excretory system

Question 1

Purpose

Answer 1

to remove excess and unwanted substances from the body and to maintain a stable internal environment.

nitrogenous waste

Question 2

Nitrogenous waste

Answer 2

nitrogen must be excretes as Ammonia, Uric Acid or Urea

Question 3

Ammonia

Answer 3

occurs in the presence of a lot of water.

in aquatic animals

Question 4

Uric Acid

Answer 4

occurs in drier condition. more concentrated with nitrogen to conserve water

Question 5

Urea

Answer 5

Mammals. requires less energy.

Question 6

Urinary System

Answer 6

elimination of nitrogenous waste

consist of two kidneys, two ureters, a bladder and a urethra.

Question 7

Kidney

Answer 7

filters waste form the blood

Question 8

Kidney structure

Answer 8

contains a renal capsule- thin layer of cells covering the kidney.

renal cortex the outer layer of the kidney

renal medulla is the inner part of the kidney. made up of renal pyramids and renal columns

renal artery is where blood enters. ureter is where the filtered waste leaves.

Question 9

Nephron

Answer 9

functional unit of the kidney

each kidney contains nephrons.

extends through the cortex and medulla of the kidney

Question 10

glomerulus

Answer 10

clump of capillaries found in the kidney

Question 11

capillaries

Answer 11

smaller blood vessels

Question 12

Bowman’s Capsule:

Answer 12

A cup-shaped structure that surrounds a network of capillaries called the glomerulus. Blood enters the glomerulus under pressure, and the filtration process begins here. Water, ions, and small molecules pass through the glomerular membrane into the Bowman’s capsule, forming the filtrate.

Question 13

Proximal Convoluted Tubule

Answer 13

The filtrate from the Bowman’s capsule enters the PCT, where a significant amount of reabsorption occurs. Nutrients such as glucose, amino acids, and a large portion of water and ions are reabsorbed into the blood.

Question 14

Loop of Henle

Answer 14

After the PCT, the filtrate moves into the Loop of Henle, which has a descending and an ascending limb. The descending limb is permeable to water but not to solutes, allowing water to be reabsorbed. The ascending limb, in contrast, is permeable to solutes but not to water, allowing sodium and chloride ions to be reabsorbed.

Question 15

Distal Convoluted Tubule

Answer 15

The filtrate then enters the DCT, where further reabsorption of sodium, chloride, and water occurs, along with the secretion of potassium, hydrogen ions, and certain drugs and toxins into the filtrate.

Question 16

Collecting Duct

Answer 16

Multiple nephrons empty into a single collecting duct. The collecting duct plays a crucial role in regulating water balance and urine concentration. Depending on the body’s hydration status, more water can be reabsorbed here, concentrating the urine. The final urine then moves from the collecting duct into the renal pelvis, from where it flows to the bladder for storage and eventual excretion.