Anatomy & Physiology I
Unit One
Anatomy and Physiology
Anatomy is the study of the structure
of the body
It is carried out by a variety of
methods and on different levels
~ dissection
~ comparative
anatomy
~ palpation
~ gross anatomy
~ auscultation ~ histology
Anatomy and Physiology
Physiology is the study of the
function of the body
It investigates how the anatomy
develops and how it works
It emphasizes cause & effect
relationships and mechanisms of
It is studied on microscopic and
action
chemical levels
Organizational Levels of Biology
Homeostasis vs. Stress
Homeostasis is the maintaining of a constant internal
environment through the function of dynamic
physiological regulatory mechanisms
Homeostasis occurs despite fluctuations in the
external environment
Homeostasis vs. Stress
Homeostasis is maintained due to the intricate and
delicate relationships between these regulatory
mechanisms
If any of these mechanisms break down, it causes a
“ripple effect” which is indicated by becoming sick
Homeostasis vs. Stress
Examples of homeostasis:
+ body temperature
+ blood pressure
+ heart rate
+ respiratory rate
+ blood particle levels
Homeostasis vs. Stress
Stress is any disruption of homeostasis that threatens
physical or emotional well-being
Stress is brought about by the breakdown of
regulatory mechanisms
Homeostasis vs. Stress
Examples of physical stress:
+ intense exercise
+ infection
+ injury
+ surgery
+ hemorrhage
+ pain
Homeostasis vs. Stress
Examples of emotional stress:
+ grief
+ depression
+ anger
+ anxiety
+ guilt
Homeostatic Control
Integrating
Center
Sensor
Stimulus
Effectors
Response
Homeostatic Model
R
a
n
g
e
Upper Limit
Set Point
Lower Limit
Sensitivity
Negative Feedback System
Defends the set point
Reverses the deviation
Produces change in the opposite direction
Dynamic process that maintains stasis
Homeostatic Example
Positive Feedback System
Opposite of negative feedback
Amplifies the deviation
Action continues in the same direction
If not controlled, this system would cause homeostatic
imbalances
Body Systems
Body Systems
Body Systems
Body Systems
Science
The observation of natural phenomena
and the methods used to determine how
those phenomena occur
Science is constrained by natural laws,
therefore science must be conducted
within the realm of these natural laws
Science
The scientific method refers to the
disciplined creativity, measured
observations, logical thinking and honest
evaluation of one’s conclusions
There are two basic avenues in which to
pursue the scientific method:
~ inductive reasoning
~ hypothetico-deductive method
Science
Inductive reasoning is conducted by
making large numbers of observations to
the point there is confidence in making a
generalization
This raises the question of proof
It is better to use the term supported
Science
The hyopthetico-deductive method
begins with a hypothesis and is
conducted through experimentation
Hypothesis – a logical answer for the
question formed from observation
An accepted hypothesis is falsifiable
Science
The hyopthetico-deductive method has
four steps:
~ observation
~ hypothesizing
~ experimentation
~ conclusions & reporting
Science
Variable – any condition of an
experiment
Experimental – group that contains the
tested variable
Control – group that does not contain
the
tested variable
Hypothesis, Theory & Law
Remember – a hypothesis is a
logical answer for a question
proposed
A theory is a concept in which a
general statement or set of
statements can be made, based on
many accepted hypotheses and
their replications
Hypothesis, Theory & Law
A law is a concept that has been
tested and replicated innumerous
times and always has the same
results
Therefore in biology most of the
generalizations are theories
Hypothesis, Theory & Law
Science is based on what can be
observed, measured & quantified
Morals, values & religion are based
on feelings and beliefs which cannot
be measured or quantified