Module 1.5: Core Principles in Anatomy and Phsiology Flashcards
How do negative feedback loops maintain homeostasis?
Receptor/Sensor picks up the Stimulus(informaiton)
Send the Stimulus to a Control Center(cells in the brain or organs of endocrine system, a gland)
Control Center determines the variable is out of the normal range
Effectors/Phsiological Responses: Control center send signals to cells/organs
(i.e. Nerve cells activate skeletal muscle cells to start shivering and producing heat).
In Homeostatic Range(if the variable returns to the normal range)
> > Control center Stops stimulating the effectors
How do positive and negative feedback loops differ?
In a negative feedback loop, the effector activity shuts off when conditions return to the normal range.
In a positive feedback loop, the effector’s activity actually increases in response to a stimulus— reinforces the initial stimulus.
What is homeostasis, and why is it important?
The maintanance of body’s stable internal environment
while adjusting to external changes (SURVIVE)
Disturbances in homeostasis, or homeostatic imbalances, can result in disease or even death if uncorrected.
What is a homeostatic imbalance?
A fluctuation from equilibrium that changes the body’s internal environment and prevents it from going back to equilibrium. Physiological imbalances occur when the cells have a structural issue or are not receiving the proper nutrition they need.
Body’s internal environment is the result of a wide range of coordinated processes or variables, including the temperature, the chemical composition of blood and other body fluids, and many more.
How are structure and function related? To what levels of organization does this relationship apply?
form follows function The form of a structure is always such that it best suits its function.
This principle applies at all levels of organization, even down to the chemical level.
i.e. The tissue of the lung are extremely thin This form follows its function of allowing gases to cross rapidly.
If the lung tissue were thick, gases would take too long to cross and our cells would suffocate from lack of oxygen. maintain homeostasis X
Definition of the term gradient
Examples of the types of gradients driving processes in the body.
: A condition in which more of somthing exists in one area than in another, and the two areas are connected
Temperature gradient
Concentration gradient: fascillitated diffusion(Ion channel, glucose transporter)
Pressure gradient: gas exchange
Why cell-cell communication is necessary in a multicellular organism?
Cells in the body must work together in a coordinated fashion to ensure that homeostasis of the entire organism is maintained.
Only if they communicate with one another, cells can work together.
What are the two major methods by which cells communicate? (How cells communicate with one another?)
Electric signals / Chemical messengers
- Electric signals
: Typically transmitted directly between neighboring cells. - Chemical messengers
: may be released from one cell directly onto another cell / into the fluid surrounding another cell / reach another cell after traveling through the blood
What are the components of a feed back loop?
What the function of each component?
Receptor/Sensor Pick up the stimulus
Send the stimulus to a Control center
Determines whether variables are out of normal range
stimulates Effectors to start Physiological Responses
(The variable to the normal range, In homeostatic range)
Negative Feedback Loop: A control center stop stimulating the effector’s activity
Why negative feedback is the most commonly used mechanism maintaining homeostasis in the human body?
An adjustment to a change in the internal or external environment requires a change in the direction of the stimulus.
These loops act to oppose the stimulus that triggers them.
In general, it allows systems to self-stabilize
cf. A positive feedback loops amplifies the deviation so that it moves the body away from homeostasis
