Our Human Body

Anatomy and physiology first lesson

Normal distribution

symmetric bell shaped where data clusters near the central average and tapers equally on both sides

• diversity is natural

• natural phenomena’s range of biological traits fits a normal distribution

• example: Bell Curve, Gaussian Distribution

Selection

a process in which some individuals survived preferentially over others due to natural processes

• environment, genetic, etc

• ex: there is less variation in traits that impact reproduction or the likelihood of living to reproductive age → natural selection. If there is more variation, it may impact future generations negatively. Genes that lower the chance of reproducing are weeded out.

Selectively neutral variation

genetic differences that have little or no effect on survival or reproductive success

• example: blood type, hair, eyes

Variation Leading to Disease

genetic or phenotypic changes that increase the risk of illness, reduce survival, or lower reproductive success

• ex: cancer, cystic fibrosis

Evolution

the change in the proportion of certain traits of a species over several generations

• relies on natural selection

Natural selection

The savored survival of certain traits over others

• ex: galapagos finches

Physiological Variation

• diverse and widespread

• physiological variables will differ not just from one individual to another, but also between

  • children vs adult (ex: medicine, adult tolerate more)

  • women vs men

• used for recognition and treatment of disease

Enzyme + active site

There is an irregularly shaped phosphate group and an enzyme with irregularly shaped active site that matches the shape of the phosphate group

• very unique to one another

• phosphate group plus enzyme yield an enzyme with altered activity

  • Phosphate group changes enzyme shape

• The phosphate group is attached to the enzyme at its active site

• The activated enzyme dissociates to form phosphate group and enzyme again

• EXAMPLE: as O2 molecule binds, it alters the conformation of hemoglobin, making subsequent binding easier (like enzyme and special key)

Prions

type of protein that can trigger normal proteins in the brain to fold abnormally

• prion disease can affect animals and humans

  • in mad cow (they go crazy)

  • Spread to humans by infected meat products

Dendritic branching

• characterized by symmetrical branching

• natural fractal patterns

  • Optimized function: this geometry maximizes surface area and transport efficiency for

    • neutrons, river, blood vessels

    • Minimizes “energy” costs

Diffusion

particles move from high concentration to low concentration until they are evenly distributed

Flow in Anatomy

• ex: flow of air through lungs, flow of blood through the vessels of the body

Binding Likelihood Changes with Shape

• As each O2 molecule binds, it alters the conformation of hemoglobin, making subsequent binding easier 

  • This means HB will have a higher affinity in oxygen rich areas, promoting oxygen loading

  • Lower affinity of O2 in oxygen starved areas, promoting oxygen unloading

• When oxygen change shape it becomes better to bind