IB Biology 11.3

Define excretion

Excretion is the removal from the body of the waste products of metabolic activities

Draw and label a diagram of the kidney

Cortex, Renal Pelvis, Medulla, Renal Artery, renal vein, and uretra

Annotate a diagram of a glomerulus and associated nephron to show the function of each part

Afferent arteriole: Brings blood to the nephron to be filtered
Efferent arteriole: Removes blood from nephron (minus filtered components)
Glomerulus: Capillary tuft where filtration occurs
Bowman's Capsule: First part of nephron where filtrate is collecte

Explain the process of ultrafiltration, including blood pressure, fenestrated blood capillaries and basement membrane

Ultrafiltration occurs when hydrostatic pressure forces blood through a semi-permeable membrane, separating blood cells and large proteins from the remainder of the serum
Ultrafiltration occurs between the glomerulus and the Bowman's capsule and requires

Define osmoregulation

Osmoregulation is the control of the water balance of the blood, tissue or cytoplasm of a living organism

Explain the reabsorption of glucose, water and salts in the proximal convoluted tubule, including the roles of microvilli, osmosis and active transport

The proximal convoluted tubule extends from the Bowman's capsule and is where most selective reabsorption in the nephron occurs
All glucose, amino acids, vitamins and hormones are reabsorbed here, along with most (~80%) of the mineral ions and water
The p

Explain the roles of the loop of Henle, medulla, collecting duct and ADH (vasopressin) in maintaining the water balance of the blood

Creating a Salt Gradient in the Medulla
The function of the loop of Henle is to create a salt bath concentration in the fluid surrounding the tubule
The descending limb of the loop of Henle is permeable to water, but impermeable to salts
The ascending lim

Explain the difference in the concentration of proteins, glucose and urea between blood plasma, glomerular filtrate and urine

Proteins:
Proteins will be present in blood plasma, but not present in glomerular filtrate or urine
This is because proteins cannot pass across the basement membrane during ultrafiltration and thus cannot form part of the filtrate
Glucose:
Glucose will be

Explain the presence of glucose in the urine of untreated diabetic patients

The urine of non-diabetic patients should contain no glucose as it is selectively reabsorbed from the filtrate in the proximal convoluted tubule
Diabetics have higher levels of blood glucose due to either a lack of insulin secretion (type I) or insensitiv

During the urine production, what happens if water content of the blood is too low?
a.) Membrane channels are produced in the cells of the collecting duct
b.) large volumes of dilute urine is formed
c.) The pituitary gland stopbs secreting ADH
d.) The col

a.) Membrane channels are produced in the cells of the collecting duct

Which of the following best describes what happens in the glomerulus?
a.) regulation of salt balance leads to the production of urine
b.) Selective reabsorption of water and molecules by active transport
c.) Ultrafiltration introduces water and other mole

d.) High blood pressure forces water and other molecules into the nephron

What is the source of glucose in the fluid in the Bowman's capsule?
a.) blood in the Glomerulus
b.) Filtrate in the distal convoluted tubule
c.) Urine in the Renal pelvis
d.) Interstitial fluid in the medulla

a.) blood in the Glomerulus

What is the processes are required for the reabsorption of glucose in the kidney tubules?
a.) simple and facillitated diffusion
b.) Facilliated diffusion and active transport
c.) Simple diffusion and active transport
d.) Active transport only

b.) Facilliated diffusion and active transport

Which structure is acted upon by ADH (vasopressin)?
a.) PRoximal convoluted tubule
b.) Loop of Henle
c.) Bowman's capsule
d.) Collecting duct

d.) Collecting duct