Thermoregulation + Endocrine system + Control of blood glucose concentration

Question 1

Describe how the brain monitors the temperature of the body

Answer 1

Body temperature is monitored and controlled by the thermoregulatory
centre in the brain

The thermoregulatory centre contains receptors
sensitive to the temperature of the blood.

The skin contains temperature
receptors and sends nervous impulses along sensory neurones to the thermoregulatory centre.

Question 2

Describe how negative feedback controls body temperature

Answer 2

if body temperature is too high:

temp receptors detect that core body temperature is too high
thermoregulatory centre acts as a coordination centre.

it receives information from the receptors and automatically triggers the effectors

Effectors produces a response to reduce body temperature e.g. shivering)

if body temp is too low:

temp receptors detect that core body temperature is too low
thermoregulatory centre acts as a coordination centre.

it receives information from the receptors and automatically triggers the effectors

Effectors produces a response to raise/increase body temperature e.g. shivering)

Question 3

What is the body temperature monitored and controlled by

Answer 3

Body temperature is monitored and controlled by the thermoregulatory
centre in the brain

Question 4

What does the thermoregulatory centre contain

Answer 4

The thermoregulatory centre contains receptors
sensitive to the temperature of the blood.

Question 5

What does the skin contain to detect temperature

Answer 5

The skin contains temperature
receptors and sends nervous impulses along sensory neurones to the thermoregulatory centre.

Question 6

Describe how the body responds to restore the normal body temperature if the body temperature is too high
e.g. if a person is exercising

Answer 6

Sweat glands release sweat onto the surface of the skin

The sweat now evaporates and this takes energy from the body to the environment, cooling the body down
_____
The body can also cool itself down by flushing
Under the surface of the skin, there is a fine network of blood capillaries

These capillaries are supplied with blood by blood vessels deeper in the skin
________
If the body gets too hot, the blood vessels supplying the capillaries dilate (they get wider). This is called vasodilation

Because the blood vessels have dilated, this means that more blood flows through the capillaries.
Heat can now transfer out of the blood so the body temperature returns back to its normal level

Question 7

Describe how the body responds to restore the normal body temperature if the body temperature is too low

Answer 7

The blood vessels supplying the capillaries constrict (they become narrower). This is called vasoconstriction.
Less blood now flows through the capillaries and less heat is lost from the body

Another way we respond when our body temperature drops too low is to shiver
When we shiver, our skeletal muscles contract.
To generate energy for this contraction the muscle cells increase their rate of respiration. This releases heat which warms the body

If our body temperature falls too low then we also stop sweating

Question 8

Describe why the control of body temperature is a good example of homeostasis

Answer 8

When the body temperature was too high or low - the thermoregulatory centre detected that the body temperature had changed from the normal value.

The body responded to reverse this change and restore the normal body temperature

Question 9

What is meant by the endocrine system

Answer 9

The endocrine system is composed of glands which secrete chemicals
called hormones directly into the bloodstream.

The blood carries the
hormone to a target organ where it produces an effect

(hormones bind to specific target organs where they trigger an effect)

(each hormone only acts on specific target organs where it produces an effect)

Question 10

State a key feature of the nervous system

Answer 10

The nervous system is extremely fast (very fast action)
The effect of the nervous system tend to be very short lived (act for a very short time)

Question 11

Compare the endocrine system and the nervous system

Answer 11

Compared to the
nervous system, the endocrine system tends to produce a much slower effect but the effect is more long lasting (effects act for longer)

endocrine system uses hormones which are chemicals and these are carried in the bloodstream

signals in the nervous system is extremely fast (very fast action)
The effect of the nervous system tend to be very short lived (act for a very short time)
uses electrical impulses which travel down neurones

Question 12

Glands which make up the endocrine system (state the endocrine glands)

Answer 12

Pancreas - releases hormones which are involved in controlling the concentration of glucose in the blood

Ovaries and testes release hormones involved in puberty and in reproduction

Thyroid gland produces hormones which are involved in growth and in regulating the body’s basal metabolic rate (how rapidly the body’s reactions take place) and temperature

The adrenal glands release the hormone adrenaline which is produced in times of fear or stress

The pituitary gland is located in the brain. This is called a master gland (extremely important)
This gland releases a number of different hormones into the blood depending on the conditions

These
hormones in turn act on other glands to stimulate other hormones to be
released to bring about effects.

(by acting on other glands the pituitary gland can trigger a range of different effects in the body)

Question 13

Describe the role of the pituitary gland in the endocrine system

Answer 13

The pituitary gland is located in the brain. This is called a master gland (extremely important)
This gland secretes a number of different (several) hormones into the blood in response (depending on) to the conditions

These (pituitary)
hormones in turn act on other glands (and they cause) to stimulate other hormones to be
released to bring about effects.

(by acting on other glands the pituitary hormones can trigger a range of different effects in the body)

Question 14

Identify the position of different endocrine glands in the human body
(draw a sketch of human body and label positions of different endocrine glands)

Answer 14

https://bam.files.bbci.co.uk/bam/live/content/zmm3kqt/small

Question 15

why is glucose important that the concentration of glucose in the blood is kept as constant as possible

Answer 15

Needed by every cell to release energy by respiration so it is very important that the concentration of glucose in the blood is kept as constant as possible

Question 16

What organ monitors and controls the blood glucose concentration

Answer 16

The blood glucose concentration is monitored and controlled by the pancreas

Question 17

describe the role of the pancreas in terms of blood glucose

Answer 17

The pancreas monitors and controls the concentration of glucose in the blood

Question 18

What could cause the concentration of glucose in the blood to rise

Answer 18

After a meal rich in carbohydrates, the concentration of glucose in the blood can rise

Question 19

Describe what happens if the blood glucose concentration is too high

Answer 19

If the concentration of glucose in the blood rises, this is detected by the pancreas. The pancreas produces the hormone insulin

Insulin travels in the bloodstream all around the body and it causes (triggers) body cells to take up glucose from the blood

(…that causes glucose to move from the blood into the
cells.)

Insulin also causes liver and muscle cells to convert excess glucose into glycogen for storage

(Insulin also triggers liver and muscle cells to store excess glucose as a storage molecule called glycogen)

Because glucose is now being taken out of the blood and stored, the concentration of glucose in the blood returns to its normal level. Homeostasis has taken place.

Question 20

What is diabetes

Answer 20

Condition where the pancreas cannot make enough insulin to control blood sugar or body cells stop responding to insulin made by pancreas

Question 21

What is it called where in some people, their blood glucose control does not work effectively

Answer 21

Diabetes

Question 22

How many types of diabetes are there

Answer 22

There are two types of diabetes

Question 23

What is type 1 diabetes

Answer 23

In type 1 diabetes, the pancreas does not produce enough insulin

Question 24

How do you know if someone has type 1 diabetes

Answer 24

It is characterised by uncontrolled high blood glucose
levels

Question 25

Describe and explain this graph

At the start of the experiment, both people ate a meal containing the same amount of carbohydrate - control variable - to ensure results are valid

https://www.youtube.com/watch?v=77oyUdNZ054&list=PL9IouNCPbCxW3lptxS1yHCP2I9YDfM2co&index=9
at 2:37

Answer 25

The concentration of glucose in the blood rises for both people.

In the person without diabetes, the blood glucose concentration rapidly returns to its normal level

That is due to the effect of insulin

However, in the person with type 1 diabetes, the blood glucose concentration rises, and then stays at a high level (only little decrease in blood glucose concentration)

This is because the pancreas cannot produce sufficient insulin

Question 26

Explain how type 1 diabetes are treated

Answer 26

People with type 1 diabetes monitor their blood glucose concentration and inject themselves with insulin if blood glucose rises too much. e.g. after a carbohydrate-rich meal

normally treated with insulin injections.

Question 27

https://www.youtube.com/watch?v=77oyUdNZ054&list=PL9IouNCPbCxW3lptxS1yHCP2I9YDfM2co&index=10
at 2:51

State what has happened, at the point of the green arrow

Answer 27

At this point the person with type 1 diabetes has injected themself with insulin

When the person with type 1 diabetes injects themself with insulin, their blood glucose concentration falls

Question 28

What is type 2 diabetes

Answer 28

In type 2 diabetes, the body cells stop responding to insulin produced by the pancreas

Question 29

Similarities between type 1 and type 2 diabetes

Answer 29

In people with these conditions their blood glucose control does not work effectively

Also in both types of people, their blood glucose levels can rise too high

Question 30

How is type 2 diabetes treated

Answer 30

Type 2 diabetes is often treated with a diet containing a controlled level of carbohydrates.

The aim of this is to prevent the blood glucose concentration from rising too high

People with type 2 diabetes are also advised to take exercise (regime)

Question 31

What is a major risk factor for Type 2 diabetes

Answer 31

Obesity is a risk factor for Type 2 diabetes.

As obesity levels are increasing in the UK, we are seeing more people with type 2 diabetes

Question 32

What is obesity in regards to type 2 diabetes

Answer 32

Obesity is a risk factor for Type 2 diabetes.

Question 33

Why are people with type 2 diabetes advised to exercise

Answer 33

Fsl: Type 2 diabetes is often linked to obesity so regulation of body weight is important. Also, exercise uses glucose by respiration, helping to regulate blood glucose levels.
____________
Obesity is a risk factor for Type 2 diabetes so exercise should be done to regulate body weight (which is important)

Also during exercise, muscle cells need energy to contract, therefore more respiration occurs, which uses up the glucose in the process (more glucose is broken down), helping to regulate blood glucose levels.

Question 34

Evaluate information
around the relationship
between obesity and
diabetes, and make
recommendations taking
into account social and
ethical issues.

Answer 34

social issues include the fact that healthy food is sometimes more expensive than calorific convenience food so people can’t always afford it. Also some people do not live near any shops where they can easily buy good quality food (these are called food deserts).

An ethical issue could be is it acceptable to tell a person what they should and should not eat and whether they are overweight?

Question 35

What could cause the blood glucose concentration to fall

Answer 35

Blood glucose concentration can fall in between meals

Question 36

Describe what happens if the blood glucose concentration is too low

Answer 36

If the blood glucose concentration is too low, this (blood glucose concentration) is detected by the pancreas.

Pancreas releases the hormone glucagon into the bloodstream.

Glucagon (causes) triggers (liver) cells to convert glycogen stores back to glucose and this glucose is released into the blood

This causes the blood glucose concentration to return to normal

Question 37

explain why the graph looks like this

https://www.youtube.com/watch?v=77oyUdNZ054&list=PL9IouNCPbCxW3lptxS1yHCP2I9YDfM2co&index=10

5:07

A persons blood glucose concentration (this person does not have diabetes)

Answer 37

A persons blood glucose concentration (this person does not have diabetes)

The blood glucose concentration rises slightly and falls slightly over the course of the day

This is because the blood glucose concentration is controlled by a balance between insulin and glucagon

If the glucose concentration rises, then the pancreas detects this change and releases insulin and this causes the glucose concentration to fall.

However, when the glucose concentration falls to a certain level, the pancreas detects this and releases glucagon. This causes the glucose concentration to rise again

Because insulin and glucagon have opposite effects on the blood glucose concentration, they form a negative feedback cycle

Question 38

explain how glucagon interacts
with insulin in a negative feedback cycle to control blood glucose (sugar)
levels in the body

Answer 38

A persons blood glucose concentration (this person does not have diabetes)

The blood glucose concentration rises slightly and falls slightly over the course of the day

This is because the blood glucose concentration is controlled by a balance between insulin and glucagon

If the glucose concentration rises, then the pancreas detects this change and releases insulin and this causes the glucose concentration to fall.

However, when the glucose concentration falls to a certain level, the pancreas detects this and releases glucagon. This causes the glucose concentration to rise again

Because insulin and glucagon have opposite effects on the blood glucose concentration, they form a negative feedback cycle

Question 39

what is glucose

Answer 39

The (a simple) sugar used in respiration

Question 40

what is glycogen

Answer 40

A storage carbohydrate found in the liver and muscles

A molecule that acts a store of glucose in the liver and muscle cells

Question 41

what is glucagon

Answer 41

a hormone that stimulates the liver to break down glycogen to glucose (hormone involved in the control of blood sugar levels)

Question 42

what is insulin

Answer 42

hormone made in pancreas that causes glucose to pass from blood into
cells, where it is needed for respiration (hormone involved in the control of blood sugar levels)

Question 43

Why is it so important to control the level of glucose in your blood

Answer 43

Glucose needed for cellular respiration,
releasing energy for body’s metabolic reactions.
Too much or too little glucose in blood causes problems with
respiration

Question 44

people with diabetes have to monitor the amount of carbohydrate in their diet. explain why

Answer 44

Carbohydrate broken down into glucose,
so the more carbohydrate-rich food that is eaten, the higher blood glucose levels will rise
and the harder it is for insulin injections to maintain safe and healthy blood glucose levels.