BHSC 1200 (CHAPTER 1) QUESTIONS & ANSWERS
Define anatomy and physiology - Answers :Anatomy is the study of the structure of
body parts and their relationships to one another, anatomy you don't need to imagine
what the body parts like body structures can be seen, felt, and examined closely
Physiology concerns the function of the body. Physiology is the study of how body parts
work and carry out their life-sustaining activities However physiology is only explained in
terms of the underlying anatomy.
Describe the structural organization of the human body from simplest to most complex. -
Answers :1) chemical level: At the chemical level atoms, tiny building blocks of matter
combine to form molecules
2) Cellular level: molecules combine to form cells (smallest unit of life). All cells share
some common components and functions but individual cell vary in shape and size
reflecting their unique functions
3) Tissue level: groups of similar types of cells that have a common function. The four
basic tissue types in the human body are epithelial tissue, muscle tissue, connective
tissue, and nervous tissue.
4) Organ level: structures made up of atleast two different types of tissues that performs
a specific function for the body.
5) Organ system level: consist of different organs that work together closely to
accomplish a common purpose make up an organ system. For example: Organs such
as the heart and blood vessels work together as the cardiovascular system.
6) Organismal: all parts of the human body functioning together
Define homeostasis - Answers :Homeostasis is the ability of the body to maintain
relatively stable internal conditions even though the outside world is changing
continuously, homoststais is a state of dynamic equilibrium and is a cycle of events in
which the status of a body condition is monitored, evaluated, changed, remonitored,
reevaluated, and so on
Describe the components of a homeostatic feedback system - Answers :The variable is
the factor or event being regulated. A stimulus produces a change in the variable
1) Receptor: a sensor that monitors the environment and detects any change. The
receptor responds to change (stumuli) by sending information (input) along the afferent
pathway to the control center
2) Control Centre: determines the level/ range at which the variable should be
maintained; it compares the input it receives to the set point and determines the
, appropriate response. Information (output) then flows from the control center along the
efferent pathway to the effector
3) Effector: carries out the controls centers response to the stimulus and produces a
response or effect that changes the controlled conditions
The results of this response then feedback to influence the effect of the stimulus either
reducing it so the whole control process is shut off or enhancing it so the whole process
continues at an even faster rate
What is the difference between afferent and efferent - Answers :the difference between
"afferent" and "efferent," is that information traveling along the afferent pathway
approaches the control center and efferent information exits from the control center.
Describe and provide an example of a negative feedback system - Answers :most
homeostatic control mechanisms are negative feedback mechanisms.
In a negative feedback system the response of the effector shuts off the original effect
of the stimulus or reduces its intensity.
Negative feedback causes the variable to change in a direction opposite to that of the
initial change, returning it to its "ideal" value
Example of negative feedback:
Body temperature: As body temperature rises receptors in the body sense this change
and then you sweat more through your sweat glands until you reach the optimal
temperature and when body temperature decreases you shiver in order for you to
produce heat by your muscles moving and creating heat until you've reached the
optimal temperature.
Blood sugar (glucose) by insulin: As blood sugar rises, receptors in the body sense this
change, and the pancreas (the control center) releases insulin into the blood. This
prompts body cells to absorb more glucose, removing it from the bloodstream and
lowering the blood sugar towards the optimal level . As blood sugar falls, the stimulus
for insulin release ends.
Describe and provide an example of a positive feedback system - Answers :In a postive
feedback mechansims the initial response of the effector enhances the original stimulus
so that further responses are even greater. Positive feedback causes the variable to
change in the same direction of the initial changes causing the variable to deviate
further and further from homeostatsis
Positive feedback mechanisms control rare events and they set off a linked sequence of
events. Once initiated the results of each reaction feed into the next like a series of
waterfalls on a river and because of this postive feedback often referred to as cascades
that amplify the original stimulus.
Examples of postive feedback
Define anatomy and physiology - Answers :Anatomy is the study of the structure of
body parts and their relationships to one another, anatomy you don't need to imagine
what the body parts like body structures can be seen, felt, and examined closely
Physiology concerns the function of the body. Physiology is the study of how body parts
work and carry out their life-sustaining activities However physiology is only explained in
terms of the underlying anatomy.
Describe the structural organization of the human body from simplest to most complex. -
Answers :1) chemical level: At the chemical level atoms, tiny building blocks of matter
combine to form molecules
2) Cellular level: molecules combine to form cells (smallest unit of life). All cells share
some common components and functions but individual cell vary in shape and size
reflecting their unique functions
3) Tissue level: groups of similar types of cells that have a common function. The four
basic tissue types in the human body are epithelial tissue, muscle tissue, connective
tissue, and nervous tissue.
4) Organ level: structures made up of atleast two different types of tissues that performs
a specific function for the body.
5) Organ system level: consist of different organs that work together closely to
accomplish a common purpose make up an organ system. For example: Organs such
as the heart and blood vessels work together as the cardiovascular system.
6) Organismal: all parts of the human body functioning together
Define homeostasis - Answers :Homeostasis is the ability of the body to maintain
relatively stable internal conditions even though the outside world is changing
continuously, homoststais is a state of dynamic equilibrium and is a cycle of events in
which the status of a body condition is monitored, evaluated, changed, remonitored,
reevaluated, and so on
Describe the components of a homeostatic feedback system - Answers :The variable is
the factor or event being regulated. A stimulus produces a change in the variable
1) Receptor: a sensor that monitors the environment and detects any change. The
receptor responds to change (stumuli) by sending information (input) along the afferent
pathway to the control center
2) Control Centre: determines the level/ range at which the variable should be
maintained; it compares the input it receives to the set point and determines the
, appropriate response. Information (output) then flows from the control center along the
efferent pathway to the effector
3) Effector: carries out the controls centers response to the stimulus and produces a
response or effect that changes the controlled conditions
The results of this response then feedback to influence the effect of the stimulus either
reducing it so the whole control process is shut off or enhancing it so the whole process
continues at an even faster rate
What is the difference between afferent and efferent - Answers :the difference between
"afferent" and "efferent," is that information traveling along the afferent pathway
approaches the control center and efferent information exits from the control center.
Describe and provide an example of a negative feedback system - Answers :most
homeostatic control mechanisms are negative feedback mechanisms.
In a negative feedback system the response of the effector shuts off the original effect
of the stimulus or reduces its intensity.
Negative feedback causes the variable to change in a direction opposite to that of the
initial change, returning it to its "ideal" value
Example of negative feedback:
Body temperature: As body temperature rises receptors in the body sense this change
and then you sweat more through your sweat glands until you reach the optimal
temperature and when body temperature decreases you shiver in order for you to
produce heat by your muscles moving and creating heat until you've reached the
optimal temperature.
Blood sugar (glucose) by insulin: As blood sugar rises, receptors in the body sense this
change, and the pancreas (the control center) releases insulin into the blood. This
prompts body cells to absorb more glucose, removing it from the bloodstream and
lowering the blood sugar towards the optimal level . As blood sugar falls, the stimulus
for insulin release ends.
Describe and provide an example of a positive feedback system - Answers :In a postive
feedback mechansims the initial response of the effector enhances the original stimulus
so that further responses are even greater. Positive feedback causes the variable to
change in the same direction of the initial changes causing the variable to deviate
further and further from homeostatsis
Positive feedback mechanisms control rare events and they set off a linked sequence of
events. Once initiated the results of each reaction feed into the next like a series of
waterfalls on a river and because of this postive feedback often referred to as cascades
that amplify the original stimulus.
Examples of postive feedback
