anatomy 1 exam Flashcards
homeostasis
the existence of a stable internal environment.
Maintaining homeostasis is vital to maintaining proper physiological
function and thus crucial for survival.
why is it important to maintain homeostasis?
Organisms (including humans) live in changing and unpredictable
environments.
By maintaining homeostasis (constant internal environment),
physiological functions can proceed in a constant environment and
avoid disruption from environmental influences.
Differentiate between the study of anatomy and the study of physiology.
-Anatomy refers to the internal and external structures of the body and their physical relationships,
- physiology refers to the study of the functions of those structures.
autoregulation.
When a cell, tissue, organ, or
organ system adjusts in response to an environmental
change. Does not involve the nervous or endocrine
systems.
System regulates itself.
Extrinsic regulation
Results from activities of the
nervous system or endocrine
system detecting a change in the
environment and sending
electrical/chemical signal to adjust
activities of another system.
Extrinsic = operating from outside.
Example:
Your nervous system detects a
drop in environmental temperature
and sends signal to muscles to
increase heat production.
difference between auto and extrinisc regulation
auto
- small scale
-system regulates itself
- no nervous and endocrine system
extrinsic
-larger scale
- nervous or endocrine system
negative feedback
Negative feedback opposes
variations from normal (set point).
Most feedback mechanisms in
human body are negative.
homeostatic regulation
Receptor- detects environmental stimulus
control center- receives and processes the information by keeping a set point
effector- Cell or Organ that responds to control center’s
commands.
positive feedback
Positive feedback mechanisms
produce a response that
enhances the original homeostatic
change.
Much less common than negative
feedback mechanisms.
neg feedback
response to the change occurs in real time not over a long period of time. Body immidiatly tries to correct error
matter
anything that takes up space.
mass
the amount of material in
matter (not the same as weight).
volume
the amount of space That matter occupies.
what are atoms composed of
subatomical particles
- protons +
- electrons -
neutrons =
Electrons orbit nucleus in ELECTRON CLOUD.
The number of protons is generally equal to the number of
electrons (results in neutrally charged atom)
atomic number
The number of protons in
the nucleus of an atom
atomic mass
Roughly equal to the
number of protons +
number of neutrons in
nucleus of atom.
Remember: #protons = # neutrons in neutrally charged atom.
For Carbon….Atomic mass = 6 protons + 6 neutrons = 12
element
a pure substance composed of only one
type of atom.
isotopes
atoms of same element that contain
different number of neutrons.
Does not change charge, but does change
atomic mass.
- Thats why the atomic mass of Carbon is not exactly 12
Radioisotopes
isotopes with unstable nuclei that break down and
give off subatomic particles or radiation.
Uses:
Cancer Treatments
Tracers/labeling
Imaging
Medical Diagnostics
Images
(top)
electron orbit, cloud, energy levels
Electrons travel around the
nucleus in defined orbits.
The area that electrons orbit
within is called the electron
cloud.
Within an electron cloud,
electrons occupy an
orderly series of energy levels
orbital energy levels
E1 – lowest energy level.
Can hold up to 2 electrons.
E2 – Can hold up to 8
electrons.
E3 – Can hold up to 8
electrons.
E1 fills before electrons
occupy E2, and so on.
valence shell
valence electrons
outermost energy level of atom
- what the valence shell contains is valence electrons
molecules
Any chemical structure
consisting of atoms held
together by shared
electrons.
compounds
pure chemical substance
made up of atoms of two
or more different
elements in fixed
proportions
molecular weight
the sum of the atomic weights of a molecules
components.
ionic bonds
chemical bonds
formed by the
electrical attraction
Between negatively
and positively
charged ions.
Ionic bonds are
weak (held together
only by electrical
charges attracting)
covalent bond
chemical bonds
formed by atoms sharing electrons
in outer most energy level.
Shared electrons orbit both nuclei
Covalent bonds are strong because
the atoms share electrons
Polar covalent bond and nonpolar
Electrons are shared
unequally.
* Electron spends more
time orbiting one atom.
* Result is one atom has
slightly negative charge
while other has slightly
positive charge.
Non-polar
* Electrons are shared
equally by both atoms.
* Electron spends equal
time orbiting both nuclei.
Rank bonds from weak to strong (1,2,3)
1 Hydrogen bonds the weakest
2 ionic bonds stronger than hydrogen bonding
3 covalent bonds are the strongest
synthesis reaction
increasing the number of bonds (anabolism)… Building more complex molecules from smaller pieces. So the number of bonds increases
decomposition reaction
catabolism… Breaking down larger molecules into smaller pieces. So the number of bonds decreases
exchange reaction
shuffling components of molecules pairing decomposition with synthesis