L-25

Question 1

What is homeostasis?

Answer 1

The tendency towards a relatively stable equilibrium at the optimal living conditions

Question 2

What is the set point for homeostasis?

Answer 2

The constant ideal condition

Question 3

What is the normal range for homeostasis?

Answer 3

The amount of fluctuation from the set point that is normal and expected for the average person

Question 4

Why may a person still exhibit symptoms of a hormone disorder if their levels are within the normal range?

Answer 4

the population normal range is wider than an individuals normal range so a level can fall outside of the individuals normal range but inside the population range

Question 5

Is neural or hormonal control systems faster acting?

Answer 5

Neural

Question 6

Does neural or hormonal control centres cause longer lasting action?

Answer 6

Hormonal

Question 7

What are hormones?

Answer 7

Chemical messengers secreted from the endocrine glands cells that are carried in the bloodstream to the target cells upon which they act

Question 8

What is a benefit of hormonal signalling occurring through the bloodstream?

Answer 8

One stimulus promoting hormone release can lead to changes in many different areas of the body including a variety of changes in different organs

Question 9

Name the 5 major endocrine glands

Answer 9

• hypothalamus
• pituitary gland
• thyroid gland
• adrenal gland
• Pancreas

Question 10

What is special about the hypothalamus?

Answer 10

Links the endocrine and nervous system

Question 11

What are the 4 main physiological variables maintained homeostatically through hormones?

Answer 11

• blood sugar concentration
• growth and repair
• basal metabolic rate
• blood calcium concentration

Question 12

What is meant by hormone action specificity?

Answer 12

A hormone can only affect cels with specified receptors for that hormone

Question 13

What are the 2 main types of hormones?

Answer 13

Water soluble and fat soluble

Question 14

What is the chemical classification of water soluble hormones

Answer 14

75% are peptides and others such as adrenaline of noradrenaline are catecholamines

Question 15

Are water or lipid soluble hormones made and stored?

Answer 15

Water soluble hormones are made and stored until required when they are released via exocytosis, as well as thyroid hormones (lipid soluble)

Question 16

How do water soluble hormones travel?

Answer 16

Dissolved in the blood

Question 17

How are lipid soluble hormones chemically classified?

Answer 17

Generally steroids

Question 18

When are lipid soluble hormones produced?

Answer 18

They are made from cholesterol as required

Question 19

How do lipid soluble hormones travel?

Answer 19

In the blood bound to a carrier protein

Question 20

Where are the receptors for water soluble hormones located?

Answer 20

In the plasma membrane

Question 21

Where are the receptors for lipid soluble hormones located?

Answer 21

in the cytoplasm or nucleus

Question 22

What is the cellular response to water soluble hormone activation (4)

Answer 22

• hormone binds to cell receptor
• this allows activation of G protein
• G protein activates/ inhibits second messenger production/reduction
• downstream proteins/pathways are activated or deactivated

Question 23

What is the cellular response to lipid soluble hormone activation? (8)

Answer 23

• lipid soluble hormone dissociates from carrier protein
• hormone diffuses across cell membrane
• hormone binds to intracellular receptor
• hormone-receptor complex acts as a specific transcription factor
• target gene is activated
• new mRNA is generated
• new protein is generated by translation of mRNA
• new protein mediates cell specific response (slow process)

Question 24

What is the difference between water and lipid soluble hormones in the mechanism of action?

Answer 24

Water soluble is through 2nd messengers and lipid soluble is by altering gene transcription

Question 25

What is the difference between water and lipid soluble hormones in speed of response?

Answer 25

Water soluble is ms to minutes, fat soluble is hours to days

Question 26

What two factors dies the amount of hormone in the blood depend on?

Answer 26

- rate of secretion | - rate of removal from blood

Question 27

How is the rate of hormone secretion controlled?

Answer 27

Negative feedback loops

Question 28

What is the pancreas

Answer 28

both and exocrine and endocrine organ

Question 29

How much or the pancreas is made up of endocrine islet cells?

Answer 29

1% ish

Question 30

What two major hormones does the pancreas secrete?

Answer 30

Glucagon and insulin

Question 31

What 4 hormones can increase blood glucose levels?

Answer 31

glucagon, growth hormone, cortisol, adrenaline

Question 32

Why is insulin so important?

Answer 32

the only hormone that can lower blood glucose concentration

Question 33

What can prolonged high glucose levels lead to?

Answer 33

Diabetes Mellitus

Question 34

What can low blood glucose lead to?

Answer 34

Hypoglycaemia

Question 35

To maintain blood glucose within the normal range in the brain, what two metabolic states do we move between?

Answer 35

The fed state and the fasting state

Question 36

What occurs in the fed state?

Answer 36

Cellular uptake of nutrients and anabolic metabolism (synthesis of glycogen, protein and fat)

Question 37

What occurs during the fasting state?

Answer 37

Mobilisation of nutrients and catabolic metabolism ( breakdown of glycogen, protein, and fat)

Question 38

Where is glucagon secretid from?

Answer 38

Pancreatic alpha islet cells

Question 39

Where is insulin secreted from?

Answer 39

Pancreatic beta islet cells

Question 40

What is glucagon released as a response to?

Answer 40

Low blood glucose conc.

Question 41

What is insulin released in response to?

Answer 41

High blood glucose conc.

Question 42

What does glucagon act on?

Answer 42

Liver cells

Question 43

What does insulin act on?

Answer 43

Liver cells, muscle cells, adipose tissue

Question 44

What does glucagon do?

Answer 44

Releases stored glucose

Question 45

What does insulin do?

Answer 45

Stores glucose as glycogen

Question 46

What is the normal range for blood glucose concentration

Answer 46

70-110mgdL^-1