Life Hierarchy Homeostasis/Metrics

SPONCH

Sulfur, Phosphorous, Oxygen, Nitrogen, Carbon, Hydrogen. The major elements of life.

The four primary tissue types in the human body

Epithelial, Connective, Muscle, and Nervous

Cell

Smallest living unit in the body

Tissue

Group of cells that perform a common function

Organ

Group of two or more tissue types

Homeostasis

The maintenance of a relatively stable internal environment.

Extracellular Fluid (ECF)

The fluid environment where the cells live, or the fluid outside the cells

Plasma

The liquid portion of blood

Interstitual Fluid (ICF)

The fluid contained within all body cells

How does the Nervous System maintain homeostasis?

Neurons within this system control rapid responses to changes from the external environment

How does the Endocrine System maintain Homeostasis?

Glands within this system regulate bodily functions that require duration, like concentration of internal volumes and electrolytes

Ideal blood pressure

120/80 mmHg

Ideal blood volume

4-5 liters

Ideal human body temperature

37 degrees celsius

Ideal body pH

7.35-7.45

Intrinsic Controls

Local controls inherently existing within an organ that makes corrections or autregulates to benefit the organ

Extrinsic Controls

Regulartory mechansisms initiated outside an organ by the nervous and endocrine systems to benefit the organism

Feedforward

System that makes responses made in anticipation of a change, like the smell of food causing gastric secretion

Negative Feedback Loop (NFbL)

Type of feedback loop that attempts to re-regulate something when the change moves a value away from its reference value, like the lowering of insulin when glucose (blood sugar) is too high.

Positive Feedback Loop (PFbL)

Type of feedback loop that enhances a change that moves away from its reference value and intensifies the original stimulus, like the stretching of the uterine walls causes contractions to stretch futher until birth.

Stimulus

The first step in a feedback system where a change occurs

Receptor

The second step in feedback system where the structures that monitor detect the change.

Afferent Pathway

The third step in the feedback system where info is communicated about the change through neurons or blood.

Control Center (Integration Center)

The fourth step in the feedback system where the CNS or Endocrine system determines the next action

Efferent Pathway

The fifth step in the feedback system where the signals are sent from the integration center to the effector organ

Effector

The sixth step in the feedback system where the organ or tissue that received the directions from the control center produces it

PFbL Response

The output that increases the original stimulus

NFbL Response

The output that removes the original stimulus

kilo (k)

10³

deci (d)

10^-1

centi (c)

10^-2

milli (m)

10^-3

micro (mc) (μ)

10^-6

nano (n)

10^-9

gram, liter, meter

10⁰

Foundation of all living things