Hormonal coordination in human

Question 1

What does the endocrine system consist of?

Answer 1

glands that secrete chemicals called hormones directly into the bloodstream

Question 2

What are hormones?

Answer 2

chemical messengers that are carried in the blood to target organ where they produce an effect

Question 3

What do hormones control?

Answer 3

things in organs and cells that need constant adjustment

Question 4

What are hormones secreted by?

Answer 4

endocrine glands

Question 5

Whats the difference between the duration and speed of the endocrine system and the nervous system>

Answer 5

the endocrine system is slower and the effects lasts for longer

Question 6

what is the pituitary gland and what does it do?

Answer 6

master gland - it secretes several hormones in response to body conditions

Question 7

What is blood glucose concentration monitored and controlled by?

what does this thing release?

Answer 7

the pancreas, it releases insuln and glucagon

Question 8

How does the body process glucose?

Answer 8

1) Glucose comes into the blood from the gut
2) the normal metabolism of cells removes glucose from the blood
3) Vigorous exercises removes much more glucose from the blood
4) excess glucose can be stored as glycogen in the liver and in the muscles
5) the levels of glucose must be kept steady

Question 9

What happens when the levels of glucose rise?

Answer 9

1) Pancrease releases more insulin
2) causes glucose to move from the blood to cells
3) in liver and muscle cells, excess glucose is converted to glycogen for storage

Question 10

What happens when the levels of glucose decrease?

Answer 10

1) Pancrease releases glucagon

2) Glucagon stimulates glycogen to be converted into glucose and released into the blood

Question 11

What is Type 1 diabetes?

Answer 11

a disorder that:

• is caused by the pancreas failing to produce sufficient insulin
• results in uncontrolled high blood glucose levels
• normally treated with insulin injections ( this makes sure the glucose is removed from the blood quickly once the food has been digested)
• this is genetic

Question 12

What is Type 2 diabetes?

• what is it caused by, risk factor, how is it controlled

Answer 12

a disorder that:

• is caused by the body cells no longer responding to insulin
• obesity is a risk
• controlled with a carbohydrate-controlled diet and regular exercise

Question 13

When and where is adrenaline produced?

Answer 13

produced by the adrenal glands (just above the kidneys)

released in response to a stressful or scary situation

Question 14

How is adrenaline produced and what does it do to the body?

Answer 14

the brain detects fear or stress and sends nervous impulses to the adrenal glands, which responds by secreting adrenaline

It increases the heart rate and boosts the delivery of oxygen and glucose to the brain and muscles, preparing the body for ‘flight or fight’.

Question 15

Where is thyroxine produced and why is it important?

Answer 15

released by the thyroid gland (in the neck)

stimulates the basal metabolic rate, important for growth and development

Question 16

How is thyroxine produced and how is it controlled?

Answer 16

Thyroxine is released in response to the thyroid-stimulating hormone (TSH), which is released from the pituitary gland

when an increase in thyroxine is detected, the release of TSH is inhibited till it gets back to normal

Question 17

Give three ways in which excess water is removed from the body.

Answer 17

Excess water is removed from the body:

Via the lungs during exhalation

From the skin as sweat

By the kidneys in urine

Question 18

Give 2 ways in which excess ions and urea are removed from the body.

Answer 18

Excess ions and urea are removed from the body…

from the skin as sweat
from the kidneys in the urine

Question 19

What do the kidneys do?

Answer 19

regulate the balance of water and ions in the body

The kidneys produce urine by filtration of the blood and selective reabsorption of useful substances such as glucose, some ions and water.

Question 20

How do the kidneys produce urine?

where does this specifically take place

Answer 20

1) Filteration -when waste substances are filtered out of the blood as it passes through the kidneys
2) Selective absorption - useful substances like glucose, some ions and the right amount of water are absorbed into the blood
3) this leaves urea and excess water and ions to form urine

take place in the tubules

Question 21

How is Urea produced?

Answer 21

• the digestion of proteins from food results in excess amino acids
• in the liver, these excess amino acids are converted to ammonia = deamination
• Ammonia is toxic, so it is immediately converted to urea in the liver
• Urea is then transported to the kidneys where it’s filtered out of the blood and excreted from the body in the urine

Question 22

What’s in urine

Answer 22

water, ion and urea

Question 23

What happens to the body cells if the concentration of the blood changes?

Answer 23

they will lose or gin too much water by osmosis

Question 24

What happens when the water content is too low?

too concentrated

Answer 24

• a receptor in the brain detects water content too low
• the coordination centre in the brain receives the information and coordinates a response
• Pituitary gland releases ADH into the bloodstream
• ADH passes in the blood to kidney tubules
• This causes more water to be reabsorbed back into the blood

Question 25

Describe what happens to body cells when the water concentration is too high

Answer 25

too much water will enter the cell via osmosis and the cell will burst = hypotonic

Question 26

Describe what happens to body cells when the water concentration is too low

Answer 26

water will leave via osmosis and the cell will shrivel = hypertonic

Question 27

What happens if your kidney’s don’t work properly?

Answer 27

Waste substances build up and you lose the ability to control the levels of ions and water in your body

resulting in death

Question 28

What are the two different types of treatment for kidney failure

Answer 28

kidney transplant and dialysis

Question 29

dialysis machine :

what does it do?
Why does it have to be done regularly?

Answer 29

it takes over the role of the kidneys, it is used to remove waste products from the blood three times a week

it has to be done regularly to keep the concentration of dissolved substances in the blood at normal levels, and to remove waste products

Question 30

How does a dialysis machine work?

Answer 30

In a dialysis machine, the person’s blood flows between partially permeable membrane surrounded by dialysis fluid.

It’s permeable to things like ions and waste substances but not big molecules like proteins (just like the membranes in the kidney)

Question 31

What are the advantages of a dialysis machine?

Answer 31

• Dialysis fluid has the same concentration of dissolved ions and glucose as healthy blood so useful dissolved ions won’t be lost from the blood during dialysis
• only waste substances and excess ions and waste diffuse across the barrier
• can buy a patient with kidney failure valuable time until a donor organ is found

Question 32

What are the disadvantages of a dialysis machine?

Answer 32

• have to have it 3x a week
• each session is 3-4 hours
• may cause blood clots or infections
• not a pleasant experience
• expensive for the NHS to run

Question 33

What are the advantages of a Kidney transplant?

Answer 33

• cheaper than dialysis in the long run

- can put an end to the hours patients have to spend on dialysis

Question 34

What are the disadvantages of a Kidney transplant?

Answer 34

• small risk to the person donating a kidney
• donor kidney can be rejected by person’s immune system
• Patient has to take immunosuppressant drugs for the rest of their life = increases risk of infection
• long waiting lists