Endrocrinology

Question 1

Describe a hormone.

Answer 1

A physiologic, organic substance synthesized by a ductless endocrine gland, which travels in the circulation in nanomolar to picomolar amounts to interact with specific receptors to inhibit, stimulate or regulate the functional activity of a target organ.

Question 2

Which Areas are concerned with the tonic release of GnRH?

Answer 2

ME, ARC, VMN

Question 3

What region is the hypothalamus within?

Answer 3

third ventricle from the optic chiasm to mammillary bodies

Question 4

Areas concerned with the surge release of GnRH and gonadotropins include?

Answer 4

PON, AHA, SCN

Question 5

Where is the pituitary gland located?

Answer 5

sella turcica in a depression of the sphnoid

Question 6

What three parts are divided into the pituitary?

Answer 6

Anterior, intermediate and posterior lobes

Question 7

What other terms are used to describe the anterior pituitary gland?

Answer 7

pars anterior, pars distalis, adenohypophysis

Question 8

What terms are used to describe the posterior pituitary?

Answer 8

pars nervosa, neurohypophysis

Question 9

What does pars mean?

Answer 9

Pituitary

Question 10

Name the 5 cell types and which of the six hormone they secrete.

Answer 10

1) Somatotrophs-GH
2) Corticortrophs-ACTH
3) Mammotrophs-Prolactin
4) Thyrotrophs-TSH
5) Gonadotrophs-FSH and LH

Question 11

How does the arterial blood enter the pituitary?

Answer 11

superior and inferior hypophseal artery

Question 12

What does the superior hypophseal artery form?

Answer 12

Capillary loops at the median eminence and anterior pituitary

Question 13

Where does the blood flow after the capillaries?

Answer 13

the portal system which begins and ends in capillaries without going through the heart

Question 14

Describe retrograde flow.

Answer 14

Blood flow from the pituitarty back to the hypthalamus

Question 15

What is the purpose of the retrograde flow?

Answer 15

Provide the pituitary negative flow

Question 16

Which pituitary does not contain a portal system?

Answer 16

Posterior

Question 17

Where are the growth factors produced?

Answer 17

From different tissues to diffuse into target cells.

Question 18

Hormone related substances control the growth and development of what?

Answer 18

Several organs, tissue and cultured cells

Question 19

What does the hypothalamus consist of?

Answer 19

Clusters of nerve cells bodies called hypothalamic nuclei

Question 20

What is the third ventricle and what surrounds it?

Answer 20

Hypothalamic nuclei surround the third ventricle which is a small cavity in the center of the brain

Question 21

What does the hypothalamus have VASCULAR connections to?

Answer 21

The anterior lobe of the pituitary

Question 22

Describe the neural connections of the hypothalamus

Answer 22

the connect to the posterior lobe of the pituitary through the hypothalamic-hypophseal tract

Question 23

What does sella turcica translation mean?

Answer 23

Turkey Saddle

Question 24

Where does the superior hypophyseal artery divide?

Answer 24

It divides into smaller capillaries at the level of the pituitary stalk into the primary portal plexus

Question 25

Describe the releasing and inhibitory hormones role in the blood flow.

Answer 25

These hormones are transferred to the secondary portal plexus and cause the release or inhibition of hormones from pituitary cells

Question 26

What hormones are made in the posterior pituitary?

Answer 26

None they are only stored there

Question 27

Where is the neurohormone released from and where does it go?

Answer 27

Release from the posterior pituitary and released into a simple arteroveneous capillary plexus

Question 28

What do gonads produce?

Answer 28

Gametes and gonadal hormones

Question 29

Describe the male gonads.

Answer 29

The interstitial cells in the ST, called Leydig cells produce testosterone

Question 30

Describe the gonads of the female.

Answer 30

Granulosa cells of the follicle make E2 | After ovulation the theca interna and granulosa cells make up the CL and produce P4

Question 31

How are the reproductive hormones divided?

Answer 31

By chemical structure - Proteins - Steroids - Fatty Acids - Amines

Question 32

Describe protein hormones

Answer 32

Polypeptides | Oxytocin, FSH, LH

Question 33

Describe the steroid hormones.

Answer 33

Derived from cholesterol | Testosterone, E2 and P4

Question 34

Describe half life of a hormone.

Answer 34

The time required of half the quantity of a hormone to disappear from the blood or body

Question 35

Describe the fatty acid hormones

Answer 35

Derived from arachidonic acid | PGF2a

Question 36

Describe amine hormones

Answer 36

Derived from tyrosine or tryptophan | Melatonin

Question 37

What has to happen for a hormone to cause a response?

Answer 37

It must interact with the target tissue. The cells of the target tissue must have receptors to bind the hormone

Question 38

What does the affinity mean in receptor signaling?

Answer 38

hold or grasp that the receptors have on the hormone

Question 39

What are the two factors of hormonal potency?

Answer 39

Receptor density and hormone receptor affinity

Question 40

Compare and contrast hormone agonists and antagonists.

Answer 40

Agonists are artificial, cause the same biological effects as the native hormone, promote greater physiological activity Antagonists- have a greater affinity but promote weaker biological activity, prevents the native hormone from binding by sitting on the receptor and blocking

Question 41

Name the four steps of the protein hormone signaling.

Answer 41

1) Hormone Receptor Binding 2) Adenylate Cyclase Activation 3) Protein Kinase Activation 4) Synthesis of New Products

Question 42

What occurs in the first step of protein hormone signaling?

Answer 42

1) Hormone diffuses from the blood into the interstitial compartment 2) Binds to the membrane bound receptor

Question 43

Where does the lock and key binding occur for protein hormones?

Answer 43

On the surface

Question 44

What happens in the second stage of protein hormone signaling?

Answer 44

Hormone receptor complex activates a membrane bound enzyme know as adenylate cyclase. Hormone receptor is formed when G protein is transformed to activate the AC enzyme

Question 45

What membrane bound protein mediates the AC activity?

Answer 45

G-protein

Question 46

The activation of AC causes what conversion?

Answer 46

ATP to cAMP + PPi in the cytoplasm of the cell

Question 47

What are the two messengers in protein hormone signaling?

Answer 47

- Hormone is the primary messenger | - cAMP is the second messenger

Question 48

What happens in stage three of the protein hormone signaling.

Answer 48

cAMP activates a family of control enzymes located in the cytoplasm called in protein kinases

Question 49

What does PK do?

Answer 49

Activate the enzymes in the cytoplasm to convert substrates to products

Question 50

How is the catalytic subunit of protein hormone signaling activated?

Answer 50

cAMP binds to the regulatory unit of PK

Question 51

What occurs in step 4 of the protein hormone signaling?

Answer 51

Products made by the cells are secreted

Question 52

Name the three pituitary hormones.

Answer 52

FSH, LH and Prolactin

Question 53

How is prolactin the exception of the pituitary hormones?

Answer 53

Secretion is under tonic inhibition by dopamine

Question 54

What does prolactin do in rodents?

Answer 54

Initiates and maintains lactation and is luteotrophic