Physiology, Endocrinology 2.

Front 1

What inhibits release of glucagon?

Back 1

Glucose.

Front 2

What is the difference between the actions of glucagon and insulin?

Back 2

The actions of glucagon antagonize those of insulin.

Front 3

What is glucagon's principal target tissue?

Back 3

Liver.

Front 4

What is glycogenolysis?

Back 4

Glycogenolysis is the conversion of glycogen polymers to glucose monomers.

Front 5

What is gluconeogenesis?

Back 5

Gluconeogenesis is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids.

Front 6

What is the main effect of glucogon?

Back 6

- Incr. glucose output;
- Incr. glycogenolysis;
- Incr. gluconeogenesis;
- Decr. fatty acid synthesis -> Incr. ketone bodies -> Can be used as fuel by muscle and CNS when glucose is low.

Front 7

What is the effect of growth hormone in regulation of blood glucose?

Back 7

Inhibition of insulin-induced glucose utilisation.
- Inhibits glucose uptake and lipogenesis;
- Increases glycogenolysis and gluconeogenesis;
- But protect protein.

Front 8

What is lypogenesis?

Back 8

Lipogenesis is the process by which acetyl-CoA is converted to fats.

Front 9

What is the effect of glucocorticoids in regulation of blood glucose?

Back 9

Protects from hypoglycemia during stress.
- Stimulation of gluconeogenesis
- Inhibits effects of insulin
- Increase effects of glucagon and adrenaline.

Front 10

What is the role of adrenaline in blood glucose regulation?

Back 10

Maintain glucose supply to brain.
- Stimulate lipolysis in adipose tissue;
- Stimulate liver gluconeogenesis and glycogenolysis.

Front 11

What is diabetes mellitus?

Back 11

Diabetes mellitus, often simply referred to as diabetes—is a group of metabolic diseases in which a person has high blood sugar, either because the body does not produce enough insulin, or because cells do not respond to the insulin that is produced.

Front 12

How do you find out about diabetes mellitus?

Back 12

Take a sample of urine. Person with diabetes has glucose in the urine due to chronic hyperglycemia.

Front 13

Name two types of diabetes.

Back 13

Type 1 - insulin-dependent (there is no production of insulin); 5-10% of cases.
Type 2 - insulin-independent (insulin resistance in target tissues); 90-95% of cases.

Front 14

Person has high insulin level AND high glucose level in blood, what could that mean?

Back 14

It has diabetes type 2, where insulin is produced, but target tissues are resistant to it.

Front 15

What is the main treatment for diabetes type 2?

Back 15

Diet and exercise, but also antidiabetic drugs.

Front 16

Name hormone-producing cells in pituitary.

Back 16

Somatotrophs (GH, liver, bone, muscle growth),
Lactotrophs (PRL, stimulates milc production in breasts),
Thyrotrophs (TSH, thyroid),
Corticotrophs (ACTH, adrenal cortex),
Gonadotrophs (FSH/LH, ovary, testis).

Front 17

Which hormone in the hypothalamus inhibits production of GH by somatotrophs?

Back 17

Somatostatin.

Front 18

Which hormone in the hypothalamus stimulates production of GH by somatotrophs?

Back 18

GHRH.

Front 19

Is GH a steroid of peptide hormone?

Back 19

Peptide.

Front 20

How does GH circulates in the plasma?

Back 20

Bind to proteins (although it is peptide hormone).

Front 21

Which gland secretes GH?

Back 21

Petuitary.

Front 22

What is the effect of GH on protein?

Back 22

Increases protein synthesis.

Front 23

What is the effect of GH on lipogenesis?

Back 23

It reduces it.

Front 24

Does GH reduce or increase blood levels of glucose?

Back 24

Increase.

Front 25

What increases GH secretion?

Back 25

Hypothalamic peptides (GHRH),
Hypoglycemia (starvation, etc.),
Peripheral hormones (Ghrelin).

Front 26

What inhibits GH secretion?

Back 26

Hypothalamic peptides (somatostatin);
Obesity;
IGF-I (insulin-like growth factor).

Front 27

What is Somatomedin?

Back 27

Somatomedin is a group of hormones that is produced, when stimulated by somatotropin (STH), to promote cell growth and division. In this way, they mediate the effect of somatotropin (growth hormone).

Front 28

What happens if there is GH excess appearing in adulthood?

Back 28

Acromegaly - There is no longitudinal growth of bones, there is increase in thickness.

Front 29

What are 5 main functions of thyroid gland?

Back 29

1. Regulation of energy metabolism;
2. Growth and development;
3. Body temperature;
4. Carbohydrate, protein and fat metabolism;
5. Regulation of nervous system, cardiovascular, muscolo-skeltal and reproduction.

Front 30

Fill in blanks.

Back 30

Front 31

Fill in blanks.

Back 31

Front 32

Fill in blanks.

Back 32

Front 33

Which substance is required for generating T3 and T4? (From diet).

Back 33

Iodine.

Front 34

Name two thyroid hormones.

Back 34

T3 (3 iodines) and T4 (4 iodines).

Front 35

What is the function of thyroglobulin?

Back 35

Tg is used by the thyroid gland to produce the thyroid hormones thyroxine (T4) and triiodothyronine (T3). It is presumed that Tg and thyroid are also an important storage of iodine for all body needs, in particular, for many iodine-concentrating organs such as breast, stomach, salivary glands, thymus, etc.

Front 36

In the follicular cells of thyroid gland, what is added by enzymes to thyroglubulin to make T3 and T4?

Back 36

Iodine.

Front 37

Which hormone is released more often - T3 or T4?

Back 37

90% of released hormone is T4, 10% - T3.

Front 38

Which of two hormones is more active - T3 or T4?

Back 38

T3 is 5x more active.

Front 39

Why in target tissues T4 is deiodinated to T3?

Back 39

Because T3 is more active.

Front 40

What is half-life of T4 and T3 hormones' release?

Back 40

T3 is one day, T4 is 6 days.

Front 41

Where are receptors of the target cells for thyroid hormones situated?

Back 41

In the nucleus of the cell.

Front 42

How can you explain the multiple effects of thyroid hormone in different target cells?

Back 42

TH binds to receptors in the target cell nucleus and then to promoter elements which activates gene transcription.

Front 43

Name 6 effects of thyroid hormones.

Back 43

1. Incr. basal metabolic rate;
2. Makes more glucose available to meet elevated metabolic demand;
3. Stimulate the synthesis of enzymes and structural proteins;
4. Incr. lipid metabolism;
5. Stimulate heart rate, cardiac outout, blood flow.;
6. Incr. neural transmission and neuronal development.

Front 44

What does TSH stand for?

Back 44

Thyroid stimulating hormone.

Front 45

In response to what is TSH released from pituitary?

Back 45

In response to secretion of hypothalamic thyrotropin-releasing-hormone (TRH).

Front 46

Which two substances inhibit TRH secretion?

Back 46

Cortisol and GH.

Front 47

What stimulates TRH release from hypothalamus?

Back 47

Sympathetic activation and cold.