Day 4.1 Psych Flashcards
Voluntarily choosing not to think of bad news
Suppression
Mature, bc it’s voluntary
Using comedy to express discomfort
Humor
Mature
Arsonist donates money to fire dept
altruism
mature
Using your aggression to succeed in business ventures
sublimation
mature
realistically planning for future discomfort
anticipation
mature
consciously postponing inner conflict until after big project is complete
suppression
mature
Redirecting impulses toward socially favorable object
sublimation
eg hitting pillow when angry
mature
Not acknowledging bad news as if it weren’t said
denial
Involuntary withholding of a feeling from conscientious awareness
repression
immature bc it’s involuntary
Veteran that can describe horrific war details without any emotion
isolation
child abuser who was abused as a child
identification
Man yells at family when had bad day at work
Displacement
this is immature bc it’s redirecting impulses to a socially unfavorable thing (vs sublimation to a favorable thing eg punching bag)
Closet homosexual hates homosexuals for the way the “make” him feel
projection
using intellectual processes to avoid affective expression
intellectualization
belief that ppl are either all good or all bad
splitting
borderline personality disorder pts do this
expressing anger thru passivity, masochism, and turning against self
passive-aggressive
believing external source is responsible for unacceptable inner impulse
projection
changing one’s character/personal identity to avoid emotional distress
dissociation
returning to earlier level of maturation to avoid conflict at current maturational level
eg stressed kids wet bed
regression
offering an explanation for an unacceptable attitude/belief/bhvr
rationalization
a thought that is avoided is replaced by an unconscious emphasis on the opposite
rxn formation
converting mental conflicts into bodily symptoms
somatization
temporarily inhibiting thinking but continuing to build more tension
blocking
schizophrenic pts do this
avoiding interpersonal intimacy to resolve conflict and obtain gratification
schizoid fantasy
extreme forms of this can result in multiple personalities
dissociation
chronically giving into impulse to avoid tension from an unexpressed unconscious wish; tantrums
acting out
Electrolyte chgs in pts who vomit a lot (eg bulemics)
hypokalemic, hypochloremic metabolic alkalosis
NT chgs in depression
decreased NE, serotonin, dopamine
opp is mania
NT chgs in anxiety
Increased NE
Decreased GABA and serotonin
NT chgs in Huntington’s
Decreased GABA and ACh
NT chgs in Alzheimers
Decreased ACh
NT chgs in schizophrenia
Increased dopamine
NT chgs in Parkinson’s
Decreased dopamine
Increased ACh
IQ
Stanford-Binet: IQ = mental age/chronological age x 100
WAIS III uses 14 subtests- can quantify intellectual decline
WISC is for kids 6-16yo
Mean IQ = 100, st dev = 15
IQ dx for MR
IQ <20 profound
Habituation, Sensitization
Habituation = repeated stimulus leads to decreased response Senitization = repeated stimulation leads to increased response
Classical conditioning
Pavlov Natural response (salivation) is elicited by a condition/learned stimulus (bell) that was presented together with an unconditioned stimulus (food).
Operant conditioning
Action is elicited bc it produces reward.
Positive reinforcement- desired reward produces action (press button, get food)
Negative reinforcement- do an action to remove a bad thing/avoid something bad (press button to avoid shock)
Punishment- adverse stimulus extinguished unwanted bhvr
Extinction- discontinuation of reinforcement eliminates bhvr
Reinforcement schedule
Pattern of reinforcement determines how quickly a bhvr is learned or extinguished.
Continuous- reward after every response. rapidly extinguished (vending machine)
Variable ratio- reward received after a random number of responses. slowly extinguished (slot machine)
Transference
Countertransference
Transference: pt projects feelings abt formative or other imp person onto doc (eg psychiatrist = parent)
Countertransference: doc projects onto pt
Goal of Freudian psychoanalysis
Mk pt aware of what is hidden in their unconscious
Id
Primal urges, food, sex, aggression.
Id drives Instinct
Entirely subconscious
“I want it”
Ego
Mediator bt primal urges and bhvr accepted in reality.
“Take it and you will get in trouble”
Superego
Moral values, conscience
Can lead to self-blame and attacks on ego
“You know you can’t take it, taking it is wrong”
Erikson’s stgs of psychosocial development
8 stgs of normal devt, each posing a new crisis. unsuccessful completion of a stage can manifest as psychosocial maladaption later in life.
Oral sensory stg 0 to 12-18mo (crisis = trust vs mistrust)
Adlescence stg 12-20 yrs (crisis - identity vs role confusion)
Ego defenses
unconscious mental processes of the ego used to resolve conflict and prevent anx and deprsn. can be immature or mature
Acting out
unacceptable thoughts/feelings expressed through actions.
tantrums
Dissociation
Temporary, drastic chgs in personality, memory, consciousness, motor bhvr, to avoid stress
Extreme forms = dissociative id disorder (mult personality)
Denial
Avoidance of awareness of a painful reality
Common newly-dx’d in cancer and AIDS pts
Displacement
Avoided ideas/feelings are txfrd to a neutral person or object (vs projection)
Mom blames kids bc she’s angry at husband
Fixation
Partially remaining at a more childish level of devt (vs regression)
Men fixating on sports games
Identification
Modeling behavior after another person who is more powerful (tho not nec admired)
Abused child is an abuser
Isolation of affect
Separation of feelings from ideas/events
Describing murder in graphic detail w no emotional response
Projection
Unacceptable internal impulse is attributed to an external source
Man who wants another woman think his wife is cheating
Rationalization
Proclaiming logical reasons for actions actually performed for other reasons, usu to avoid self-blame
After getting fired, saying job wasn’t imp anyway.
Reaction formation
Warded-off idea/feeling is replaced by an unconsciously derived emphasis on its opposite
pt w high libido enters monastery
Repression
Involuntary withholding of idea/feeling from conscious awareness
Not remembering conflictual/traumatic experience, pressing bad thoughts into unconscious
Regression
Turning back maturational clock and going back to earlier modes of dealing w the world
kids under stress (bedwetting)
pts on dialysis (crying)
Splitting
belief that ppl are all gd or bad at different times due to intolerance of ambiguity.
Seen in borderline personality disorder
Pt says all nurses are insensitive but all docs are friendly
Altruism
Guilty feelings alleviated by unsolicited generosity toward others
Mafia boss mks donation toward charity
Mature
Humor
Appreciating the amusing nature of an anx-provoking/ adverse situation
Nervous med student jokes abt boards
Mature
Sublimation
Replacing unacceptable wish w course of action that is similar to the wish but does not conflict w one’s value system
Actress using experience of abuse to enhance her acting.
mature
Suppression
Voluntary withholding of an idea or feeling from conscious awareness (vs repression, which is involuntary)
Choosing not to think abt USMLE until week of exam
Mature
Mature ego defenses (4)
Mature women wear a SASH: Sublimation Altruism Suppression Humor
Infant deprivation effects
Long-term deprivation results in: 1. decrsd musc tone 2. poor lang skills 3. poor socialization skills 4. lack of basic trust 5. anaclitic deprsn 6. weight loss 7. physical illness Severe deprivation can result in infant death. 4 W's weak, wordless, wanting, wary If deprivation >6 mo, irrev chgs
Child abuse signs
healed fractures on x-ray cigarette burns subdural hematoma mult bruises retinal hemorrhage/detachment sexual: genital/anal trauma, STDs, UTIs
Child abuse epi
abuser usu female and primary caregiver
3000 deaths/yr in USA
if sexual:
abuser usu male and known to victim
peak incidence 9-12 yo (prepuberty)
Child neglect
failure to provide adequate food, shelter, supervision, education, affection
most common form of childhood mistreatment.
evidence: poor hygiene, malnutrition, withdrawal, impaired social/emotional devt, FTT
Must be reported to authorities
More common than overt abuse
Anaclitic deprsn (hosptialism)
Deprsn in infant d/t continued separation from caregiver. Infant withdrawn, unresponsive.
Reversible, but prolonged separation can result in FTT or devt disturbances - delayed speech.
Regression in children
Regression to younger bhvr patterns under condition of stress- physical illness, punishment, new sibling, fatigue.
eg bedwetting
ADHD
limited attn span, poor impulse control.
onset <7yo
hyperactivity, motor impairment, emotional lability
normal intelligence but difficulties in school
cont to adulthood in 50%
assoc w decreased frontal lobe volume
Rx for ADHD
methylphenidate (ritalin)
amphetamines (dexedrine)
atomoxetine (non-stimulant SNRI)
Conduct disorder
repetitive, pervasive bhvr violating social norms- physical aggression, destruction of property, theft.
After 18yo is antisocial personality disorder
Disregard for rights of others
Cruelty to animals
Oppositional defiant disorder
pattern of hostile, defiant bhvr toward authority
but, not serious violation of social norms
don’t disregard rights of others
Tourette’s synd
sudden rapid reccurent non-rhythmic sterotyped motor mvmts or vocalizations- tics. persist for >1year Lifetime prev .1-1% of general pop Coprolalia (obscene speech) found in 20% assocd w OCD onset <18yo
Rx for Tourette’s
antipsychotics old (in FA): haloperidol now (in DIT): anti-dopamine agents- fluphenazine, pimozide, tetrabenazine
Separation Anx Disorder
overwhelming fear of separation from home or loss of attachment figure. may lead to faking illness to stay home from school
age 7-9 onset
Autistic disorder
MR
severe lang impairment, poor social interactions, greater focus on obj than ppl.
repetitive bhvr
savants rarely
M>F
Rx: bhvrl therapy and supportive therapy to improve communication and social skills
Asperger’s disorder
Normal intelligence
milder autism. all-absorbing interests, repetitive bhvr, problems w social relationships
no verbal or cognitive deficits, no lang impairment
Rett’s disorder
X-linked dominant, so affects girls only (boys die in-utero/after birth)
Normal to age 4, the regression- loss of devt, MR, loss of verbal abilities, ataxia, stereotyped midline handwringing.
Childhood disintegrative disorder
Marked regression in multiple areas of fn’g after at least 2 years of apparently normal devt. Loss of expressive or receptive lang skills, social skills, adaptive bhvr, bowel/bladder control, play, motor skills.
Common onset 3-4 yo
M>F
Orientation
order of loss:
first lose time, then place, then person.
(can also lose circumstances- don’t know why they’re in the hospital. lose this last)
Common causes of loss of orientation:
alch/drugs, fluid/electrolyte imbalance, head trauma, hypoglycemia, nutritional deficit
Retrograde amnesia
can’t remember what occurred before CNS insult
Anterograde amnesia
no new memory- can’t remember what occur after CNS insult
Korsakoff’s amnesia
anterograde amnesia (no new memory) caused by thiamine deficiency.
leads to bilateral destruction of mammillary bodies.
can also lead to retrograde amnesia
seen in alcoholics, assocd w confabulations
Dissociative amnesia
inability to recall imp personal info, usu subsequent to severe trauma or stress
Delirium
Waxing/waning lvl of consciousness
Acute onset (hrs/days)
Rapid decrease in attn span and lvl of arousal
Acute chg in mental status, disorg’d thinking, hallucinations (often visual), illusions, misperceptions, disturbance in sleep-wake cycle, cogntv dysfn
Often reversible
Most common psych illness in hospital
Abn EEG
2 most common causes of delirium:
Drugs (esp those w anti-ACh side effects)
UTIs
Dementia
Gradual decline in cognition (wks/mo/yrs)
NO chg in lvl of consciousness
Mem deficits, aphasia, apraxia, agnosia, loss of abstract thought, bhvr/personality chgs, impaired judgement
Pt is alert.
Increased incidence w age
Normal EEG
Irreversible
Pseudodementia
In elderly pts, depression presenting like dementia.
If you are depressed you have memory loss and you know you have memory loss
Pts w actual dementia don’t know they have memory loss.
So if pt himself complains of mem loss, it’s not dementia, may be deprsn.
Cause of Dementia
Alz dz Vascular thrombosis/hemorrhage (esp multi-infarct thrombosis)- can have acute or subacute onset HIV Pick's dz Substance abuse (esp alch) CJD
Drugs used in ADHD
Methylphenidate (ritalin) and dextroamphetamine (adderall) are amphetamines- they increase pre-synaptic NE rls
Atomoxetine is a NE reuptake inhibitor
Uses of stimulants (NE releasers, NE uptake inhibitors)
ADHD
Narcolepsy (modafinil)
Obstructive sleep apnea (excessive daytime sleepiness)
Mjr depressive disorder- bridge until other drugs start working
Most common genetic causes of MR
Downs
Fragile X
Rett synd
Non-genetic prenatal causes of MR
Congenital hypothyroidism
FAS (most common)
Prenatal toxin exposure (lead, merc, valproate- anticonvulsant, mood stabilizer)
Non-genetic postnatal causes of MR
trauma/abuse CNS hemorrhage hypoxia (near drowning) toxins psychosocial deprivation malnutrition intracranial infection CNS malignancy
Trichotillomania
Compulsive nervous hair-pulling young girls wire-brush feel, pattern of broken hair Rx: education, CBT only if those don't work: fluoxetine or clomipramine
Hallucination
see something that’s not there (absence of external stimuli)
schizophrenic- auditory
alch withdrawal- tactile
dementia- visual
Illusion
See things that are there but misinterpret them
Delusion
false belief not shared w others of culture.
maintained in spite of proof to contrary
Loose associations
disorders in form of thought/way ideas are tied together.
Gender identity disorder
cross-gender identification. persistent discomfort/anx w one’s sex
transsexual- chg body w surgery to relieve the anx
not transvestite
Anorexia nervosa
excessive dieting
can be with or w/o purging
commonly coexists w depression
rx CBT
Bulemia nervosa
binge eating
can be w or w/o purging
use laxitives
assoc w parotitis bc increased salivary amylase (systemically)
russell’s sign- hand callus from inducing vom
electrolyte disturbances, alkalosis
rx SSRIs
What electrical disturbances happen when you vom a lot?
Vomit = get rid of HCl, so you have hypochloremia and metabolic alkalosis
Also get hypokalemia: cells have H+/K+ countertransporter. To counteract the alkalosis, cells put acid into serum, which means they pull the K+ out of serum and into cells.
Hypochloremic, hypokalemic metabolic alkalosis.
Why do Down Syndrome pts have an increased risk of Alz?
familial form early-onset Alz is assoc’d with APP gene, which is on chromosome 21. Down syndrome pts have 3 copies of chr 21.
APP = amyloid precursor protein
Genes assoc’d with Alz
Familial form (10% of Alz) is assoc’d with:
Early-onset: APP on Chr 21
Presenilin-1 on Chr 14
Presenilin-2 on Chr 1
Late-onset: ApoE4 on Chr 19 (Apo E4 is a chaperone protein that helps induce B-sheet formation)
Protective gene:
ApoE2 on Chr 19
Histological findings in Alz
Diffuse widespread cortical atrophy
Decreased ACh
Senile plaques (extracellular B-amyloid core)- can cause amyloid angiopathy, leading to intracranial hemorrhage (AB-amyloid is synth’d by cleaving amyloid)
Neurofibrillary tangles
What are neurofibrillary tangles?
Intracellular, abnormally phosphorylated tau protein, making insoluble cytoskeletal elements.
Tangles correlate with degree of dementia
High potency neuroleptic (antipsychotic)
Haloperidol
Fluphenazine
Thiothixene
Trifluoperazine (can also be considered moderate potency)
High potency means more EPS side effects, less anti-ACh side eff
Moderate potency neuroleptic (antipsychotic)
Molindone
Loxapine
Trifluoperazine (can also be considered high potency)
Low potency neuorleptic (antipsychotic)
Chlorpromazide
Theoridazine
Low potency means less EPS side effects, but more anti-ACh side effects (hot as a hare, dry as a bone, etc)
Atypical antipsychotics
Olazapine Risperidone Quetiapine Clozapine Aripiprazole
Halperidol
High potency neuroleptic
Molindone
Moderate potency neuroleptic
Loxapine
Moderate potency neuroleptic
Fluphenazine
High potency neuroleptic
Risperidone
Atypical antipsychotic
Clozapine
Atypical antipsychotic
Thiothixene
High potency neuroleptic
Theoridazine
Low potency neuroleptic
Olanzapine
Atypical antipsychotic
Trifluoperozine
High/moderate potency neuroleptic
Chlorpromazine
Low potency neuroleptic
Quetiapine
Atypical antipsychotic
Apiprazole
Atypical antipsychotic
Alz dz epi
More common in elderly, down synd pts have increased risk.
10% familial
Pick’s dz
Frontotemporal dementia.
Change in personality, behavior (1st), then dementia, aphasia, parkinsonian sympt
Spares parietal lob and posterior 2/3 of superior temporal gyrus, but pt has frontotemporal atrophy.
Pick bodies
What are Pick Bodies?
intracellular (inside of neurons), aggregated tau protein
Stain with silver
seen in Pick’s dz (frontotemporal dementia)
In which dz’s are Lewy bodies seen?
Lewy body dementia
Alzheimer’s (the diffuse lewy body type of Alz)
Parkinson’s
Lewy Body Dementia
Parkinsonism plus dementia and visual hallucinations, with repeated falls and syncopal episodes.
alpha-synuclein defect
see lewy bodies
CJD
Prion dz- infections proteins chg alpha helix to beta sheet, which are resistant to proteases and heat
Rapidly progressive dementia (wks-months) with myoclonus
Causes spongiform cortex
Causes of dementia
Alz, Pick's, Lewy body, CJD Multi-infarct (2nd most common in elderly) syphilis HIV B12 deficiency Wilson's dz (copper accumulations)
Drugs for Alz
Memantine
Donepezil
Galantamine
Rivastigmine
Donepezil
Anti-AChE
for Alz
Memantine
NMDA receptor antagonist
for Alz
Galantamine
AChE inhibitor
for alz
Rivastigmine
AChE inhibitor (indirect muscarinic agonist) for alz
Haloperidol
dopamine receptor antagonist
neuroleptic
for Huntington’s
Memantine- mech, toxicity
Used for Alz
NMDA (glutamate) receptor antagonist
helps prevent excitotoxicity (mediated by Ca2+)
Toxicity: dizziness, confusion, hallucinations
Donepezil, Galatamine, Rivastigmine
Used for Alz
ACh-E inhibitors
Toxicity: nausea (start low, go slow!)
also dizziness, insomnia
Sumitriptan
Serotonin 1b/1d agonist
use for acute migrane, cluster headaches
Schizophrenia pos sympt
Adding something: Delusions Hallucinations (esp auditory) Disorganizes speech (loose assoc) Disorganized/catatonic bhvr
Schizophrenia neg sympt
Takes something good away: flat affect social withdrawal lack of motivation lack of thought, speech (alogia) thought blocking (abruptly halt train of thought) poor grooming
Dx of schizophrenia
req’s 2 of 5 things (the 4 pos sympt + negative symptoms counts as 1)
Brief psychotic disorder
<1month
usu stress related
Schizophreniform disorder
1-6months
6mo = schizophrenic
Schizoaffective disorder
at least 2 wks of STABLE mood w psychotic sympt
plus a mjr depressive, manic, or mixed (depressive+manic) episode
2 subtypes:
bipolar
depressive
Schizophrenia
Periods of psychosis and disturbed bhvr with a decline in functioning
>6mo
Associated with increased dopaminergic activity (too much dopamine) and decreased dendritic branching
Mj use is a risk factor in teens
5 subtypes of schizophrenia
paranoid (delusions) disorganized (wrt bhvr, speech, affect) catatonic (automatisms) undifferentiated (elements of all types) residual
Which is more imp for schizophrenia, genes or env?
Genes
Schizophrenia epi
Lifetime prev 1.5% (!!) M = F Black = white Presents earlier in men (late teens- early 20s) than women (late 20s/early 30s) Pts are at increased risk for suicide
List the neuroleptics/antipsychotics (typical)
Haloperidol Trifluoperazine Fluphenazine Thioridazine Chlorpromazine (haloperidol + -azine)
How do neuroleptics work?
They block D2 dopamine receptors, thereby increasing cAMP.
Schizophrenia is increased dopamine, so it’s good to block the receptors.
D2 = Gi, which decreases cAMP. Block the inhibitor to increase cAMP.
Use of neuroleptics
Schizophrenia (mainly pos sympt) psychosis acute mania Tourette's synd to decrease agitation in delerium, dementia
Toxicity of neuroleptics
- slowly removed from body (bc highly lipid soluble so stored in body fat)
- EPS side effects
- endocrine side effects (D2 receptor antagonism means dopamine no longer suppresses prolactin, so hyperprolactinemia, so galactorrhea)
- side eff from blocking muscarinic receptors (dry mouth, constipation), alpha receptors (hypotension), and histamine receptors (sedation)
- NMS, Tardive dyskinesia
What is Neuroleptic malignant syndrome (NMS)?
Rigidity, myoglobinuriam autonomic instability, hyperpyrexia Caused by neuroleptics. Breakdown of muscle --> myoglobinura -->kidneys clog (rhabdomyolysis) --> renal failure For NMS think FEVER: Fever Encephalopathy Vitals unstable Elevated enz Rigidity of muscles
Rx for NMS
Dantrolene Dopamine agonists (bromocriptine)
What is tardive dyskinesia?
Stereotypical oral-facial mvmts d/t long-term anti pscyhotic use.
Often irrev
Low potency neuroleptic side effects
low potency = less EPS side effects but more anti-ACh side effects
Chlorpromazine- Corneal deposits
Thioridazine- reTinal deposits
EPS extra pyrimidal symptoms
4hrs- acute dystonia (muscle spasm, stiffness, oculogyric crisis-rotating eyeballs, torticollis-neck twisting
4days- akinesia (parkinsonian sympt)
4wks- akathisia (restlessness, can’t stop mvmt)
4mo-tardive dyskinesia
List the atypical antipsychotics
OLanzapine, CLOzapine, QUETIapine, RISPERidone, Aripiprazole, Ziprasidone
It’s atypical for OLd CLOsets to QUIETly RISPER from A to Z
How do the atypical antipsychotics work?
They block serotonin, alpha, H1, and dopamine receptors.
Have less side effects bc they block both dopamine and serotonin, but do get alpha and H1 side effects
Schizophrenia sympt for <1mo
brief psychotic disorder, usu stress related
Schizophrenia sympt for 1-6mo
Schizophreniform disorder
Schizoid
Avoidant
Schizotypal
Odd thinking
Schizophrenic sympt >6mo + bipolar or depressive mood disorder
Schizoaffective
Schizophrenic sympt >6mo
Schizophrenia
visual hallucinations
delerium
auditory hallucinations
schizophrenia
olfactory hallucinations
aura of psychomotor epilepsy
esp burning rubber smell
tactile hallucinations
alch withdrawal
formication-ants crawling in skin
also seen in cocaine abuse - cocaine bugs
hypnagogic hallicinations
when going to sleep
hypnopompic hallucinations
while waking up from sleep
delusional disorder
> 1mo fixed persistent NON-bizarre belief system
functioning not impaired
often self limited
strange thoughts, but not outside scope of reality
shared psychotic disorder
folie a deux
devt of delusions in a person in a close relationship w someone else w delusional disorder.
often resolves upon separation
dissociative identity disorder
mult personality disorder
presence of 2 or more distinct identities or personality states
F>M, assoc w hx of sexual abuse
depersonalization disorder
persistent feelings of detachment or estrangement from oneself
dissociative fugue
abrupt chg in geographic location w inability to recall past, confusion abt personal identity, or assumption of new identity
assocd w traumatic circumstances (natural disaster, wartime, trauma)
leads to significant distress/impairment
not the result of substance abuse or medical condition
Clinical use for atypical antipsychotics
Schizophrenia (both pos and neg sympt)
Olazapine is used for OCD, anx disorder, depression, mania, bipolar, Tourette’s, depression
Quetine can treat psychosis d/t parkinson’s
Toxicity of atypical antipsychotics
Fewer EPS and anti-ACh side effects than traditional antipsychotics (haloperidol and the -azines), but olanzapine, clozapine, quetine can cause signficant weight gain (and DM bc of it).
Clozapine can cause agranulocytosis and req’s weekly monitoring of WBCs
Since they block alpha receptors, there can be some HTN, sedation, dizziness
The H1 blockage is responsible for the weight gain, and also sedation.
Rx for side effects: Amantidine (Parkinson’s med)
Dantrolene
Drug used for malignant hyperthermia and NMS- neuroleptic malignant syndrome.
Prevents rls of Ca2+ from Sarcoplasmic Reticulum of skel musc, therefore stopping muscle contraction.
Malignant hyperthermia
Uncontrolled increase in skeletal muscle oxidative metabolism- causing high temp, incrsd HR and respi rate, increased O2 consumption with increased CO2 production, acidosis, rigid muscles (contraction), rhabdomyolysis.
Caused by concomitant use of inhalation anesthetics (the -anes, except N2O) and succinylcholine (NMJ blocker).
Genes involved in malignant hyperthermia
Autodom gene mutation in RYR1 gene, which makes the skeletal muscle’s ryanodine Ca2+ receptor
