Endo 4

Question 1

What is addison’s disease?

Answer 1

Hypofunction of the adrenal cortex:

The cortex will no longer produce cortisol and aldosterone (adrenocortical hormones)

Question 2

What will be the physiological effects of a lack of cortisol (glucocorticoid hormone)? What will be the associated symptoms?

Answer 2

In Addison’s disease, a glucocorticoid hormone deficiency will cause a drop in blood sugar (less lipolysis)
- Lack of energy
- Muscular weakness
- Inability to take stress

Question 3

What will be the physiological effects of a lack of Aldosterone (mineralocorticoid hormone)? What will be the associated symptoms?

Answer 3

There will be an electrolyte imbalance (low Na and high K), low ions, and water will be lost in urine. Plasma volume will decrease as well as as CO

Death by shock after 7 days without mineralocorticoids

Question 4

What are the possible causes of addison’s disease?

Answer 4

Total destruction of the gland because of:
- Autoimmune attack on the adrenal gland
-Tuberculosis

Question 5

What is Cushing’s disease?

Answer 5

Hyperfunction of the adrenal cortex:

Excessive production of glucocorticoids and mineralocorticoids

Question 6

What are the possible causes of Cushing’s disease?

Answer 6

increased circulating levels of ACTH from
- Pituitary tumor
- Adrenal tumor

(characterized by a hyperplasia of one or two of the endocrine sites

Question 7

What will be the physiological effects of an increase of cortisol (glucocorticoid hormone)? What will be the associated symptoms?

Answer 7

Blood glucose and insulin production will increase. This is bc of a decrease in protein synthesis but increase in protein breakdown

-Osteoporosis (loss of protein and Ca in bone)
-Puffiness in face because of fluid retention

Question 8

What will be the physiological effects of an increase of Aldosterone (mineralocorticoid hormone)? What will be the associated symptoms?

Answer 8

Plasma Na will increase from being reabsorbed and can lead to hypertension because of an increase in plsma volume

Question 9

CASE STUDY: surgery from Cushing disease caused a momentary Addison’s disease

Answer 9

Slide 3

Question 10

What are the endocrine structures of the pancreas?

Answer 10

The islets of Langerhans

Question 11

What percentage of the islets of Langerhans produce which hormones?

Answer 11

60%: beta cells that synthesise insulin
25%: alpha cells that synthesise glucagon

Question 12

Why is insulin more important that glucagon?

Answer 12

bc it is the only hormone that can lower blood sugar

Question 13

Where can glucose be found in the body (and in different tissues)?

Answer 13

It is always in the blood, but very little is free in the tissues, it will be transported into cells with insulin and then:
- converted to glycogen in the liver
- Converted to fat and stored in adipose tissue
- Oxidized to produce energy in other various cells

Question 14

When does insulin deficiency occur?

Answer 14

When beta cells are destroyed because of autoimmune disease (causes Diabetes Mellitus)

Question 15

What happens during insulin deficiency?

door is locked

Answer 15

Glucose can’t enter cells, and causes a negative feedback loop to increase breakdown of protein, and get more glucose (keep blood glucose high) with increased gluconeogenesis. The body tries to find new sources of energy with free fatty acids

Question 16

How is fat used as energy in an insulin deficiency? WHat can this kind of energy usage lead to?

Answer 16

There is an increased lipolysis to get access to free fatty acids. However, fat is not effectively used and has incomplete oxidation. This results in an increased circulating acetone and other acids (smelly breath-Ketosis)

Question 17

What happens if insulin deficiency stays untreated for too long?

Answer 17

The build-up in acids lowers the blood pH, a diabetic coma and even death if untreated

Question 18

What are all the symptoms of Diabetes Mellitus

Answer 18

Glucose spilled into urine: GLYCOSUREA
Water follows into urine: POLYUREA
KETOSIS
METABOLIC ACIDOSIS

Question 19

What is the difference between Type 1 and Type 2 diabetes?

Answer 19

Type 1 (insulin dependent): an insulin deficiency because of lack of synthesis or because of a defective insulin release

Type 2 (insulin independent): When insulin levels are normal or abnormally high but are hyporesponsive

Question 20

Why is there a hyporesponsiveness of insulin in type 2 diabetes?

Answer 20

Obesity and overeating cause prolonged high insulin levels which decreases the number of receptors for insulin

Question 21

What is the treatment for Type 1 diabetes?

Answer 21

Administration of insulin. Not too much to not lower blood sugar into a coma inducing state

Question 22

What is the treatment for type 2 diabetes?

Answer 22

A proper diet and exercise to decrease insulin and upregulate the amount of receptors

Question 23

How is the glucose tolerance test used to asses the presence of diabetes?

Answer 23

After an overnight fasting, a patient is given a known amount of glucose. Blood glucose is measured before and after administration (30 mins interval) to see how blood sugar levels react.

If blood sugar returns to normal –> No diabetes
If blood sugar stays high –> low tolerance = diabetes
If blood sugar goes low –> high tolerance = hyperinsulinism

Question 24

What allows control of insulin secretions? (stimulis and receptors/effectors)

Answer 24

• Beta cells respond to the levels of blood sugar
• Gastrin and vagal impulses from the digestive tract go to the beta cells to induce release of insulin before there even is a change in blood glucose levels

Question 25

What kind of hormone is Glucagon? Where is it synthesized and released from?

Answer 25

a peptide hormone It is synthesized and released from the alpha cells of the pancreas

Question 26

What are the functions of glucagon? (2)

Answer 26

- Raising blood sugar by promoting glycolysis and glucogenesis in the liver - increases rate of lipolysis in adipose tissue to increase fatty acid concentration in circulation

Question 27

What is glucagon release controlled by and where is it released from?

Answer 27

The concentration of glucose in circulation modifies the activity of pancreatic alpha cells (low blood sugar = more synthesis and release)

Question 28

What is GLP-1? where is it produced?

Answer 28

It's a glucagon-like-peptide, derived from the same precursor as glucagon. It is produced by an enteroendocrine L cell in the intestine

Question 29

What are the GLP-1 actions? (4) (muscle and adipose cells, pancreas, digestive tract and brain, heart)

Answer 29

- It increases glucose uptake and oxidation to lower blood sugar - It increases insulin secretion in the pancreas - It slows down digestion as well as lowering appetite and increasing satiety - It can decrease risks of heart disease

Question 30

What are GH and where are they released from?

Answer 30

It's a single chain polypeptide produced by the anterior lobe of the pituitary

Question 31

What is the function of the GH?

Answer 31

- Increase protein synthesis in many tissues - Increases the rate of lipolysis to use fatty acids as a source of energy

Question 32

How does the GH increase protein synthesis?

Answer 32

It enhances amino acid uptake by cells and increases transcription and translation of mRNA

Question 33

What effect of the GH is NOT mediated by the somatomedins?

Answer 33

The increased rate in lipolysis

Question 34

What is the primary role of the somatomedins?

Answer 34

They increase protein synthesis and stimulate growth

Question 35

How is the release of GH controlled?

Answer 35

(i) GRH (somatoliberin) stimulates the release of GH (ii) GIH (somatostatin) inhibits the release of GH --> the presence of somatomedians in the blood has a negative feedback loop effect on the GRH --> Exercise, sleep, stress and low blood sugar enhance somatostatin effects

Question 36

When, in a day, is there less GH in the circulation? why?

Answer 36

During the night because sleep enhanced somatostatins which inhibit GH release

Question 37

Why does exercise impede growth?

Answer 37

The energy will be directed towards activity and movement rather than growth

Question 38

What are the effects of a GH deficiency on young people?

Answer 38

It leads to a PROPORTIONAL decrease in physical growth (a form of dwarfism)

Question 39

What are the effects of a GH excess on young people?

Answer 39

It leads to gigantism

Question 40

What are the effects of a GH excess later in life?

Answer 40

A pituitary tumour can cause acromegaly, where many bones (especially cartilaginous regions) get longer and heavier

Question 41

What are the two function of gonads?

Answer 41

1-Gametogenesis (the production of reproductive cells aka gamets) 2-Secretion of sex hormones: testosterone (androgen) in males and estrogen and progesterone in female

Question 42

Is the difference in reproductive endocrinology in males and females quantitative or qualitative?

Answer 42

Quantitative means both produce the same hormones, but not in the same amount.

Question 43

What is the primary function of estrogen in males?

Answer 43

Maintain bone density.

Question 44

How is estrogen produced in males?

Answer 44

Produced locally in tissues by converting testosterone into estrogen estradiol with aromatase.

Question 45

What are the consequences of estrogen deficiency in males?

Answer 45

1-Leads to increased body fat 2-CAN decrease sexual desire and erectile function

Question 46

How is reprodructive function (general hormones and gamets) controlled?

Answer 46

1-GnRH (Gonadotropin releasing hormone) is secreted by the hypothalamus to reach the anterior pituitary gland. 2-This stimulates the release of pituitary gonadotropins (FSH and LH) 3-Both hormones stimulate the development of spermatozoa or ova and secretion of sex steroids. 4-Sex steroids have effect in gonads and other parts of the body.

Question 47

What do gonads produce to control gonadotropin release?

Answer 47

Produces inhibin proteins which feed back on the anterior pituitary to block the release of FSH.

Question 48

What is the principal function of testies?

Answer 48

1-Spermatogenesis: Production of mature germ cells 2-Steroidogenesis: Production of steroid hormones

Question 49

Guess what?

Answer 49

I lovvvve youuu

Question 50

How long is the process or maturation from a spermatogonia to the mature spermatozoon?

Answer 50

Approx. 60 days

Question 51

What two cells are critical for maturation of spermatozoa and where are they?

Answer 51

1-Leydig cells. They are outside the seminiferous tubes. 2-Sertoli cells. They are within the seminiferous tubes.

Question 52

Do you want o go on a date?

Answer 52

Only answer is yes duh.

Question 53

What is the function of leydig cells?

Answer 53

In response to LH, they synthesise androgens.

Question 54

What is the function to sertoli cells?

Answer 54

In response of FSH, they synthesise ABP (Androgen binding protein) and inhibin.

Question 55

What is spermatogenesis dependent on? What assures the correct conditions?

Answer 55

High androgens concentration in the seminiferous tubes. These concentrations are insured by the presence of ABP.

Question 56

Last thing now

Answer 56

You want to marry me?

Question 57

What is the testicular androgen synthesis regulated by? (sexual cells feedback in males)

Answer 57

1-Hypothalamic-pituitary-Leydig cell axis: GnRH stimulates LH which stimulates Leydig cells to produce androgen which inhibits GnRH, LH and FSH. 2-Hypothalamic-pituitary-seminiferous-tubules axis: GnRH stimulates FSH which stimulates spermatogenesis and Sertoli cells to produce inhibin. Inhibin inhibits FSH release only.