Homeostasis AQA GCSE Flashcards
What is homeostasis?
Homeostasis is the process by which living organisms maintain a stable internal environment despite external changes.
True or False: Homeostasis only applies to temperature regulation.
False
Fill in the blank: Homeostasis involves the regulation of __________, pH, and ion concentrations.
temperature
What is the importance of homeostasis?
It is crucial for the proper functioning of cells and overall health of an organism.
Which organ system is primarily responsible for thermoregulation?
The integumentary system.
What is negative feedback?
Negative feedback is a control mechanism that counteracts a change in a physiological variable, helping to restore it to its set point.
Give an example of a negative feedback mechanism.
The regulation of blood glucose levels.
True or False: Positive feedback mechanisms help return a system to its set point.
False
What role do receptors play in homeostasis?
Receptors detect changes in the environment and send signals to effectors to initiate a response.
What are effectors in the context of homeostasis?
Effectors are organs or cells that act to bring about a change in response to signals from receptors.
Name a hormone involved in the regulation of blood sugar.
Insulin.
What is the set point for human body temperature?
Approximately 37 degrees Celsius (98.6 degrees Fahrenheit).
Fill in the blank: The maintenance of water balance in the body is known as __________.
osmoregulation
True or False: Homeostasis can be disrupted by external factors such as temperature and pH changes.
True
What is thermoregulation?
Thermoregulation is the process of maintaining an optimal body temperature.
Which part of the brain is responsible for thermoregulation?
The hypothalamus.
What happens to the body during hyperthermia?
The body temperature rises above normal levels, which can lead to heat stroke.
Fill in the blank: The process of sweating helps to __________ the body.
cool
What is the role of the kidneys in homeostasis?
The kidneys regulate water balance, electrolyte levels, and waste removal.
Name one way the body responds to hypothermia.
Shivering to generate heat.
True or False: Homeostasis is a static process.
False
What is the physiological response to a drop in blood glucose levels?
The pancreas releases glucagon to raise blood glucose levels.
Fill in the blank: The __________ system is involved in the regulation of blood pH.
respiratory
What role does the liver play in homeostasis?
The liver regulates blood glucose levels, detoxifies harmful substances, and produces bile.
What is osmosis?
Osmosis is the movement of water across a semi-permeable membrane from a region of low solute concentration to a region of high solute concentration.
True or False: Homeostasis is only relevant to multicellular organisms.
False
What happens during the process of vasodilation?
Blood vessels widen to increase blood flow and release heat.
Fill in the blank: The __________ feedback loop amplifies changes rather than reducing them.
positive
What is the primary function of the endocrine system in homeostasis?
To release hormones that regulate various body functions.
What does the term ‘homeostatic imbalance’ refer to?
A disruption in homeostasis that can lead to disease or dysfunction.
Fill in the blank: The __________ reflex helps to maintain blood pressure.
baroreceptor
What is the primary role of the hypothalamus in the endocrine system?
To regulate the release of hormones from the pituitary gland.
True or False: Blood pressure is an example of a regulated variable in homeostasis.
True
What is the function of antidiuretic hormone (ADH)?
To promote water reabsorption in the kidneys, reducing urine output.
Fill in the blank: The __________ system helps control body temperature through perspiration.
integumentary
What is the primary purpose of the feedback mechanisms in homeostasis?
To maintain equilibrium within the body.
What physiological changes occur during fight or flight response?
Increased heart rate, dilated pupils, and heightened alertness.
Fill in the blank: __________ is the process of maintaining stable blood oxygen levels.
Oxygen homeostasis
What is the role of the pancreas in regulating blood glucose?
The pancreas produces insulin and glucagon to lower and raise blood glucose levels, respectively.
True or False: All organisms have the same homeostatic mechanisms.
False
What does the term ‘set point’ refer to in homeostasis?
The ideal value for a physiological variable that the body tries to maintain.
Fill in the blank: The __________ system helps regulate body fluids and electrolytes.
renal
How does the body respond to increased temperature?
By increasing sweating and dilating blood vessels.
True or False: Homeostasis is a dynamic process that requires constant adjustment.
True
What role do electrolytes play in homeostasis?
They help maintain fluid balance, nerve function, and muscle contractions.
Fill in the blank: The __________ is responsible for regulating the body’s internal clock.
suprachiasmatic nucleus
What is the role of glucagon?
Glucagon raises blood glucose levels by promoting glycogen breakdown in the liver.
True or False: Homeostasis can be affected by stress and environmental changes.
True
What is the primary function of the hypothalamic-pituitary axis?
To regulate the endocrine system and maintain homeostasis.
Fill in the blank: __________ is the process by which the kidneys filter blood to form urine.
Filtration
What happens to the body during dehydration?
The body retains water by reducing urine output and increasing thirst.
True or False: Homeostasis is only necessary for human health.
False
What is the role of the respiratory system in homeostasis?
To regulate oxygen and carbon dioxide levels in the blood.
Fill in the blank: __________ are specialized cells that respond to changes in the environment.
Receptors
What is the significance of the body’s pH range?
A narrow pH range is essential for enzyme function and metabolic processes.
True or False: The body can tolerate large fluctuations in internal conditions.
False
What is the primary goal of homeostatic regulation?
To maintain stability and optimal functioning of the organism.
Fill in the blank: __________ is a state of equilibrium in the body’s internal environment.
Homeostasis
What is the role of feedback loops in biological systems?
To coordinate physiological processes and maintain homeostasis.
True or False: Homeostasis is maintained by both neural and hormonal signals.
True
What is the physiological response to high blood pressure?
Blood vessels dilate and heart rate decreases to lower blood pressure.
Fill in the blank: The __________ reflex helps regulate heart rate.
baroreceptor
What is the purpose of the hypothalamus in temperature regulation?
To detect changes in temperature and initiate appropriate responses.
True or False: Homeostasis is a passive process.
False
What is the role of the autonomic nervous system in homeostasis?
To control involuntary bodily functions and responses.
Fill in the blank: __________ feedback mechanisms are essential for childbirth.
Positive
What is the importance of maintaining blood calcium levels?
Calcium is crucial for bone health, muscle function, and nerve signaling.
True or False: The body can function optimally outside of its homeostatic range.
False
What role does the adrenal gland play in stress response?
It releases hormones like adrenaline and cortisol to prepare the body for stress.
Fill in the blank: __________ homeostasis is crucial for the function of the nervous system.
Ion
What is the significance of the body’s temperature range?
It is essential for enzyme activity and overall metabolic processes.
True or False: The body can maintain homeostasis indefinitely without energy.
False
What is the function of the thyroid gland in homeostasis?
To regulate metabolism and energy homeostasis through hormone production.
