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