Learning Aim B Understand the homeostatic mechanisms used by the human body
Applied Science Level 3 BTEC
Unit 9: Human Response and Regulation
Prepared For: UK Charity
Purpose: This report is about raising awareness and to provide patients with support with up
to date and easy to understand information about the disorders of homeostasis
This report is about common homeostatic disorders mainly covering the endocrine
system. its purpose is to create an illustrated report that details both normal and
abnormal functioning of the endocrine system
I'm writing this report i've volunteered for a uk charity that works to raise awareness
and provide support to patients dealing with disorders of homeostasis, its purpose is
to create an informative document that provides up to date information that's easy to
understand about homeostatic disorders (mainly related to the endocrine system).
I'm going to cover the normal functions of the endocrine system, and the normal state
as well as the abnormal states and to show the up to date treatments for these
disorders.
Introduction
Homeostasis is the process by which living organisms maintain a stable internal
environment, ensuring factors such as temperature, pH, glucose levels, and hydration
remain within optimal ranges for proper biological functioning. This balance is essential for
supporting metabolic processes, cellular activity, and overall health. Without homeostasis,
the body’s system becomes imbalanced, leading to disruptions that can result in conditions
like hyperthermia, hypothermia, diabetes, or even organ failure, which, if prolonged, may be
life-threatening. Understanding the role of homeostasis and the impact of its failure provides
critical insights into how the body functions, the development of diseases, and the
importance of medical interventions and healthy behaviours in maintaining balance and well-
being [1].
Part 1: Homeostasis
Homeostasis and Responses to Internal and External Changes
Homeostasis is the process by which the body maintains a stable internal environment
despite changes in external and internal conditions. It ensures that factors such as
temperature, pH levels, and glucose concentration remain within a narrow, optimal range.
When a change occurs, the body responds through regulatory mechanisms to restore
balance. For example, if body temperature rises due to hot weather, the body triggers
sweating to cool down. Similarly, if blood sugar drops, the pancreas releases glucagon to
raise glucose levels. These responses help the body function efficiently and prevent damage
caused by extreme fluctuations [1].
,Set Point and Examples in the Human Body
A set point refers to the desired or optimal level of a physiological condition that the body
works to keep stable through homeostatic processes.It acts as a reference point, and any
deviation from it triggers corrective mechanisms. Examples in the human body include body
temperature, which is typically around 37°C, blood glucose levels, which are maintained at
approximately 90 mg/dL, and blood pH, which stays close to 7.4. If these values change
beyond acceptable limits, homeostatic processes work to restore them to their set points [1].
Roles of Different Parts in Homeostasis
1. Stimuli and Receptors
A stimulus is any internal or external change in the environment that disrupts the body’s
state of equilibrium. Receptors are specialised cells or organs that detect these changes and
send signals to the central nervous system or endocrine system. For example,
thermoreceptors in the skin detect temperature changes, and chemoreceptors in blood
vessels monitor oxygen and carbon dioxide levels.
2. Coordinators
Coordinators, such as the brain, spinal cord, and endocrine glands, receive signals from
receptors and process the information to determine the appropriate response. The
hypothalamus in the brain plays a key role in regulating body temperature and hormone
release. It acts as a control centre, sending instructions to effectors to bring conditions back
to the set point.
3. Effectors and Response
Effectors are organs, glands, or muscles that carry out the response to restore homeostasis.
The response is the action taken to counteract the change. For example, when body
temperature drops, muscles contract in shivering to generate heat, and blood vessels
constrict to retain warmth. Similarly, when blood sugar levels rise, the pancreas releases
insulin to help cells absorb glucose. These responses ensure that the body remains in a
stable and functional state.
By working together, these components of homeostasis help maintain the body’s internal
equilibrium, allowing it to adapt to changes and function properly [1].
,Figure 1: The general process of Homeostasis [2]
Importance of Homeostasis and Consequences of Its Failure
Homeostasis is crucial for maintaining a stable internal environment, ensuring proper cell
and organ function. It regulates temperature, pH, hydration, and blood glucose, allowing the
body to adapt to changes and support essential processes like metabolism and enzyme
activity.
If homeostasis fails, serious health issues can arise. For example, temperature imbalances
may cause hyperthermia or hypothermia, while poor blood sugar regulation can lead to
diabetes. Uncontrolled blood pressure increases the risk of heart disease and stroke. Severe
disruptions can result in organ failure, coma, or death.
The nervous and endocrine systems play key roles in maintaining homeostasis, constantly
adjusting conditions to prevent these dangers [3].
Part 2: Feedback and Control
The Role and Effects of Positive Feedback
Positive feedback is a process where an initial change in a system is amplified, leading to a
greater response. Unlike negative feedback, which maintains stability, positive feedback
reinforces changes, often resulting in rapid effects.
, In biology, positive feedback is essential for certain processes. During childbirth, the
hormone oxytocin stimulates uterine contractions, which trigger the release of more oxytocin,
intensifying contractions until birth occurs. Another example is blood clotting, where platelets
release chemicals that attract more platelets, allowing a rapid clot to form and prevent
excessive bleeding.
In technology, positive feedback enhances signals and maintains processes. In electronics,
amplifiers use it to strengthen signals in devices like microphones and hearing aids.
However, excessive positive feedback can cause microphone feedback, producing a loud,
high-pitched noise. In engineering, uncontrolled positive feedback can lead to system
instability.
In economic and social systems, positive feedback drives trends and behaviours. In finance,
rising stock prices attract more investors, further inflating prices, and sometimes leading to
market crashes. In social media, viral trends spread as increasing engagement attracts more
attention, accelerating growth.
The effects of positive feedback can be both beneficial and harmful. It enables rapid
responses in biological and technological systems but can also cause instability if
uncontrolled. For example, in climate change, melting ice reduces the Earth’s ability to
reflect sunlight, leading to further warming and more ice melting.
In conclusion, positive feedback amplifies changes in biological, technological, and social
systems. While it can be useful, it must be managed to prevent instability and negative
consequences [4].
Example of Positive Feedback: Childbirth
One of the best examples of positive feedback in the human body is childbirth, where the
hormone oxytocin plays a key role in stimulating uterine contractions.
1. Stimuli and Receptors – The stimulus is the baby’s head pushing against the cervix.
Stretch receptors in the cervix detect this pressure and send nerve impulses to the
brain.
2. Coordinators – The hypothalamus in the brain acts as the coordinator. It processes
the nerve signals and signals the pituitary gland to release more oxytocin into the
bloodstream.
3. Effectors and Response – In this context, the muscles of the uterus act as the
effector. Oxytocin causes stronger uterine contractions, which push the baby further
down, increasing pressure on the cervix. This leads to more oxytocin release, further
intensifying contractions until birth occurs.
This cycle continues until the baby is delivered, at which point the stimulus (pressure on the
cervix) is removed, stopping the feedback loop [5].
Applied Science Level 3 BTEC
Unit 9: Human Response and Regulation
Prepared For: UK Charity
Purpose: This report is about raising awareness and to provide patients with support with up
to date and easy to understand information about the disorders of homeostasis
This report is about common homeostatic disorders mainly covering the endocrine
system. its purpose is to create an illustrated report that details both normal and
abnormal functioning of the endocrine system
I'm writing this report i've volunteered for a uk charity that works to raise awareness
and provide support to patients dealing with disorders of homeostasis, its purpose is
to create an informative document that provides up to date information that's easy to
understand about homeostatic disorders (mainly related to the endocrine system).
I'm going to cover the normal functions of the endocrine system, and the normal state
as well as the abnormal states and to show the up to date treatments for these
disorders.
Introduction
Homeostasis is the process by which living organisms maintain a stable internal
environment, ensuring factors such as temperature, pH, glucose levels, and hydration
remain within optimal ranges for proper biological functioning. This balance is essential for
supporting metabolic processes, cellular activity, and overall health. Without homeostasis,
the body’s system becomes imbalanced, leading to disruptions that can result in conditions
like hyperthermia, hypothermia, diabetes, or even organ failure, which, if prolonged, may be
life-threatening. Understanding the role of homeostasis and the impact of its failure provides
critical insights into how the body functions, the development of diseases, and the
importance of medical interventions and healthy behaviours in maintaining balance and well-
being [1].
Part 1: Homeostasis
Homeostasis and Responses to Internal and External Changes
Homeostasis is the process by which the body maintains a stable internal environment
despite changes in external and internal conditions. It ensures that factors such as
temperature, pH levels, and glucose concentration remain within a narrow, optimal range.
When a change occurs, the body responds through regulatory mechanisms to restore
balance. For example, if body temperature rises due to hot weather, the body triggers
sweating to cool down. Similarly, if blood sugar drops, the pancreas releases glucagon to
raise glucose levels. These responses help the body function efficiently and prevent damage
caused by extreme fluctuations [1].
,Set Point and Examples in the Human Body
A set point refers to the desired or optimal level of a physiological condition that the body
works to keep stable through homeostatic processes.It acts as a reference point, and any
deviation from it triggers corrective mechanisms. Examples in the human body include body
temperature, which is typically around 37°C, blood glucose levels, which are maintained at
approximately 90 mg/dL, and blood pH, which stays close to 7.4. If these values change
beyond acceptable limits, homeostatic processes work to restore them to their set points [1].
Roles of Different Parts in Homeostasis
1. Stimuli and Receptors
A stimulus is any internal or external change in the environment that disrupts the body’s
state of equilibrium. Receptors are specialised cells or organs that detect these changes and
send signals to the central nervous system or endocrine system. For example,
thermoreceptors in the skin detect temperature changes, and chemoreceptors in blood
vessels monitor oxygen and carbon dioxide levels.
2. Coordinators
Coordinators, such as the brain, spinal cord, and endocrine glands, receive signals from
receptors and process the information to determine the appropriate response. The
hypothalamus in the brain plays a key role in regulating body temperature and hormone
release. It acts as a control centre, sending instructions to effectors to bring conditions back
to the set point.
3. Effectors and Response
Effectors are organs, glands, or muscles that carry out the response to restore homeostasis.
The response is the action taken to counteract the change. For example, when body
temperature drops, muscles contract in shivering to generate heat, and blood vessels
constrict to retain warmth. Similarly, when blood sugar levels rise, the pancreas releases
insulin to help cells absorb glucose. These responses ensure that the body remains in a
stable and functional state.
By working together, these components of homeostasis help maintain the body’s internal
equilibrium, allowing it to adapt to changes and function properly [1].
,Figure 1: The general process of Homeostasis [2]
Importance of Homeostasis and Consequences of Its Failure
Homeostasis is crucial for maintaining a stable internal environment, ensuring proper cell
and organ function. It regulates temperature, pH, hydration, and blood glucose, allowing the
body to adapt to changes and support essential processes like metabolism and enzyme
activity.
If homeostasis fails, serious health issues can arise. For example, temperature imbalances
may cause hyperthermia or hypothermia, while poor blood sugar regulation can lead to
diabetes. Uncontrolled blood pressure increases the risk of heart disease and stroke. Severe
disruptions can result in organ failure, coma, or death.
The nervous and endocrine systems play key roles in maintaining homeostasis, constantly
adjusting conditions to prevent these dangers [3].
Part 2: Feedback and Control
The Role and Effects of Positive Feedback
Positive feedback is a process where an initial change in a system is amplified, leading to a
greater response. Unlike negative feedback, which maintains stability, positive feedback
reinforces changes, often resulting in rapid effects.
, In biology, positive feedback is essential for certain processes. During childbirth, the
hormone oxytocin stimulates uterine contractions, which trigger the release of more oxytocin,
intensifying contractions until birth occurs. Another example is blood clotting, where platelets
release chemicals that attract more platelets, allowing a rapid clot to form and prevent
excessive bleeding.
In technology, positive feedback enhances signals and maintains processes. In electronics,
amplifiers use it to strengthen signals in devices like microphones and hearing aids.
However, excessive positive feedback can cause microphone feedback, producing a loud,
high-pitched noise. In engineering, uncontrolled positive feedback can lead to system
instability.
In economic and social systems, positive feedback drives trends and behaviours. In finance,
rising stock prices attract more investors, further inflating prices, and sometimes leading to
market crashes. In social media, viral trends spread as increasing engagement attracts more
attention, accelerating growth.
The effects of positive feedback can be both beneficial and harmful. It enables rapid
responses in biological and technological systems but can also cause instability if
uncontrolled. For example, in climate change, melting ice reduces the Earth’s ability to
reflect sunlight, leading to further warming and more ice melting.
In conclusion, positive feedback amplifies changes in biological, technological, and social
systems. While it can be useful, it must be managed to prevent instability and negative
consequences [4].
Example of Positive Feedback: Childbirth
One of the best examples of positive feedback in the human body is childbirth, where the
hormone oxytocin plays a key role in stimulating uterine contractions.
1. Stimuli and Receptors – The stimulus is the baby’s head pushing against the cervix.
Stretch receptors in the cervix detect this pressure and send nerve impulses to the
brain.
2. Coordinators – The hypothalamus in the brain acts as the coordinator. It processes
the nerve signals and signals the pituitary gland to release more oxytocin into the
bloodstream.
3. Effectors and Response – In this context, the muscles of the uterus act as the
effector. Oxytocin causes stronger uterine contractions, which push the baby further
down, increasing pressure on the cervix. This leads to more oxytocin release, further
intensifying contractions until birth occurs.
This cycle continues until the baby is delivered, at which point the stimulus (pressure on the
cervix) is removed, stopping the feedback loop [5].
