Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

A Level Biology > Module 5.1.2 Excretion As An Example Of Homeostatic Control > Flashcards

Module 5.1.2 Excretion As An Example Of Homeostatic Control Flashcards

(72 cards)

Start Studying
1
Q

What are the different organs involved with the liver?

A

gallbladder
bile duct
duodenum
small intestine
pancreas
hepatic portal vein
hepatic artery
hepatic vein
aorta
posterior vena cava

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

What is the function of the gallbladder?

A

produces bile

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

What is the duodenum?

A

The point which the bile duct meets the small intestine

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

What is a hepatocyte?

A

A liver cell

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

What is the structure of a hepatocyte?

A

large nuclei
prominent Golgi apparatus
lots of mitochondria
divide & replicate frequently

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

Why do hepatocytes have prominent Golgi apparatus?

A

The liver is involved in metabolic processes meaning it has to do a lot of packaging lipids & extracellular proteins

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

Why do hepatocytes have lots of mitochondria?

A

The liver is a very large & metabolically active organ so it requires lots of energy (ATP)

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

Why do hepatocytes need to divide & replicate frequently?

A

Damage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the 2 main blood vessels that enter the liver?

A

The hepatic artery
The hepatic portal vein

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

What is the function of the hepatic artery?

A

Carries oxygenated blood from the heart to the liver via the aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the function of the hepatic portal vein?

A

Takes deoxygenated blood rich in the products of digestion from the intestines to the liver?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the structure of the hepatic artery?

A

narrow & unbranched

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

What is the structure of the hepatic portal vein?

A

wider & branched

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

What is the main blood vessel that exits the liver?

A

The hepatic vein

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

What is the function of the hepatic vein?

A

Re-joins the vena cava taking the products of liver metabolism away

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is a lobule?

A

A 6 sided structure made up of hepatocytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the structure of a lobule?

A

Arranged in irregular branching & interconnected plates around a central vein (hepatic vein)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does blood flow from the hepatic artery & hepatic portal vein to the hepatic vein?

A

Blood passes through sinusoids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are sinusoids?

A

Large endothelium lined spaces where blood flows from the hepatic artery & hepatic portal vein to the hepatic vein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a Kupffer cell?

A

A specialised macrophage (A white blood cell)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the role of a Kupffer cell?

A

Destroy worn out red or white blood cells, bacteria & foreign matter arriving from the digestive tract as well as breaking haemoglobin down into bilirubin (brown pigment in faeces)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is excretion?

A

The removal of metabolic waste, by-products or unwanted substances from normal cellular processes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How does excretion differ to secretion or egestion

A

secretion: internal process of producing useful products e.g. sweating
egestion: discharge of undigested by-products e.g. vomiting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the main excretory organs?

A

Lungs
Kidneys
Ureter
Bladder
Urethra

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What are the main substances that need removing?
CO2 (cellular respiration) Urea (excess amino acids)
26
How is CO2 & Urea excreted from the body?
Taken to their excretory organ via the bloodstream
27
How is CO2 transported in the body?
85% transported as HCO3- ions 10% transported as carboaminohaemoglobin 5% transported in the plasma as carbonic acid
28
What is the formula equation for the production of carbonic acid in the blood?
CO2 + H20 ---> H2CO3
29
What is the formula equation for the dissociation of carbonic acid?
H2CO3 ---> H+ + HCO3-
30
What happens if there is too high blood CO2 levels?
the pH of the blood decreases & you can get respiratory acidosis
31
What are the complications of respiratory acidosis?
slow/difficulty breathing, headache, drowsiness, tremors, confusion etc.
32
What are the functions of the liver?
bile production removal of excess amino acids detoxification
33
What is the function of bile?
emulsifies fats (breaks them down so their surface area is larger) neutralisation of stomach acid
34
What 2 processes remove excess amino acids?
Deamination The ornithine cycle
35
What happens during deamination?
The toxic amine group is turned into ammonia in the liver
36
What is the word equation for deamination?
Amino acid + oxygen ---> Keto acid + Ammonia
37
What happens during the ornithine cycle?
Ammonia is reacted with CO2 to form urea
38
Does the ornithine cycle require ATP?
Yes
39
What is the word equation for the ornithine cycle?
Ammonia + Carbon dioxide ---> urea + water
40
What is detoxification?
the breakdown of substances that aren't needed or are toxic by the liver
41
What substances does the liver detoxify?
Lactate Alcohol Hormones Medicinal Drugs
42
What different structures make up the gross kidney structure?
Nephron Capsule Cortex Medulla Renal Vein Renal Artery Pelvis Ureter
43
What is the function of the capsule?
A protective outer layer
44
What is the the cortex?
the outer darker layer of the kidneys
45
What is the medulla?
The inner pale layer of the kidneys
46
What is the function of the renal vein?
returns deoxygenated blood to the heart via the vena cava
47
What is the function of the renal artery?
supplies oxygenated blood to the kidneys via the aorta & carries urea to the kidneys
48
What is the function of the pelvis?
funnels the urine that is produced into the ureter
49
What is the function of the ureter?
carries urine to the bladder
50
What are the 3 functions of the kidneys?
ultrafiltration selective reabsorption control of water potential
51
What is a nephron?
Part of the kidneys that carry out ultrafiltration of the blood to produced the most concentrated urine possible
52
What are the different structures in the nephrons?
The bowman's capsule Glomerulus (not apart of the nephron) The proximal convoluted tubule (PCT) The loop of Henle The distal convoluted tubule (DCT) The collecting duct
53
What is the function of the Bowman's capsule?
The site of ultrafiltration
54
What is ultrafiltration & how does it happen?
small molecules e.g. water, urea, amino acids are filtered out of the blood & passed into the nephrons through the 3 part filter
55
What 3 structures make up the three part filter?
The endothelium of blood capillaries (glomerulus) Basement membrane Epithelium of the renal capusle
56
What is the structure & function of the endothelium of blood capillaries
Very thin containing 1000s of pores 10nm in diameter which cover 30% of the capillary wall Provides a barrier so that cells cannot pass through but plasma proteins can pass through
57
What is the structure & function of the basement membrane?
A meshwork of collagen & glycoprotein fibres Allows water & small molecules to pass through but proteins cannot as they get repelled by the negative charges of the fibres
58
What is the structure & function of the renal capsule?
Made of podocytes which are specialised for filtration
59
What relative molecular weight must ions & molecules be under to be able to be filtered?
69000 so RBC & WBC cannot
60
What molecules can be filtered & what is this also known as?
water, glucose, amino acids, many vitamins & drugs e.g. penicillin glomerular filtrate
61
What are podocytes?
foot like extensions that wrap around capillaries of the glomerulus & interlink with extensions from neighbouring cells. They fit together loosely leaving filtration slits about 25nm wide which fluid passes through during filtration
62
What is the glomerulus?
a knot of capillaries where blood is filtered from the bowman's capsule
63
What blood vessel delivers blood to the glomerulus?
the afferent arteriole
64
What blood vessel delivers blood away from the glomerulus?
The efferent arteriole
65
Why is the afferent arteriole wider than the efferent arteriole?
The pressure rises as blood enters the glomerulus so high hydrostatic pressure is generated to push the blood into the glomerulus
66
What is the proximal convoluted tubule?
The tube closest to the Bowman's capsule where selective reabsorption occurs
67
What is the loop of Henle?
A tube that descends into the medulla & connects both PCT & DCT together which adds salt to the urine in order to concentrate it & remove as much water as possible
68
What is the distal convoluted tubule?
The tube furthest away from the bowman's capsule that delivers urine to the collecting duct & removes the salt from the urine
69
What is the collecting duct?
a tube that collects all the urine & removes any more water to ensure urine has a low water potential & it is extremely concentrated
70
Where does selective reabsorption occur?
The PCT -> the fluid is altered by the reabsoption of all sugars, most salts & some water?
71
Why is absorption selective?
Because urea would end up being reabsorbed into the blood
72
How is water potential controlled in the kidneys?
Loop of Henle -> adds salt to decrease water potential DCT -> removes salt to regulate water potential Collecting duct -> more water removed to further decrease & lower the water potential of urine & making sure it is concentrated

A Level Biology (18 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions