Fundamentals & The Hypothalamo-Hypophysial axis

Question 1

Functions of the Endocrine System?

Answer 1

1. Growth and development
2. Sex differentiation
3. Metabolism
4. Adaptation to an ever-changing environment

Question 2

Hormones function how?

They move through what to distant target sites of action?

WHat if they act more locally? 2

Answer 2

chemical messengers

blood/lymph

paracrine or autocrine messengers

Question 3

1. Endocrine intracellular communication happens how?
2. Neuroendocrine intracellular communication happens how?
3. Paracrine intracellular communication happens how?
4. Autocrine intracellular communication happens how?

Answer 3

1. Hormone is released from cell and travels through the blood to the target cell
2. neuron relased hormone travels through the blood to the target cell
3. Cell releases hromone, travels through interstitial fluid to target cell
4. Hormone acts on the cell/tissue that released it

Question 4

Factors Affecting Response of a Target Cell to a Hormone

3

Answer 4

1. Blood level of the hormone
2. Relative number of receptors
3. Affinity of these receptors for hormones

Question 5

How can the number of receptors be regulated?

2

Answer 5

Up-regulation

Down-regulation

Question 6

Control of hormone levels can be affected in which type of way?
4

Answer 6

1. Affected by fluctuations that vary with the sleep–wake cycle
2. Secreted in a complicated cyclic manner
3. Regulated by feedback mechanisms that monitor substances such as glucose (insulin) and water (ADH) in the body
4. Regulated by feedback mechanisms that involve the hypothalamic-pituitary-target cell system

Question 7

Examples of hormones that are Affected by fluctuations that vary with the sleep–wake cycle? 2

Example of a hormone that is Secreted in a complicated cyclic manner?

Answer 7

Growth hormone (GH) and adrenocorticotropic hormone (ACTH)

Female sex hormones

Question 8

IF a hormones is water soluable what is needed for transport of the hormone to the target cell?

What about lipid/fat soluable hormones?

Answer 8

First messenger

Can diffuse through the lipid bilayer and into the nucleus of the cell for use in transcription

Question 9

Beta blocker up or down regulate a cell?

Answer 9

down regulation 
(less binded, higher symtpathetic response, higher cardiac output)

Question 10

What type of neurons act in the hypothalamus and what are their effects seen in?
4

Answer 10

1. Autonomic neurons to preganglioinc to postganglioic to
   Pancreatic islet releasing insulin
2. Autonomic neuron to preganglioic to adrenal gland to release adrenaline
3. Magnocellular neurosecretory neuron to posterior lobe releases oxytocin and ADH
4. Parvocellular neurosectretory neuron release releasing hormones to control a number of hormones in the anterior pituitary

Question 11

What acts as the first messenger often in hormone effect on a target cell?
What about the second messenger?
What connects them? 2

Answer 11

Hormone itself

cAMP

transducer and effector (G-protein and adenyl cyclase)

Question 12

What plays an important role in the affinity of insulin receptors?

Answer 12

pH of the body fluids

Question 13

Where do fat soluable hormones usually bind in the cell?

Where do water soluable hormones usually bind in the cell?

Answer 13

receptor sites outside the cell and also inside the target cell (steroids)

usually only outside the cell (AA derivatives- epi and norepi)

Question 14

1. If capillary blood contains low concentration of Ca2 this will stimulate what?
2. What type of stimuli is this an example of?
3. Pregnanglionic SNS fiber stimulates adrenal medulla cells to secrete what?
4. What kind of stimuli is this an example of?
5. The hypothalamus secretes hormones that stimulate the anterior pituitary. What are three examples of organs that this works on?
6. What kind of stimuli is this an example of?

Answer 14

1. Parathyroid gland to secrete PTH
2. Humoral
3. catecholamines
   (epi and norepi)
4. Neural

5. 
Thyroid gland
Adrenal cortex
Gonad (testes)
6. Hormonal

Question 15

Diurnal variation in glucocorticoid secretion. Peak glucocorticoid levels are present sometime between?

Answer 15

8 and 9 AM (cardiac events happen when you first get up)

Lowest around midnight

Question 16

What is the first 14 days of the ovarian cycle called and what are the four (3.5 phases) in it?

What are the last 14 days or so of the ovarian cycle and what are the 2.5 phases in it?

Answer 16

Follicular phase

1. primary follicle
2. Secondary follicle
3. Vesicular follicle
4. Ovulaiton

Luteal phase

1. Ovulation
2. Corpus luteum
3. Degenerating corpus luteum

Question 17

What are the phases of the uterine cycle and on what says do they occur?
3

Answer 17

Days 1-5 menstrual cycle
Days 5-13 Proliferative phase
Days 13-28 secretory phase

Question 18

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Answer 18

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Question 19

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Answer 19

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Question 20

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Answer 20

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Question 21

Categories of Hormones According
to Structure?
4
(Cat 2 has 5 in its group)

Answer 21

1. Biogenic amines
2. Amino acids,
   peptides,
   polypeptides,
   proteins, and
   glycoproteins
3. Steroids
4. Fatty acid derivatives

Question 22

Peptide and Protein Hormones released?

1. Hypothalamus -5
2. Anterior pituitary -6
3. Posterior pituitary -2
4. Thyroid -1
5. Pancreas -3
6. Liver -1
7. Parathyroid -1

Answer 22

1.  
TRH
GnRH
CRH
GHRH
Somatostatin

2. 
ACTH
TSH
FSH
LH
PRL
GH

3. Oxytocin
   ADH
4. Calcitonin
5. Glucagon
   Insulin
   Somatostatin
6. Somatomedin
7. PTH

Question 23

Peptide and Protein Hormones released?

1. Placenta -3
2. Kidney -1
3. Heart -1
4. G.I. tract -6
5. Adipocyte -1

Answer 23

1. HCG
   HCS
   HPL
2. Renin
3. ANP

4. 
Gastrin
CCK
Secretin
GIP
Somatostatin
GLP-1

5. Leptin

Question 24

There are two groups of hormones derived from the amino acid tyrosine:
2

Name the three specific hormones?

Answer 24

1. Thyroid hormones are basically a “double” tyrosine with the critical incorporation of 3 or 4 iodine atoms.
2. Catecholamines include epinephrine and norepinephrine, which are used as both hormones and neurotransmitters.
3. Thyroxine
4. Epinephrine
5. Norepinephrine

So tyrosine can either become thyroxine or Epi

Question 25

What does the initial insulin sequence start as? When the signal sequence is cleaved what is the chain called? What is cleaved to make proinsulin into insulin?

Answer 25

preproinsulin proinsulin Chain C

Question 26

What are the three zones in the renal cortex and what do they each make? middle - 2 outside- 1 inside- 1 What is the important intermediiate for all these?

Answer 26

Zona fasciclutata- cortisol and corticosterone Zona glomerulosa- aldosterone Zona reticularis- Androstenedione Pregenolone

Question 27

Adipose tissue creates what kind of hormones? 5 What are the hormones called collectively?

Answer 27

``` adiponection resistin LEPTIN-saitety TNF alpha IL6- paracrine ``` adipokines

Question 28

The hypothalamic releasing or inhibitiing hormones are transported through the anterior pituitary how?

Answer 28

Portal vessels

Question 29

ADH and oxytocin are produced by what kind of cells? They are then transported through what to the posterior pituitary? Through what arteries is the pituitary blood supply come from?

Answer 29

nerve cells supraoptic and paraventricular nuclei of the hypothalamus inferior and superior hypophyseal arteries

Question 30

The hypophyseal portal system begins where? ANd drains where?

Answer 30

hypothalamus anterior pituitary

Question 31

What are the acidophils that the anterior lobe of the pituitary secretes? 2 What are the basophils that the anterior pituitary secretes?

Answer 31

GH and prolactin ``` TSH ACTH FSH LH beta- LH ```

Question 32

What does the intermediate lobe of the pituitary secrete?

Answer 32

MSH (melanin stimulating hormone)

Question 33

Describe what the release of a releasing hormone in the hypothalamus stimulates? 3

Answer 33

1. anterior pituitary to release a tropic hormone to excite the target gland. 2. This target gland releases a hormone which acts on the target cell 3. but also produces inhibiting effects on the ant. pit and the hypothalamus

Question 34

What stimulates the anterior pituitary to release GH? What does this inhibit alternatively?

Answer 34

somatotropin releasing hormone directly inhibits SRH on the hypothalamus (neg feedback)

Question 35

What does the release of GH from the Anterior pituitary do? | 2

Answer 35

1. inhibits the hypothalamus from releasing SRH and somatostatin 2. Stimulates the liver to produce somatomedin

Question 36

What does somatomedin stimulate? 2 The present of somatostatin released from what three organs causes what?

Answer 36

1. increased levels of somatostatin 2. inhibits SRH Hypothalamus Anterior Pit Liver Inhibits the release of more somatostatin (neg feedback)

Question 37

The hypothalamus releases what thyroid related hormone? This affects what organ? This causes the release of what? Which works on what? To release what?

Answer 37

TRH Thyrotroph cells in the ant pit TSH Thyroid follicles to release thyroid hormones (T3, T4)

Question 38

What stimulates the production of testosterone? What stimulates sperm production in men? Where are these produced and what stimulates the production of these?

Answer 38

LH FSH Produced in the anterior pituitary and stimulated by GnRH from the hypothalamus

Question 39

Five Cell Types of the Anterior Pituitary Gland

Answer 39

``` Thyrotrophs Corticotrophs Gonadotrophs Somatotrophs Lactotrophs ```

Question 40

1. Thyrotrophs produce what? 1 2. Corticotrophs produce what? 1 3. Gonadotrophs produce what? 2 4. Somatotrophs produce what? 1 5. Lactotrophs produce what? 1

Answer 40

1. produce thyrotropin, also called thyroid stimulating hormone (TSH) 2. produce corticotrophin, also called adrenocorticotropic hormone (ACTH) 3. produce the gonadotropins—leutenizing hormone (LH) and follicle-stimulating hormone (FSH) 4. produce growth hormone (GH) 5. produce prolactin