Chapter 1.6 Flashcards
Life
A collection of properties that help distinguish living from nonliving things
Organization
Living things exhibit a far higher level of organization and then the nonliving world around them. They expended great deal of energy to maintain order, and a breakdown in this order is accompanied by disease and often death
Cellular composition
Living matter is always compartmentalized into one or more cells
Metabolism
Living things take in molecules from the environment and chemically changed them into molecules that form their own structures, controller physiology, or provide them with energy. Metabolism is the sum of all this internal chemical change.
Responsiveness and movement
The ability to sense and react to stimuli
Stimuli
Changes in the environment
Homeostasis
Organism maintains relatively stable internal conditions despite environmental changes
Development
Any change in form or function over the lifetime of the organism
Differentiation
The transformation of cells with no specialized function into cells that are committed to a particular task
Growth
An increase in size; Occurs through chemical change or metabolism
Reproduction
Living organisms producing copies of themselves, passing jeans to new, younger containers: their offspring
Evolution
genetic change from generation to generation
Homeostasis
The body‘s ability to detect change, activate mechanisms that oppose it, and maintain relatively stable internal conditions
Pathophysiology
The study of unstable conditions that result in our homeostatic control go awry
Dynamic equilibrium
A balanced change, in which there is a setpoint or average value for a given variable and conditions fluctuate slightly around this point
Negative feedback
A process in which the body senses a change in activates mechanisms that negate or reverse it. Keeps a variable close to it set point. 
Feedback loops
The system maintains a state of dynamic equilibrium in which the temperature averages and it’s only slightly from the set point
Vasodilation
The widening of blood vessels: warm blood Flows closer to body surface loses heat surrounding air. If that’s not enough, the body will generate sweat
Vasoconstriction
Narrowing of the blood vessels in the skin, which serves to retain warm blood deeper in your body and reduce heat loss. If that’s not enough, the brain activate shivering – muscle tremors that generate heat
Baroreflex
Reflexive correction of blood pressure
(rise from bed - blood drains from torso: homeostatic imbalance - baroreceptors above heart respond - send signals to cardiac center of brain stem - heartbeat accelerates - blood pressure rises to normal: back to homeostasis
Common components of a feedback loop
Receptor, integrating center, effector
Receptor
A structure that senses change in the body.
Integrating center
A mechanism that processes receptor information, relates it to other available information, and makes a decision about what the appropriate response should be
Effector
The cell or organ that carries out the final corrective action.
Positive feedback
Self – amplifying cycle in which a physiological change leads to an even greater change in the same direction, rather than producing the corrective effects of negative feedback.
Can be normal (ex: birth: cervix- nerve endings- oxytocin from pituitary gland- stimulates uterine contractions and pushes fetus toward cervix) however is more often harmful or life-threatening (ex: fever)
Physiological gradient
Difference in chemical concentration, electrical charge, physical pressure, temperature, or other variable between one point and another. 
Down the gradient
If matter or energy moves from the point where this variable has a higher value to the point with a lower value.(ex: Warner to cooler point, high chemical concentration to lower)
Up the gradient
Matter or energy raise from the point where the variable has a lower value to A higher value
Pressure gradient
That or energy flows down from high pressure point to low pressure point (ex: garden hose)
Concentration gradients
Chemicals flow down concentration gradients. (Ex: water flows through cell membranes and epithelia by osmosis, from the side where it is more concentrated to the side where it is less so)
Electrical gradients
Charged particles flow down electrical gradients. (Ex: Sodium ions flowing down an electrical gradient into a cell (positive outside to negative inside)
Electrochemical gradients
Ions flow down electrochemical gradient
Thermal gradient
Heat flows down a thermal gradient. (Ex: Air temperature around body is cooler he will flow from blood to surrounding air down its thermal gradient and be lost from the body)
