L23. Endocrine System 1

Question 1

What is the function of the pituitary gland

Answer 1

• provides a functional connection between the CNS and the periphery NS
• regulates every cell in the body

Question 2

How many lobes does the pituitary gland have, what are it’s lobes called?

Answer 2

• 2 lobes anterior and posterior

Question 3

Where does the direct pathway occur

Answer 3

posterior lobe of the pituitary

Question 4

Where does the indirect pathway occur

Answer 4

anterior lobe of the pituitary

Question 5

Describe the function of hormones

Answer 5

• circulate in the blood

- can be lipophilic or hydrophilic ( depending on whether it is a steriod or peptide hormone)

Question 6

What classes of hormones are there

Answer 6

• monoamines
• lipophilic
• peptide

Question 7

What is the function of sex steroid hormones

Answer 7

• regulate reproductive and cognitive function

- regulate emotions and feelings

Question 8

What are the 3 different signaling parameters?

Answer 8

• autocrine
• endocrine
• paracrine

Question 9

What is an autocrine signaling pathway

Answer 9

hormones produced by a cell binds to the receptors on the same cell

Question 10

What is a paracrine signaling pathway

Answer 10

hormones produced by cells binds to receptors close to the hormone-producing cell

Question 11

What is an endocrine signaling pathway

Answer 11

hormones produced by the cell can enter the bloodstream and travel great distances

Question 12

Describe peptide hormones

Answer 12

• composed of amino acids
• it is hydrophilic and is soluble in the blood stream
• arranged as a complex chain or simple string of amino acids

Question 13

How many amino acids is oxytocin composed off

Answer 13

9

Question 14

What are monoamine hormones

Answer 14

contain one amino acid connected to an aromatic ring

Question 15

Describe steroid hormones

Answer 15

composed of 4 fuse chains and 1 side ring
activity varies with functional group
lipophilic
circulate in the blood only after when attached to a transporter

Question 16

Describe monoamines

Answer 16

hydrophilic

Question 17

what amino acid is part of the hormone adrenaline?

Answer 17

tyrosine

Question 18

Describe the thyroid hormone

Answer 18

• derived from 2 amino acids (tyrosine)
• bound to transport proteins so it can circulate the blood
• lipophilic

Question 19

draw the mode of amine and peptide hormones (pg 8b

Answer 19

pg 8b L 23

Question 20

Draw the mode of action for steriods and thyroid hormones ( pg 9a)

Answer 20

pg 9a

Question 21

Where are the receptors for peptides and monoamine hormones found?

Answer 21

cell surface (membrane) receptor

Question 22

Where are the receptors for thyroid hormones found?

Answer 22

have nuclear receptors

Question 23

Where are receptors for steroid hormones found?

Answer 23

nuclear receptors

membrane receptors

Question 24

What is the difference between the function between the anterior pituitary and posterior pituitary?

Answer 24

the anterior pituitary both synthesizes and secretes the hormone
the posterior pituitary only secretes the hormone ( the hormones are produced elsewhere)

Question 25

What are the hormones produced by the anterior lobe ?

Answer 25

``` FLAT P(E)G FSH, LH , ACTH, TSH, Prolactin, Growth hormone ```

Question 26

What are the hormones secreted by the posterior lobe of the pituitary?

Answer 26

ADH | Oxytocin

Question 27

What is the function of the anterior pituitary

Answer 27

- contains several different cell type that secretes a unique stimulating hormone - different cell types in the anterior pituitary are regulated by different hypothalamic nuclei

Question 28

What are corticotropes

Answer 28

they are one of the unique cell types on the anterior pitutary that secretes the stimulating hormone ACTH

Question 29

Describe the capillary endothelium in the CNS

Answer 29

- forms a tight continuous junction | - known as the blood brain barrier

Question 30

What is median eminence

Answer 30

a specialized region that circumvents the blood brain barrier where neurons can either exit or terminate - nerual axons to the posterior pituitary project through the ME - neural axons towards the anterior pituitary terminate at the ME

Question 31

where is the ME located?

Answer 31

located below the 3rd ventricle

Question 32

describe the indirect pathway

Answer 32

1. CRH or TRH producing cells secrete hormones/ have their neurons terminate in the median eminence 2. there are nerve terminals near the hypophyseal artery 3. the chromophil cell in the anterior pituitary produces (ACTH) 4. ACTH is then released into the hypophyseal vein

Question 33

what hormones are secreted through the indirect pathway

Answer 33

all hormones secreted by the anterior pituitary ( FLAT PEG)

Question 34

describe the direct pathway

Answer 34

1. AVP or OT producing cells have their tracts passing through the median eminence and the hormones are secreted directly to the herring body 2. hormones from the herring body are then released to the hypophyseal vein

Question 35

Draw the direct and indirect pathway (pg 14b and pg 15a)

Answer 35

pg 14 b and pg 15a

Question 36

what does a nucleus mean in the CNS

Answer 36

group or cluster of cell bodies in the CNS

Question 37

Where is the paraventricular neuron located

Answer 37

It is located beside the 3rd ventricle

Question 38

Where is the supraoptic nucleus located

Answer 38

on top of the optic tract

Question 39

In the paraventricular nucleus , what are the 2 types of cells where are they in terms of medial/ lateral positions

Answer 39

parvocllular ( medial) | magnocellular ( lateral)

Question 40

Where do the substrates of parvocellular cells end up ?

Answer 40

They pass through the median eminence and enter the anterior pituitary

Question 41

Where do the substrates of magnocellular cells end up?

Answer 41

They go directly to the posterior pituitary

Question 42

What is the zona interna of the Median eminence

Answer 42

fibers en passage to the posterior pituitary

Question 43

What is the zona externa of the median eminence

Answer 43

it integrates with the pituitary portal system ( needed for indirect pathway)

Question 44

Describe the similarities/difference between the paraventricular nerves ( PVN) and the SON

Answer 44

- PVN and SON synthesize polypeptides - unlike SON, PVN also contains neurosecretory neurons that terminate within BOTH the posterior pituitary and median eminence - the peptide synthesizing neurons occupy different regions of the nucleus

Question 45

How are the brain and the pituitary connected

Answer 45

through direct and indirect pathway