Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Biology > Chapter 18 - Excretory system > Flashcards

Chapter 18 - Excretory system Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

Explain why living organisms need to excrete

A
  • Some waste products can be poisonous and, if not excreted, can slow down metabolism in cells
  • Some waste products like salts and water in are in excess, and if not excreted, can damage cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Name the main excretory organs, along with the waste products excreted by each organ

A

Lungs: Carbon dioxide and water vapour
Skin: Water, salts, small amounts of urea
Kidneys: Nitrogenous waste products, excess water and excess salts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Name the waste products of metabolism, and explain how they are formed

A
  • Carbon dioxide: Produced during the Krebs cycle in mitochondria
  • Bile pigments: Formed in the liver and spleen during the breakdown of haemoglobin. Excreted in faeces
  • Urea: Formed in the liver during deamination
  • Water vapour: Formed during cellular respiration
  • Excess water: Taken in with fluids during nutrition
  • Excess salts: Taken in during nutrition
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Name the part in the brain responsible for osmoregulation

A

Hypothalamus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Define excretion

A

The removal of metabolic waste from the body, along with the removal of excess substances like water and salts from the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe cellular secretion, and give a few examples

A

Cells produce usefull substances during metabolism and release it to perform important funcitons, like hormones, digestive juices and milk

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Where does the carbon dioxide which is used during deamination come from?

A

Respiration in the liver

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe the breaking down of alcohol, drugs and hormones in the liver

A
  • Alcohol is broken down into water and carbon dioxide. This process is known as detoxification
  • Drugs are broken down by the liver
  • Hormones which are continuously produced by endocrine glands are broken down in the liver to prevent accumilation thereof in tissue
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Study the sketches of the kidneys and excretory system

A

Heh?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Describe the functions of the kidneys

A
  • Excretion of nitrogenous waste
  • Osmoregulatory function by excreting excess water or reabsorbing water when necessary
  • Regulate salt concentrations by excreting salts or reabsorbing water and salts
  • Regulation of pH
  • Reabsorbtion of usefull substances
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Name the cells, their adaptions and function, of which the inner wall of the bowman’s capsule consists

A
  • Podocytes
  • Filtration slits
  • Ultra-filtration
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Why is the blood pressure in the glomerulus so high?

A

The diameter of the afferent arteriole is much larger than the efferent arteriole

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Study the sketch of the nephron

A

Ehe!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Give another name for “vasa recta”

A

Peritubular capillaries

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Name the three main functions of the nephron

A
  • Ultra-filtration
  • Tubular reabsorbtion
  • Tubular secretion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Why are small molecules in blood able to filtrate into the bowman’s capsule?

A
  • The walls of glomerulus is made of one epithelial cell layer
  • The podocyte layer has filtration slits which form an ultrafine filter
17
Q

Name the adaptations of the Malpighian body for ultra-filtration

A
  • Very high blood pressure in glomerulus
  • Capillary network of glomerulus provides a large surface area
  • Bowman’s capsule is cup-shaped to give it a large surface area
  • Thin walls of bowman’s capsule and walls of glomerulus
  • Podocytes have filtration slits
  • Capillaries of glomerulus are in close contact with the bownman’s capsule
18
Q

Describe tubular reabsorbtion of usefull substances in the proximal convoluted tubule

A
  • Usefull substances like glucose and amino acids which pass into filtrate must now be reabsorbed
  • Selective reabsorbtion of substances like ALL glucose, amino acids etc. are absorbed by active transport
  • Usefull minerals such as sodium ions are absorbed by active transport and facilitated diffusion
19
Q

Name the adaptations of the proximal convoluted tubule for tubular reabsorbtion

A
  • Micro villi to maximise absorbtion area
  • Endothelial cells contain many mitochondria to release energy for active transport
  • Endothelial layer is a single layer for easy passage of substances
20
Q

Describe tubular reabsorbtion of water in the loop of Henle

A
  • Filtrate enters the loop of Henle where water is conserved
  • There is always a high Na and Cl concentration outside the loop
  • The higher the NaCl concentration outside the loop, the more water will be reabsorbed by osmosis
  • The descending limb is permeable to water and water is absorbed into vasa recta by osmosis
  • Sodium ions are actively pumped out of the ascending limb, and chlorine follows passively
  • Water will not follow because the ascending limb is inpermeable to water
  • The longer the loop of Henle, the more water can be absorbed
21
Q

Describe tubular reabsorbtion of usefull substances in the distal convoluted tubule

A
  • Further absorbtion of usefull substances occurs here
  • Regulates pH of blood
  • When blood is acidic, H+ ions is secreted into the blood
  • When blood is alkaline, less H+ ions are secreted and bicarbonate ions are secreted from the blood into the tubules
22
Q

Describe osmoregulation in terms of hormones released

A
  • Water content too low: Posterior pituitary gland secretes ADH, which causes the walls of the collecting duct to become more permeable so more water can be absorbed
  • Vica versa for too high water content
23
Q

Describe tubular secretion

A
  • Substances are secreted from blood in vasa recta into proximal and distal convoluted tubules
24
Q

Name the main constituents of urine

A
  • Water
  • Metabolic waste
  • Inorganic salts
  • Foreign substances
  • Drugs
25
Q

Suggest reasons for kidney failure

A
  • Infections of kidneys
  • Accidents
  • Hypertension
  • Diabetes mellitus
  • Heart failure
  • Cysts
26
Q

Explain dialysis

A
  • Blood enters from patient’s artery in arm
  • Blood pumped
  • Blood passes through dialysis tubing
  • Tubing is partially permeable and filters blood
  • Tubing surrounded by dialysis fluid
  • Fluid contains glucose and amino acids, and some salts, BUT NO urea or uric acid
  • Dialysis fluid has same osmotic potential as blood
  • Waste substances and excess substances diffuses into dialysis fluid
  • Bubble trap removes air bubbles and warms blood
  • “Clean” blood enters through a vein in patient’s arm
27
Q

Name the advantages of kidney transplants

A
  • Normal life
  • Independent of machines
  • Continuous filtration
28
Q

Name the disadvantages and risks of kidney transplants

A
  • Rejection of transplanted kidneys could occur
  • Immunosuppressant drugs need to be taken (may even be lifelong)
  • Isolation
  • Operation is risky
  • Very expensive
  • The tissue type and blood group of donor must closely match
29
Q

Name the advantages of dialysis

A
  • No donor
  • Rejection impossible
  • A life saver if transplant is not immediately possible
30
Q

Name the disadvantages of dialysis

A
  • Time consuming
  • No normal life
  • Must live close to hospital
  • There may be a shortage of machines
  • Expensive
  • No continuous filtration
  • Loss of some minerals like calcium and iron
  • No sport :(

Biology (40 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions