Homeostasis Flashcards
the ability of living organisms to maintain a
stable and relatively constant internal
environment despite external changes.
Homeostasis
a crucial aspect of life because it ensures that the conditions necessary for the proper functioning of cells, tissues, and organs are consistently met.
Homeostasis
involves the regulation of various physiological variables, such as temperature, pH, blood
glucose levels, and ion concentrations, within a narrow and optimal range.
Homeostasis
target value for each regulated variable. This set point represents the
ideal or optimal level of the variable. For example, in humans, the set point for body temperature is around 98.6°F (37°C).
Set point
- Organisms have specialized sensors or receptors that continuously monitor the internal conditions and detect any deviations from the set point. These
sensors are typically located in various parts of the body and send signals to control centers when changes are detected.
Sensors or receptors
often located in the brain or other
central nervous system structures, receive and process information from the sensors. They compare the current conditions to the set point and
generate appropriate commands to regulate the variable.
Control centers
are the organs, tissues, or cells that carry
out the control center’s commands. They can either increase or decrease the variable being regulated to
bring it back to the set point. For example, if body temperature rises above the set point, effectors like sweat glands are activated to cool the body down.
Effectors
- Homeostasis is typically maintained through feedback loops, which are self-regulating mechanisms.
Feedback loops
Two main types of feedback loops
Negative feedback and Positive feedback
- any deviation from the set point triggers a response that opposes or counteracts the deviation, bringing the variable back towards the set point. This type of feedback helps maintain stability. - Ex. Body temperature regulation
Negative feedback
-the response amplifies the initial deviation from the set point, rather than opposing it. It is less common in homeostasis and is often associated with processes like blood clotting and childbirth, where a rapid change or response is needed.
Positive feedback
Homeostasis is maintained through different control systems in our body, including feedback loops, hormones, and the nervous system.
Control system
Mechanisms of Homeostasis
Control systems, Negative feedback loops, Positive feedback loops
Importance of Homeostasis
Balance and Stability
Optimal Functioning
Protection against External Factors
Prevention of Diseases
It ensures that various
systems work in harmony to support our overall health and well-being.
Balance and stability
Homeostasis enables our body to function optimally by regulating essential processes such as body
temperature, blood pressure, pH levels, and nutrient levels
Optimal functioning
By maintaining internal stability, homeostasis helps
protect our body from external factors such as
changes in the environment or exposure to toxins.
Protection against External factors
Homeostasis plays a vital role in disease prevention. Imbalances or disruptions to homeostasis can lead
to the development of various disorders and illnesses.
Prevention of diseases
The development of stimuli as a
result of physiological parameter deviations from
the normal value is the initial stage in the negative
feedback loop. Physiological parameters can deviate
from the norm in either direction
Stimulation
The control unit receives changes in
physiological parameters through a variety of
receptors located throughout the body. Nerves and
other thermoreceptors are examples of common
receptors engaged in stimulus transmission.
Reception
The brain serves as the loop’s
control unit, determining whether a change in a physiological parameter necessitates loop activation or inhibition. The brain sends out signals to erase the alterations in different ways depending on the direction of departure.
Processing
The control unit sends out signals at the end of the loop to cancel out the impacts that cause changes in physiological variables. Changes can take several forms and be directed at different sections of the body.
Counteract on the stimulus
What are the temperature regulation?
Sweat and vasodilation
Evaporative cooling and convection cooling
Drop in temperature
Goosebumps and vasoconstriction
Less convection
allows blood surface area to be
exposed to cooler environment
Vasodilation
What are the negative feedback mechanisms?
Temperature regulation
Blood pressure regulation (Baroflex)
Osmoregulation
What are the positive feedback mechanisms?
- Blood clotting mechanisms
- Childbirth
What are the factors affecting homeostasis?
- External influences
- Internal causes
Factors like extreme temperature, toxins, and stress can disrupt homeostasis by causing imbalance or intefering with the body’s control mechanism
External influences
Imbalances can also arise from internal factors such as hormonal imbalances, genetic disorders, or organ dysfunction
Internal causes
What are the common homeostatic disorders?
Diabetes
Hypertension
Hypothyroidism
Hyperthyroidism
is a common disorder caused by the body’s inability to regulate blood glucose levels effectively. It can lead to hyperglycemia or hypoglycemia, affecting various organ systems.
Diabetes
occurs when
the body fails to maintain normal blood pressure
levels, leading to increased strain on the heart and
blood vessels
Hypertension
is a condition where the thyroid
gland fails to produce sufficient thyroid hormone, resulting in a slowdown of the body’s processes.
Hypothyroidism
characterized by an overactive thyroid gland, causing an accelerated metabolism and other symptoms.
Hyperthyroidism
Ways to support homeostasis
Healthy lifestyle habits
Seek medical treatment
