The Pituitary Gland

Question 1

What are the 2 principle organisers of the endocrine system?

Answer 1

Hypothalamus and the PG

Question 2

How is the PG connected to the hypothalalmus?

Answer 2

Infundibulum

Pituitary stalk

Question 3

Is the hypothalamus neuro or endocrine tissue?

Answer 3

Neuro

Question 4

Where is the hypothalamus located?

Answer 4

Below the thalamus

At the base of the brain `

Question 5

In which bones does the PG sit?

Answer 5

Sphenoid bone

Question 6

What are the 2 parts of the PG?

Answer 6

Anterior PG

Posterior PG

Question 7

What type of tissue is the Posterior PG?

Answer 7

Neuro

Question 8

What type of tissue is the anterior PG?

Answer 8

Endocrine

Question 9

What is the posterior PG a continuation of?

Answer 9

The hypothalamus

Question 10

What are tropic hormones?

Answer 10

Hormones which govern the release of another hormone

Question 11

What type of hormones does the hypothalamus release?

Answer 11

Neurohormones

Question 12

Where do the hormones from the hypothalamus travel down to?

Answer 12

Posterior PG

Question 13

Where are hormones stored in the posterior PG?

Answer 13

In vesicles

Question 14

Which hormones are released from the anterior PG?

Answer 14

Classic endocrine hormones

Question 15

What are the 2 forms of hypothalamic hormones?

Answer 15

Tropic

Non-tropic

Question 16

Where do tropic hormones travel from the hypothalamus?

Answer 16

Secreted into the capillaries traveling to anterior PG- bind to receptors on the anterior PG - govern the release of anterior PG hormones

Question 17

Where do non-tropic hormones travel from the hypothalamus?

Answer 17

Travel to the posterior PG where they are released into the blood

Question 18

What type of hormones are all hypothalamic hormones except from dopamine?

Answer 18

Peptides

Question 19

What are the 5 releasing hypothalamic hormones?

Answer 19

Thyrotrophin Releasing Hormone (TRH) 
Corticotropin Releasing Hormone (CRH) 
Growth Hormone Releasing Hormone(GHRH)
Gonadotrophin Releasing Hormone (GnRH) 
Prolactin Releasing Hormone (PRH)

Question 20

What are the 2 hypothalamic inhibiting hormones?

Answer 20

Growth hormone inhibiting hormone

Dopamine (prolactin inhibiting hormone)

Question 21

What is the hypophyseal portal system?

Answer 21

Network of tiny vessels which transfer trophic hormones from the hypothalamus to the anterior PG

Question 22

How is the anterior PG connected to the hypothalamus?

Answer 22

Via the hypophyseal portal system

Question 23

What % does the anterior and posterior PG make up?

Answer 23

Anterior - 66%

Posterior - 33%

Question 24

What is the production of anterior PG hormones controlled by?

Answer 24

Hormone release from the hypothalamus

Question 25

Which hormones are released from the anterior PG?

Answer 25

``` Thyroid stimulating hormone Adrenocorticotrophic hormone FSH LH Growth hormone Prolactin ```

Question 26

Which is the only hormone from the anterior PG to have a direct effect?

Answer 26

Prolactin

Question 27

What does prolactin stimulate?

Answer 27

Milk production during lactation

Question 28

What are the 3 integration centres in controlling anterior PG feedback?

Answer 28

Hypothalamus Anterior PG Target endocrine tissue

Question 29

What is a long loop feedback?

Answer 29

When the feedback comes from the endocrine target tissue

Question 30

What is a short loop feedback?

Answer 30

When the feedback is from the anterior PG to the hypothalamus

Question 31

What often acts as the negative feedback signal?

Answer 31

The hormone itself

Question 32

What are the 2 peptide neurohormones released from the posterior PG?

Answer 32

Vasopressin (ADH) | Oxytocin

Question 33

Where are neurohormones synthesised?

Answer 33

In magnocellular neurons

Question 34

Where do axons project from the hypothalamus?

Answer 34

Down the infundibulum to the posterior PG

Question 35

In what ways do oxytocin and vasopressin behave as normal peptide hormones?

Answer 35

They are synthesised in advance Stored in large vesicles Target cell surface receptors

Question 36

What is the main function of ADH/vasopressin?

Answer 36

To regulate water balance

Question 37

When is vasopressin release triggered?

Answer 37

When there is an increase in plasma osmolarity | Or decrease in plasma volume

Question 38

What is the action of ADH?

Answer 38

Increases water reabsorption | Increases BP

Question 39

What is the main function of oxytocin?

Answer 39

Milk ejection | Uterine contraction

Question 40

When is oxytocin released?

Answer 40

By babies head in contact with the cervix | Suckling of baby on nipple

Question 41

What is hyposecretion?

Answer 41

Too little hormone secreted

Question 42

What is hypersecretion?

Answer 42

Too much hormone secreted

Question 43

What is hyporesponsiveness?

Answer 43

When there is reduced response of the target cell

Question 44

What is hyperresponsiveness?

Answer 44

Increased response of the target cell

Question 45

What are primary disorders?

Answer 45

When there is a defect in the cells that secrete the hormone

Question 46

What are secondary disorders?

Answer 46

When there is too little or too much tropic hormone from the pituitary gland

Question 47

What are tertiary disorders related to?

Answer 47

Hypothalamic defects