Intro to the Excretory System

What is homeostasis mean in humans?

• production of blood cells

• formation of a blood clot to prevent loss of blood

• regulation of stable internal conditions

• center of the brain that controls our reflexes

What is the primary function of the excretory system?

• To maintain the right levels of water and dissolved substances

• To digest food

• To circulate blood

• To control body temperature

Which animals convert ammonia into urea?

• Reptiles and fish

• Mammals and amphibians

• Insects and reptiles

• Birds and insects

How much of the blood filtered by the kidneys gets reabsorbed?

• none, the kidneys do not filter blood

• 20%

• 66%

• 99%

Which of the following is a component of filtrate?

• red blood cells

• protein

• glucose

• water

What is the role of nephrons in the kidneys?

• To produce hormones

• To digest food

• To filter blood and form urine

• To pump blood

A concentration gradient allows for what kind of movement of substances?

• diffusion

• active transport

• phagocytosis

• pinocytosis

What happens in the Loop of Henle?

• Food is digested

• Blood is pumped

• Water and salts are reabsorbed

• Hormones are produced

Why do kangaroo rats have very concentrated urine?

• They have short Loops of Henle

• They have a high protein diet

• They live in water-rich environments

• They cannot spare water