Paper 2: Topic 5 Homeostasis & response - Hormonal coordination in humans (LV) Flashcards Preview

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Flashcards in Paper 2: Topic 5 Homeostasis & response - Hormonal coordination in humans (LV) Deck (157)
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1

Describe the endocrine system (2)

  • Glands which secrete hormones directly into the bloodstream
  • Which travel in the plasma to their target organs

2

Define the term hormone (3)

  • A chemical messenger molecule
  • that is produced and secreted by an endocrine gland and
  • travels via the bloodstream to its target organ where it causes as response

3

Define the term endocrine gland (2)

An organ that produces a hormone which it secretes directly into the bloodstream

4

Define the term target organ

An organ made of cells who have receptors on their cell membranes that are complementary to specific hormones

5

State 6 differences between the nervous system and endocrine system

  1. Nervous system uses nerve impulse, endocrine system uses hormones
  2. Nervous system causes a quick response, endocrine system causes a slower response
  3. Effect of the nervous system is short-lived, effect of the endocrine system is longer-lasting
  4. Nervous system uses neurones, endocrine system involves glands and hormones
  5. Nervous system uses an electrical signal, endocrine system uses a chemical messenger
  6. Nervous system acts on a very precise area, endocrine system acts in a more general way

6

Name the master gland and exaplain why it is called this

Pituitary gland

 

Reason: It produces hormones which act on other glands to make them produce different hormones

7

Name 4 hormones produced and secreted by the pituitary gland

  1. Anti-diuretic hormone
  2. FSH (Follicle stimulating hormone)
  3. Luteinising hormone (LH)
  4. Thyroid Stimulating Hormone (TSH)

8

Why is the pituitary gland called the ‘master gland’

It produces several different hormones which act on other glands to stimulate other hormones to be released and cause different effects in the body

9

Describe the position of the pituitary gland

Specialised region of the brain

10

Describe the position of the pancreas

Part of the digestive system, located above the small intestine but below the stomach

11

Describe the position of the thyroid gland

Located in the neck region

12

Describe the position of the adrenal glands

Located just above the kidneys (one adrenal gland per kidney)

13

Describe the position of the ovaries

Part of the reproductive system, located in the pelvic region

14

Describe the position of the testes

Part the reproductive system, located in the scrotum

15

Describe the function/role of the pituitary gland

  • Produces and secretes several different hormones into the bloodstream
  • e.g. TSH, LH, FSH and ADH

16

Describe the function/role of the pancreas

Produces and secretes insulin and glucagon into the bloodstream

17

Describe the function/role of the thyroid gland

  • Produces and secretes thyroxine into the bloodstream
  • To regulate the heart rate, core body temperature and metabolic rate

18

Describe the function/role of the adrenal glands

  • Produces and secretes adrenaline into the bloodstream
  • To increases the heart rate for ‘flight, fright and fight’

19

Describe the function/role of the ovaries

  • Produces and secretes oestrogen into the bloodstream
  • To control puberty and the menstrual cycle

20

Describe the function/role of the testes (3)

  • Produces and secretes testosterone into the bloodstream
  • To control puberty
  • To control sperm production

21

Name the two hormones involved in regulating blood glucose levels

Insulin and glucagon

22

What is the difference between glucagon and glycogen?

  • Glucagon is a hormone produced by the pancreas when blood glucose levels are low
  • Glycogen is a complex, insoluble carbohydrate that is used to store energy in skeletal muscles and the liver

23

Describe what happens to excess glucose absorbed into the bloodstream

  • The glucose is absorbed into the cells of the skeletal muscles and liver
  • And it's then converted to glycogen for storage
  • This reduces the blood glucose levels

24

Name the organ that monitors and controls the blood glucose levels

Pancreas

25

Name the target organs for insulin

  • Liver
  • Skeletal muscles

26

Name the target organs for glucagon

  • Liver
  • Skeletal muscles

27

Describe what happens if the blood glucose level falls too low

  • The pancreas detects the fall in the blood glucose levels
  • The pancreas produces and secretes glucagon into the bloodstream
  • Glucagon travels in the bloodstream to its target organs, the liver and skeletal muscles
  • The cells of the liver and skeletal muscle respond to the glucagon by breaking down stored glycogen into glucose
  • The glucose is released from the liver and skeletal muscle cells into the bloodstream
  • This raises the blood glucose levels and restores the blood glucose level to normal

28

Describe what happens if the blood glucose level becomes too high

  • The pancreas detects the rise in the blood glucose concentration in the blood
  • The pancreas produces and secretes insulin into the bloodstream
  • Insulin travels in the bloodstream to its target organs, the liver and skeletal muscles
  • The cells of the liver and skeletal muscles respond to the insulin by absorbing more glucose from the blood plasma
  • The glucose converted into glycogen inside the liver and skeletal muscle cells
  • The glycogen is stored in the liver and skeletal cells
  • This removes glucose from the bloodstream
  • This lowers the blood glucose concentration and restores the blood glucose level to normal
  • This is an example of negative feedback

29

Name the term that describes how blood glucose levels are regulated by the body

Negative feedback

30

Describe a negative feedback loop/cycle

  • An internal factor e.g. blood glucose levels is elevated The elevated factor is detected by receptors
  • The co-ordination centre receives the information
  • The co-ordination centre co-ordinates a response
  • The body responds by casing internal changes that lower the internal factor
  • The internal factor is returned to its normal level

Remember the same happens when the internal factor is too low but the body responds causing internal changes that raise the internal factor

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