B5 Hormones And Negative Feedback Flashcards Preview

Biology > B5 Hormones And Negative Feedback > Flashcards

Flashcards in B5 Hormones And Negative Feedback Deck (27)
Loading flashcards...
1
Q

What are hormones?

A

Chemical messengers sent in the blood

2
Q

Where are hormones produced?

A

Endocrine glands

3
Q

What is the system that the glands that produce hormones makes up?

A

Endocrine system

4
Q

What does the endocrine system allow you to respond to?

A

Internal and external stimuli

5
Q

Both the nervous system and hormones allow you to respond to internal and external stimuli. Explain the difference between these responses

A

Hormones are slow compared to nervous impulses.

Hormones have a longer lasting effect than nervous impulses.

6
Q

Where are hormones released?

A

Directly into the blood.

7
Q

How are hormones carried to other parts of the body?

A

In the blood

8
Q

What makes a hormone produce a response?

A

Particular effectors

9
Q

How do particular effectors stimulate a response in hormones?

A

They have receptors that the hormones bind to.

When hormones bind to receptors, they stimulate a response.

10
Q

What is adrenaline?

A

A hormone

11
Q

What release adrenaline?

A

Adrenaline glands

12
Q

Where are the adrenal glands located?

A

Just above the kidneys

13
Q

What does adrenaline prepare the body for?

A

Fight or flight

14
Q

How does adrenaline prepare the body for fight or flight?

A

By activating processes that increase the supply of oxygen and glucose to cells.

15
Q

List the steps involved in adrenaline supplying more oxygen and glucose to cells

A

Adrenaline binds to specific receptors in the heart.

The heart (effector) contracts more frequently and with more force, increasing heart rate and blood pressure.

Increased blood flow to the muscles, so cells receive more oxygen and glucose for increased respiration.

Adrenaline also bind to receptors in the liver.

The liver breaks down it’s glycogen stores to release glucose.

This increase the blood glucose level, so there is more glucose in the blood to be transported to the cells.

16
Q

How does your brain get your body ready for action in stressful situations?

A

The brain detects a stressful situation, sends nervous impulses to the adrenal glands, which respond by secreting adrenaline, which gets the body ready for action.

17
Q

What is negative feedback?

A

When the body detects that the level of a substance has gone above or below the normal level, it triggers a response to bring the level back to normal again.

18
Q

What does thyroxine regulate?

A

Metabolism

19
Q

Where is thyroxine released?

A

By the thyroid gland (in the neck)

20
Q

What does thyroxine help to regulate?

A

The metabolic rate.

21
Q

What is metabolic rate?

A

The speed at which chemical reactions in the body occur.

22
Q

What processes does metabolic rate affect?

A

Growth and protein synthesis

23
Q

What response triggers the release of thyroxine?

A

Thyroid stimulating hormone (TSH)

24
Q

Where is TSH (thyroid stimulating hormone) released from?

A

The pituitary gland

25
Q

How does a negative feedback system keep thyroxine in the blood at the right level?

A

When the level of thyroxine in the blood is higher than normal, the secretion of TSH from the pituitary gland is inhibited.

This reduces the amount of thyroxine released from the thyroid gland so the level of the blood falls back towards normal.

26
Q

See p74 for diagram

A

.

27
Q

Explain how the endocrine system allows communication within the body? (5 marks)

A

Endocrine glands secrete hormones (1 mark)
These act as chemical messengers (1 mark) and travel in the bloodstream (1 mark) to effectors (1 mark)
These have receptors so they can respond to the hormone (1 mark)

Decks in Biology Class (73):