The Foundation of Physiology
Human Physiology - the scientific study of the functions of our body
Teleogical Approach - explains the body functions in terms of meeting a bodily need, without
considering how this outcome is accomplished, it emphasizes the “why” or purpose of body
Physiologists use the mechanistic approach
Mechanistic Approach –view the body as a machine whose mechanisms of action can be
explained in terms of cause-and-effect sequences of physical and chemical processes, the same
types of processes that occur in other components of the universe
Physiologists explain the “how” of events that occur in the body.
Example: Why do you shiver when you are cold?
Teleogical Response: to help warm you up, because shivering generates heat.
Mechanistic Response: shivering is that when temperature-sensitive nerve cells detect a
fall in body temperature, they signal the temperature-sensitive area of the brain. In response,
the brain activates nerve pathways that ultimately bring about involuntary, oscillating
contraction-relaxation of skeletal muscle (shivering).
Structure and Function
Anatomy - the study of the structure of the body.
Physiological mechanisms are made possible by the structural design and relationship of
the various body parts that carry out each of these functions.
Levels of Organization in the Body
The human body is made up of a combination of specific chemicals.
Common atoms in the human body; Oxygen, Carbon, Hydrogen and Nitrogen, they make up
99% of total body chemistry. Calcium, Phosphorus and Potassium contribute roughly 1%.
The atoms combine to form the molecules of life; such as proteins, carbohydrates, fats
and nucleic acids (DNA). These atoms and molecules are the ingredients from which all living
The cell, the basic or fundamental unit of both structure and function in a living being, is
the smallest unit capable of carrying out the processes associated with life.
*Cell physiology Chapter 2 Plasma Membrane - extremely thin, oily barrier which encloses the contents of each cell,
separating these chemicals from those outside the cell
Because the plasma membrane can control movement of materials into and out of the
cell, the cell’s interior contains a combination of atoms and molecules that differs from the
mixture of chemicals in the exterior environment surrounding the cell.
Organisms - independent living entities. Examples; Bacteria and Amoebas
Cell Differentiation - cells become specialized to carry out a particular function. Therefore, your
body is made up of many different specialized types of cells.
Basic cell functions:
1. Obtaining food (nutrients) and oxygen from the environment surrounding the cells.
2. Performing chemical reactions that use nutrients and oxygen to provide energy for the
3. Eliminating from the cell’s internal environment carbon dioxide and other by-products,
or waste, produced during these chemical reactions.
4. Synthesizing proteins and other components needed for cell structure, for growth and
for carrying out particular cell functions.
5. Controlling to a large extent the exchange of materials between cells and its
6. Moving materials from one part of the cell to another when carrying out cell activities.
Some cells are even able to move through their surrounding environment.
7. Being sensitive and responsive to changes in the surrounding environment.
8. For most cells, reproducing. Some body cells, notable nerve cells and muscle cells, lose
the ability to reproduce after they are formed during early development. This is why
strokes, which result in losing nerve cells in the brain, and heart attacks, which kill heart
muscle cells, can be so devastating.
o Consists of cells specialized for contracting and generating force.
o Skeletal Muscle
Moves the skeleton
o Cardiac Muscle
Pumps blood out of the heart
o Smooth Muscle
Encloses and controls movement of contents through hollow tubes and
organs (Food through the digestive tract)
o Consists of cells specialized for initiating and transmitting electrical impulses,
which carry information over various distances, for example, one body part.
o Found in the brain, spinal cord, and peripheral nerves. Epithelial Tissue
o Consists of cells specialized in exchange of materials between the cells and its
o Any substance entering or leaving the body must cross and epithelial barrier.
o Two general types;
Epithelial cells join tightly to form sheets of tissue that cover and
line various parts of the body. (Your skin)
Boundaries that separate the body from external environments.
Glands: epithelial tissue derivatives specialized for secreting.
Secretion: the release from a cell, in response to appropriate
stimulation, of specific products that have been produced by the
Exocrine glands: secrete through ducts to the outside of the body.
Endocrine glands: lack ducts and release their secretory products,
known as hormones.
o Connects, supports, and anchors body parts.
o Includes diverse structures such as loose connective tissue that attaches
epithelial tissue to underlying structures; tendons, which attach skeletal muscles
to bones; bone, which gives the body shape, support, and protection; and blood,
the cells within connective tissue produce specific structural molecules that they
release into the extracellular spaces between the cells.
Consists of two or more types of primary tissue organized together to perform a
particular function or functions.
Example: The stomach is made up of all four pri