Module Two Flashcards
what are 5 common forms of movement in humans
locomotion
climbing
throwing
jumping
swimming
what type of symmetry do humans show
bilateral symmetry- allows organisms to move purposefully and efficiently.
what are the features of monkeys that allow for swinging
long arms
flexible rotating wrists
highly mobile joints
more narrow rib cage
upright posture
scapulas that allow for overhead reaching
what caused us to move to bipedalism?
it was favoured by natural selection, through walking on two feet it meant that hominins could travel further in more open habitats
what did becoming taller do to hominins
it lengthened the back muscles at the base of the spine and hips
what evolutionary changes helped to centre the force of gravity in humans?
the thigh bone got an inward slope down to the knee which required gluteal abductors- developed a big strong bum
what are the human adaptions that favour endurance activities like running?
arched feet with a heel bone
large hip, knee and ankle joints
strong hip and knee muscles (gluteus maximus)
multiple sensitive balance organs
tall narrow body
hairless, sweating and other thermoregulatory mechanisms (this is the most important one for thermoregulation in hot environments)
What is the equation for BMI
mass/ height^2
what does BMI correlate with?
with disease prevalence and mortality rates
what is the only direct measurement of body density
cadaver
they show ratios over internal to subcutaneous fat masses
what are the pros and cons of imaging of tissues
pros
- they can measure fat free mass and bone density
-high accuracy (1-2% error)
cons
-expensive
-technical problems ie atheletes size or recent meal
is fat mass or fat free mass denser?
fat free mass is denser
what are some issues with densirometrey?
pro is that is it accurate with 2-3% typical error
doesnt give info on the distributions of the fat mass or fat free mass.
may have residual air volume in the lungs
trapped air in clothing hair or GI tract
what are five assumptions as a measure of skin folds?
- constant compressibility (within people)
- Skin thickness negligible or constant fraction of skinfold
- Fixed adipose tissue patterning
- Constant fat fraction in adipose tissue
- fixed proportion of internal to external (subcutaneous) fat
why is skeletal muscle mass important?
provides physical capabilities
largest glucose sink
produces heat
insulator
major endocrine organ
major determinant of daily energy use
why is fat mass important?
valuble energy source
insulator
why is fat a valuable energy source?
Its twice as energy dense as carbs and protein?
fat cells provide muscle cells with energy during exercise.
what can relative energy deficit disorder cause in the body and what is it due to ?
it is due to insuffient fat, not having enough energy stores
osteoperosis
amenorrhoea (no period)
can affect males too
what do excess fat gains to do the cells of the body?
cause the cells to be larger (hypertrophy) and mostly causes there to be more cells (hyperplasia)
what can occur once you get hyperplasia?
the fat mass is regulated at a higher set point.
this makes it harder to prevent the regain of any lost fat
what are myokines?
muscle factors?
what are adipokines?
adipocyte (fat ) factors
what do myokines promote?
anti-inflammatory
anti tumour
help mobilise fat from adipocytes
what do adipokines promote
pro-inflammatory
they drive low grade inflammation
why is adipose tissue a functionally intergrative tissue?
because it contains immune cells
what are intra-muscular triglycerides? what circumstances do they occur in and what are they valuable for?
they are fats within muscle tissue
athletes, people with obesity or diabetes have increased levels
it is a valuable fuel source- only for atheltes
obese or diabetics cannot use it as an energy sourcew
what is sarcopenic obesity and what does it impair?
high fat content which takes over broken down muscles
sarcopenia- active loss of muscle mass and strength
this impairs movement
what are some practical suggestions for maintaining your body compositon?
regular exercise and deemphasise weight loss as a reason for doing exercise
nutrition
sleeping well
avoiding any prolonged stress
where is our mass concentrated?
in our core
what traits do our proximal muscles tend to have?
wider, stronger and heavier.
what is an example of a class one lever in the body?
atlanto-occipital joint (skull to spine)
what is a class 2 joint, and an example in the body
restistance and effort applied on one side of axis (ie wheelbarrow). Able to lift lots of mass with less force
metatarsophalangeal joint
what are some reasons why you can calf raise so much?
there is a class two level at the ball of the foot- good for generating lots of force
the gastrocnemius and the solus muscles are able to generate lots of force
what does increasing flexion angle do up to a certain point?
as the flexion angle increases, torque increases. therefore more force is able to be generated.
theres a peak angle, if it exceeds this then torque and force decrease
explain the effect of using chains in resistance training
as bar height increases resistance increases, this means that the end of the lift should feel as hard as the start.
explain which joints have a mechanical disadvantage
most joints involving long bones, as they require much greater muscle force than resistive force to move or maintain equilib
why did evolution favour this to occur?
-the tendon attatchment close to the joint increases range of motion.
-allows the end of the limb to reach high speeds
-this is because muscles are limited in how much they can shorten
what purpose do the lower extremity joints serve?
for weight bearing
what purpose do the upper extremity joints serve?
for range of motion and speed
what is co activation and what is its purpose?
muscles around a joint contracting together, function is for stabilising and protective.
what occurs during isometric contraction?
no change in length of muscle occurs ie holding
why is knowing hydration state important and how what can indicate a measurement of hydration state?
water is the majority of our body mass as it is both in and around cells
urine colour or urine specific gravity tests can indicate hydration levels
what is labelled water dilutions and what are the pros and cons of it
a technique that measures energy expenditure by enriching a person’s body water with heavy oxygen and heavy hydrogen. gives you the amount of fat mass that a person has
pros- accurate (appros 2% error)
cons-time consuming, need to be euhydrated, total body water isnt always 73% FFM
doesnt give you distributions of FFM and FM
what is bio-impedence analysis, what are its pros and cons
a low frequencey current through the body assuming FFM is 73% water and electrolytes
pros
-quick and convenient
-multi electrodes may differentiate between all limbs and trunk
cons
-need standard conditions
-accuracy is 4-5% and decreases with higher fat mass
pros and cons of using skinfolds as a measure of adiposity
good reliability within tester- need intra tester
mainly used to track within a person
pros- quick and convenient
cons- typical error approx 4%
technique and equipment is important
sensitivity of clients
not used with people who have a high BF %
what are two paradoxes (true statement that seems to contradict itself) of fat with muscle
1- intramuscle triglycerides- only athletes can utalise as a fuel source
2-sarcopenic obesity- high fat content taking over atrophied muscles . this impairs movement and many muscle processes
