Endocrine System

Question 1

Give a brief summary of endocrine transmission

Answer 1

• chemical secreted
• sent to all parts of the body via the blood stream
• hormones act only in cells with correct membrane receptor proteins

Question 2

Describe communication by hormones

Answer 2

• many cells in different parts of the body
• coordinated
• slow to act
• effects persist

Question 3

What are the endocrine glands

Answer 3

• hypothalamus
• pituitary
• thyroid
• parathyroid
• pancreas (islets)
• adrenal
• GI tract endocrine cells
• gonads (ovaries and testes)
• placenta
• pineal gland
• thymus

Question 4

What are the two classifications of hormones

Answer 4

• steroids
• non steroids

Question 5

What are steroid hormones based on

Answer 5

Based on the cholesterol ring structure

Question 6

Give some examples of steriod hormones

Answer 6

• cortisol
• aldosterone
• testosterone
• oestrogen
• progesterone

Question 7

What are non steroid hormones

Answer 7

Amino acid derivatives
- amines - adrenaline ect
- noradrenaline
- melatonin
Iodinated amino acids
- triiodothyronine
- tetraiodonthyronine (thyroxine)

Question 8

What else can non-steroid hormones be composed of

Answer 8

• long chain(proteins) and short chain peptides

Question 9

Give some examples of some short chain non steroid hormones

Answer 9

• oxytocin
• somatostatin

Question 10

Give some examples of long chain non steriod hormones

Answer 10

• growth hormone
• insulin
• glucagon

Question 11

Give some examples of non steriod hormones which are glycoproteins (protein with attached carbohydrate groups to amino acids)

Answer 11

• follicle stimulating hormone
• luteinizing hormone
• thyroid stimulating hormone

Question 12

What are local tissue hormones

Answer 12

Some hormone like substances have a local (paracrine) effect
- prostagrandins
- leucotrienes
- thromboxanes

Question 13

What are the functions of local tissue hormones

Answer 13

• blood flow regulation
• haemostasis
• mucosal protection (stomach)
• inflammation

Question 14

Why are non steroid hormones commonly referred to as second messengers

Answer 14

• most non steroid hormones act via second messenger systems within the target cell
• two common ones are cAMP and Ca++
• steroid hormones can pass through the outer cell and directly reach Intracellular receptors

Question 15

Give an overview of hormone action

Answer 15

• synthesis and storage
• release in response and stimulus
• transport in blood
• action on target cells (role as 2nd messengers)
• metabolism and/or excretion

Question 16

What is the difference between steroid hormones and non steroid hormones

Answer 16

Steroid hormones can pass right through the cells on the other hand non-steroid hormones need to activate a second messenger in the cells to induce a response

Question 17

How is the endocrine system commonly controlled

Answer 17

Most hormone systems are regulated by negative feedback

Question 18

What is the function of parathyroid hormone

Answer 18

Controls Ca++ concentration in the body

Question 19

What word is used to describe excess secretion of hormones

Answer 19

Hypersecretion

Question 20

What word is used to describe decreased secretion of hormones

Answer 20

Hyposecretion

Question 21

What word is used to describe more receptors

Answer 21

Upregulation

Question 22

What word is used to describe fewer receptors

Answer 22

Downregulation

Question 23

What is hyperfunction

Answer 23

Excess production and secretion
Upregulation of receptors
Failure to metabolise hormone

Question 24

What is hypofunction

Answer 24

Decreased production and secretion
Downregulation of receptors
Receptors non functioning

Question 25

Describe pro hormones

Answer 25

Pre-prohormone are inactive forms of the hormone contained in the endoplasmic reticulum > prohormone is a slightly active form of the hormone which is contained within the Golgi apparatus > active hormone is then secreted from the vesicles

Question 26

Why does the body store preprohormones

Answer 26

In case the body needs the preprohormone to be converted into the active form

Question 27

Why can people with type 1 diabetes die without adequate glucose

Answer 27

The brain will be starved of glucose - hypoglycaemia

Question 28

What organ metabolises hormones

Answer 28

Liver

Question 29

What organ is responsible for excreting hormones

Answer 29

Kidney

Question 30

What is negative feedback control

Answer 30

Most hormone systems are regulated by negative feedback

Question 31

Give an example of negative feedback control

Answer 31

Raised blood plasma calcium levels acts on parathyroid glands to reduce secretion of PTH

Question 32

What is the word used to describe excess secretion

Answer 32

Hypersecretion

Question 33

What is the word used to describe decreased secretion

Answer 33

Hyposecretion

Question 34

What is sensitivity of target cells related to

Answer 34

Number of membrane receptors

Question 35

More receptors = …

Answer 35

Upregulation

Question 36

Fewer receptors = …

Answer 36

Downregulation

Question 37

What are the effects of hyperfunction

Answer 37

- excess production and secretion - Upregulation of receptors - failure to metabolise hormones

Question 38

Effects of hypofunction

Answer 38

- decreased production and secretion - Down-regulation of receptors - receptors non functioning