exam 1 review Flashcards
relevant features of the infant/toddler exam:
delayed growth
development
abuse/neglect
Immunizations
relevant features of the child exam (3-12 years):
visual/hearing deficits
accidents
abuse/neglect
immunizations
relevant features of female youth (3-12 years) exam:
rubella immunization, contraception, STDs, substance abuse
relevant features of the male youth (13-24 years) exam:
MVA, STDs, contraception, substance abuse
relevant features of the adult exam (25-44 years):
Female: CA, BP, substance abuse, eating disorders
Males : MVA, BP, cholesterol, DM, substance abuse, family violence
relevant features of middle aged exams (45-54 years):
Females: osteoporosis, DM; lung, colon, skin, and breast CA
Males: prostate/lung/skin/colon CA, ischemic heart, DM
relevant features of senior citizen exams:
Elder abuse, falls, drug related interactions, nutrition, CA
which vaccine is given to newborns immediately following birth? (AKA first vaccine received)
Hep B
In addition to Hep B, which other vaccines are received starting 1-2 months post-birth?
RV, DTaP, Hib, PCV13, IPV, yearly influenza (starting at 6 months)
key milestone at 6 months:
begins to sit without support
key milestone at 12 months:
says “mama” and “dada”
key milestone at 18 months:
begins to walk around towards the end of 18 months
minors who are allowed to consent to services on their own, without parental consent:
Minor who has graduated from HS
Minor who has been pregnant
Minor who has been married
Minor who has received court’s decree of emancipation
what are some treatments/diagnostic tests that minors can receive without parental consent:
Can provide informed consent for diagnostic tests and treatments related to a “reportable disease”:
Contraception, pregnancy, and STD testing
Health services to treat pregnancy, STDs, and prenatal care, “not including abortions”
Inpatient mental health treatment (voluntary consent, 14+ years)
Outpatient mental health (any minor over 14 years)
Substance abuse treatment
Emergency situations
How do USPSTF grade guidelines?
Grade A through Grade I
Grade A - recommends the service as there is a high certainty that the net benefit is substantial. Suggest to provide the service.
vs.
Grade I - concludes that current evidence is sufficient to asses the balance of benefits and harms, evidence is lacking, is of poor quality, or is conflicting. Balance of benefits and harms cannot be determined. Suggestion is that if the service is offered, patients should know about the uncertainty.
explain basic concepts of XR imaging:
XRays shot towards the patient
There is either absorption, partial absorption, scatter, or penetration
XRs that pass through the patient and penetrate the detector film, create an image
Few pass through - white
Many pass through - black
Differential tissue absorption based on:
Atomic weight (density)
Tissue depth (thickness)
2D representation of 3D structures - superimposition
explain the concept of CT imaging:
XRs used but in narrow slices
Generator and detector rotate completely around the patient
Computer reconstructs data to create a 2D image slice
Scan = series of multiple slices
Cross sectional anatomy
explain the concept of US imaging:
uses sound waves, based on the density of the tissue
explain the concept of MRI imaging:
magnetic and radiographic waves, non-ionizing radiation
explain the concept of nuclear medicine:
injects radioactive substance into the body to visualize function (PHYSIOLOGY), uses ionizing radiation
what does radiopaque/radiodensity mean:
few XRs pass through - appears white - metal
what does radiolucent mean?
many XRs pass through - appears black - air
Categorize different tissues from least to most opaque on x-ray including: air, fat, soft tissue, bone, and metal.
(least opaque) Air - fat - soft tissue (solid organs and fluid) - bone - metal (most opaque)
define hypodense/hypoattenuating:
CT terminology
appears dark
e.g. air
define isodense/isoattentuating:
CT terminology
two structures appear the same
define hyperdense/hyperattenuating:
CT terminology
appears bright
i.e. metal
what imaging modalities use ionizing radiation?
CT, XR, nuclear med
define “screening”:
presumptive identification of previously unrecognized condition
how are screenings conducted?
Conducted via procedures, exams, tests
Preliminary in design
Confirmation of diagnosis required (additional tests, exams, evaluations)
define sensitivity:
Correctly identify as diseased as those who actually have the disease
Sn=1-false negative rate
Sn= (true positive)/(true positive)+(false negative)
SNOUT - high sensitivity to rule out
If it is 100% sensitive, all negatives are true negatives
define specificity:
Correctly identify as non-diseased as those actually without the disease
Sp=1-false positive rate
Specificity=(true negative)/(true negative)+(false positive)
SPIN - high specificity to rule in
If it is 100% specific, positives are true positives
define positive predictive value:
Proportion of true positive of all those testing positive
PPV (+) = (true positive)/(true positive)+(false positive)
define negative predictive value:
Proportion of true negative of all those testing negative
NPV (-) = (true negative)/(true negative)+(false negative)
how does prevalence affect PPV, sensitivity, NPV, and specificity?
As prevalence increases, PPV and sensitivity increase (more common in population, more likely to be a true positive)
As prevalence increases, NPV and specificity decrease (more common in population, less likely to be a true negative)
what is a dietary reference intake (DRI)?
estimates of the amounts of nutrients required to prevent deficiencies and maintain optimal health and growth; expand the recommended daily allowances and establish upper limits on the consumption of some nutrients. Focuses on lifelong health - goes beyond just dietary deficiencies
what is an EAR?
EAR - estimated average requirement
Average daily nutrient requirement estimated to meet the requirement of ½ of the healthy individuals in a particular life stage and gender group
Intakes below the EAR need to be improved because the probability of inadequacy is 50%
what is an RDA?
RDA - recommended dietary allowance
Average daily nutrient intake level sufficient to meet the requirements of NEARLY ALL individuals in a particular life stage and gender group
Intakes between the EAR and RDA likely need improvement because the probability of adequacy is <98%
Intakes at or above the RDA can be considered adequate
what is an adequate intake (AI)?
Set if sufficient scientific evidence is not available to calculate an EAR or RDA
Based on nutrient intake by a group of apparently healthy people
Intakes above AI can be considered adequate
what is the tolerable upper intake level?
Highest average daily nutrient intake level that is likely to pose no risk or adverse health effects to almost all individuals of the general population
Intakes between the UL and RDA can be considered to have no risk for adverse effects
what is an estimated energy requirement (EER)?
amount of food energy (calories) needed to balance energy expenditure to maintain body size, body composition, and a level of necessary and desirable physical activity consistent with long term good health
what is the EER for women?
2100 kcals
what is the EER for men?
2900 kcals
what are the 3 main energy needs in humans?
resting metabolic rate (RMR) - 60%
thermic effect of food - 10%
physical activity - 30%
what are some factors that can affect resting metabolic rate (RMR)?
-growth
-hospitalization during recovery from serious injuries such as infection or burns
-pregnancy
-lactation
what is BMI?
body mass index
used as an index of an ideal body weight
may not be appropriate for muscular individuals
BMI= weight (kg)/height squared (m2)
BMI and body weight ranges for adults:
BMI <18.5: underweight
BMI 18.5 to <25: healthy
BMI 25 to <30: overweight
BMI 30 or higher: obesity
describe MyPlate:
MyPlate: designed by the US Department of Agriculture to graphically illustrate its recommendations as to what food groups and how much of each should be consumed daily
5 food groups: vegetables, grains, protein, fruit, and dairy
number of servings depends on age and sex
cons: does not include fats, people need to have access to the graphic
what were the changes made to the nutrition facts label on July 1, 2021?
Servings/calories noted with larger, bolder type
Added sugars, vitamin D, and potassium are included
Vitamins A and C, total fat, and calories from fat removed
Serving size adjusted to reflect amounts people are now consuming
Updated daily values
Proposed addition/removal of certain micronutrients is based on newer data on the risk for underingestion
summarize the key steps during pre-initiation of eukaryotic DNA replication:
TIME SETTING: in the final phases of mitosis
- ORC (origin replication complex) recognizes eukaryotic origins of replication/identifies epigenetic modifications; works in conjunction with HBO1
- Cdt1 and Cdc6 (origin licensing factors) use ATP to load the replicative helicase complex (MCM) onto the DNA next to the origin
- phosphorylation via DDK –> DDK dependent complex (G1 phase - pre-replicative complex)
- polymerase E added —> helicase activated (CMG complex/pre-initiation complex/S phase)
- polymerase alpha and delta added —> complete replisome/ready for DNA replication
how does the MCM helicase complex “melt” into DNA?
hydrolyzes ATP to hydrolyze DNA
when do the pre-replicative and pre-initiation processes take place?
pre-replicative - G1 phase
pre-initiation - S phase
compare and contrast the pre-replicative and pre-initiation phases?
pre-replicative:
DDK is phosphorylating, allowing other proteins to bind
occurs in G1 phase
pre-initiation:
polymerase E added and activates helicase (CMG complex)
followed by polymerase alpha and delta
complete replisome is formed
occurs in S phase
what is the function of polymerase alpha?
-reads the template strand and synthesizes RNA primer from 5’ to 3’ on the complementary strand
-the primer contains a free 3’ -OH end upon which DNA polymerase can add nucleotide monomers
what is the function of replication protein A?
RPA
prevents re-annealing
in what direction does DNA replication occur?
nucleotides are added in the 5’ to 3’ direction
what is the function of polymerase E?
reads parental strand and synthesizes the complementary strand in a CONTINUOUS fashion
lEading - Epsilon
what is the function of polymerase delta?
reads parental strand and synthesizes the complementary strand in a DISCONTINUOUS fashion
therefore, needs numerous primers and numerous polymerases
Okazaki fragments and DNA ligase
deltA - lAgging
what is proliferating cell nuclear antigen (PCNA)?
fits around DNA primer and template strand
DNA polymerase attaches to it
acts as a progressivity factor and increases speed
what is the function of Fen 1?
flap endonuclease that removes DNA overhang (DNA sequences that overlap with the primer)
what is the function of RNAse H1?
removes RNA primer fragments
what is involved in DNA replication termination?
-destruction of the MCM (CMG) complex
-activity of topoisomerase IIA
-activity of Holiday Junction Resolvase (helps merge the replication bubbles together)
replication forks/bubbles merge as they expand
form larger replicons until the chromosome is replicated
what is the function of topoisomerases?
superhelical tension is created by the helicase, in front of the replication fork
may prevent replication from occuring further
tension relieved by topoisomerases
contrast activities of Type 1A, 1B, and IIA topoisomerases:
1A: single DNA strand is nicked and then the opposite strand is passed through to relieve superhelical tension, happens fast
1B: introduces a single strand nick and the strand is rotated around, happens fast
IIA: introduces a double strand break, using homodimeric enzymes in eukaryotes (the things holding the spaghetti), slower process, USED IN DNA REPLICATION
what is common between all topoisomerase types?
break DNA via a transesterification reaction using an active site tyrosine as a nucleophile to attack the sugar phosphate backbone
explain the “telomere end replication problem”
-eventually, run out of space to put primers at the 3’ end of the lagging strand
-some DNA will be lost
-cells undergoing rapid synthesis/growth will lose DNA especially
-overall loss of telomere length
what is the telomere repeat?
(TTAGGG)n
what is the result of the telomere end replication problem?
loss of telomere sequences leads to cell senescence
AKA permanent shit down of the cell cycle within a cell
prevents CA (turning off replication)
**cell senescence is linked to premature aging - secretes factors that cause stem cells to age prematurely
what is the function of telomerase?
replicates single stranded telomere DNA
what are the 2 main subunits of telomerase?
nucleoprotein complex of multiple protein subunits combined with an RNA molecule.
TERT: RNA dependent DNA polymerase
TERC: RNA molecule that serves as a template to synthesize the telomeric sequence repeats
“teRt Reads”
when is telomerase known to be activated during?
embryogenesis (fetal tissue) and in stem cells
research says during other times too
describe the telomerase process:
- telomerase binds to the 3’ end of the telomere sequence, along with an RNA template
- telomerase catalyzes the addition of bases, restoring the telomere length
- DNA polymerase extends and seals the DNA strands
effects of genotoxic agents:
XRs, oxygen radicals, alkylating agents, spontaneous reactions
UV light, polycyclic aromatic hydrocarbons
Replication errors
etc.
what are the cellular consequences of exposure to genotoxic agents?
-transient cell cycle arrest
-inhibition of transcription, replication, and chromosome segregation
-apoptosis
-senescence (cell cycle arrest)
-mutations or chromosome aberrations (cancer, aging, inborn disease)
what is genomic instability?
-a process by which the cell accumulates mutations or chromosome damage
-DNA repair mechanisms may not be able to cope with or recognize the changes
may lead to:
-replication fork stalling
-loss of polymerase proofreading ability
-defects in DNA repair mechanisms
-translesion DNA synthesis over DNA damage
-reduced dNTPs selectivity
how does DNA polymerase proofreading work?
-3’ to 5’ exonucleotide ability
-removes incorrect bases
-polymerase “chews back” and fixes the 3’ end incorrect base
describe the Mismatch Repair (MMR) system:
- recognition by Msh2 and Msh6
- recruitment of endonuclease (Mlh1, Pms2) complex
- Exo1 exonuclease removes the mismatched base
- DNA synthesis (polymerase E or D) and ligation (DNA ligase)
what is Lynch Syndrome? What causes it?
genetic disorder characterized by early onset non-polyposis colorectal CA
caused by inherited mutations that effect Mismatch Repair System (MMR)
what are microsatellite DNA?
regions of small repetitive DNA stretches (2-6 bases)
tandemly repeated multiple times
also known as “short tandem repeats” (STR)
due to their repetitive structure, they are prone to strand misalignment during DNA replication - INDELS (insertions and deletions)
which repair system recognizes INDELS?
Mismatch Repair (MMR)
prevents micro-satellite instability that leads to triplet expansion genetic disorders: Fragile X and Huntington’s Chorea
compare and contrast DNA proofreading with MMR:
DNA proofreading can chew back on one base at a time, whereas MMR can recognize micro-satellite regions and correct INDELS (numerous base pairs)
both utilize exonuclease activity
DNA proofreading doesn’t use endonucleases? (DNA polymerase is what chews back on it)
explain how the NER pathway is multirole:
can remove both UV induced DNA damage (cyclobutane pyrimidine dimers, CPD) and bulky adducts cross linked to DNA
what is the nucleotide excision repair (NER) pathway:
- recognition (Centrin2)
- recruitment of TFIIH complex - a basal transcription factor)
- excision of damaged DNA strand (XPD, XPB helicases)
- incision of DNA strand (XPF, XPG incisionases)
- DNA synthesis and ligation (with replication machinery)
what are the 2 forms of NER repair:
- transcription coupled repair (TCR)
- global genomic repair (GGR)
what is transcription coupled repair (TCR)?
-targets transcriptionally ACTIVE genes
-“fast” repair
-RNA polymerase II works in conjunction with the XP proteins to remove UV damage
-uses CSA and CSB (transcription factors?)
the TFIIH complex is carried with the RNA polymerase II, TFIIH system is “built into” RNA polymerase
what is global genomic repair (GGR)?
-uses the NER pathway (not built-in)
-slow repair of UNTRANSCRIBED regions
-removal of DNA damage can take days
why is the double strand break repair process important?
A double-strand break repair model refers to the various models of pathways that cells undertake to repair double strand-breaks (DSB). DSB repair is an important cellular process, as the accumulation of unrepaired DSB could lead to chromosomal rearrangements, tumorigenesis or even cell death.
what are the 2 modes of double strand break repair?
- non-homologous end joining (NHEJ)
- homologous recombination (HR)
what are some causes of double strand breaks (DSB)?
ionizing radiation
fork collapse
oxidative damage
drug induced damage
what are the 2 main signaling kinases and DSB damage sensors?
ATM
ATR
**MRN complex interacts with ATM and ATR directly and indirectly. it is the primary sensing complex for DSB. regulates cell cycle and initiates the repair of DSB.
what cells do NHEJ target?
cells at any stage of the cell cycle
what cells do HR (homologous recombination) target?
replicating or G2 cells
describe the NHEJ process:
- end recognition of the DSB by Ku heterodimers
- additional proteins recruited (DNA protein kinase K)
- processing of DNA ends, limited repair synthesis, and ligation
- end product = repaired DNA that has suffered a deletion of nucleotides
what is the downside of NHEJ?
DNA can be lost
think fast, half hazard, and nonspecific!
describe the homologous recombination process?
-occurs during S and G2 phase
-slower process than NHEJ (think slow and regulated)
-for sister chromatids
- MRN complex detects DSB
- exonuclease degrades 5’ ends
- strand invasion at branch point
- DNA synthesis and migration of branch point
- continued branch migration with pairing of newly synthesized DNA with the synthesis of the top strand
- DNA ligation
- DSB is accurately repaired
what would happen if there was a mutation in the DSB repair proteins?
MRN complex proteins: MRE11, Rad50, NBS1
ATM, ATR
mutation in these genes would have an negative impact on:
-sensing for DSBs
-cell cycle regulation (checkpoint repairs)
-transcription of DSB genes
-initiating repair of the DSB genes
how are BRCA1 and BRCA2 related to the HR pathway?
BRCA1: ubiquitin ligase, works directly in HR repair, tumor suppressor, transcription factor
BRCA2: promotes HR repair and recombination, activates the S phase checkpoint
both promote HR repair and ensure that there are not any double stranded breaks present prior to DNA replication (S phase)
what are the phases of the eukaryotic cell cycle?
G0: resting phase when cell has left the cell cycle and has stopped dividing
G1: cells increase in size, G1 checkpoint ensures that everything is ready for DNA synthesis, ensures there’s no DNA damage
S: DNA replication occurs
G2: gap between synthesis and mitosis, cells continue to grow, G2 checkpoint ensures everything is ready for mitosis
M: CELL GROWTH STOPS and cellular energy is focused on division into x2 daughter cells; metaphase to anaphase transition checkpoint (making sure spindle fibers are correctly attached)
phases of meiosis:
meiosis I and II
prophase: chromosomes condense, nuclear membrane disintegrates, find sisters and tetrads form (crossing over)
metaphase: migrate to metaphase plate
anaphase: tetrads split, chromosomes pulled to either pole by spindle fibers
telophase: cleavage furrow forms, cytokinesis
difference between anaphase I and anaphase II?
anaphase I - 2 TETRADS line up in the middle, and whole chromosomes are pulled apart
anaphase II - a chromosome lines up in the middle, the axis divides it into 2 SISTER CHROMATIDS
mitosis phases:
prophase
metaphase
anaphase (sisters are pulled apart, like meiosis II)
telophase
differences in mitosis and meiosis:
mitosis (cellular division): cell division (2n–>2n)
meiosis (reductional division): reproductive, gamete producing
(2n –>n)
what are the 2 types of cell death?
necrosis and apoptosis
morphological features of apoptosis:
-PROGRAMMED cell death
-can be intrinsic (stress) or extrinsic (induced by an external cell, i.e. macrophage)
-cell loses structure and the membrane blebs
-blebs are phagocytosed (cleaned up)
-NON-INFLAMMATORY
-controlled
-energy required
morphological features of necrosis:
-cell death due to injury or disease
-NOT PROGRAMMED
-external (e.g. infection) or internal triggers (e.g. ischemia)
-MESSY
-cell bursts and decomposes
-triggers INFLAMMATORY response
-passive/no energy needed
-debris is ultimately phagocytosed
what is common between the intrinsic and extrinsic apoptotic pathways?
both pathways eventually rely on caspase proteolytic cascades to achieve cell death
what is the differences between the intrinsic and extrinsic caspases?
intrinsic - caspase 9
extrinsic - caspase 8
BOTH have caspase 3 as the last step
describe the intrinsic apoptotic pathway:
- apoptotic stimulus disrupts the mitochondrial membranes (Bax and Bak poke holes)
- cytochrome C is released into the cytosol (also releases SMACS - apoptosis inhibitors)
- Cytochrome C binds to ATP and APAF-1 —> apoptosome
- procaspase 9 –> caspase 9
- caspase 3 activated
describe the extrinsic pathway process for macrophage interaction:
- external cell initiates apoptosis via signaling proteins
- signaling proteins (i.e. TNF-alpha - inflammatory cytokine) bind to death receptor on membrane
- cytosolic part of death domain dives deep into the cell (the death domain)
- death inducing signaling complex - DISC (FADD and TRADD) change shape and binds numerous proteins to form signaling complex
- procaspase 8 –> caspase 8
- caspase 3 activated
how is the extrinsic apoptotic pathway different for cytotoxic T cells:
T cell recognizes that the cell is expressing foreign antigens on its surface (MHC1)
Fas ligand (of T cell) binds the Fas receptor on the cell.
Changes the shape of the death domain signaling complex (DISC-FADD)
Same caspase pathway (caspase 8 –> caspase 3) as macrophage initiated.
what is a mutual part of the macrophage initiated and T cell initiated apoptotic pathways:
-both cause the death domain to bind to other proteins to form the DISC
-both initiate the same caspase cascade (caspase 3)
what is normal flora?
refers to the microorganisms including bacteria, fungi, and viruses that inhabit the human body or live on its surfaces
normal microbiota = normal flora = not harmful
why is the normal flora important?
-aid immune system in preventing infection
-key role in metabolism (GI)
-necessary for survival
what is symbiotics?
-live in harmony with their human host
-“mutualism”
-human body provides benefits necessary for bacteria’s survival and the bacteria offers benefits to the host
-e.g. symbiosis in the gut
what is an opportunist?
-potential pathogens that would not normally inhabit the body but can take advantage of an opportunity to
-in times of weakened immune responses or skin breaks
-cancer chemotherapy, anti-rejection drugs, catheter or central line insertions
what is a pathobiont?
-typically a benign endogenous microorganism
-potentially pathogenic and may cause disease when overgrowth occurs
-e.g. C diff - usually present in GI tract and is usually kept in check by other bacteria. Growth spurt after antibiotics. Causes toxin release and inflammation, colitis, diarrhea, abd pain, fever. Has endospores that can survive the stomach.
what is the role of human intestinal microbiota in health and disease?
GI tract bacteria keep one another in check
Prevents overgrowth
e.g. C diff infections
what is the predominant normal flora of the skin?
staphylococcus epidermis
what is the predominant normal flora of the nose?
staphylococcus epidermis, colonizing staph aureus
what is the predominant normal flora of the oropharynx?
viridians group
S mitis
S mutans
what is the predominant normal flora of the mouth?
streptococcus mutans
what is the predominant normal flora of the colon?
bacteroides fragilis (anaerobe)
E coli (faculative)
what is the predominant normal flora of the vagina?
lactobacillus, also colonized by group B strep (S agalactae) and E coli
what is tissue tropism?
pathogens and normal flora exhibit a PREFERENCE for specific tissues to live and grow
bacterial tropism is primarily driven by:
-tissue pH
-metabolic products
-immune factors
-oxygen levels
-other local tissue environmental factors
viral tropism is largely driven by host cell receptors that allow the virus to attach to the cell
what causes dysbiosis:
normal flora imbalance
causes:
-overgrowth
-too few bacteria
-inappropriate types
examples of dysbiosis in the gut:
small intestinal bacterial or fungal growth
-Klebsiella species (not normally present) found in the feces of IBS or gastroenteritis patients (indicating dysbiosis)
-alcohol induced dysbiosis can weaken the body’s defenses against Klebsiella pneumoniae (normally in mouth and skin), leading to PNA
example of dysbiosis in the vagina:
low pH maintained by Lactobaccillus
If Lactobacillus is decreased (i.e. Abx treatment), pH rises and potential pathogens can grow
yeast infection - Candida albacans overgrowth
BV - Lactobacilli replaced by Gardnerella vaginalis
examples of dysbiosis in the oral cavity:
normal bacteria: diptheroids and corynebacterium (overgrowth is harmful)
Pseudomembranous pharyngitis: C diphteriae proliferation due to oropharyngeal dysbiosis
creates a pseudomembrane = thick, grayish adherant exudate formed by cell debris and inflammatory products
normal blood pressure:
normal systolic: 120
normal diastolic: 80
what are the 3 factors that affect blood pressure?
- cardiac output
- fluid volume in the artery
- degree of constriction by arterioles (resistance)