So help me god

control

-treated the same as the experimental group except independent variable isn't changed from the comparator or original value -esnures that changes are due to the independent variable, not confounders -some studies have subjects serve as own control group by measuring dependent variables before and after treatment (pre/post, crossover and time series)

controlled variable

factors that are the same for control and experimental group so that there is only one independent variable

sample

-a subset of the population -sample taken from the population

population

all members of the specific group being studied

independent variable

-altered/manipulated variable -should only be one =explanatory variable =categorical variable in descriptive studies

dependent variable

-non-altered, measured variable -may be multiple of these -depends on independent variable

categorical variable

-a distinct category that each subject can only be assigned to (ex. blood type) =independent variable in descriptive studies

comparator

reference point, control, baseline

scientific method steps

1.ask a question 2.do background research 3.construct a hypothesis (directional) 4.perform experiment and collect data 5.analyze data, interpret results, draw conclusions (reject or fail to reject hypothessis) 6.communicate results

research question

=narrow focussed, testable question about an observation -includes: 1.independent variable being manipulated (categorical variable for categorical data) 2.comparator group/condition (control, baseline, ref pt.) if appropriate 3.dependent variable(s) being measured 4.population being studied

-ex.:"Does a 3-week aerobic exercise regimen improve fitness level as compared to (baseline condition)

directional hypothesis

-proposes that the dependent variable will increase or decrease when the independent variable is changed -includes: 1.independent variable being manipulated 2.comparator group/condition (control,baseline,ref. point) if appropriate 3.dependent variable(s) being measured 4.population being studied 5.phrased as a directional statement -ex. "A 3-week aerobic exercise program will improve fitness level as compared to (baseline condition)

random selection of subjects

-subjects of controlled experiments must be... -minimizes/eliminates confounding variables

study designs

-Based on the research question and methodological constraints 1.descriptive or 2.experimental studies

1.descriptive study designs

-observational collection of data without manipulation of sample -describes "what is", no intervention -easier to conduct, good for describing and predicting relationships -case, cross-sectional, longitudinal, retrospective -collection of data without manipulation of sample/subjects -NO INDEPENDENT VARIABLE-> use a categorical variable to see if it predicts an outcome -ex. "Does the height of M and F 6th graders differ?" -dep var=height, cat var=sex

2.experimental study

intervention/treatment/manipulated variable is intentionally introduced -randomized controlled, pre/post, time series, cross-over -have a control (either separate group or same subjects before/after treatment) -allows researchers to determine whether changing a variable will cause a particular effect (tests causality)

case study

-descriptive study -1-2 instances of an observed phenomenon

cross-sectional study

-descriptive study -a random subset of a population is sampled to observe the occurance of a phenomenon (ex. sampling incoming CU freshman to see what % are smokers)

longitudinal study

-descriptive study -a group of subjects is followed over time to observe how a variable changes -ex. children's heights initially measured at age 5 then yearly upon physical exam

retrospective study

-descriptive study -a search is made for a relationship between current phenomenon or condition and one that occurred in the past to examine whether exposure to a suspected risk or prospective factor led to an outcome -ex.:asking subjects with or without colon cancer to estimate weekly veggie consumption over past 10 yrs.

randomized controlled study

-experimental study -subjects randomly assigned to experimental or control group

pre/post study

-experimental study -dependent variable is measured in each subject before manipulation (baseline) and after manipulation -each subject serves as his/her own control

time series study

-experimental study -dependent variable is measured in each subject before manipulation (baseline) and several times after manipulation to observe how the dependent variable changes over time -independent variable=time -each subject serves as his/her own control

crossover study

-experimental study -subjects are divided into dif groups, w/ each recieving all treatments but in a different order with a washout period between each different treatment -eliminates potential ordering effect -each subject serves as his/her own control

graph features

1.independent variable is graphed on x-axis 2.dependent variable is graphed on y-axis 3.for this class, create a single graph per dependent variable 4.if the experimental design is valid and the hypothesis is supported, changes in the independent variable (x-axis) will cause changes in the dependent variable (y-axis) in an experimental study 5. for descriptive studies, the independent variable (categorical variable-not the measured variable) is on the x-axis 6.axis has units and labels 7. if multiple groups are shown on one graph, the lines or bars representing the groups may have different labels or a key to show what symbols and colors represent 8.Figure caption (legend): located below each graph, begins with (Figure #) a.description of the experimental variables(ind, dep), including any comparator group or condition b.Methodology (equipment used, how each dependent variable was measured c.sample being tested and sample size (#of subjects) d.indication of the statistical test used e.explanation of any symbols on the graph used to indicate stat. significance at chosen level of sig. and alpha level f. figure caption should provide enough detail so that another reader can recreate experiment without reading supporting text

Figure caption

8.=(legend): located below each graph, begins with (Figure #) a.description of the experimental variables(ind, dep), including any comparator group or condition. include units b.Methodology (equipment used, how each dependent variable was measured c.sample being tested and sample size (#of subjects) d.indication of the statistical test used e.explanation of any symbols on the graph used to indicate stat. significance at chosen level of sig. f. should provide enough detail so that another reader can recreate experiment without reading supporting text

Graph type used

-determined by the independent (or grouping) variable or whether the data is paired -line, bar,scatterplot

bar graphs

-used when the independent variables of the experiment are categorical -use for pre/post studies

line graphs

-used when the independent variable on the x-axis is continuous -each point on the graph may be an average of a set of observations -symbols used to indicate the actual points at which data were collected -because the independent variable is a continuous function, the data points can be connected with a line interpolation:connecting points allows reader to estimate values between measured values -extrapolation: extending the graph beyond the plotted points

scatterplots

-used to show the relationship b/w 2 variables -ex. time spent studying and performance on exam -often used with descriptive studies -each point represents observations of one member of a test population -best fit line/trendline/regression may indicate a trend in the data but does not connect all points

raw data tables

-use to record data in experiment and necessary calculations -columns: 1.subject # 2.independent var. (units if ap) 3. dependent var. (units if ap)

summary tables

-used to report extensive numerical data in an organized manner -one per experiment -columns: 1.independent variable in 1st 2.dependent variable(s) with standard deviations (+/-) in subsequent columns -title:located above summary table, (Table #) followed by: a.description of experimental variables (ind, dep) including units and comparator cond. if ap b.methodology (equipment used, how measured) c.sample being tested and sample size for each group d.data represent average (+/-) SD e.type of statistical test used and alpha level f. explain symbols denoting stat. significance

experimental conclusion

=statement of what researchers think they have learned about the physiology based on performing experiment (answer to research question based on their interpretation of the results) -includes: a.experimental manipulation b.how the dependent variable changed in response to manipulation c.trend d.whether the results were statistically sig. -ex. format: "These data suggest that (exp. man.-specific manip 2), as compared to (comparator), did/did not lead to a significant inc./dec. in (dep var 1)...repeat for additional dep vars..in (population) ex. These data support that there are sex differences in hematocrit with male college students having a significantly higher hematocrit than female college students (since descriptive study-we cannot infer cause/effect)

experimental limitations

-researchers must consider of confounding (unforseen, uncontrolled) variables could have influenced their results/conclusion 2 types: 1.methodological: limitations due to the actual methodology (experimental procedure, equipment) 2.physiological: limitations due to physiological factors (age, health status, etc.)

statistical tests

1.calculate how likely/unlikely a collection of sample data is assuming the null hypothesis is true 2.rejecting the null hypothesis if the data is extremely unlikely to have occurred by chance alone or failing to reject Ho if data are not surprising -never prove anything with stats-just support/suggest

null hypothesis (Ho)

-hypothesis that sample observations result from chance -no observed effect for experiment -ex. no dif b/w sample and population means->fail to rejcect Ho ex. statistically significant dif b/w sample and population means-> reject Ho -p would be < alpha in this case

alternative hypothesis

-hypothesis that the sample observations are influenced by some non random cause -rejecting Ho->accept Ha

p-value

-provided by statistical test and/or post-hoc analysis -small p value (pobservations are extremely unlikely under Ho->reject HO and accept Ha -statistically significant small p value is determined by alpha=cutoff point for p value -alpha usually=0.05 -we never prove anything with stats

chi-square analysis

1.comparison of observed vs. expected distributions, "goodness of fit" 2.used to determine if there is a significant relationship b/w 2 categorical variables -fail to reject Ho->no sig. relationship -reject Ho->sig relationship 3.non-parametric staats test used to compare whether observed distribution of characteristics in a sample (ex. # observations displaying characteristic) matches the expectations according to a specific hypothesis ex.use to determine whether handedness in physiology class is representative of world population

dependent (paired) t-test

1. used to determine whether 2 means are significantly different from each other 2.dependent means it compares means when some subject is tested more than once or when some other natural pairing exists b/w measurements (ex. twins, same subjects at 2 time pts.) 3.Ho=no difference b/w means -Ho is rejected or failed to be rejected based on p-value

independent t-test

1.used to determine whether 2 means are significantly different from each other 2.independent compares means when 2 groups are not related to one another (ex. experimental v. control, male v. female) 3.Ho=no difference between means -Ho is rejected or failed to reject based on p-value

repeat measures ANOVA test

1.used for differences between >2 means of groups, doesn't tell which means are different until post-hoc analysis 2.repeat measures when means represent the same subjects evaluated at multiple time points 3.Ho=all groups come from the same population and therefore have the same means 4.Ho is rejected or failed to reject based on p-value->reject (significant p value)->bonferonni post-hoc analysis 5.bonferonni post-hoc analysis p value determines which means are significantly different. (p value is adjusted to minimize familywise error rate by p<(0.05/k) k=total #comparisons performed

one way anova test (b/w groups or w/in groups)

1.used to test differences between >2 means of groups, does not tell which means are different until post-hoc analysis 2.one-way when single variable is measured in multiple unrelated groups, or multiple treatments for one subject 3.Ho=all groups come from the same population and therefore have the same means 4.Ho is rejected or failed to be rejected based on p-value->reject (significant p value)->Tukey Honest Significant Difference post-hoc analysis test 5. HSD post hoc analysis of p-value determines which means are significantly different

blood

=connective tissue =plasma (extracellular fluid)+ cellular elements (erythrocytes, leukocytes, thrombocytes/platelets)

plasma

=extracellular fluid in blood =mainly water, but contains plasma proteins such as immunoglobins, gases, nutrients, hormones, waste products, electrolytes -transport of materials

erythrocytes (RBCs)

=flat biconcave disks. no nucleus. no mitochondria. most abundant cell in blood. -contain hemoglobin- a protein that carries oxygen and CO2 -production of RBCs=erythropoiesis in bone marrow->regulated by erythropoietin hormone from kidneys -erythropoietin secretion is stimulated by hypoxia detected by kidneys -androgens increase erythropoietin production

leukocytes

-less than 1% of blood cells -mainly in tissues not circulation -immune fn. -high leukocytes=infection, inflammation, illness -low leukocytes=neutropenia=may indicate immunodefficiency or disease

platelets (thromobocytes)

=cellular fragments -derived from megakaryocytes -clotting via coagulation cascade

hematocrit

=%erythrocytes in total blood volume -US male avg=45% -US female avg=40% -increased: with increased eryhtrocyte production (dehydration-decreased plasma volume, blood doping, high altitude) -decreased: with increased blood loss, decreased RBC production (iron or B12 deficiency), or increased RBC breakdown (sickle cell anemia, malaria, autoimmune) -decreased hematocrit may indicate anemia (condition causing the decrease in oxygen carrying capacity of blood)

blood types ABO and Rh

-presence or absence of 2 antigens (A and B) on erythrocyte surface. Rh=presence/abscence of D antigen -antibodies (anti-A and Anti-B, anti-D/Rh) made against antigens not present on cell surface -blood types are heritable traits influenced by ethnic groups -ABO gene encodes for a glycosyltransferase -A, B, and O alleles -A and B co-dominant, O recessive. Rh+ dominant -ex. someone with blood type A may be homozygous for A allele (A,A) or heterozygous (A,O) blood type antigens antibodies freq A A B 42% B B A 10% AB A,B none 4% O none A, B 44% Rh+ Rh none 85% Rh- none Rh 15%

blood transfusion

-incompatible blood types causes the antibodies of the patient to agglutinate with the antigens of the donor->clotting blood type donate to: receive from: A A, AB A, O B B, AB B,O AB AB any O any O

blood typing with Eldon cards

-card contains antibodies -look for agglutination->if agglutination occurs, that antigen is present in blood sample -control=antibody that doesn't bind to any blood antigens

hydration level and hematocrit

-dehydration increases hematocrit, which leads to a decrease in EPO levels

3 phases of general adaptation syndrome

How animals respond in response to stressors 1.Alarm phase: mobilize resources 2.Resistance phase: cope with stressor 3.exhasution phase: reserves depleted

1. Alarm phase of GAS

-body mobilizes energy stores and prepares for physical activity="fight or flight response" initiated by SNS -stress resistance is low -fight or flight response induces physiological changes via the SNS: a.response begins at hypothalamus b.hypothalamus activates preganglionic nueron in CNS that projects to autonomic ganglion outside of CNS using acetylcholine c.postganglionic neuron receives Ach singal in ganglion synapse via cholinergic nicotinic receptors d.postsynaptic neuron's axon synapses at target tissue where it releases norepinephrine, or postsynaptic neuron in adrenal medula receives Ach signal and releases epinephrine from chromaffin cells into blood d.catecholamines bind to adrenergic (alpha or beta adrenergic) receptors to initiate fight or flight response

alpha vs. B2 vs B1 adrenergic receptors

-B2 adrenegic receptors increase blood flow via vasodilation -found in tissues active during FOF response: liver, skeletal muscle, blood vessels to heart -these tissues are not innervated by SNS and therefore responsd mainly to epi in blood -alpha adrenergic receptor decrease blood flow via vasoconstriction -found in organs nonessential to FOF: GI tract -B1 adrenergic receptors on cardiac tissue increase HR and force of contraction

adrenergic receptor type and response

1.adipose tissue: B adrenergic+glucocorticoid ->lipolysis 2.Adrenal cortex ACTH receptor ->synthesis+release of cortisol 3.Adrenal medulla chromaffin cells-nicotinic rec. ->release of catecholamines 4.anterior pituitary CRH receptor ->release of ACTH 5.blood vessels to heart, liver, skeletal muscle (essential organs) B2 adrenergic ->vasodilation 6.blood vessels to GI tract (nonessential organs) alpha adrenergic ->vasoconstriction 7.heart B1 adrenergic ->increase HR and contractility 8.liver B adrenergic and glucocorticoid ->gluconeogenesis, gylcogenolysis 9.postganglionic neurons cholinergic nicotinic receptor ->release catecholamines 10. skeletal muscle B adrenergic and glucocorticoid ->protein catabolism, gluconeogenesis

Resistance phase of GAS

-stress resistance increases and is high -body adapts to stressor and tries to sustain energy -HPA axis activated: a.Hypothalamic Adrenal Pituitary axis begins in hypothalamus which is activated by stress and releases CRH (corticotrophin-releasing hormone) b.CRH directs Anterior pituitary to release ACTH (adrenocorticotrophic hormone) c.ACTH directs adrenal cortex to secrete cortisol, a steroid hormone, into the blood d.cortisol attaches to glucocorticoid target tissues such as liver, skeletal muscle, or adipose tissue to help mobilize energy stores by promoting lipolysis, skeletal muscle catabolism and gluconeogenesis. immune function is also supressed e. negative feedback loop of cortisol decreases ACTH and CRH secretion

exhaustive phase of GAS

-stress resistance falls and becomes very low -all resources/energy stores have been depleted. -a prolonged exhaustive phase may cause damage to the body

Enzyme-Linked Immunosorbent Assay (ELISA)

-relies on antibodies to detect and bind to antigens in liquid based samples -antibody based -can detect minute amounts of disease substances, hormones, drug use, pregnancy

Direct ELISA

-Assays sample for presence of certain antigens 1.add primary antibody that binds to antigen 2.add sample possibly containing antigen of interest 3.add secondary antibody (enzyme linked) 4.add chromogen->enzyme linked to secondary antibody facilitates chemical reaction that changes color of chromogen -color change indicates antigen is present

Indirect ELISA

-assays blood sample for presence or absence of antibodies against a particular pathogen or antigen whose presence would indicate that the patient's body has launched an immune response.

ELISA negative control well

-contains all components of ELISA except for cortisol: primary antibody (primary antibody to human cortisol), enzyme-linkded secondary antibody (to human cortisol), chromogen

ELISA positive control well

-ensures antibodies are actually binding to the correct antigen -contains all components of ELISA: primary antibody (primary antibody to human cortisol), enzyme-linkded secondary antibody (to human cortisol), antigen (positive control sample containing cortisol), chromogen