4B3 Maintaining Homeostasis Flashcards
Describe how organisms maintain homeostasis through hormones, feedback mechanisms, and behaviors.
What is homeostasis?
The steady state of internal conditions maintained by an organism despite a changing environment.
What are the three main systems of homeostasis in body systems?
- Thermoregulation
- Osmoregulation
- Chemical regulation
What is thermoregulation?
The process of regulating body temperature to maintain a core temperature of 37 degrees Celsius.
What is osmoregulation?
The maintenance of the body’s salt and water balance in homeostasis.
What is chemical regulation?
The process of maintaining homeostasis of chemicals in the body.
What are the main body systems for maintaining homeostasis?
- Endocrine system
- Nervous System
What is the main organ system acting as a sensor in homeostasis?
The nervous system.
The nervous system includes cells called neurons containing receptors that sense changes in the environment.
What stimuli is your nervous system able to perceive?
- Visual (sight)
- Auditory (sound)
- Tactile (touch)
- Olfactory (smell)
- Gustatory (taste)
What are the effectors in homeostasis?
Organs that carry out processes to maintain homeostasis, controlled by the endocrine and nervous systems.
What is a feedback loop in homeostasis?
A control loop where the product of the system regulates itself.
What are the two main types of feedback loops?
- Positive feedback loops
- Negative feedback loops
What occurs in a positive feedback loop?
The product of the effector stimulates the effector and increases the product.
Example: During childbirth when the baby’s head presses on the cervix, causing the release of oxytocin to promote further contractions. This continues until the baby is born.
What occurs in a negative feedback loop?
The original state is restored due to a response that opposes the change.
Example: Your body will respond to cold temperatures by restricting blood flow to extremities as well as causing goosebumps and shivering. Once your body is back to a normal temperature the goosebumps go away, normal blood flow is restored and shivering stops.
How does the body regulate temperature?
Through a negative feedback loop controlled by the hypothalamus in the brain, causing changes like sweating and dilating blood vessels to release excess heat.
How does a fever initiated by an immune response help your body reach homeostasis?
The fever will kill any pathogens causing the immune response. Once the pathogens have been eliminated the body will return to homeostasis.
What is the role of the hypothalamus in regulating body temperature?
It processes sensory information and causes changes in effector organs to decrease or increase temperature.
How does the pancreas regulate blood glucose levels?
It secretes insulin when blood glucose levels are too high and glucagon when levels are too low.
What disease is attributed to a disfunction of the pancreas resulting in a lack of insulin production and secretion?
Diabetes
What organ secretes antidiuretic hormone?
Pituitary Gland
How does antidiuretic hormone help maintain homeostasis?
It promotes the reabsorption of water from the kidneys.
By increasing the reabsorption of water, blood pressure as well as salt content in the body can stay in homeostasis.
What is the center in the brain that takes cues from the environment about determining the optimal times for sleep?
Suprachiasmatic nucleus
(SCN)
How does sleep help the body to maintain homeostasis?
- Allowing the body time to regulate hormones.
- Allow time to regulate blood pressure and reduce inflammation.
- Allow time for the production of white blood cells that aid in immunity.
What are the 4 common types of sleep patterns in organisms?
- Diurnal
- Nocturnal
- Crepuscular
- Cathemeral
What characterizes a diurnal sleep pattern?
Active and awake during the day and sleep at night.
Organisms with diurnal sleep patterns: Humans, primates, and some birds.
