rrd 1 Flashcards
basic concepts, genetic influence in disease, intracellular function and disorders
physiology
study of functions and processes that occur in body > mostly the normal processes
pathophysiology
the study of the underlying changes in body physiology that result from disease or injury
physiologic amenorrhea vs pathophysiological amenorrhea?
phys: menstrual flow ceases because of menopause, pregnancy, etc.
pathophys: menstrual flow ceases because of cancer, etc.
homeostasis
maintenance of constant conditions in the body’s internal environment
cells must have a constant supply of (1) ______, ______, _____, and exist in narrow (2) ______ and ______ range.
(1) nutrients, H2O, O2
(2) pH, temperature
Maintaining homeostasis is essentially a ______ act. Body is always trying to _____ when homeostasis is challenged by changes.
balancing, right itself
stressors
the challenges to the body’s balance
compensation
return to homeostasis after being challenged by a stressor (aka adaptation or healing)
how is compensation achieved?
control/compensatory mechanisms
what is the compensatory response when the body is exposed to elevated external temperatures or heavy exercise?
- Body temperature rises.
- The hypothalamus senses the elevated core temperature.
3 (1). The hypothalamus sends a signal to the skin to produce sweat.
4 (1). Heat loss through evaporation
3 (2). dilation of the superficial blood vessels occurs
4 (2). Heated blood circulates from the core to the periphery.
5 (2). Heat loss through radiation (heat removed from body into surrounding air)
what kind of stressor is elevated external temperature or heavy exercise?
“normal” daily-life stressors
what is the compensatory response’s MAIN GOAL when you lost a lot of fluid such as blood (massive bleeding) or water (dehydration)?
keep the remaining fluid volume circulating as effectively as possible - temporary measures until the cause of the problem is fixed
what is the compensatory response for blood loss?
- HR would increase to get blood around faster to temporarily make up for the loss of volume
- periphery arteries (arms and legs) would constrict to shunt whatever blood volume is left to the central areas (brain, heart, lungs, kidneys)
- cool hands and feet
what does it mean when the control mechanisms are exhausted?
the body is unable to appropriately meet the challenge of the stressors
what happens when the control mechanisms are exhausted?
compensation can deteriorate either rapidly or slowly into decompensation
decompensation
failure to compensate, adapt, heal, etc.
disease
harmful condition of the body (and/or mind)
disorder
distrubance in the healthiness of the body
syndrome
collection of symptoms
are disease, disorder, and syndrome interchangeable?
for the class, YES
risk factors
factors that or contribute to/increase probability that a disease will occur > “setting the stage”
examples of risk factors
heredity, age, ethnicity, lifestyle (smoking, eating habits, etc.), environment
precipitating factor
a condition or event that triggers a pathologic event or disorder > “kick-off”
etiology
the cause of a disease > includes all factors that contribute to the development of the disease
examples of etiology
- etiology of AIDS: HIV
- etiology of rheumatic heart disease: autoimmune rxn
- etiology of TB: mycobacterium
idiopathic
disease with an unidentifiable cause
iatrogenic problem
occurs as a result of a medical treatment
example of iatrogenic problem
kidney failure due to improper use of antibiotics prescribed by a healthcare provider
- etiology of the kidney failure was iatrogenic
nosocomial problems
result as a consequence of being in a hospital environment
example of nosocomial problem
urinary tract infection is an nosocomial infection if it developed while the patient was in the hospital
clinical manifestations (S&S)
the demonstration of the presence of a sign and/or symptom of a disease
signs
manifestations that can be objectively identified by a trained observer
symptoms
subjective manifestations that can only be reported by the person experiencing them - pain, nausea, fatigue
S&S
signs and symptoms
- also known as S/S
- “symptoms” is a shortcut in medical vernacular instead of saying signs and symptoms
local S&S
redness, swelling, heat, rash, and lymphadenopathy in a particular area
systemic S&S
fever, urticaria (hives), malaise (“I feel dragged out” or “awful all over”), systemic lymphadenopathy
acute S&S
fairly rapid appearance of S&S of disease (over a day to several)
- usually last a short time
example of acute S&S
the patient had acute URI (upper resp infection) that resolved within a few days
acute S&S can also mean what?
increase in severity
- ex: The acuity of the patient’s URI increased and he had to be hospitalized.
chronic S&S
develop more slowly
- often insidious and last longer
- can wax and wane over months or years
remissions in chronic S&S
periods when S&S disappear or diminish significantly (wane)
exacerbations in chronic S&S
periods when S&S become worse or more severe (wax)
- ex: The patient had an exacerbation of his chronic asthma and had to go to the hospital.
central location of manifestations
refers to a problem/situation that is occurring towards the center/core of the body
what organ systems are being referred to in central location of manifestations?
essential organ systems like the brain, heart, lungs, kidneys
example of central location of manifestations
when someone loses a lot of blood, the body shunts most of the remaining blood away from non-essential areas (guts, hands, feet) so the essential organs are oxygenated
- most of the blood volume left ends up circulating centrally
the more central an area/problem is, the more _____ to the core it is
proximal
example of proximal in a sentence
the arm was fractured proximal to the elbow -> break between the elbow and the shoulder
peripheral location of manifestations
refers to a problem/situation that is occurring toward the outer parts of the body, away from the core
example of peripheral location of manifestations
if there is large blood loss, the blood vessels of the periphery often constrict so that not a lot of blood can circulate in those areas (why a sign of shock is cool, pale extremities)
shock
low BP + S&S of not getting enough blood to different parts of the body
- ex: confusion from not getting blood to brain
the more peripheral an area/problem is, or further ____ from the core of the body, the more _____ it is.
away, distal
example of distal in a sentence
distal to the blood clot in the left coronary artery, the tissue lost oxygenation and died
prognosis
predicted outcome of a disease based on certain factors > the usual course of that particular disease
prognosis based on age
patients at either end of the age spectrum (infants and elderly) are at a higher risk for a poor prognosis due to immature or worn-out immune systems
prognosis based on presence of comorbidities
two or more coexisting medical conditions increases the chance of poor prognosis
- ex: the patient’s comorbidities of heart and lung disease contributed to his poor prognosis in recovering from pneumonia
sequela (plural: sequalae)
aftermath of a disease > any abnormal condition that follows and is the result of disease, injury, or treatment
- complications
another term for sequela is?
outcome
- ex: a positive sequela of getting pneumonia was that the patient stopped smoking
*sequela is usually used with a negative connotation
the _____ of sequela varies
severity
examples of sequelae with various degrees of seriousness
- sequela of rheumatic fever can sometimes be a bad heart valve
- possible sequela of chicken pox is scarring
- possible sequela of stroke is weakness on one side of the body
gene
segment of DNA molecule that is composed of an ordered sequence of nucleotide bases (adenine, guanine, cytosine, thymine)
main function of genes
coding for synthesis of proteins that form our traits and functional characteristics
examples of permanent proteins that genes code for
- eye pigment, hair color, blood type in developing fetus
- personality and susceptibility to certain diseases
examples of “day-to-day” functional proteins genes code for
hormones, antigens, antibodies, enzymes
when there is a _____ of a gene, the ______ it is responsible for often malfunctions
mutation, protein
example of a mutation causing protein malfunction
- gene that codes for lactase mutated
- lactase cannot properly breakdown and process lactose
- lactose ingestion causes diarrhea
^Lactose Intolerance
chromosome
rod-shaped body in the nucleus that contains “beads” of DNA information > DNA helix containing genes that take shape of a chromosome
hierarchy of genetic information
- sequence of nucleotide bases forms a gene
- genes make up a DNA molecule
- DNA molecule forms into a specialized shape (chromosome)
a person receives ____ chromosomes from each parent, so you end up with ____ pairs or a total of _____.
23, 23, 46
how many pairs are autosomal? what does it mean to be autosomal?
22 pairs, NON-sex chromosomes
each of the 22 pairs that are autosomal are _________.
closely alike
what is the 23rd pair of chromosome?
sex chromosomes - XX or XY
the autosomal chromosome pairs each has genes that ______ on the other chromosome.
closely match or partners
partner genes have the ______ location (LOCUS) on each respective chromosome and code for the _____ trait.
same, same
partner genes on the same location and code for the same trait are?
a pair of alleles
difference a pair of alleles can have?
one can be dominant, the other recessive (can be both dom or both rec though)
genotypes
- AA, aa, Aa > the notation for dominant/recessive alleles
- represent what was inherited from mom and dad
- overall genetic composition
- refers to a specific set of alleles
AA is?
homozygous dominant
aa is?
homozygous recessive
Aa is?
heterozygous
what would a geneticist use to find the percent chance of two people with certain genotype having a child with certain genetic characters?
punnett square
phenotype
a person’s observable characteristics (anatomic, physiologic, biochemical, behavioral) as determined by genes and environment
genetic disorders
a disease caused by abnormalities in an individual’s genetic material
example of inherited genetic disorders
sickle cell disease is caused by an inherited, altered (mutated) gene
example of spontaneous genetic disorders
- free radicals from as a result of aging
- causes damage to the DNA
- protein synthesis is altered leading to gene mutations
- an “oncogene” develops which causes rapid, wild proliferation of cell growth
- cancer may develop
what are other ways to categorize genetic disorders?
mitochondrial DNA, multifactoral, chromosomal, single-gene
mitochondrial DNA disorders
small bits of DNA are found in the mitochondria
- disorders of this type uncommon
environmental is used to mean?
any influence other than inherited
multifactorial genetic disorders
combo of environmental triggers and variations/mutations of genes + sometimes inherited tendencies
example of multifactorial genetic disorders involving lung cancer
- smoke and toxins irritating bronchial tissue
- one or more genes in cells of tissue deranged - oncogenes created
- code for wild, uncontrolled growth of cells
what are other examples of multifactorial genetic disorders?
- hypertension (HTN)
- coronary artery disease (CAD)
- diabetes mellitus (DM)
teratogen
any influence (drugs, radiation, viruses, etc.) that can cause congenital defects
congenital defects
abnormalities that are either detectable at birth and/or can be attributed to fetal development “glitches”
examples of teratogenic disorders/congenital defects
- FAS (fetal alc syndrome) -> toxicity of alc causes gene mutations during gestational development
- thalidomide babies -> born with abnormal arms and legs due to moms taking thalidomide for nausea during early pregnancy
chromosomal disorders (chromosomal aberrations)
type of genetic disorders that result from:
1. alterations to the numbers/structures of a chromosome
2. alters local genes (genes in immediate area)
3. gene’s functionality disrupted
4. genes don’t code for protein correctly
5. rise of phenotype of the disorder
example of chromosomal disorder due to alteration to numbers of chromosome
Down’s syndrome - disorder of numbers of chromosomes and sometimes associated with pregnancies of women > 35 yrs old
Down’s syndrome is a glitch that occurs in very early ______ division and chromosomal distribution of a __________
cellular, fertilized egg
how many chromosomes does a fetus end up when experiencing the glitch associated with Down’s syndrome?
47 chromosomes (instead of 46)
where does the extra chromosome occur with Down’s syndrome?
at site #21 - the 21st chromosome set comes with 3 instead of 2
another name for the 21st chromosome associated with Down’s syndrome
trisomy 21
phenotype of trisomy 21
- mental retardation
- low-set ears
- epicanthic fold to eyes
- short limbs
- larger-than-normal tongue
some types of chromosomal aberrations are caused by alterations of chromosomal _______, such as deletion, duplication, rearrangement of gene sites (______) on the chromosome
structure, translocation
example of chromosomal disorder due to alterations to chromosome structure
Philadelphia chromosome
Philadelphia chromosome
results from translocation
polysomy
more chromosomes than normal
- ex: Down’s
single-gene disorders
- due to an inherited mutated gene
- mutated gene causes abnormal protein that cannot carry out its normal function -> disorder
patterns of single-gene disorders
autosomal recessive, autosomal dominant, sex-linked
autosomal recessive disorder
mutated (diseased), recessive (weak) gene partners up with an allele that is also recessive and diseased, causing the protein they code for to malfunction -> abnormality/disease/disorder will occur based on bad protein
example of an autosomal recessive disorder
sickle cell anemia
sickle cell anemia genotype development
- @ certain locus on certain pair of chromosomes, a pair of alleles has job of coding for normally shaped Hgb
- during fertilization: person inherits the sickle-cell disease gene from mom and dad (recessive, mutated Hgb-coding gene)
- homozygous recessive genotype: dd
sickle cell patho development
- abnormal-shaped Hgb (sickle-shaped) makes RBC sickle-shaped
- RBCs more susceptible to damage as they move thru blood stream -> less than normal #s of RBCs (anemia)
sickle cell anemia phenotype (S&S caused by geno and patho development)
SOB (shortness of breath), weakness & fatigue, and ischemic pain
what is SOB, weakness & fatigue by sickle cell anemia specifically due to?
decreased O2 being carried to tissues of the body
the decreased capacity of O2 being carried to the tissue of the body in context of sickle cell anemia is because of?
- anemia: less #s of RBCs to carry Hgb which in turn carries O2
- deformed Hgb cannot carry usual #s of O2 molecules
what is ischemic pain from sickle cell anemia caused by?
*especially in joints
- deformed RBCs clog up capillaries that usually carry O2-rich blood to tissues
- distal tissues starved to O2 and “cry out” in pain (womp womp)
ischemia / ischemic pain
- cells not getting enough O2 due to circulatory malfunction
- pain in the tissue that is not getting enough oxygen
genotype of person who inherits a sickle-cell disease gene from one parent but a NORMAL Hgb-coding gene from the other parent?
Dd
a person that has a heterozygous genotype for sickle cell anemia is considered a ______ because?
carrier, does not have the disease but has the gene for it to carry to offspring
T/F a carrier can have a milder phenotype of the disease (mild S&S) - “having the trait”
TRUE
in context to sickle-cell anemia, a person that is DD is considered?
homozygous normal - do not have to worry about having/passing the disease
autosomal dominant disorders
- when a person inherits a mutated, diseased gene that is dominant
- gene that codes for disease dominant while gene that codes for normal is recessive
example of autosomal dominant disorder
polycystic kidney disease (PKD)
genotype development of PKD
- @ certain locus on certain pair of chromosomes, pair of alleles code for normal kidney tissue
- during fertilization: person inherits mutated kidney tissue gene that codes for abnormal kidneys
- even when mutated gene is paired with normal allele, it will override normal allele’s coding
patho development of PKD
kidney tissue develops cysts, which can reduce various kidney fxns and lead to kidney failure as person goes thru life
genotype notation for PKD
PP or Pp
what is the genotype notation for a person that does not have PKD? what is it called?
pp, homozygous recessive
S&S of PKD
- hematuria (blood in urine), proteinuria, frequent kidney infections
- pain at costovertebral angles and abdomen
- kidney stones
recombinant DNA
a form of genetic engineering
recombinant DNA is _____ DNA that results from purposefully combining two or more _______ sources of DNA
new, different
example of recombinant DNA engineering
altering DNA codons in bacteria to make proteins that bacteria would not ordinarily produce
current applications of recombinant DNA process
- human GH for children lacking it
- exogenous (from outside the body) insulin for diabetics
- factor VIII for hemophiliacs
- drugs (tPA & tenecteplase) given as clot-busters in patients having MI (myocardial infarction: clot in coronary artery, blocking blood flow to distal tissue)
many normal daily changes in body _________ can affect the metabolic pathway and usually, the body can adjust and maintain ___________. ongoing ________.
homeostasis, equilibrium, fine-tuning
when there are problems that disrupt homeostasis of cellular metabolism and the provision of ATP for body needs, what happens to the body?
more difficult for the body to adjust and return to equilibrium
many disorders and diseases processes either ______ or are ______ some sort of cellular-level disruption that eventually leads to a decrease in ______.
cause, caused by, ATP
etiology of cellular disruptions include:
- hypoxia
- nutritional problems
- changes in balance of electrolytes and other solutes (acid/base imbalance)
- changes in fluid distribution
hypoxia
decrease in amt of oxygen to cell or ability to use oxygen appropriately
example of nutritional problems that can cause cellular disruptions
- decreased glucose
- vitamin availability for cell use
hypoxia has a spectrum of?
etiology and seriousness
- overworked muscles in extreme exercise (muscle use up immediate avail O2)
- difficulty breathing and can’t get enuf O2 to heart to circulate to tissues
- artery in arm cut so tissues distal to trauma cannot get O2
if there is hypoxia, cellular metabolism has to recycle through ________ rather than continue down the usual aerobic pathway.
glycolysis
why does cellular metabolism use glycolysis during hypoxia?
glycolysis is the only step that can operate under normal, aerobic conditions and anaerobic conditions
positive side of anaerobic glycolysis
- give 2 ATP per glucose molecule to give energy to cell
- temp stop-gap measure to keep body going until cells can get more O2 and reestablish aerobic metabolism
negative side of anerobic glycolysis
- 2 ATP not enough to keep going for a long time
- every time metabolic process must recycle thru glycolysis -> multiple pyruvate (pyruvic acid) accumulate -> acidosis
acidosis
state of greater-than-usual concentration of acidic substances in the blood and cells
two main sequela result from hypoxia
- deficiency of ATP for cellular fxns
- altered acid/base balance
hypoxia can cause?
damage and death to tissue
example of deficiency of ATP for cellular fxns due to hypoxia
w/o ATP, Na/K pump of each cell cannot maintain normal electrical cell membrane status + propagation of electrical impulses will be disrupted
example of altered acid/base balance due to hypoxia
acidosis can tip body pH out of its narrow, desirable range quickly
glycogen
- molecule too large to be used for energy as is
- can be stimulated to break down into small glucose molecules that can be used for energy
- stored glucose
glucose
obtained from carbohydrates to begin cellular metabolic pathway that leads to ATP
vitamins
provide support staff for metabolic pathway (along with other substances)
process of glucose access and usage depends on ______________ at any given moment
cellular metabolic needs
if you have just eaten and have normal glucose system, what happens with your glucose levels? what is triggered?
- glucose levels in blood normally goes up - temp hyperglycemia state
- pancreas triggered to secrete insulin to circulate to cells
- insulin assist in getting glucose molecules from blood into cell to use as main source of cellular energy
if intake of food/glucose is ______ than immediate cellular energy needs, insulin directs the ______ glucose to be stored as glycogen in the liver. what is this called?
greater, excess, glycogenesis
insulin triggers ________ building up process of 1). ______ entering cells and 2). creation of ______ (glycogenesis)
regulatory, glucose, glycogen
if you don’t eat and/or the availability of glucose is less than cellular energy needs a state of __________ (low blood sugar) usually exist.
hypoglycemia
what hormones are triggered by low blood glucose?
counterregulatory hormones
counterregulatory hormones are also called ____ because?
stress hormones because hypoglycemia is stressful for the body - they come to the rescue
what hormones are counterregulatory hormones?
- epinephrine from the adrenal medulla
- cortisol from the adrenal cortex
- growth hormone (GH) from the pituitary
- glucagon from the pancreas
what roles do the counterregulatory hormones have with hypoglycemia?
- alarms: sensations of hunger, shakiness, sweating, irritability telling you to EAT
- stimulate backup plan #1: glycogenolysis if you don’t eat
glycogenolysis
- conversion of glycogen to glucose for energy use in cells
- corrects hypoglyemia, results in higher blood sugar
- stop-gap measure until we can take in glucose
if glucose is either unavailable/cannot get into the cell to participate in metabolic pathway + glycogenolysis already exhausted person’s glycogen store, what happens?
gluconeogenesis (backup plan #2)
gluconeogenesis
- break down fats and protein
- use of any other substances besides carbohydrates for cellular energy
what is one of the breakdown products of fats and proteins?
ketones
good characteristic of ketones
offer body some energy - usually enuf to be a stop-gap until glucose is available
bad characteristics of ketones
- acids: over time, danger of acidosis
- can’t be used by brain cells - brain cells must have glucose for energy
dizzy, dull-witted, or cognitively challenged when hypoglycemic, what is happening? clinical significance?
brain cells are reliant on glucose for energy
- when deprived, become electrically disturbed
- can lead to unconsciousness, seizure, and/or death
- test blood sugar if patient presents with altered level of consciousness
glycogenolysis and gluconeogenesis are considered to be ___________, ___________ processes triggered by counterregulatory hormones when hypoglycemia is present.
breaking-down, counterregulatory
examples of disease processes related to cellular metabolism “back-up plans”
- glycogen storage diseases
- Type 1 diabetes
glycogen storage diseases
abnormalities in glycogenesis or glycogenolysis
example of glycogen storage disease
McArdle’s disease
- autosomal recessive disease in which normal ability to breakdown glycogen (glycogenolysis) is diminished
S&S of McArdle’s disease
muscle weakness and cramps during exercise bc no energy reserves
type 1 diabetes
gluconeogenesis taken to extreme
1). can’t make insulin
2). no insulin, glucose cannot get into cell
3). blood glucose level rise
4). body turns to sustained gluconeogenesis as main energy pathway
5). ketone overaccumulation in blood = hyperketonemia
hyperketonemia manifested/seen in tests by?
- blood test showing high serum ketones
AND ONE OF THE FOLLOWING: - blood test showing low (< 7.35) blood pH (ketoacidosis)
- urine test showing ketonuria (ketones spill into urine)
- S&S like acetone breath (excretion via lungs)
how does alterations in vitamin and mineral access or usage contribute to disruption in metabolic pathway?
- vitamins + minerals necessary to maximize ATP creation (need only small amts but is crucial for well-being)
- sufficient amts cannot be made by our body, so have to be supplied by diet
- vitamin deficiencies due to lack of availability of certain foods, poor dietary habits, and/or chronic disease
what is an example of a type of patient nurses often see who would be high risk for vitamin deficiencies?
an alcoholic
the byproducts of the body’s normal metabolic activities are slightly more ________ than ______. to counteract that _____ tendency, the body likes to keep a very narrow and slightly ______ pH range of blood, which is _____.
acidic, alkaline, acidic, alkaline, 7.35 - 7.45
often an alcoholic has very _____ diet - obtains ______ iron and B vitamins such as thiamine (and other ______)
poor, minimal, deficiencies
sequela of iron deficiency
- iron-deficiency anemia
- S&S related to low ATP and low oxygenation: weakness, fatigue, SOB
thiamine deficiency is called _____ and sequelae include _____ problems
beriberi, neuro
beriberi is the disease name of general thiamine deficiency. what is the group of neurologic S&S especially see in in alcoholics with beriberi?
Wernicke-Korsakoff syndrome
how does Wernicke-Korsakoff syndrome manifest?
memory loss and ataxia (staggering, uncoordinated gait)
____ is important in neurologic cell functioning. many S&S of depletion of this vitamin show up as ______ problems such as _____ and _____.
B1, neurologic, Wernicke-Korsakoff syndrome, paresthesia
paresthesia
numbness and tingling or other unusual sensations, usually in legs
- pins and needles feeling
T/F some medicinal & street drugs generally don’t interfere with vitamin absorption
FALSE
what poison can contribute to disruption in metabolic pathway?
cyanide
- present in insecticides, rodenticides, metal polish, burning wool, certain drugs (like nitroprusside)
- considered potential bioterrorism drug
S&S of poison toxicity
headache, agitation, confusion, vomiting, eventually resp problems, death
mechanism of action for poison disrupting metabolic pathway
inhibits cytochrome oxidase
homeostasis of solutes in the body means what?
there are approx the same sum of ions & other solutes inside each fluid compartment compared to the compartment “next door”
alteration in the solution composition in one compartment, a ________ begins
domino effect
what is the domino effect beginning when there is an alteration in the solution composition in one compartment referring to?
diffusion of solute particles resulting in changes in the next compartment, then the next, etc.
why does diffusion of solute particles occur in the following compartments?
body is always striving to return to normal/homeostatic composition of solutes in each compartment
changes in solute and fluid balance occurs first in the _____ then spreads to the _______.
plasma compartment (blood), tissue (interstitial fluid and cells)
_____ exist until body can right itself or get medical intervention as needed
changes/imbalances
therapeutic example of the domino effect of solute shifts from compart to compart
1). take K+ pills, digested and absorbed into blood vessels in lining of stomach + duodenum
2). K+ enters blood steam and increases K+ level -> electrolyte imbalance
3). blood circulates to various tissues
4). K+ eventually diffuse into tissue bc tissue has less K+ than blood
hyperkalemia
higher-than-normal numbers of K in blood
hypokalemia
lower-than-normal numbers of K in bloodh
hypernatremia
high Na+ in blood
hyponatremia
low Na+ in blood
hypercalcemia
high Ca2+ in blood
hypocalcemia
low Ca2+ in blood
normal electrical status exists when there is a normal distance (_________) between the two poles of:
polar gap status
- RMP of -90 mV
- goal charge of +30 mV (charge need for cell to contract/work)
what is affected when a disorder/disease/situation disrupts the normal balance of electrolytes in the blood?
balance of cations and anions in the tissue cells will be affected
the balance of cations/anions in the tissue cells causes the ______ of the cells’ RMP to a more positive # or less positive #
resetting
hypopolarization
RMP is reset to a MORE positive number than normal
- shorten polar status
hyperpolarization
RMP is reset to a LESS positive number than normal
- lengthen polar status
hypopolarized states
situations in which cell membranes have been reset to a MORE positive number than normal
- shortening polar gap status
- more sensitive
examples of states which cells become hypopolarized
- hypocalcemia
- hyperkalemia
- hypernatremia
general concept of hyperkalemia and hypernatremia causing hypopolarization
more cations (+) in the blood means that eventually, more cations will diffuse from the blood INTO cells
steps for hyperkalemia and hypernatremia causing hypopolarization
1). more cations in blood
2). cations diffuse from blood into cells
3). more positive state within the cell
4). cell membrane reset to more positive RMP
5). polar gap has shortened - less distance for cells’ change to get to depolarization point when stimulated by incoming electrical signal
6). increased sensitivity and quicker to contract/work
how does hypocalcemia cause hypopolarization?
- presence of low calcium levels in blood as blood circulates tissue beds triggers an INCREASE in permeability of cell membranes to Na+
- MORE Na+ allowed INTO the cell than normal
- more cations into cell causes increased positivity
S&S of hypopolarization
- muscles that are too sensitive (hyperactive, irritable)
- contact with smaller-than-normal stimulation, result in muscle tics or spasms (positive Chvostek’s sign)
- severe and/or unrelenting spasms is tetany
hyperpolarized states
situations in which cell membranes have been reset to a LESS positive number than normal
- lengthen polar gap status
- less sensitive
examples of states in which cells become hyperpolarized
hypercalcemia, hypokalemia, hyponatremia
general concept of hypokalemia and hyponatremia causing hyperpolarization
less cations in the blood, eventually more cations will diffuse OUT of the cells INTO the blood
steps for hypokalemia and hyponatremia causing hyperpolarization
1). less cations in blood
2). more cations diffuse out of cell into blood
3). less positive state within the cell since cations moved out
4). cell membrane reset to less positive RMP
5). cell hyperpolarized
6). more distance for cells’ charge to get to depolarization point when stimulated by incoming electrical signal
7). less sensitive - takes longer for cell to contract
hypercalcemia causes hyperpolarization how?
1). high calcium levels in blood as blood circulates in tissue beds
2). decrease in permeability of cell membranes to Na+
3). less Na+ allowed into the cell than normal
4). decreased cations in cell
5). decreased positivity
S&S of hyperpolarization
- muscles less sensitive than usual (hypoactive)
- contract more slowly
- fatigue, lethargy, mental slowness
ABGs stand for? what is it?
arterial blood gases: a measurement of oxygenation and acid/base balance in blood
CO2 and H+ in context of pH are?
acidic
HCO3 (bicarbonate) in context of pH is?
alkaline
too much CO2/H+ or too little HCO3?
acidosis
too little CO2/H+ or too much HCO3?
alkalosis
lungs control what gas? what do they have little control over?
CO2, HCO3
what organ rules over HCO3 and H+?
kidneys
pH normal range
7.35-7.45
HCO3 normal range
22-28
pCO2 normal range
35-45
pO2 normal range
80-100
SaO2 normal range
97-100%
acidosis
- most often clinically measured as part of ABGs: blood pH is < 7.75
body needs narrow range of slightly ______ to counteract an overall tendency of metabolic activates towards ______, which is a state not tolerated by the body
alkaline, acidosis
S&S of acidosis
- headache, disorentation
- nausea, vomiting
- muscle pain, cramps
- SOB, low BP, shock
- organ fail, death
metabolic acidosis
- acid/base imbalance releated to problem in the kidneys and/or any other disorder/body system except lungs
- low pH and low HCO3
metabolic acidosis is caused by a metabolic problem that results in one or more of what?
- excess accumulation of H+ (and other acids) in body
- not enough excretion of H+ in the urine
- not enough HCO3 being made
- too much HCO3 being excreted in the urine
example of metabolic acidosis etiology
1). available O2 in muscle used up from exercising too hard
2). hypoxia in tissue - anaerobic glycolysis for energy needs
3). pyruvate molecules created during glycolysis converted to lactic acid (full of H+)
4). lactic acid can convert to glucose in liver for emergency
5). too much lactic acid either locally or systemically become irritating to tissue and/or organ system
other examples of processes that may result in metabolic acidosis
- kidney failure: sick kidneys can’t excrete H+ or make HCO3 -> acid accumulation
- diabetic ketoacidosis: ketones accumulated bc body sustained gluconeogenesis
- posions, drug overdose, alc: breakdown products are acidotic
compensation for metabolic acidosis
- primary means via lungs
- lungs try to decease acids by INCREASING amt of CO2 EXHALED
- increase rate and/or depth of respirations
respiratory acidosis
state of low pH caused by ventilation problem such as diminished effectiveness of breathing or decreased resp rate
respiratory acidosis results in what?
retention of CO2 (acid accumuation)
respiratory acidosis is compensated by what?
kidneys: HCO3 production by the kidneys increased to buffer situation/counteract acid
alkalosis
- blood pH > 7.45
- less common than acidosis
- high pH and high HCO3
etiology of metabolic alkalosis
- excess accumulation of HCO3 in the body
- not enough excretion of HCO3 in the urine
- too much acid (H+ and others) being excreted in urine or lost in other metabolic ways
- not enough acid being made
causes of metabolic alkalosis
- large amount of vomiting
- over-ingestion of bicarbonate (HCO3)
compensation of metabolic alkalosis
via lungs - decease rate and depth od respirations
respiratory alkalosis
state of high pH caused by hyperventilation
- increase rate of breathing = blowing off more CO2 = less CO2 in blood = higher pH
example of a cause of respiratory alkalosis
anxiety - when anxious, begin hyperventilating
compensation of respiratory alkalosis
kidneys, decrease amt of of HCO3 made or increase excretion
