Human A&P 120
May 3, 2008 REVIEW for FINAL EXAM
REMINDER: Exam is semi-comprehensive, covering some introductory material, and some nerve and hormone features, that apply the concepts to the last part of the course. Other systems wonÕt be covered except as noted.
Parts to review from the 1st THREE EXAMS:
BIOETHICAL
PRINCIPLES: be able
to apply to topics discussed in class
A. AUTONOMY – individual choice/freedom
B.
NON-MALEFICENCE: Above
all, do no harm –
the first medical principle
C. BENEFICENCE--relationship to others not just self; oft cited as the 2nd
medical principle
-- 1. basic
version: positive obligation to do good [active]
-- 2. Strong version=PATERNALISM: higher
authority enforces its idea of good
D. JUSTICE--equal or fair treatment, equal rights,
equal goods:
Basic
Negative Feedback System! know
all diagram components including DISTURBANCE, State Regulated, Receptor/Sensor,
Integrator, Effector. KNOW VARIATIONS:
a) DUAL effector control: 2 effectors that have
opposite corrective effects (e.g., furnace, air conditioner), or 1 effector
that can be boosted or inhibited (e.g., liver as regulated by insulin and
glucagon).
b) Effectors may be behaviors, e.g., thirst, hunger + eating, etc
B. REGULATED CHANGE --not
everything has a constant optimum. 2 different mechanisms:
1. RESET System: changes the set point of a negative feedback system.
a) temporary emergencies: e.g., fever;
stress; b) cyclical ÒclocksÓ:
2. POSITIVE FEEDBACK System--one which accentuates a change
rather than reducing it.
Sometimes this is not adaptive but a dangerous malfunction as in anaphylactic
shock. BUT sometimes it
can be useful for desired rapid changes: e.g., orgasm, parturition, ovulation
1. DELAY PROBLEM: Over and/or Undercompensations!
Delay problems are INHERENT in a simple feedback
system because there are always delays in getting a signal from the disturbed state
to the effectorÕs response—e.g., first exposure with specific immunity
-- if delays are too long and/or disturbance too fast,
the system over and/or under-compensate – e.g., blood glucose with a
fast-digesting carbohydrate
-- What to do
about delays?
Sometimes nothing can be done, but sometimes there is a way:
ANTICIPATION system --one which activates a feedback
system before the disturbance alters the body; e.g., short-term stress
system activated when
spotting a predator in the distance. Also, specific / acquired immunity in effect does this with its memory B
and T cells ( anticipates
future attacks). Smell/taste anticipate food arrival
2. NEW-SITUATION PROBLEM: existing
feedback system may not work well at high altitude, with new diet or activity regime,
with new diseases, etc. Solution =
ACCLIMATIZATION
/ "ADAPTATION" system: change
effectiveness of feedback component. Example: Acquired immunity!!!!
TWO LEVELS of EXPLANATION in
Biology: see lecture &
reading examples
1. "MECHANISTIC" = proximate
explanation: Òhow does it workÓ analysis; e.g., how does LEPTIN work
2. "EVOLUTIONARY" = historical/selective reason; Òwhy
did it end up this wayÓ
analysis; e.g., why a high Body Adipose set point only arose in a
feast-or-famine habitat!
B. Essentials of Evolution
with Natural Selection
---1. Members of
a species reproduce, usually
more than needed to replace parents;
---2. Offspring have (semi)random differences in genes due to a) sex and b) mutations and
c) Other Genome changes (some newly discovered)
---3. "Survival
of the fittest"
ensues: in the long run, those with "better" genes will leave more
successful offspring, so
the "better" genes eventually dominate the species
SO: Species
change, diverge over generations since environments (which include other
species that are also evolving) change over millenia, so this is a never-ending
process!
DETAILS:
STEP 2--SEMI-RANDOM
VARIATION is Not predictive, cannot
anticipate future needs
a) Sex: new combinations of existing genes in
the parents
b) Mutations: alterations in codes of existing genes
c) Other Genome changes --Pseudogenes, gene shuffling, duplications, etcÉ.
STEP 3--SURVIVAL OF THE FITTEST
How? "Consumption, Competition, Cooperation"--fittest genetic combinations lead
to more viable offspring by better ability to eat, avoid being eaten,
competing, and/or cooperating.
IMPLICATIONS/OUTCOMES OF
NATURAL SELECTION
--1) Can produce exquisite ADAPTATIONS: e.g., kidney as a filter --better than
any human-made filters
--2) IMPERFECTIONS
due to Historical constraints and SLOWness --often evolution is slow relative to one or a few generations, and
usually builds on pre-existing features, resulting in:
----- a) Vestigial
features: once-useful
adaptations become useless or harmful, usually because environments or other
adaptations changed and evolution has not caught up or cannot modify. E.g., human
appendix, gill pouches and yolk sac in embryo.
----- b) Compromises: useful adaptations with flaws; e.g.
human spine; female birth canal vs size of baby's head; internal disease
conditions like sickle-cell anemia that protect from external diseases .
---3) Creates
GENETIC DIVERSITY
-- diversity is inherent
to life, changes each generation, and provides the raw material for natural
selection; there is no "perfect/ideal Platonic human" (or any other
organism) towards which evolution is aiming! AND--> Species and populations
(subgroups of single species) with higher genetic diversity tend to survive
better. EXAMPLES: IMMUNITY!
E.g., Native Americans and European diseases
I.
ATOMS & MOLECULES
B. MOLECULES (atoms join) & COMPOUNDS (molecules with different atoms joined)
--BONDS:
1. COVALENT (STRONG) BONDS [=atoms SHARE electrons]:
a) NON-POLAR molecules: Equal affinities,so equal share;
EXAMPLE: fats, oxygen!
b) POLAR --unequal share: EXAMPLE: water!!
C. Hydrophobic or Non-polar interaction: apply to lipids/fat in diet!
Non-polar compounds forced out of water as water molecules,
unable to bind to non-polar molecules, attract other water molecules. So
non-polar compounds are squeezed out of the way into a separate
layer--"oil and water do not mix".
D. INORGANIC Ions and
Molecules:
|
1.
Inorganic ions:
electrolytes, acids dissolved in water, etc. (know others not shown here such
as CALCIUM): a)
Na+, plus b) Cl- dominate extracellularly; c) K+
dominates in cells; others later d) H+ --determines ACIDITY |
2.
Inorganic molecules:
many not shown. E.g., a) Water:
H2O or H-O-H b) O2
or O=O: c) CO2 or
O=C=O |
E. ORGANIC compounds: have C and H, plus usually other atoms.
4 categories of basic types of
small unit molecules to macromolecules:
1. CARBOHYDRATES: made of C,
H, O:
|
a) Monosaccharide
sugars such as GLUCOSE=C6H12O6 USES:
i) energy ii) make larger
molecules----> |
b)
Disaccharides such as SUCROSE
=glucose+fructose USES:
mainly for energy |
c)
Polysaccharides such as GLYCOGEN in
liver, muscle, etc =large chains of
Glucose USE--energy
storage |
2. AMINO ACIDS (AAs)
& PROTEINS:
|
a) AAs: C, H, O, N in specific array; --20 different
AAs with unique properties according to "R" = side groups USES: i)
energy; ii) neurotransmitters; iii) join in chains to form proteins |
b)
PROTEINS --specific
folded linear chains of AAs: AA sequence yields specific 3-D shape due to attractions and repulsions among
various R (side) groups . Most active cell functions due to proteins with specific binding sites; each type of protein attracts &
binds one specific type molecule due to bonds: Òlock & keyÓ model: SEE LECTURE; this is a KEY CONCEPT |
PROTEIN USES:
i) major cell/tissue/organ STRUCTURES
ii) ENZYMES: catalyze specific REACTIONS [note: enzymes usually have names with Ò-aseÓ suffix]
iii) TRANSPORTERS and other MEMBRANE proteins--—move
molecules around
iv) REGULATORS--control other proteins or genes
3. LIPIDS: dominated by non-polar C-H bonds (hydrophobic!)
|
a)
Fatty acids etc. single long C-H
chains with acid group Uses: energy,
making larger molecules |
b) Fats Triglyceride
[TG]= main animal
storage: 3 long C-H chains linked together (with a glycerol; a sugar) Use: energy
storage |
c)
Phospholipids 2 long C-H
chains, a sugar, and polar group |