Brainscape's Knowledge GenomeTM

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


See full index

AP Biology > Feedback > Flashcards

Feedback Flashcards

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

What is the purpose of a negative feedback loop?

A

When a system is disturbed, it returns it to normal by responding to the stimulus opposingly

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

What are negative feedback loops used for?

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

What is the purpose of a positive feedback loop?

A

Amplify a stimulus with a response,

- Stimulus increases due to responds

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

What are feedback loops used for?

A
  • Responding to internal/external stimuli

- Maintain internal environments

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

What part of the brain is responsible for thermoregulation?

A

Hypothalamus

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

How do our bodies respond to heat?

A
  • Blood vessels dilate
  • Increased breathing rate
  • Sweating
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How do our bodies respond to cold?

A
  • Blood vessels constrict
  • Shivering
  • Increased metabolism by secretion of Thyroid hormone from the thyroid gland
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What type of feedback loop is thermoregulation?

A

Negative feedback, temperatures are restored to their normal levels

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

Can the hypothalamus detect temperature changes on its own?

A

Yes

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

What type of feedback loop is ovulation?

A
  • Positive originally

- Negative after the formation of the Corpus luteum

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

Explain the positive feedback loop in ovulation.

A
  • The ovaries secrete estrogen
  • This triggers the hypothalamus to secrete gonadotropin releasing hormone and the anterior pituitary to release luteinizing hormone
  • The gonadotropin releasing hormone from the hypothalamus also stimulates the release of luteinizing hormone from the pituitary
  • Luteinizing hormone stimulates the ovaries to increase estrogen production, therefore the secretion of gonadotropin releasing hormone and luteinizing hormone also increase in the blood due to this positive feedback loop
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain the negative feedback loop in ovulation.

A
  • The Corpus luteum is formed in the ovaries,
  • The Corpus luteum secretes progesterone in response to the luteinizing hormone,
  • Progesterone inhibits the release of gonadotropin releasing hormone and luteinizing hormone from the hypothalamus and anterior pituitary respectively,
  • Blood levels of these hormones decrease due to this negative feedback loop.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What type of feedback loop is labour preceding child birth?

A

Positive

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

Describe the labour preceding child birth feedback loop.

A
  • First, the loop is initiated by contractions of the uterus moving the baby’s head to the cervix
  • The pressure from the baby on the cervix stretches the cervix and stimulates nerves which send a message to the brain,
  • These impulses are received at the hypothalamus which secretes oxytocin into the blood capillaries of the pituitary gland and travels to the uterus,
  • When the uterus receives the oxytocin, the contractions increase and more pressure is applied to the cervix,
  • This creates a positive feedback loop as more signals are sent to the hypothalamus and more oxytocin is secreted,
  • This continues to dilate the cervix and push the baby at greater rates and intensities until the baby is delivered,
  • The positive feedback cycle ceases as the baby is born and no pressure is being applied to the cervix
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is pancreatic juice made of?

A
  • Digestive enzymes
  • Water
  • Sodium bicarbonate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the role of sodium bicarbonate in pancreatic juice?

A

Neutralize the stomach acid so that digestive enzymes can work

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

What is the role of insulin?

A

A hormone that tells cells to store sugar from the blood, and the liver to stop the production of sugar

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

What is the role of glucagon?

A

A hormone that tells cells and the liver to release glucose in the blood

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

Where are insulin and glucagon produced in the pancreas?

A

Islets of Langerhans

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

What type of feedback loop is blood sugar regulation?

A

Negative

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

What are some consequences of diabetes?

A
  • Heart attack
  • Stroke
  • Kidney failure
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does diabetes do to your body?

A
  • Insulin production is less/stopped
  • Blood glucose levels are too high
  • The blood hardens and prevents blood flow
23
Q

What is type 1 diabetes?

A

The body doesn’t produce any insulin because an autoimmune system destroys the insulin-producing cells in the body

  • Most commonly found in childhood,
  • 10% of all diabetes cases, typically found under 40yrs of age
24
Q

How does the body try to remove high levels of glucose in the blood in type 1 diabetes?

A

Through filtering in the kidneys, glucose expelled in urine

25
Q

What are the main symptoms of diabetes?

A
  • Frequent urination (body needs to release excess glucose)
  • Blurred vision (glucose builds up around the eye)
  • Tiredness (less energy from glucose)
  • Weight loss (no glucose in cells for energy so use fat deposit)
  • Thrush or genital itching (bacteria can survive better near glucose)
  • Slow-healing wounds (bacteria survives around the cut)
  • Thirst (water loss in the urine)
26
Q

How is type 1 diabetes treated?

A

Insulin

27
Q

What is type 2 diabetes?

A

Insulin is produced but either don’t work properly or there is not enough produced
- Around 90% of cases

28
Q

Why does insulin not work properly in type 2 diabetes?

A
  • Fat deposits build up in the cells, this means insulin cannot open cells to glucose since they no longer fit in the protein
29
Q

In type 2 diabetes what is the relationship between glucose levels and insulin levels initially?

A
  • Blood glucose increases
  • Insulin increase to counter this but is not very effective so blood glucose continues to rise
  • Insulin increases as glucose increases
30
Q

How quickly do symptoms arise for each type of diabetes?

A
  • Type 1: very quickly (weeks)

- Type 2: very slowly (years)

31
Q

How do you treat type 2 diabetes?

A
  • Controlled diet
  • Increased exercise
  • Medication
32
Q

How are the levels of water in the body maintained?

A
  • Hypothalamus detects low levels of blood water
  • Posterior pituitary releases ADH
  • ADH travels in the bloodstream to blood vessels and the kidneys
  • Kidneys increase water retention and prevent as much water from leaving in the urine
  • Blood vessels vasoconstrict to increase pressure and compensate for low blood pressure caused by lack of water
33
Q

What is a receptor?

A

A protein molecule where a signal molecule can bind

34
Q

What is a ligand?

A

The molecule that binds to a receptor, typically smaller than the receptor

35
Q

What are the steps to cell signalling?

A
  • Reception (receptor receives a signal)
  • Transduction (the receptor changes shape and passes on the signal to other molecules)
  • Response (how the cell responds to the singal)
36
Q

What are the types of signalling?

A
  • Direct contact
  • Paracrine signalling
  • Synaptic signalling
  • Endocrine signalling
  • Autocrine signalling
37
Q

What is direct contact signalling?

A

Signals between cells through the plasmata or gap junctions

38
Q

What is paracrine signalling?

A

A type of local signalling where ligands are ejected from cells to travel a short distance and bind to another cell,
- It must be local because ligands are rapidly absorbed and degraded

39
Q

What is synaptic signalling?

A

Neurotransmitters being the ligand between nerves

40
Q

What is endocrine signalling?

A

Signalling involving hormones

41
Q

What is autocrine signalling?

A

When a cell signals itself by releasing a ligand that rebinds to a receptor imbedded in the cell membrane or a peripheral protein
- If excessive growth factor is released by the cell could lead to cancer

42
Q

What are the three classes of protein receptors?

A
  • G-protein coupled receptor
  • Ion channel receptors
  • Enzyme couple receptors
43
Q

Do ligands use energy when it binds to a ligand transport channel?

A

No, these transport channels use passive transport/ facilitated diffusion

44
Q

What type of protein do hydrophobic ligands bind to?

A

Cytoplasmic protein receptors

45
Q

What type of protein do hydrophilic ligands bind to?

A

Transmembrane protein receptors

46
Q

What is signal trasnduction?

A

When the receptor receives a ligand, it undergoes some sort of change (usually a change in shape) and produces a signal inside the cell

47
Q

What do osteoblasts do?

A

Build up bone tissue

48
Q

What do osteoclasts do?

A

Break down bone tissue

49
Q

Where is PTH secreted and what is its function?

A 
Secreted from the parathyroid gland
- Increases calcium levels in the blood when they are too low by activating osteoclasts and causing them to degrade bones to release calcium into the blood
(negative feedback)
- Stimulates osteoclast activity
- Inhibits osteoclast activity
50
Q

What is the function of calcitriol/ vitamin D?

A

Absorbs calcium into the gut

51
Q

What two hormones are used to increase blood calcium levels?

A
  • Calcitriol

- PTH

52
Q

How is the release of PTH stimulated from the parathyroid glands?

A

Low levels of calcium

53
Q

What is secreted when blood calcium levels are too high?

A

C cells/ parafollicular cells from the thyroid secrete Calcitonin

54
Q

What is the function of calcitonin?

A

Stimulate osteoblast activity/ build bone matrix to reduce blood calcium levels
(negative feedback)

AP Biology (19 decks)

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