Week 3 Sem 2 Med1022 Flashcards

Question

other notes for cross bridge cycle

Answer 1

the faster u split the ATP the faster the cycle can keep going/repeat (i.e. faster rate of cycle) the faster the muscle can contract/shorten ie myosin ATPase activity is a determinant of muscle speed

Answer 2

muscle stays same length tension mite be fluctuating, e.g. holding weights still the invisible chair

Answer 3

u overcome the force n the muscle shortens muscle contracts against a load that it is able to move eg lifting up dumbell

Answer 4

tension stays the same length of muscle changes energy required by muscle changes

Answer 5

the opposing force is greater than the force created by the muscle and the muscle lengthens e.g. putting down dumbbells walking down steep hill if u keep doing this u get DOMS (Delayed Onset Muscle Soreness)

Answer 6

muscles with opposing actions one muscle is flexing and one is extending the joint eg bicep n tricep

Answer 7

muscles doing same action two muscles which work in conjunction with one another to perform the same movement across a joint

Answer 8

when a resting muscle is stretched Reflects passive elastic property of the muscle nothing to do wit contraction

Answer 9

force generated by the crossbridges during a contraction depends on the length of the muscle

Answer 10

channels that release Ca2+ on Lateral sac of sarcoplasmic reticulum

Answer 11

at optimal muscle length: all cross bridges attached = max force is produced ??? at longer lengths less force less overlap bw thin n thick filaments less cross bridges ??? at shorter lengths less force but reason is complex Z-lines hit ends of thick filaments causing them to buckle

Answer 12

‘voltage sensors’ on T-tubule

Answer 13

work done= load x distance

Answer 14

1.amount by which the muscle shortens: lighter the load the further the muscle can shorten?? 2. velocity, or speed, at which it shortens lighter the load the faster the muscle can shorten

Answer 15

Distance Shortened/ time

Answer 16

relationship between load and the velocity of muscle shortening fastest velocity of shortening (Vmax) occurs with zero load (determined by its myosin ATPase activity bc this determines how quickly the crossbridges can cycle) lowest velocity of shortening = zero wen muscle cant move the load (i.e. isometric contraction)

Answer 17

rate at which work is done

Answer 18

Power= work done/time power= load x distance/time load=force, distance/time=velocity =\> power= force x velocity

Answer 19

determined by the force muscle is generating and the velocity at which it is shortening

Answer 20

wen muscle is contracting wit 1/3 max force and 1/3 max velocity

Answer 21

Response to a single action potential contraction lasts much longer than the AP that triggered it also a latent period bw AP and contraction (cos takes time for EC-coupling (excitation-coupling) to occur)

Answer 22

wen a second contraction builds on the first, producing an overall higher force occurs wen a 2nd AP produced while muscle still contracting to 1st AP.

Answer 23

Response to repetitive stimulation if stimulation not very frequent, get unfused tetanic contractions if stimulation very frequent, get fused tetanic contractions

Answer 24

optimal muscle length + force in a fully fused tetanic contraction

Answer 25

only recieves

Answer 26

wen we vary the number of motor neurons going to a whole muscle so that we can get different numbers of muscle fibers being contracted (btw, wen there is an AP in a motor neuron, ALL of the muscle fibers innervated by that neuron (ie motor unit) will contract

Answer 27

generally smaller motor units r recruited first befor bigger ones (cos they have smaller cell bodies, hence, lower thresholds for excitation)

Answer 28

1. _Contractile strength gradation _: the more motor units recruited, the stronger the overall contraction will be (each motor unit can also grade its own contraction by varying the frequency of AP firing) 2. _Fatigue reduction_: allow the contractile work 2 b shared bw muscle fibers (fanks to asynchronous activation of different motor units)

Answer 29

1. Varying muscle length Length - Force Relation of Muscle 2. Varying the frequency of excitation varying the rate of firing motor nerves 3. Varying the number of motor units activated Recruitment

Answer 30

anaerobic aerobic

Answer 31

1. The Creatine Phosphate (CP) immediate energy pathway 2. Anaerobic metabolism (ie glycolysis) 3. Aerobic metabolism (aka Oxidative Phosphorylation)

Answer 32

basically creatine phosphate + ADP -\> ATP + Creatine very fast but limited (depends on availability of creatine phosphate

Answer 33

Relatively insufficient-only get 2 ATP per glucose molecule Need glucose as fuel (from blood or muscle glycogen stores vERY fast don’t need oxy- but lactic acid produced

Answer 34

very efficient (get 38 ATP per glucose but slow can use glucose, fats or proteins

Answer 35

mainly use FATS

Answer 36

mainly use CARBO

Answer 37

the longer it takes to exhaustion (aka " carbo loading ")

Answer 38

1. Type I fibers/slow fibers/slow-oxidative fibers/slow motor units 2. Type IIA fibers/fast-oxidative fibers/ Fast fatigue-resistant motor units 3. Type IIB fibers/fast-glycolytic fibers/Fast fatigueable motor units

Answer 39

1. Mainly does oxidative phosphorylation 2. Fibers r small in diameter 3. Motor units r small 4. Lots of capillaries (cos need 02) n mitochondria present 5. Myoglobin content high (red muscle) 6. For prolonged contractile activity with high endurance (e.g. maintaining posture)

Answer 40

1. Mainly does oxidative phosphorylation 2. Fibers r intermediate in diameter 3. Motor units r intermediate 4. Lots of capillaries n mitochondria present 5. Myoglobin content high (red muscle) 6. For relatively fast movements with medium endurance

Answer 41

1. Mainly does glycolysis 2. Fibers r large in diameter 3. Motor units r large 4. Few capillaries n mitochondria present 5. Myoglobin content high (red muscle) 6. For rapid, powerful movements

Answer 42

decrease in ability to generate force during prolonged activity

Answer 43

very resistant to fatigue moderately resistant to fatigue fatigues most rapidly

Answer 44

1. speed of contraction cant change 2. slow fibre cant change to fast fibre 3. transition bw type II fibres possible 4. proportion of type I and type II fibres genetically determined

Answer 45

increases oxidative capacity of all muscle fibres involved (doesnt matter type) mito, oxidative enzymes + capillaries increase can increase diameter of type I fibers (makes them stronger) some type IIB fibers may change to type IIA fibers

Answer 46

increases capactiy of anaerobic pathways in fibers involved increases conc of glycolytic enzymes type IIA to type IIB transitions increase muscle fiber size (diameter) in all muscle types (greater increase achieved than with endurance ttraining)

Answer 47

more actin n myosin laid down= get bigger cells btw testosterone promotes synthesis of actin n myosin never get MORE muscle cells

Answer 48

age related decrease in skeletal muslce mass n strength exercise as treatment strategy

Answer 49

Basic Trust vs. Mistrust (Infancy) (0-1 yr) basically, kid is dependent on n looked after by caregiver (usually mother) consistantly the care of caregiver develops basic sense of trust n openess in kid

Answer 50

Autonomy vs. Shame and Doubt (1-3 years) * children starts to have control over own action n does 'cool stuff' eg run around, manipulate objects * but if fail, there is shame n doubt * eg 'i willcarry my lego by myself', then drops it

Answer 51

Initiative vs. Guilt (3-5 years) * Children develop imagination for possibilities * kids' imagination in play flourishes * if they want to play somethin, but someone else doesnt, guilt comes in for the child who’s at odds with other children, the challenge here is being able to cooperate with others * get support from parents= initiative and cooperation are developed

Answer 52

* basically, attachment (human behaviour) is a evolutionary survival advantage * attachment= security + need for physical closeness with someone * usually attachment to mother, but could b any caregiver

Answer 53

1. Preattachment Stage (Birth to 6-8 weeks) 2. Attachment in the Making (6-8 wks to 6-8 mnths) 3. True Attachment (6-8 months to 18 months) 4. Reciprocal Relationships (18 mnths on)

Answer 54

in this stage, newborns will attach to anyone, not picking who’s who yet

Answer 55

starts to work out who mother is thinks mothers do it better can select out mum eg at party, kid passed around but kid cries, wen back to mum, stops cring

Answer 56

gives the infant a secure base to explore the world eg kid crawls forward, then looks back to mother 2 check if its ok

Answer 57

the infant has basic capacity to care for the parent eg kid wants to go to the park, so gets sneakers n gives them to parent (so parent can help him tie on his shoelaces

Answer 58

* usually its attachment to mum first, then father relationship development follows * dad tends to spend more time playin kid, while mum more for comforting eg dad plays with kid, but wen kid falls n hurts himself, calls mum first to care

Answer 59

1. SECURE ATTACHMENT * wen mum returns, kid is comforted/cryin stops. kid explores again 2. AVOIDANT ATTACHMENT * kid just ignores/turns away fr mum, continues wat kid was doin * child doesnt get much from mother- there is this expectiation that kid should be independent 3. RESISTANT ATTACHMENT * kid is upset n remains upset * stress n ambivalence present * ‘i need u to be here n u werent here!’ ‘im really not happy bout this situation’ 4. DISORGANIZED ATTACHMENT * kid is confused-not sure how to react * most concerning type * seen where there is abuse/neglect * ns wat's gonna happen next/wat mother can provide

Answer 60

1. most kids r in secure attachment, least % of kids in disorganised attachment 2. this attachment is kindof 2 way: not just kid but also parent has effect. * ESSENTIALS FOR PARENTING 1. warmth 2. sensitivity 3. responsiveness 4. dependability

Answer 61

* basically kids wit more secure attachments= better social relationships later on, more confident and successful with peers, better mental health etc * children use early attachments as prototypes (ie the internal workin model) for later relationships and interactions

Answer 62

expectations derived from early caregiving experiences (concerning the availability of attachment figures and one’s interaction with those figures)

Answer 63

1. 1 year= kids play alongside each other without much interaction 2. 15-18 months= kids do similar activities (eg most play lego) + smile at each other in simple social play , but no intergrated play yet 3. 2 years=kids play togez eg lets play chasey, or build this structure etc interactive play

Answer 64

1. bw ages 2-3, boys tend 2 play wit boys, girls play wit girls for all types of activities 2. Girls tend to support girl peers in enabling 3. boys tend to compete/contradict/threaten boy peers in activity known as constricting

Answer 65

## Footnote any behavior that benefits others

Answer 66

1. behavior that does not benefit oneself but does benefit others, such as helping and sharing 2. kids as young as 18 mnts show altruism 3. skill underlying altruistic behaviour is empathy

Answer 67

someone wit disease/condidtion that we're interested in

Answer 68

someone who doesnt have the disease/condition that we're interested in (opposite to case)

Answer 69

anything that influences the likelihood of someone getting the disease/condition we''re interested in

Answer 70

1. eg **ideas/editorials/opinions**, **case reports** (wen ppl have seen something unusual n they’ve written it up), **case series** (=series of those observations) 2.

Answer 71

1. observations made on GPS not INDIVIDUALS (hence not on flow chart) 2. can suggest that something is associated wit somethin =good for makin hypothesis 3. problem: ecological fallacy: eg info collected about alcho. consump. n liver cirrho. was not collected from the same ppl\>so cant assume cause n effect

Answer 72

1. basically ask ppl about themselves (ie the exposure) n their health (ie the outcome) at the same time but bc of this we have a **problem**: cant tel which caused which 2. eg end up with: people who report cannabis use are more likely to be depressed BUT we dont noe whether: cannabis caused depression or depressed ppl choose to use cannabis more

Answer 73

we start wit the disease state: whether they’ve got the disease ( hence they’re a case) or if they didnt have the disease (=the control) then we go bak in time n see if they were exposed to something we’re interested in * good for finding causes of RARE DISEASES * use ODDS RATIOS

Answer 74

to find relationship bw exposure n disease to calculate odds ratio, its pretty much wat r the odds of exposure in the cases vs the odds of exposure in the controls odds ratio= odds of exposure in cases [(disease + exposure)/(disease+ no exposure)] / odds of exposure in controls [(control + expos.)/(control + no exp.)] ``` the outcome (11.6) shows that the disese was much more likely to happen with those that were exposed ```

Answer 75

1. basically u start with the exposure (or no exposure) then u follow ppl through til some ppl get the disease n some dont 2. 2 types: PROSPECTIVE= u start the study tday n u expose/dont expose the patients today to the future RETROSPECTIVE= u identify the exposure that occured in the past and u follow ppl up, to the present (maybe useful inthings like cancer causation. BUT often need very good/unbiased documentation of exposure from past=difficult to get) 3. always move forward in time 4. gud for estimatin risk of developin disease due to a particular exposure 5. outcome is risk ratio aka relative risk

Answer 76

HIGHLIGHT bout these is that 1. u get documentation of exposure BEFOR devel. of outcome 2. dont need to assess all blood samples in cohort basically, there’s a large gp of eg women. then u follow them through til eg some of them get breast cancer. these will be called ‘cases’. those that didnt, we take a subgroup of them n call them ‘control’. At the beginning, u mite have collected all their blood samples and looked at something of interest eg blood oestrogen levels. Now u mite say ‘i wonder if their blood eostrogen levels yrs n yrs before hand had something to do wit their breast cancer BC now that u have ur two little gps, u only need to check their blood samples ( rather than all samples from the the originial gp) to see if blood eostrogen levels had something to do with the breast cancer

Answer 77

1. Gold-standard study design for findin causation 2. but cant do RCT all the time (eg cant expose ppl to somethin dangerous eg smokin vs non smoke, just to see wat happens 3. can answer simple questions such as in the ASPREE trial (eg ' is it better for people who are otherwise well and over the age of 70 years to take a low dose of aspirin daily or not? (n~20,000) ") 4. commonly used to show treatment works/doesnt eg drug trials, vaccine trails, behavioural interventions 5. ususally every1 is blinded as to who is in gp A wit the tablet or who is in gp B with the placebo /double blinding

Answer 78

not getting randomization of individuals, rather we're getting gps randomized. eg gps were randomised to say different things to all their patients NOT gp say different things to each of THIER patients (since not possible)

Answer 79

1. combo of trials n data from them to get the bigger pic and also get more stable results than if it were just from 1 trial by itself 2. thing about meta is that it is only as free of bias as the individual studies that contributed to it

Answer 80

* UL(upper limb) flexors are stronger; LL(lower limb) extensors are stronger * spasticity(increasedmuscletone=unusual "tightness", stiffness, or "pull" of muscles) * hyperreflexia (reflex overactive/overresponsive, get eg twitching * extensor plantar reflex

Answer 81

* weakness of all innervated muscles of the affected nerve (ie extensors n flexors r equally affected) * atrophy (muscle wasting) * fasciculations (smll muscle twitch) * hypotonia (decreased tone) * hyporeflexic or areflexic (below normal or absent reflexes, opposite of hyperreflexia

Answer 82

substantia nigra neurones degenerate, so not enough dopamine provided to the basal ganglia "underactive" movement disorder

Answer 83

"Overactive" movement disorder autosomal dominant Involuntary movements, ie couldnt keep still (constantly fidgeting)

Answer 84

pumps Ca2+ from cytoplasm to inside. releases ca2+ without atp to cytoplasm wen action potential comes etc etc

Answer 85

plasma membrane

Answer 86

bags of ca2+ has LOTS of Ca2+ (compared to cytoplasm) (so must PUMP Ca2+ from cyto back into sarcoplasmic ret)

Answer 87

1. AP runs down sarcolemma n depolarise T tubule 2. dihydropyridine receptor on T tubule tells ryanodine receptors on lateral sac of sarcoplasmic reticulum to open 3. Ca2+ released from SR down its conc gradient

Answer 88

1. vary muscle length (length-force relation) 2. vary rate of firing neurons 3. vary number of motor units recruited