Metabolism S7 - Endocrinology Flashcards Preview

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Flashcards in Metabolism S7 - Endocrinology Deck (38):
1

Define tropic hormones

A hormone that has another endocrine gland as their target

2

Define trophic hormones

a hormone that stimulates growth in a target tissue

3

Define hormones

Chemical signals produced in endocrine glands or tissue, which travel in the bloodstream causing an effect on other tissues

4

List the classes of hormones

1) Polypeptide hormones (largest group)
2) Glycoprotein hormones
3) Amino acid derivatives
4) Steroids

5

Where is thyrotropin released from?

Hypothalamus

6

What does thyrotrophin stimulate?

Release of thyroid stimulating hormone

7

Where is thyroid stimulating hormone released from?

The anterior pituitary

8

Where is corticotrophin released from?

Hypothalamus

9

What does corticotrophin stimulate?

The release of adrenocorticotrophic hormone

10

Where is adrenocorticotrophic hormone released from?

Anterior pituitary

11

What does somatotrophin stimulate?

Growth hormone

12

Where is growth hormone released from?

Anterior pituitary

13

Where is somatotrophin released from?

Hypothalamus

14

How are steroid hormones inactivated?

Relatively small changes in their chemical structure increases their water solubility. This allows them to be easily excreted from the body in the urine or via the bile

15

How are protein hormones inactivated?

undergo extensive chemical changes and are degraded into amino acids that are then reused

16

What major action does insulin have on carbohydrates, lipids and amino acid metabolism?

- Increased glycogenesis
- Increased glycolysis in liver/adipose tissue
- Increased lipoprotein lipase activity in capillary bed of tissues such as adipose tissue
- Increase amino acid uptake and protein synthesis in liver, muscle and adipose tissue
- Decreased proteolysis in liver, skeletal muscle and adipose tissue
- Decreased glycogenolysis in liver/muscle
- Decreased gluconeogenesis in liver
- Decreased lipolysis in adipose tissue
- Decreased ketogenesis in liver

17

What major action doe glucagon have?

- Increased glycogenolysis
- Increased gluconeogenesis in the liver
- Increased ketogenesis in the liver
- Increased lipolysis in adipose tissue
- Decreased glycogenesis in liver

18

What do β-cells in the islets of Langerhaans produce?

Insulin

19

What do α-cells in the islets of Langerhaans produce?

Glucagon

20

What are the main, general features of control systems in the body?

Communication - Hormones, action potentials
Control centre - Determines set point, analyse input, determines response
Receptor - Signal afferent pathway
Effector - Efferent pathway

21

Give two examples of biological rhythms?

Circadian rhythm - controlled by the suprachiasmatic nucleus in the hypothalamus

Menstrual cycle

22

Describe two methods of hormone transport?

Lipophilic - bound to transport proteins
hydrophilic - free in plasma

23

What type of hormone would bind to cell surface receptors?

polypeptide and glycoprotein hormones

24

What type of hormone binds to intracellular receptors, cytoplasmic or nucleus?

Steroid

25

Where is the control centre for appetite?

Arcuate nucleus in the hypothalamus

26

What hormone stimulates the primary excitatory centre?

Ghrelin - released from empty stomach

27

What is released from primary excitatory centre?

Neuropeptide Y

Agouti-related peptide

28

What hormones stimulate the primary inhibitory centres?

Leptin - released from adipose
PYY - Released from small intestine
Insulin and amylin - released from the pancreas

29

What is released from the primary inhibitory centre?

POMC - a pro-hormone that is cleaved to give:

- α-MSH which act on melanocortin 4 receptors which suppresses appetite
- ACTH
- β-endorphins - reward system, euphoria and tiredness

30

List the features of metabolic syndrome?

Hypertension, impaired glucose tolerance, insulin resistance, dyslipidaemia

31

What is metabolic syndrome?

A common pattern of symptoms that arise in obese patients

32

What is the Developmental Origins of Health and Disease?

Study that the incidence of certain adult disease are related to low birth weight. This suggests that the experience of the foetus in utero during development somehow determines the future health of the individual

33

What is metabolic acidosis?

Metabolic acidosis is a condition that occurs when the body produces excessive quantities of acid or when the kidneys are not removing enough acid from the body

34

Describe results you would see for a glucose tolerance test if glucose utilisation was abnormally slow?

Glucose levels rise but stay abnormally high for a long time and take a while to drop down to normal levels

35

What enzyme is rate limiting in glycogenolysis?

Glycogen phosphorylase

36

Give one example of negative feedback in the body?

- Insulin release in response to hyperglycaemia

37

Give one example of positive feedback in the body?

Blood clotting

Ovulation

38

Explain why epigenetic is different to genetic mutation?

Genetic mutation involves changes in the nucleotide sequence (changes in DNA sequence)

Epigenetics involves methylation of DNA and changes in histone structure that affect gene transcription