Necessities for Life
and
Body Regions
The 8 necessary life functions for all
organisms:
1.
2.
3.
4.
5.
6.
7.
8.
Maintaining Boundaries
Movement
Responsiveness
Digestion
Metabolism
Excretion
Reproduction
Growth
Maintaining Boundaries
• Why do we need to maintain boundaries?
• What organ system allows us to maintain
boundaries?
Movement
• Why is movement important?
• What body systems allow us to have
movement?
Responsiveness
• Explain why responsiveness helps us stay
alive.
• What systems are involved in responsiveness?
Digestion
• What does digesting food provide our bodies?
• Note: Cells are “digestion factories” that
further digest absorbed nutrients.
Metabolism
• Once food is ingested (taken in) what does
metabolism do for us?
• What two organ systems are involved in
metabolism?
Excretion
• Why is excretion useful?
• Why do we want to get rid of waste?
• What organ systems are involved?
Reproduction
• Why do we want to reproduce at the
organismal level?
• Why do we want to reproduce at the cellular
level?
Growth
• What is necessary for growth to occur?
Survival Needs
• Nutrients: Used for energy and cell building
– Carbohydrates = energy
– Proteins and fats= building cell structures
– Fats= cushion organs and are fuel storages
– Vitamins and minerals= for chemical reactions
• Oxygen: chemical reactions require oxygen to
occur. Human cells cannot survive without
oxygen.
Survival Needs Cont…
• Water (universal solvent): ~60-80% of body
weight. Necessary for chemical reactions to
occur.
• Body Temperature: Must be maintained
around 98F. If body temp. decreases too low
metabolic reactions get slower. If body temp.
too high proteins denature (unravel).
At both extremes death can occur!!
Survival Needs Cont….
• Atmospheric Pressure: Allows for even
exchange between oxygen (O2) and carbon
dioxide (CO2) in lungs.
– At high atmospheric pressures (high altitudes) air
becomes too thin and adequate gas exchange may
not be possible.
Homeostasis
• 3 Control Factors
– Receptor
– Control Center (hypothalamus)
– Effector
How do they work together?
2 types of Feedback Mechanisms
Negative Feedback
• Most Common type
• Response of receptor is to
do the opposite of the
original stimulus.
• Used in regulating heart
rate, glucose (sugar) blood
levels, oxygen, carbon
dioxide, minerals, body
temperature, etc.
Positive Feedback
• Least Common Type
• Response of receptor is to
amplify original stimulus.
• Used mainly during
pregnancy (contractions)
and blood clotting.
Anatomical Position
• Body erect, feet
slightly apart, palms
facing forward,
thumbs point away
from body
Figure 1.7a
Anterior Toward or at the
(ventral)* front of the body;
in front of
The breastbone
is anterior to the
spine
Posterior Toward or at the
(dorsal)* back of the body;
behind
The heart is
posterior to the
breastbone
Orientation and Directional Terms
Superior vs. Inferior
• Superior: Towards the head
– The shoulder is superior to the
stomach
• Inferior: Away from head
– The ankle is inferior to the
knee.
*Whereas the terms ventral and anterior are
synonymous in humans, this is not the case in fourlegged animals. Ventral specifically refers to the
"belly" of a vertebrate animal and thus is the
inferior surface of four-legged animals. Likewise,
although the dorsal and posterior surfaces are the
same in humans, the term dorsal specifically refers
to an animal's back. Thus, the dorsal surface of
four-legged animals is their superior surface.
dorsal
anterior
(cranial)
posterior
(caudal)
ventral
Medial Toward or at the
midline of the
body; on the
inner side of
The heart is
medial to
the arm
Lateral Away from the
midline of the
body; on the
outer side of
The arms
are lateral
to the chest
Intermediate
Between a
more
medial
and a
more
lateral
structure
The collarbone is
intermediate
between the
breastbone and
shoulder
Proximal Closer to the origin of the
body part or the point of
attachment of a limb to
the body trunk
The elbow
is proximal
to the wrist
Distal
The knee
is distal to
the thigh
Farther from the origin of
a body part or the point
of attachment of a limb to
the body trunk
Used For Appendages!!
Superficial Toward
(external) or at the
body
surface
The skin is
superficial to
the skeletal
muscles
Deep
(internal)
The lungs
are deep to
the skin
Away
from the
body
surface;
more
internal
Body Cavities
Labeled Body Cavities
Abdominopelvic Regions
Abdominopelvic Quadrants
Terms to Memorize