Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

AQA GCSE Biology > `Topic 5: Homeostasis and Response > Flashcards

`Topic 5: Homeostasis and Response Flashcards

(54 cards)

Start Studying
1
Q

What is homeostasis?

A

Regulation of the internal conditions of a cell or organism to maintain optimum conditions for function in enzyme actions all cell functions

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

What are examples homeostasis are in control of in the human body?

A
  • Blood Glucose Concentration
  • Body Temp.
  • Water Levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does the body maintain controlled conditions within the body?

A

Under involuntary control where brain stem and spinal cord are involved (non-conscious part of brain)

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

What are the two control systems responsible for homeostasis?

A
  • Nervous System
  • Endocrine System
    ALSO HAVE OTHER ROLES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is the constant pattern for control systems in the body?

A
  • Receptor detects changes
  • Coordination Centre process info
  • Effector restores levels
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are the differences between the nervous and endocrine system?

A
  • Signals using electrical impulses / using chemical messengers
  • Fast / Slow Acting
  • Short-lived / Long lasting
  • Precise location of effect / Affect multiple tissues and organs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the human endocrine system composed of?

A

Composed of glands which secrete chemicals called hormones directly into bloodstream which is then carried to a target cell/organ to produce an effect

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

What are the important structures of the endocrine system?

A
  • Pituitary Gland (Brain): Also known as the master gland, making hormones like FSH, LH,ADH and HGH
  • Pancreas: Produces insulin to regulate blood glucose levels and glucagon
  • Thyroid Gland: Thyroxine which controls metabolic rate and affects growth
  • Adrenal Gland: Produces adrenaline, above kidney
  • Testes: Testosterone
  • Ovaries:
    Oestrogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is the endocrine system?

A

Organ system that controls the body via homeostasis via hormones

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

What are hormones?

A

Chemical messenger that travels via bloodstream to a target cell

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

What organ is blood glucose concentration monitored?

A

Pancreas

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

What is the pancreas?

A

Endocrine gland which also has a vital but separate role in digestion

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

What food can cause an increase in glucose in the bloodstream?

A

Foods which contain high carbohydrates

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

How does the pancreas reduces blood glucose concentration levels when it is too high?

A

Produces hormone insulin to bring it back down which stimulates cells, particularly liver and muscle, to take in glucose from bloodstream

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

What happens if there is too high of a blood glucose concentration level?

A

Cells of the body can lose water by osmosis which can be dangerous

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

What happens if liver and muscle cells have excess glucose?

A

Excess glucose is converted into glycogen for storage

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

What is Type 1 Diabetes?

A

Disorder in which the pancreas fails to produce sufficient insulin to control blood glucose levels as a result of person’s own immune system destroying the cells of the pancreas that make insulin during development

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

How is Type1 diabetes often treated?

A

Insulin injections

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

How does Type 2 Diabetes differ to Type 1 Diabetes?

A

Body cells no longer respond to the insulin, it is still made but cells are resistant and don’t respond as well as they should which can also lead to high, uncontrollable blood glucose levels

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

What are common treatments of Type 2 Diabetes?

A

Carbohydrate-controlled diet and an exercise regime

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

What happens if blood glucose concentration is too low?

A

Pancreas produces the hormone glucagon that causes glycogen to be converted into glucose and released into the blood

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

What is negative feedback control and how does it control blood glucose levels in body?

Study These Flashcards
A
  • Insulin produces which stimulates cell and reduces level when high
  • Glucagon produce which stimulates cell and increase level when low
23
Q

What is the cycle found in almost all biological control systems?

Study These Flashcards
A

Negative Feedback Control

24
Q

What is the difference between glucagon and glycogen?

Study These Flashcards
A
  • Glucagon is the hormone
  • Glycogen is the polysaccharide glucose is stored as
25
What happens if body cells lose or gain too much water by osmosis?
- Too much water in blood result in cells swelling as water moves them, causes a diluting effect and can lead to cell lysis (bursting) - Too little water in blood/ too high ion conc. and cells lose water by osmosis has a dehydrating effect and can lead to cell death
26
How is water lost?
- Leaves the body via the lungs during exhalation - Water, ions and urea re lost from the skin in sweat
27
What is a risk factor for Type 2 Diabetes?
Obesity
28
Why does the pituitary gland secrete several hormones in blood?
Response to body conditions and hormones in turn act on other glands to simulate other hormones to be released to bring about effects
29
Do lungs and skin have control of what is lost?
No control over how much water, ion or urea is lost via exhalation or sweating
30
As lungs and skin have no control of water, ion and urea loss, where can controlled loss take place?
Excess water, ions and urea are removed via the kidneys when they filter the blood to produce urine
31
What is deamination?
Process of breaking down excess protein and predominantly occurs in the liver
32
Describe the process of deamination
Enzymes in the liver split amino acid molecules, with the part containing carbon turning into glycogen and the part containing nitrogen turning into ammonia
33
What must happen immediately after deamination?
Ammonia must be converted to urea as it is toxic to cells, with the urea then being transported around the body via the blood safely for excretion by the kidneys
34
What does the kidney help to control?
Controls the water content of the body and the concentrations of substances dissolved in the fluids of the body
35
Describe filtration in the kidney
- Kidney contains highly branched capillary networks that form filters which contain pores with an average radium of 3 nanometres - As blood passes through, the pressure increases as it is pushed into filters and this high-pressure mass flow forces molecules that are small enough out of bloodstream
36
What does the kidney selectively reabsorb?
In an active process of a healthy kidney, the kidney reabsorbs all of the glucose and some of the ions from the filtrate (liquid formed)
37
What happens to molecules which are not selectively reabsorbed by the kidney?
Forms urine, which is then stored in the bladder until excreted
38
Give an example of something which is not selectively reabsorbed
Urea, formed by the deamination of amino acids in liver
39
What can the kidney control in terms of water?
Can control the volume of water lost in the production of urine
40
What are tubules?
Structures of the kidney which filtrate passes through on its way to the bladder
41
How do tubules control water volume?
Water reabsorption occurs along tubules: - If water conc. of blood is high, less water is reabsorbed - If water conc. of blood is low, more water is reabsorbed
42
How does ADH affect water reabsorption?
How much ADH is released by the pituitary gland is dependent on how much water the kidney reabsorbs from the filtrate
43
What is the control of water reabsorption by the tubules an example of?
Negative Feedback Control
44
What are the dangers of both kidneys being damaged?
A quick build-up of toxic wastes present in body which will be fatal if not removed
45
What is the common treatment of someone with kidney failure?
Dialysis
46
What is dialysis?
- Patient connected to dialysis machine - Acts as artificial kidney to remove most of urea and maintain water and salt balance in blood - Unfiltered blood taken from artery, pumped through machine, and returned in vein
47
How does exchange occur in a dialysis machine to filter blood?
Blood and dialysis fluid are separated by a partially permeable membrane in which blood flows in to opposite direction to fluid, allowing for exchange to occur between the two where a conc. gradient exists
48
What does dialysis fluid contain?
- Glucose concentration similar to normal level of blood - Concentration of salts similar to normal level of blood - No urea
49
What is a better long term solution to kidney failure instead of dialysis?
Kidney transplants
50
What are the disadvantages to kidney failures?
- Donors won't have the same antigens on cell surfaces so there will be some immune response to new kidney
51
How is risk of rejection in a kidney transplant reduced?
Can be reduced by tissue typing the donor and the recipient first (not removed)
52
How can immune responses by kidney transplants be suppressed?
Recipient can take immunosuppressant drugs for rest of their lives but can also have long term side effect and leave patient vulnerable to infections
53
What issue is there about kidney donors?
Not enough donors to cope with demand
54
What are the benefits of transplant over dialysis when a healthy, close matched kidney is available?
- Patient has more freedom (not tied to dialysis several times a week) - Diets less restrictive - Dialysis machines are expensive (cost removed) - Long term solution whereas dialysis will only work for a limited time

AQA GCSE Biology (7 decks)

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