Chapter 1- Homeostasis Flashcards Preview

Physiology- Sutherland-Chan-Term1 > Chapter 1- Homeostasis > Flashcards

Flashcards in Chapter 1- Homeostasis Deck (23)
Loading flashcards...

What does the lack of internal uniformity of homeostasis ?

1. the inside of the body is not uniform
2. Homeostasis mechanisms function key differences in the


What is the feedback systems, what is called ? and how many cycle of events does it go through ?

- a cycle of events in which the internal environment is
1. monitored
2. evaluated
3. changed
4. re-monitored
5. re-evaluated


What is the controlled condition ?

- the variable being monitored -- B/p, Blood Sugar


what is Stimulus ?

- whatever disrupts or changes the controlled condition
- disruptions can be internal or external .
e.g Orthostatic hypotension;
called postural hypotension — is a form of low blood
pressure that happens when you stand up from sitting
or lying down.
Orthostatic hypotension can make you feel dizzy or
lightheaded, and maybe even faint.
e.g hot to cold or cold to hot


What is homeostasis?

- the condition of balance in the body's internal environment
due to the constant interaction of the body's many internal
regulatory processes.
- the body is dynamic and it is constantly changing
- from the cells to the organ systems, all structure contribute to
maintaining homeostasis
- as long as the body's response can recover homeostasis, the status
of normal is retained.
- when something disrupts homeostasis (e.g shifts in one direction),
there are mechanisms that will have the opposite effect.
- most disruptions are mild and temporary and the return to
homeostasis is relatively quick
- there are limits within which all the different parts of your body can
and should function .
- homeostasis represent the ongoing processes that keep the internal
environment within those limits.


what are the components of the feedback system/loop ?

1. a sense or receptor
2. transmission pathways
3. a control Centre
4. an effector


What are the characteristics of the sensor/receptor?

1. monitor changes in a controlled condition
2. detect chemical , electrical and mechanical changes
3. sends information to the control Centre (via transmission pathways)
e.g baroreceptors - senses the B/p on the Aorta and other regions
of the body.


What is the characteristics of the transmission pathways?

1. the nervous and the blood vessel pathways(as well as their
signaling molecules)
2. relay messages between
- the sensor/receptor and;
- the control centre and;
- the effector


The head quarter of the feed back system is called the control Centre? how does it work?

1. comprised of the nervous and endocrine sys. (hormone)
2. sets the range of values within which the controlled condition
should be maintained.
3. evaluate and compares the input received from the sensor/ receptor
against the set range.
4. determines the body's responses to the change in the controlled
5. sends the commands (when needed) to the effector (via
transmission pathways)


What does the effector do?

- produces the response to given stimulus
- receive the commands from the control Centre
- produces the response that will change the controlled


what is the characteristics of the negative feedback?

1. function to reverse the changes in the internal environment (respond to a disturbance by moving the controlled condition back towards the initial set range)
2. very stable
3. predominant system/loop


Give an example of the negative feedback sys/loop?

- Stimulus (high blood pressure )
- Disrupting the homeostasis
- blood pressure (controlled condition)
- receptors (baroreceptors in certain blood vessels)
- nerve impulses send signals to
- the brain (control Centre)
- then the nerve impulses send signals to
- the heart (effectors)
- Response ( a decrease in the heart rate and the dilation of the
blood vessels cause B/p to decrease)
- Return to normal B/P(normal homeostasis)


What is the characteristics of the positive feedback?

1. function to strengthen changes in the environment (respond
to a disturbance by moving the controlled condition farther
from the initial set range)
2. mechanism that shuts down the response
3. inherently unstable
4. uncommon

e,g Oxytocin, prolactin , bleeding from a cut.


In homeostasis, there are limits to how much the body can compensate ?True or False



the body fuel is ATP ? True or False



As we age , the ability to maintain and efficiently return to homeostasis decreases? True or False



When do u notice homeostasis ? (in the short term & long term)

- if it is moderately affected , disease states can occur
- if it is severely affected then death is possible


When do not notice the homeostasis?

- when it is mildly affected , you may not notice it (symptoms
maybe mild)


If part of the body is dysfunctional how does homeostasis interact ?

- it can't or is less able to contribute to the maintenance of
- homeostasis will be harder to maintain or may not be
- there are limits to how much the bod can compensate


What is the adjustment of an organism to its environment ?



The adjustment of an organism to counter balance a defect?



The body can change the parameters within which it is acceptable to function ? True or false



If all controlled conditions remain within established limits, homeostasis is maintained and the body stays healthy? True or False