Chapter 7: Exchange of Nutrients and Wastes

Question 1

What is mechanical digestion?

Answer 1

The physical break down and/or mixing of ingested substances, with no chemical exchange occurring

Question 2

What is chemical digestion?

Answer 2

The break down of large molecules progessively into different smaller molcules in chemical reactions catlysed by digestive enzymes

Question 3

What are villus?

Answer 3

An elongated projection from the lining of the small intestine that hugely increases surface area and thus the capacity for exchange of materials

Question 4

What is an epithelial cell?

Answer 4

A cell in a sheet of cells covering any external or internal surface in a milticellular organism

Question 5

What is a lymph vessel?

Answer 5

A thin-walled tube forming part of the lymphatic system, which collects and transports lymph, a plasma-like fluid, containing cell debris and bacteria, and returns it to the circulatory system

Question 6

What is a lacteal?

Answer 6

A vessel that transports materials to and from the villi of the small intestine; branch of lymph vessel

Question 7

What are the four main types of large biological molecules?

Answer 7

Carbohydrates, proteins, lipids and nucleic acids

Question 8

What is deamination?

Answer 8

A process that removes the nitrogen-containing amine group from the rest of the amino acid

Question 9

What is ammonia?

Answer 9

A product of amino acid breakdown that is extememly toxic in humans

Question 10

What is the removal of ammonia process in mammals?

Answer 10

Cells in the liver convert ammonia to urea, then it is carried to the kideneys where it is diluted with water to form urine

Question 11

What is uric acid?

Answer 11

A nitrogenous waste produced by desert animals, birds, reptiles and insects

Question 12

How do fish get rid of ammonia?

Answer 12

They excrete it directly into their environment

Question 13

What is a nephron?

Answer 13

A specialised structural and functional unit within the kidney where elimination of waster molecules from the blood and regulation of solute and water levels occur

Question 14

What is the renal artery?

Answer 14

The branch of the aorta that brings blood (containing nitrogenoud waste and water, blood proteins, red blood cells and minerals dissolved in the blood plasma) to each kidney

Question 15

What is the glomerulus?

Answer 15

A net work of capillaries, contained within the Bowman’s capsule, from which the blood contents are filtered by the structures of the nephron

Question 16

What is the Bowman’s capsule?

Answer 16

The nephron structure in which the glomerulus is positioned, and into which the filtrate from the glomerulus blood is forced

Question 17

What is filtrate?

Answer 17

The liquid that has passed through a filter

Question 18

What is the proximal tubule?

Answer 18

The section of the tubule in the nephron that leads from the Bowman’s capsule to the loop henle

Question 19

What is the loop of Henle?

Answer 19

The portion of a nephron that connects the proximal convoluted tubule to the distal convuluted tubule

Question 20

What is the distal tube?

Answer 20

The portion of the nephron between the loop of Henle and the collecting duct

Question 21

What is the order of tubules in the nephron? (structer)

Answer 21

The Bowman’s capsule, the proximal tube, then to the loop of Henle, the medulla, then to the distal tubule and finally a collecting duct

Question 22

What is a collecting duct?

Answer 22

A duct in the kidney that collects and transports fluid from several distal tubules to the renal pelvis

Question 23

What is the renal pelvis?

Answer 23

The section of the kidney where urine is collected and directed to the ureter

Question 24

What does afferent mean?

Answer 24

Bringing towards, as in blood vessel carrying blood to an organ

Question 25

What does efferent mean?

Answer 25

Taking away from, as in blood vessel carrying away from an organ

Question 26

What is the peritubular capillary?

Answer 26

A capillaery in a network surrounding the tubules of the nephron

Question 27

What is interstitial fluid?

Answer 27

Extracellular tissue fluid, fluid in spaces surrounding cells

Question 28

What is conter-current multiplication

Answer 28

A system operating between two tubes connecting by a hairpin bend and with fluid flowing in opposite directions, where energy is used to transport a material accross a membrane of one tube, enabling the production of a much greater concentration of solutes in the hairpin bend that could otherwise be acheived