B12. (Triple only) Thermoregulation and Kidney

Question 1

What is thermoregulation?

Answer 1

Thermoregulation is the process by which organisms maintain their internal body temperature within a certain range, despite changes in the external temperature.

Question 2

What is the role of the hypothalamus in thermoregulation?

Answer 2

The hypothalamus, located in the brain, acts as the body’s thermostat. It detects changes in body temperature and triggers responses to maintain it within a narrow range.

Question 3

How does the body response to cold conditions?

Answer 3

The body regulates temperature through mechanisms such as shivering, vasoconstriction (narrowing blood vessels) and hairs on skin standing up.

Question 4

How does the body respond to hot conditions?

Answer 4

The body regulates temperature through mechanisms such as sweating, vasodilation (widening of blood vessels) and hairs standing lying flat on the skin.

Question 5

Describe vasodilation and vasoconstriction in thermoregulation.

Answer 5

• Vasodilation is the widening of blood vessels near the body surface, allowing more blood to flow close to the skin’s surface, facilitating heat loss.
• Vasoconstriction is the narrowing of blood vessels, reducing blood flow near the skin’s surface to conserve heat.

Question 6

What is the role of sweating in thermoregulation?

Answer 6

Sweating is the body’s mechanism to cool down. Sweat glands release moisture onto the skin’s surface, which evaporates, taking heat energy from the body and cooling it down.

Question 7

How does shivering help in thermoregulation?

Answer 7

Shivering is the rapid contraction and relaxation of muscles, which generates heat. It helps increase body temperature when it drops below the normal range.

Question 8

Explain the significance of insulation in thermoregulation.

Answer 8

Insulation, such as fat or fur, helps to reduce heat loss from the body. It acts as a barrier, preventing the transfer of heat between the body and the environment, thus helping to maintain a stable internal temperature.

Question 9

How do organisms adapt to extreme temperatures in their environment?

Answer 9

Organisms adapt to extreme temperatures through behavioral adaptations (seeking shade or sun, burrowing) and physiological adaptations (changing metabolic rate, altering insulation).

Question 10

Discuss the consequences of thermoregulation failure in organisms.

Answer 10

Failure in thermoregulation can lead to overheating (hyperthermia) or excessive cooling (hypothermia), both of which can result in serious health issues, organ damage, and even death if not corrected promptly.

Question 11

What is the main function of the kidneys?

Answer 11

The main function of the kidneys is to filter waste products and excess substances, such as urea, salts, and water, from the blood to form urine.

Question 12

What 2 main processes occur in the kidney before urine is formed.

Answer 12

1) Ultrafiltration of the blood.
2) Selective reabsorption of useful substances.

Question 13

Describe the structure of the kidney.

Answer 13

The kidney is bean-shaped and has an outer layer called the renal cortex, an inner region called the renal medulla.

Question 14

What are nephrons?

Answer 14

Nephrons are the microscopic units within the kidneys responsible for filtering blood and producing urine.

Question 15

Explain the process of urine formation in the kidney.

Answer 15

Urine formation involves three main processes: filtration, reabsorption, and secretion.

Question 16

What are some common problems that can affect the kidneys?

Answer 16

Common kidney problems include urinary tract infections (UTIs), kidney stones, kidney infections, chronic kidney disease (CKD), and acute kidney injury (AKI).

Question 17

Describe the symptoms of kidney problems.

Answer 17

Symptoms of kidney problems may include changes in urine frequency or color, pain or discomfort in the abdomen or lower back, swelling (edema), fatigue, nausea, and changes in blood pressure.

Question 18

What are some factors that can increase the risk of kidney problems?

Answer 18

Risk factors for kidney problems include high blood pressure, diabetes, obesity, smoking, family history of kidney disease, certain medications, and aging.

Question 19

Describe the different ways that water is lost from the body?

Answer 19

• Water leaves the body via the lungs during exhalation.
• Water, ions and urea are lost from the skin in sweat.
• Excess water, ions and urea are removed via the kidneys in the urine.

Question 20

What is deamination?

Answer 20

Digestion of the protein we eat results in excess amino acids. These amino acids are deaminated (amine group removed) by the liver to form ammonia. Ammonia is toxic and therefore immediately converted to urea for safe excretion.

Question 21

Which hormone controls water levels in the bloodstream?

Answer 21

Anti-diuretic hormone (ADH) which is produced by the pituitary gland in the brain.

Question 22

How does the hormone ADH affect the permeability of the kidney tubules?

Answer 22

ADH makes the walls of the kidney tubules more permeable which increases water reabsorption back into the blood stream.

Question 23

Which part of the brain detects the blood is too concentrated or too dilute?

Answer 23

Hypothalamus

Question 24

What is meant by the term ‘dialysis’

Answer 24

Kidney dialysis is a medical procedure used to artificially remove waste products and excess fluids from the blood when the kidneys are unable to perform this function adequately.

Question 25

How does hemodialysis work?

Answer 25

In hemodialysis, blood is pumped out of the body and through a dialyzer (artificial kidney), where waste products and excess fluids are removed. The cleaned blood is then returned to the body.

Question 26

How often is dialysis typically required for individuals with kidney failure?

Answer 26

Dialysis is typically required several times per week for individuals with kidney failure, as it needs to compensate for the loss of kidney function on an ongoing basis.

Question 27

How does kidney dialysis differ from a kidney transplant?

Answer 27

Kidney dialysis is a temporary treatment that involves removing waste products and excess fluids from the blood using a machine or a special fluid, whereas a kidney transplant involves surgically replacing a failed kidney with a healthy donor kidney, providing a more permanent solution.

Question 28

Can you think of 2 disadvantages of having a kidney transplant?

Answer 28

• Risk of the transplanted kidney being rejected from the body as a result of the immune system recognising the antigens on the donor organ as foreign.
• The chance of this happening can be reduced by using immunosuppressant drugs.