System Physiology Lecture 1
Professor Widmaier BRB 531
Office Hours -T 304, W/F-3-4
Lab director/Registration Issues
Dr. Angela Seliga
Labs: SCI 440 or 438
Main Ideas From this Lecture:
Two key topics covered in this lecture firstly, discussed about the hierarchical
structure of the human body. Firstly can think of the varying types of cells that form tissues
and two or more different tissue types form organs and a collection of organ systems from
humans. The four different types of cells are: nerve, muscle, connective, epithelial cells.
They form respectively, nervous tissue, muscle tissue, connective tissue, and epithelial
tissue. Important to note that blood is considered part of the connective tissue.Another way
to understand the organization of the human body is through fluid compartmentalization.
You have have the blood plasma, interstitial fluid (located in the interstitium) and the
intracellular fluid. The water content of these fluids in decreasing order is the intracellular,
interstitial fluid and plasma.
The second key topic covered in this lecture is homeostasis. It is the maintenance of
a steady state. The maintenance of life requires a narrow range of dynamic equilibrium to
be maintained. It is very important when discussing steady state to understand the
difference between equilibrium and steady state. Equilibrium requires no energy to
maintain while steady state does. When an individual is unable to respond to changes, it is
called pathophysiology. The most common mechanism to adjust to changes of homeostatic
variables it through a negative feedback loop known as the reflex arc. The receptor will
detect a change in a homeostatic variable (for ex body temperature) and send a signal to
the integrating center (usually the brain) through the afferent pathway. Here the brain will
compare the signal to the set point and if action is required a signal will be sent to effector
along the efferent pathway to counteract this change. This is known as negative feedback
and is much more common in the human body than positive feedback because positive
feedback has no foreseeable end and to stop the process in the human body, usually
necessitates rapid and extreme changes.
free website associated with the book:
figures he shows in lecture are very important!
1. Fig 1.3-illustrates another level of organization in the body
2. Fig 1.5- Good Study guides, being able to summarize and understand- it illustrates how
steady state is maintained (the variable is body temperature).Demonstrates your body’s response to a decrease in body temperature due to decreased room temperature.
3. Fig 1-7- Describes how any Reflex works/ compensatory mechanism
Basic overview/organization/What is System Physiology-understanding the system and how
physiology of a/the system affects health
1. What is an organ system
Asystem of organs, composed of tissues, which are made from the 4 types of cells
● what are the 4 types of cells?
● what are the the 3 types of muscle cells?
● what cell is blood considered part of?
● What are the names of the 4 tissues (collections of cells)?
● What is an organ, and what is it commonly miscalled?
● What is an organ system?
● What are the two basic kinds of organ system?
● What is another organization system of organs/tissues/cells?
● How is fluid compartmentalized/organized in/out of blood vessel
● What is the fluid inside cells of the body called?
● Where is the most of the fluid (water) located in the body?
● What is the fluid between/around the cells?
● What is the space/compartment that contains the interstitial fluid called?
● What is the decreasing order of water/fluid component of the three fluids in the body
● What is osmosis
● If your blood is too concentrated with ions how does your body compensated ?
● What are the consequences of your bodies compensatory actions?
1. epithelial cells
2. muscle-smooth (involuntary), cardiac(involuntary), skeletal (voluntary)
4. connective tissue cells-blood is considered as a connective tissue, although it does not
connect different structures it is in bone
1. epithelial tissue
2. muscle tissue
3. nervous tissue
4. connective tissue cell (blood is a tissue)
● An organ is a collection of 2 or more types of tissue , it is commonly miscalled tissue
● ex. he