder characterized by prolonged hyperglycemia and hypoinsulinmia
Adipose
cells that store energy as fat, compromising adipose tissue
Obesity
Excess adipose tissue, especially at the waist
Body mass index (BMI)
estimation of body fat calculated as body weight (in kilograms) divided by heigh (in meters) squares
Bioelectrical Impedance
resistance of body tissue to the flow of a small harmless electrical signal
Hypertrophy
increase in size of adipocytes due to TRG accumulation in existing adipocytes
Hyperplasia
Increase in number of adipocytes due to recruitment of new adipocytes from precursor cells; don’t die
Adipokines
cytokines secreted by adipocytes; over-filled cells release more immune-messengers and may undergo apoptosis, recruiting even more immune cells
ghrelin
hormone secreted by stomach that stimulates food intake
cholecystorinin
hormone secreted by duodenum involved in signaling satiety
peptide yy
hormone secreted by GI tract involved in signaling satiety
leptin
pro-inflammatory adipokine secreted by fat cells to signal current TRG (energy) levels
