4B3 Maintaining Homeostasis

Question 1

Define:

homeostasis

Answer 1

The steady state of internal conditions maintained by an organism despite a changing environment.

Question 2

What are three major processes involved in maintaining homeostasis?

Answer 2

• Thermoregulation
• Osmoregulation
• Chemical regulation

Question 3

Define:

thermoregulation

Answer 3

The process of regulating body temperature to maintain a core temperature of 37 degrees Celsius.

Question 4

Define:

osmoregulation

Answer 4

The maintenance of the body’s salt and water balance in homeostasis.

Question 5

Define:

chemical regulation

Answer 5

The regulation of chemical concentrations such as blood glucose, pH, and hormones to maintain homeostasis.

Question 6

What are the main body systems for maintaining homeostasis?

Answer 6

• Endocrine system
• Nervous System

Question 7

What is the main organ system acting as a sensor in homeostasis?

Answer 7

The nervous system.

The nervous system includes cells called neurons containing receptors that sense changes in the environment.

Question 8

What stimuli is your nervous system able to perceive?

Answer 8

• Visual (sight)
• Auditory (sound)
• Tactile (touch)
• Olfactory (smell)
• Gustatory (taste)
• Thermoreception (temperature)
• Nociception (pain)
• Proprioception (body position)
• Chemoreception (chemical detection such as in taste and smell)

Question 9

What are the effectors in homeostasis?

Answer 9

Organs that carry out processes to maintain homeostasis, controlled by the endocrine and nervous systems.

Question 10

What is a feedback loop in homeostasis?

Answer 10

A control loop where the product of the system regulates itself.

Question 11

What are the two main types of feedback loops?

Answer 11

• Positive feedback loops
• Negative feedback loops

Question 12

What occurs in a positive feedback loop?

Answer 12

The product of a process enhances or amplifies that process.

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.

Question 13

What occurs in a negative feedback loop?

Answer 13

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.

Question 14

How does the body regulate temperature?

Answer 14

Through a negative feedback loop controlled by the hypothalamus in the brain, causing changes like sweating and dilating blood vessels to release excess heat.

Question 15

How does a fever initiated by an immune response help your body reach homeostasis?

Answer 15

Fever can help slow the growth of some pathogens and enhances immune system activity. As the immune response resolves the infection, body temperature returns to normal and homeostasis is restored.

Question 16

What is the role of the hypothalamus in regulating body temperature?

Answer 16

It processes sensory information and causes changes in effector organs to decrease or increase temperature.

Question 17

How does the pancreas regulate blood glucose levels?

Answer 17

It secretes insulin when blood glucose levels are too high and glucagon when levels are too low.

Question 18

What disease is attributed to a dysfunction of the pancreas resulting in a lack of insulin production or secretion?

Answer 18

Diabetes

A disorder caused by the body’s inability to produce or respond to insulin properly, affecting blood glucose regulation.

Question 19

What organ secretes antidiuretic hormone?

Answer 19

Pituitary Gland

Question 20

How does antidiuretic hormone help maintain homeostasis?

Answer 20

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.

Question 21

What is the center in the brain that takes cues from the environment about determining the optimal times for sleep?

Answer 21

Suprachiasmatic nucleus

(SCN)

Question 22

How does sleep help the body to maintain homeostasis?

Answer 22

• 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.

Question 23

What are the 4 common types of sleep patterns in organisms?

Answer 23

• Diurnal
• Nocturnal
• Crepuscular
• Cathemeral

Question 24

What characterizes a diurnal sleep pattern?

Answer 24

Active and awake during the day and sleep at night.

Organisms with diurnal sleep patterns: Humans, primates, and some birds.

Question 25

What characterizes a **nocturnal sleep pattern**?

Answer 25

Animals **sleep during the day** and are active at night. ## Footnote Organisms with nocturnal sleep patterns: Coyote, Leopard, Hippopotamus.

Question 26

What characterizes **hibernation**?

Answer 26

A **state of dormancy** in which metabolic activity significantly decreases, allowing survival during harsh environmental conditions like winter. ## Footnote Organisms that exhibit hibernation include hedgehog, bees, groundhogs.

Question 27

What are the **benefits** of a hibernation sleep pattern?

Answer 27

* Protection from harsh conditions. * Energy conservation. * Reduced risk of predation.

Question 28

What is **basking** and how does it relate to homeostasis?

Answer 28

A **behavioral adaptation** used by ectotherms to **regulate body temperature** by absorbing heat from external source like the sun. ## Footnote Examples of organisms includes lizards, turtles, and snakes.

Question 29

What are animals called that **cannot** regulate their body temperature?

Answer 29

Ectotherms ## Footnote Also known as being cold-blooded. Examples: Lizard, snakes, turtles.

Question 30

What are animals called that can **regulate** their **body temperature**?

Answer 30

Endotherms ## Footnote Also known as being warm-blooded. Examples: Humans, dogs, birds.