Transcript lecture 1 - Perkins Science

LECTURE 1
INTRODUCTION
PHYSIOLOGY – 3
PHYSIOLOGY – THE STUDY OF FUNCTION OF THE
BODY
• From the Greek “physis” which
means nature; logos = study
• Comparative Physiology – the
physiology of invertebrates and
different vertebrate groups
• Pathophysiology is the study of
how physiological processes are
altered by disease.
SCIENTIFIC METHOD
1) OBSERVATION
YOU SEE SOMETHING INTERESTING AND YOU…
2) GATHER DATA
3) ANALYZE THE DATA
4) COME TO A CONCLUSION AS TO HOW YOU THINK
SOMETHING WORKS (A WORKING HYPOTHESIS, OR EDUCATED
GUESS)
5) TEST THE HYPOTHESIS
6) SET UP A SERIES OF EXPERIMENTS: IF I DO X, THEN Y SHOULD
HAPPEN.
7) GATHER DATA
8) REANALYZE THE DATA
9) CONCLUSION, AND COME UP WITH A NEW HYPOTHESIS
10) KEEP REPEATING THIS UNTIL YOU COME UP WITH A
HYPOTHESIS THAT EXPLAINS THE PHENOMENON.
11) PUBLISH THE DATA IN A PEER-REVIEWED JOURNAL
“PEER-REVIEWED”
• A SCIENTIST’S PEERS REVIEW
THE WORK AND ACCEPT OR
REJECT THE PAPER
• OTHER SCIENTISTS TRY TO
REPRODUCE THE RESULTS. IF
THEY CAN’T, THEN THE
EXPERIMENTS ARE NOT
BELIEVABLE.
• E.G. ALUMINUM WAS THOUGHT
TO CAUSE ALZHEIMER’S DISEASE,
BUT does IT?
Theory
• In science, a theory is a proven fact, which is
supported by huge amounts of experimentation,
results, evidence!
EXAMPLES
Evolution
Cell theory
Brief history of physiology
1. Aristotle – Greece (384-322 BC) – speculated about body
function (thinkers, not doers)
2. William Harvey – England (1578-1657) – demonstrated that
the heart pumps through a closed system of vessels
3. Claude Bernard – France (1813-1878) – observed that the
internal environment (milieu interieur) stays relatively constant
although changes are occurring
4. Walter Cannon – US (1932) – coined the term,
homeostasis, to describe the internal consistency of the body
NEGATIVE FEEDBACK LOOP
Set Points
How Body Temperature is Maintained Within the Normal Range
Shivering and sweating are two antagonistic mechanisms
THE HUMAN BODY PLAN
CELLS
TISSUES
ORGANS
ORGAN SYSTEMS
MULTICELLULAR
ORGANISM
Tissue: “A group of cells with a common function.”
4
TYPES
MUSCLE
NERVOUS
CLICK HERE FOR AN EXPLANATION
EPITHELIAL
CONNECTIVE
3 types of muscle
skeletal
smooth
cardiac
An ORGAN is a group of tissues with a specific
function.
Examples
Heart pumps blood, which
transports nutrients
TESTES
make sperm
Pancreas regulates blood sugar;
aids digestion
The heart is
composed of
nervous,
connective,
The femur supports
epithelial
the thigh
and muscle
tissues.
Kidney
filters blood
An ORGAN SYSTEM is a group of organs with a common
function.
EXAMPLE: The Urinary System
filters the blood to remove wastes,
makes urine, and regulates water
balance in the body
There are 11 organ systems in the human body
Integumentary
Skeletal
Muscular
Nervous
Endocrine
Digestive
Excretory (Urinary)
Cardiovascular (circulatory)
Respiratory
Reproductive (Male/Female)
Immune
You must
memorize
the organ
systems
and their
functions
Stem Cells
Stem cells are totipotent, which means they can
become anything. Cells of the early embryo are stem
cells. Scientists are working to grow stem cells into
organs for transplant.
Adult stem cells are pleuripotent. They can become a
number of different types of cells, but they cannot
become any cell.