Brainscape's Knowledge GenomeTM

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


See full index

Biology - Year 13 > Homeostasis > Flashcards

Homeostasis Flashcards

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

Explain how insulin reduces the blood glucose concentration (3)

A
  1. More insulin binds to receptors
  2. Stimulates uptake of glucose by channel proteins
  3. Activates enzymes which convert glucose to glycogen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Explain the action of glucagon (3)

A
  1. Attaches to receptors on target cells and activates enzymes
  2. Glycogen to glucose
  3. Gluconeogenesis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Explain the effect of sweating or panting on temperature control (2)

A
  1. Evaporation of water
  2. Heat transferred from blood
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Describe how a change in blood pH or blood pressure can cause a change in heart rate (6)

A
  1. CO2 detected by chemoreceptors and pressure detected by baroreceptors
  2. Medulla involved
  3. More impulses to SA
  4. Decrease pH detected by chemoreceptors in carotid artery
  5. Sends impulses to medulla
  6. More nerve impulses sent by sympathetic nervous system to SAN
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Less CO2 in the blood leads to a reduction in heart rate. Describe how (5)

A
  1. Detected by chemoreceptors
  2. Located in carotid artery
  3. Fewer impulses to medulla oblongata
  4. More impulses along parasympathetic nerve
  5. To SAN
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Describe the secondary messenger model (3)

A
  1. Adenylate cyclase is activated and converts ATP to cAMP
  2. Activates protein kinase enzymes
  3. Glycogenolysis ang gluconeogenesis occurs
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Describe the role of glycogen formation and its role in lowering the blood glucose levels (4)

A
  1. Glucose concentration in liver falls
  2. Below that in the blood plasma
  3. Creates concentration gradient
  4. Glucose enters cell by facilitated diffusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Describe how blood glucose levels can be increased using hormones (3)

A
  1. Release of glucagon
  2. Leads to formation of glucose in liver cells
  3. From non-carbohydrates and fatty acids
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Describe how ultrafiltration occurs in a glomerulus (4)

A
  1. Higher than normal high hydrostatic pressure
  2. Small molecules such as water, urea and ions leave
  3. Pass through fenestrations in endothelium of capillary
  4. Through basement membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Explain why a thicker medulla leads to more concentrated urine (3)

A
  1. Thicker medulla so longer loop of henle
  2. Increase Na+ concentration so Na+ gradient maintained for longer
  3. Water potential gradient maintained so more water reabsorbed by osmosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Describe the action of ADH in the kidney (4)

A
  1. Permeability of membrane is increased
  2. More water absorbed from distal convoluted tubule
  3. Smaller volume of urine
  4. Urine becomes more concentrated
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Explain why glucose is found in the urine of a person with untreated diabetes (3)

A
  1. High concentration of glucose in blood
  2. Not all glucose is reabsorbed at proximal convoluted tubule
  3. Carrier proteins are working at maximum rate
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is meant by negative feedback? (1)

A

An increase or decrease from the set point, the opposite is instigated so returns the value back to the norm

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

What is meant by the term positive feedback? (1)

A

Deviation from the optimum causes even greater deviation from the normal

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

What is meant by the term positive feedback? (1)

A

Deviation from the optimum causes even greater deviation from the normal

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

Explain what occurs in the loop of henle (3)

A
  1. Concentration increases in descending limb because water moves out by osmosis and Na+ enter by facilitated diffusion
  2. Concentration decreases in ascending limb because Na+ leave by active transport using ATP
  3. Water remains because walls of ascending limb are impermeable
17
Q

Each year, a few people with type 1 diabetes are given pancreas transplants. Give two reasons why pancreas transplants are not used for the treatment of type 2 diabetes (2)

A
  1. Individuals with type 2 produce insulin
  2. But receptors become unresponsive to insulin
18
Q

Explain how inhibiting adenylate cyclase may help to lower the blood glucose concentration (3)

A
  1. Less ATP is converted to cyclic AMP
  2. Less protein kinase is activated
  3. Less/no glycogen is converted to glucose

Biology - Year 13 (12 decks)

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