Exam 1 Material Flashcards
Homeostasis
The relatively stable physical and chemical composition of the internal environment of the body which is the result of REGULATORY SYSTEMS
(An ordered system, a steady state, around a set point of an operating point)
Steady State
no net change, needs constant input of energy, dynamic, how living things are
Equilibrium
no net change but no energy is needed, static, non-living things.
Steady State Examples
Temperature, plasma growth hormone, plasma cortisol, urinary potassium
Homeostatic Examples
Water, Ions (Na+, Cl-, Ca2+, K+), plasma glucose, blood pH, temperature
Compartments of Homeostasis
- External is dynamic
- Internal is static
1) Extracellular Fluid (ECF) is 80% intercellular fluids and 20% plasma
2) Intracellular Fluid is inside of the cell
Homeostatic Reflex Arc
1) Stimulus (exogenous=inside Endogenous=external)
2) Receptor/Sensor - responds to stimulus
3) Afferent Pathway
4) Integration Center
5) Efferent Pathway
6) Response
7) Feedback Loop - either negative (most are) or positive (blood clotting or enzyme activity) goes back to receptor or sensor.
Temperature Reflex Arc
1) Stimulus - it is cold
2) Receptor/Sensor - temperature sensitice nerver endings
3) Afferent Pathway - afferent nerves carry action potential
4) Integration Center - the brain
5) Efferent Pathway - efferent nerves carry message to
6a) smooth muscle in blood vessels
6b) skeletal muscles
7a) Response - smooth muscles constrict to limit heat loss
7b) shiver induced to increase heat
8) Feedback Loop - increased heat goes back to temp sensitive nerve endings as negative feedback
Homeostatic Reflex Arc Plasma Calcium
Decrease in plasma calcium
1) parathyroid glad detects drop
2) parathyroid hormone released into circulatory system
3) Osteocytes release calcium
4) plasma calcium increases and thus minimizes initial stimulus
Biologically Insignificant
P is greater that 0.05
Primary Chemical Messengers
Hormone, neurohormone, neurotransmitter, paracrine, autocrine
Thyroid Hormone Releasing Pattern
Hypothalamus = thyrotropin releasing hormone
Anterior Pituitary = thyroid stimulating hormone
Thyroid Glad = Thyroxine or Triiodothyronine
Target Cells = Increase metabolism
Reactive Homeostasis
respond to changes that have already occurred
Predictive Homeostasis
Response is increased in anticipation of a predicted changes. Usually involves circadian rhythms over 24 hour light/dark period for core temp, oxygen consumption, appetite.
Homeostatic Modifications
Acclimatization, biological rhythms, aging
Acclimatization
An adaptive change in the function of a physiologic system induced by prolonged exposure to an environmental stress without any genetic change. Usually reversable
Examples
1) Adapting to ambient temperature
2) Altitude/change in oxygen partial pressure
3) Developmental - very narrow windows of opportunity for growth
Mammalian
Relating to the class mammalia, endothermic mostly homeothermic, amniote, cares for young (milk), hair. D: Eukarya K: Animalia P: Chordata C: Mammalia
Physiology
A branch of biology dealing with the functions and vital processes of living organisms which includes whole organisms, parts of organisms, organs, cells.
Physiology
biology
chemistry math physics
Aging
Decrease in compensation for various challenges as life continues. Due to genetic and environmental reasons. Examples: Wear and tear, exposure, failure of mitosis (apoptosis)
Apoptosis
Programmed cell death. Examples: Webbing between fingers, only 1/5 of nerve cells grow out and survive by connecting to skeletal muscle.
Water Properties
1) bond angle of 105
2) Dipolar
3) Cohesive
4) High specific heat
5) High heat of vaporization
6) Most dense at 4C
7) Transparent
8) Universal Solvent. pH=7
Notes: Water forms hydrogen bonds with itself. The polar molecules surround ions to form hydrated radius.
Buffers
A substance that reversibly binds hydrogen and this reaction minimizes a change in pH. Examples: Bicarbonate, phosphate, heoglobin
Carbonic Anhydrase
Enzyme that mediates the reaction of H2O + CO2 — H+ + HCO3-
Very reversible 500,000/s
A Cell
The smallest structural unit (of an organism) that has the characteristic of life.