Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Physiology > Physiology wk9 > Flashcards

Physiology wk9 Flashcards

1
Q

what factors affect performance

A
  • the type of exercise itself
  • strength and skill acquired – practise and genetics
  • energy demands
  • environment
  • diet
  • psychological component – motivation and reward
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what is the definition of fatigue

A

inability to maintain power output or force during repeated muscular contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what is central fatigue

A

fatigue of the central nervous system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what is peripheral fatigue

A

fatigue of:
* neural factors
* mechanical factors
* energetics of contraction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

how do you characterize cns fatigue

A

reduction in motor unit activation and firing frequency

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what neural factors influence peripheral fatigue

A

Sarcolemma and t-tubules –
* altered muscle membrane to conduction and action potentials, inability of Na/K pump to maintain
* an action potential block in t-tubules, reduced sarcoplasmic reticulum Ca release

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

what mechanical factors affect peripheral fatigue

A

cross bridge cycling and tension depend on:
* arrangement of actin and myosin
* Ca binding to troponin
* Atp availability

High h+ conc contributes to fatigue:
* Reduce force per cross bridge
* Inhibit Ca release from SR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how do energetics of contraction influence peripheral fatigue

A

Imbalance between ATP supply and demand, causes accumulation of Pi leading to:
* Inhibits maximal force
* Reduced cross-bridge binding to actin
* Inhibits Ca release from SR

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what are free radicals

A

molecules with an unpaired outer orbital electron, capable of damaging proteins and lipids in muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

how do radicals hurt the body

A
  • Damage contractile proteins (myosin/troponin)
  • Depress Na/K pump activity
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

what two things should we consider when performing

A

source of energy and fibers used for production

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

what are the principles of training

A

overload
specificity
reversibility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

what is the formula for o2 consumption

A

cardiac output x A-V o2 diff

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

what does heritbility mean

A

genetics, determines vo2 max and training response

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

formula for vo2 max

A

maximal cardiac output x a-v02 difference

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

how does endurance training increase sv

A
  • Increases preload (edv)
  • Increases plasma volume
  • Increases venous return
  • Increases ventricular volume
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

how else does endurance training help the athlete

A

lowers afterload
increases contractility

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

why is resting hr lower after training

A
  • Vagal tone increase
  • Greater filling time (edv)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

how does training increase a-vo2 difference

A
  • Less sns vasoconstriction
  • Increases diameter and compliance of arteries
  • Increased capillary density
  • Increases mitochondrial number
20
Q

what is the ability to perform prolonged submaximal exercise dependent upon

A

ability to maintain homeostasis

21
Q

what adaptions occur in muscles after endurance training

A
  1. Shift in muscle fiber type (fast-to-slow) and increased number of capillaries.
  2. Increased mitochondrial volume.
  3. Training-induced changes in fuel utilization.
  4. Increased antioxidant capacity.
  5. Improved acid-base regulation.
22
Q

what is mitophagy

A

breakdown of damaged mitochondria

23
Q

what is the significance of increased subsarcolemmal and intermyofibrillar mitochondria

A

greater capacity of etc
decreased cytostolic adp due to increased ADP transporters, results in less lactate/H+ and less PC depletion

24
Q

how does endurance training change fuel utilization

A

Increased utilization of fat and sparing of plasma glucose and muscle glycogen

25
Q

what happens to free radicals after endurance training

A

skeletal muscles have a higher capacity to deal with free radicals by increasing antioxidant capacity

26
Q

how does endurance training help stop fatigue

A
  • increased NADH shuttles – less NADH for lactic acid formation
  • change in LDH isoform – less lactic acid formation
27
Q

how does training promote protein synthesis

A
  • Exercise stress activates gene transcription
  • Muscle contraction activates primary and secondary messangers
  • Results in expression of genes and synthesis of new proteins
28
Q

what primary signals promote exercise induced adaptions

A
  • Mechanical stretch - resistance
  • Calcium - endurance
  • AMP/ATP - endurance
  • Free radicals - endurance
29
Q

what are the secondary signals that promote training adaptions

A

AMPK
mitogen-kinase
PGC-1a
CaMK
calcineurin
NFkb

30
Q

what is muscular strength

A

maximal force that a muscle group can generate

31
Q

what is muscular endurance

A

ability to make repeated contractions against a submaximal load

32
Q

what is sarcopenia

A

loss of muscle mass

33
Q

how does resistance training stop sarcopenia

A

promotes hypertrophy and nerve innervation

34
Q

what is responsible for early gains in strength

A

the nervous system

35
Q

what adaptions does the nervous system create

A
  • Increased Neural Drive (measured via EMG).
  • Increased number motor units recruited.
  • Increased firing rate of motor units.
  • Increased motor unit synchronization.
  • Improved neural transmission across neuromuscular junction.
  • Incr. size of NMJ and vesicles containing Ach
36
Q

what mechanisms are responsible for increased tension in type ix

A
  • be linked to increased calcium sensitivity - resulting in greater number of cross-bridges bound to actin.
  • Enables more actin-myosin cross-bridge formation = more force per m.u.
  • Evidence to support strength gains independent of muscle growth per se
37
Q

what is hyperplasia

A

increase in the number of fibers

38
Q

what is hypertrophy

A
  • increased cross-sectional area of muscle fibres (Type II changes > Type I)
39
Q

why does muscle growth occur

A

synthesis > breakdown (for multiple weeks)

40
Q

key factors for increases synthesis

A
  • mRNA increases resulting in protein synthesis at the
  • ribosome (https://www.2minuteclassroom.com/ribosomes).
  • Ribosomes increase in number and elevate muscle’s
  • protein synthesis capacity.
  • Activation of the protein kinase “mechanistic target
  • of rapamycin” (mTOR) is the key factor accelerating protein synthesis following a bout of resistance training.
41
Q

what two molecules stimulate mTOR activation

A

Phosphatidic acid (PA) & Ras homolog enriched in brain (Rheb)

42
Q

what are satellite cells

A

stem cells located between the sarcolemma and basal lamina.
to divide and fuse with adjacent muscle fibers to increase myonuclei.

43
Q

what is the main cause of difference in muscle mass between individuals

A

genetics

44
Q

in what training does reversibility occur the quickest

A

endurance

45
Q

how can radicals affect muscle mass

A

promotes muscle atrophy

46
Q

is it best to complete strength and endurance training together

A

no, they can impair each others performance and gains

Physiology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions