physiology secrets

PHYSIOLOGY SECRETS
What is Hill’s hyperbola? How it is applicable in muscles? Compare and apply it for different kinds of muscles in our body.
Ans-Hyperbola is an open curve and it continues indefinitely to infinity. It is related to F-V (force-velocity curve) of muscles.
Skeletal muscle-F-V curve shows inverse relation between velocity of shortening and force (after load). (Fig-1)
Vmax(maximum velocity of shortening.)If no load is applied, the muscle will shorten at its greatest possible speed, a velocity known as Vmax.in this graph the value is extrapolated bcz muscle cannot contract in the absence of any load. (Fig-1)
Y-intercepts represent extrapolated value for maximum velocity-Vmax.Algebrically Y intercepts is a point where X is zero.
Fmax i.e. Po :( Maximum isometric force).represents the point where after load is so great that the muscle cannot shorten.
X-intercepts is a point where Y is zero.
Smooth muscle’s F-V curve is compared with skeletal muscle. (fig-2) here the peak force may be similar but velocity of shortening is 100 times lower than skeletal muscle.
Cardiac muscle-F-V curve is influenced by changes in initial length (preload) and the changes in the contractility. (Fig3-A, 3-B)
If preload is increased (within physiological limits) Fmax increases, as well as velocity of shortening, but doesn’t alter the Vmax. (Fig-3-A)
Changes in ionotropism also alter the F-V.If ionotropic effect of cardiac muscle is increased, there is parallel shift up and right and increase in both Fmax and V max. (Fig 3-B).

PHYSIOLOGY TUTORIAL

Physiology tutorial
REASONING OUT/COMMENT
Q) Citric acid and ascorbic acid tend to acidify the blood and urine.
Ans: wrong.they cause alkalinisation of blood and urine, bcz mostly they exists in anionic form and are metabolized to Hco3.Acidification will only occur if it is excreted unmetabolized.

PHYSIOLOGY TUTORIAL

PHYSIOLOGY TUTORIAL
Reasoning out/comment
Q. Like the heart diaphragm must contract in rhythmic manner, does it undergo fatigue?
ANS: Refer –vinodha’s blog-April-3,2009.

THE SECRET OF FITNESS

The Secret of fitness
Exercise, proper diet and peace of mind make your body and mind healthy.
Exercise regularly; any sustained moderate physical activity, done for 30mts/day helps achieve a longer healthier life and lower the risk of heart diseases. Whether it is walking or bicycling in the park or using exercise machines in an indoor environment.
Exercise machines fall in to 2 main categories.
Aerobic machines-help you build cardiovascular strength by working the lungs, heart and muscles. [Treadmills, rowing machines or stationary bikes]
Weight lifting machines-tone and strengthen your muscle.
Two in one –exercising on a rowing machine and on an orbitrek provides not only an aerobic workout but also strength training. It is a total body workout,[waist slimming, cardiovascular strength with a power of resistance training all in one revolutionary machine, so you get an awesome muscle sculpting and calorie burning at the time!
Calories burned on exercise machines-
Treadmill 3 mph [20 mt mile]-215 calories/hr for females, 300 for males
7 mph [8.5 mt mile]-590 for females, 700 for males
Stationary bike-5 mph [12 mt mile]-200 and 245
Diet
*plant based may reduce the risk of several chronic diseases, limit caffeine and alcohol; don’t smoke
Peace of mind
*Sit quietly, breathe deeply and think peaceful thoughts for 15 to 20 mts a day. Be happy; don’t worry.
*Take a break in the office. Occupational stress is a silent killer.
*Laughter is accompanied by a release of hormones including endorphins which is released during exercise stimulates the feeling of well being.
*Learn to plan for a better and organised tomorrow.
*Focus on the good side; Be +ve


.

physiology secrets

PHYSIOLOGY SECRETS
1. What is Incretin/Anti incretin Hypothesis-?
Incretin hormones-GIP&GLP-1 are released when we eat. These hormones increases insulin and slow down nutritient absorption and inhibit glucagon secretion.
Antagonistic anti-incretins are released in the small intestine. When there is an incretin/anti-incretin balance, there is sufficient insulin. In type 2 diabetes, the balance is disrupted. Then incretins bind with antiincretins to decrease the insulin efficiency.
2. What are whey proteins?
Liquid material created as a by-product of cheese production called whey contain high core of BCAA-branched chain amino acid.
Benefits-increases protein synthesis,
Increases cellular glutathione-antioxidant,
Consistent whey intake and consistent exercise causes consistent muscle building,
Also aids in weight loss (thro’ gut satiety mechanism, whey protein releases satiety hormones-insulin, CCK, ghrelin)
Side effects-lactose intolerance people may produce allergic reactions.
High doses affects kidney and liver fns, and because of imbalance of minerals in bones –osteoporosis.

New year greetings

HAPPY NEW YEAR 2011
WITH THE WARMEST
OF
WISHES
FOR
THE BEST
OF
EVERYTHING

Unconventional NT-Endocannabinoids-Brain's own Marijuana?

Conventional NT is H2O soluble and is stored in high concentration in little packets or vesicles. Unconventional NT like Endocannabinoids are fats and are not stored but synthesized from components of cell membrane. Unconventional neurotransmitters have many exceptions to normal neurotransmitter.1.not stored at synapses [produced locally and used immediately].2.not exocytose [diffuses freely across the membrane] 3.very unstable and reactive.
Scientist have discovered that the brain manufactures protein that act like marijuana at specific receptors in the brain itself.[THC receptor]The main active chemical in marijuana is delta-9-tetrahydro cannabinol;THC for short. Endocannabinoids-retrograde transporters like NO- nitric oxide, and are involved in a variety of physiological processes including appetide, pain sensation, emotion, learning and memory. It is named for endocannabinoids the endogenous lipids that bind cannabinoid receptors CB1 and CB2 located in the CNS and periphery respectively [the same receptors that mediate the psychoactive effects of cannabis.CB1 receptors have been found mainly in the CNS, but also in lymphocytes, ovary, uterus, testes, vas and urinary bladder.CB2 receptors have been identified mainly in immune cells but are expressed also in astrocytes and in the brain stem.