Download Homeostasis: The Essence of Life

Human Physiology
A short introduction
to the field of human
physiology
Introduction
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Living systems possess a special
organization
Physiology studies two related
aspects of that organization:
structure and function
For this reason physiology is
closely related to Anatomy and
Biochemistry
Homeostasis
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This is the name for the
processes which keep the
condition and environment
of the tissues in the proper
condition to sustain life.
Cells
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Cells are the basic units of life
they make up tissues and organs
in the body
Cells can only come from other
cells (The CELL THEORY)
Tissues
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muscle
nervous
epithelial
connective
Glands
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Epithelial tissue
Specialized for secretion
Exocrine glands: secrete through
ducts to the outside of the body
Endocrine glands: ductless glands
which produce hormones which
are released into the blood
Organs
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Two or more types of primary
tissue
Organized to perform a particular
function
Examples of Organs
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Stomach
Heart
Liver
Kidneys
brain
many others
Homeostasis: The
Essence of Life
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Cells live in a fairly constant
environment
The cells, in turn, constitute the
tissues which provide that
environment
Homeostasis
Body systems
Cells
Body Systems
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Nervous
Endocrine
Immune
Circulatory
Muscle/skeletal
Integument
Respiratory
Urinary
Digestive
Reproductive
Negative Feedback
Fall in temperature
-
+
Thermostat
Connecting
Circuit
Heat
Furnace
+
Negative Feedback
Fall in blood pressure
-
+
Pressure sensors
Increase in
blood pressure
Nerves
Heart and blood
vessels
+
Failure of Homeostasis
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Often leads to sickness and
eventually death